Mechanics of limb bone loading during terrestrial locomotion in the green iguana (Iguana iguana) and American alligator (Alligator mississippiensis).

PubMed

Blob, R W; Biewener, A A

2001-03-01

In vivo measurements of strain in the femur and tibia of Iguana iguana (Linnaeus) and Alligator mississippiensis (Daudin) have indicated three ways in which limb bone loading in these species differs from patterns observed in most birds and mammals: (i) the limb bones of I. iguana and A. mississippiensis experience substantial torsion, (ii) the limb bones of I. iguana and A. mississippiensis have higher safety factors than those of birds or mammals, and (iii) load magnitudes in the limb bones of A. mississippiensis do not decrease uniformly with the use of a more upright posture. To verify these patterns, and to evaluate the ground and muscle forces that produce them, we collected three-dimensional kinematic and ground reaction force data from subadult I. iguana and A. mississippiensis using a force platform and high-speed video. The results of these force/kinematic studies generally confirm the loading regimes inferred from in vivo strain measurements. The ground reaction force applies a torsional moment to the femur and tibia in both species; for the femur, this moment augments the moment applied by the caudofemoralis muscle, suggesting large torsional stresses. In most cases, safety factors in bending calculated from force/video data are lower than those determined from strain data, but are as high or higher than the safety factors of bird and mammal limb bones in bending. Finally, correlations between limb posture and calculated stress magnitudes in the femur of I. iguana confirm patterns observed during direct bone strain recordings from A. mississippiensis: in more upright steps, tensile stresses on the anterior cortex decrease, but peak compressive stresses on the dorsal cortex increase. Equilibrium analyses indicate that bone stress increases as posture becomes more upright in saurians because the ankle and knee extensor muscles exert greater forces during upright locomotion. If this pattern of increased bone stress with the use of a more upright posture is

The progressive onset of cholinergic and adrenergic control of heart rate during development in the green iguana, Iguana iguana.

PubMed

Sartori, Marina R; Leite, Cleo A C; Abe, Augusto S; Crossley, Dane A; Taylor, Edwin W

2015-10-01

The autonomic control of heart rate was studied throughout development in embryos of the green iguana, Iguana iguana by applying receptor agonists and antagonists of the parasympathetic and sympathetic systems. Acetylcholine (Ach) slowed or stopped the heart and atropine antagonized the response to Ach indicating the presence of muscarinic cholinoceptors on the heart of early embryos. However, atropine injections had no impact on heart rate until immediately before hatching, when it increased heart rate by 15%. This cholinergic tonus increased to 34% in hatchlings and dropped to 24% in adult iguanas. Although epinephrine was without effect, injection of propranolol slowed the heart throughout development, indicating the presence of β-adrenergic receptors on the heart of early embryos, possibly stimulated by high levels of circulating catecholamines. The calculated excitatory tonus varied between 33% and 68% until immediately before hatching when it fell to 25% and 29%, a level retained in hatchlings and adults. Hypoxia caused a bradycardia in early embryos that was unaffected by injection of atropine indicating that hypoxia has a direct effect upon the heart. In later embryos and hatchlings hypoxia caused a tachycardia that was unaffected by injection of atropine. Subsequent injection of propranolol reduced heart rate both uncovering a hypoxic bradycardia in late embryos and abolishing tachycardia in hatchlings. Hypercapnia was without effect on heart rate in late stage embryos and in hatchlings. Copyright © 2015 Elsevier Inc. All rights reserved.

The biogeography of threatened insular iguanas and opportunities for invasive vertebrate management

USGS Publications Warehouse

Tershy, Bernie R.; Newton, Kelly M.; Spatz, Dena R.; Swinnerton, Kirsty; Iverson, John B.; Fisher, Robert N.; Harlow, Peter S.; Holmes, Nick D.; Croll, Donald A.; Iverson, J.B.; Grant, T. D.; Knapp, C. R.; Pasachnik, S. A.

2016-01-01

Iguanas are a particularly threatened group of reptiles, with 61% of species at risk of extinction. Primary threats to iguanas include habitat loss, direct and indirect impacts by invasive vertebrates, overexploitation, and human disturbance. As conspicuous, charismatic vertebrates, iguanas also represent excellent flagships for biodiversity conservation. To assist planning for invasive vertebrate management and thus benefit threatened iguana recovery, we identified all islands with known extant or extirpated populations of Critically Endangered and Endangered insular iguana taxa as recognized by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. For each island, we determined total area, sovereignty, the presence of invasive alien vertebrates, and human population. For the 23 taxa of threatened insular iguanas we identified 230 populations, of which iguanas were extant on 185 islands and extirpated from 45 islands. Twenty-one iguana taxa (91% of all threatened insular iguana taxa) occurred on at least one island with invasive vertebrates present; 16 taxa had 100% of their population(s) on islands with invasive vertebrates present. Rodents, cats, ungulates, and dogs were the most common invasive vertebrates. We discuss biosecurity, eradication, and control of invasive vertebrates to benefit iguana recovery: (1) on islands already free of invasive vertebrates; (2) on islands with high iguana endemicity; and (3) for species and subspecies with small total populations occurring across multiple small islands. Our analyses provide an important first step toward understanding how invasive vertebrate management can be planned effectively to benefit threatened insular iguanas.

The ultrastructure of the spermatozoon of the lizard Iguana iguana (Reptilia, Squamata, Iguanidae) and the variability of sperm morphology among iguanian lizards

PubMed Central

Vieira, Gustavo H C; Colli, Guarino R; Báo, Sônia N

2004-01-01

The spermatozoon of Iguana iguana is filiform and resembles that of other iguanian lizards, being most similar to Tropidurus. All sperm synapomorphies of Tetrapoda, Amniota and Squamata are present in the sperm of Iguana iguana. By reconstructing the evolution of 30 sperm characters we identified a novel synapomorphy of Iguania: the presence of a well-developed acrosomal ridge at the level of the epinuclear lucent zone. Because of the poor topological resolution among iguanian clades we could not discount the possibility of convergence or neutral selection as determinant of the variability in characteristics of the sperm cell. In agreement with previous studies, we identified heterogeneous rates of evolution among the three main regions of the sperm cell, namely the head, midpiece and tail. PMID:15198687

Characterization of Salmonella Occurring at High Prevalence in a Population of the Land Iguana Conolophus subcristatus in Galápagos Islands, Ecuador

PubMed Central

Franco, Alessia; Hendriksen, Rene S.; Lorenzetti, Serena; Onorati, Roberta; Gentile, Gabriele; Dell'Omo, Giacomo; Aarestrup, Frank M.; Battisti, Antonio

2011-01-01

The aim of the study was to elucidate the association between the zoonotic pathogen Salmonella and a population of land iguana, Colonophus subcristatus, endemic to Galápagos Islands in Ecuador. We assessed the presence of Salmonella subspecies and serovars and estimated the prevalence of the pathogen in that population. Additionally, we investigated the genetic relatedness among isolates and serovars utilising pulsed field gel electrophoresis (PFGE) on XbaI-digested DNA and determined the antimicrobial susceptibility to a panel of antimicrobials. The study was carried out by sampling cloacal swabs from animals (n = 63) in their natural environment on in the island of Santa Cruz. A high prevalence (62/63, 98.4%) was observed with heterogeneity of Salmonella subspecies and serovars, all known to be associated with reptiles and with reptile-associated salomonellosis in humans. Serotyping revealed 14 different serovars among four Salmonella enterica subspecies: S. enterica subsp. enterica (n = 48), S. enterica subsp. salamae (n = 2), S. enterica subsp. diarizonae (n = 1), and S. enterica subsp. houtenae (n = 7). Four serovars were predominant: S. Poona (n = 18), S. Pomona (n = 10), S. Abaetetuba (n = 8), and S.Newport (n = 5). The S. Poona isolates revealed nine unique XbaI PFGE patterns, with 15 isolates showing a similarity of 70%. Nine S. Pomona isolates had a similarity of 84%. One main cluster with seven (88%) indistinguishable isolates of S. Abaetetuba was observed. All the Salmonella isolates were pan-susceptible to antimicrobials representative of the most relevant therapeutic classes. The high prevalence and absence of clinical signs suggest a natural interaction of the different Salmonella serovars with the host species. The interaction may have been established before any possible exposure of the iguanas and the biocenosis to direct or indirect environmental factors influenced by the use of antimicrobials in agriculture

Characterization of Salmonella occurring at high prevalence in a population of the land iguana Conolophus subcristatus in Galápagos Islands, Ecuador.

PubMed

Franco, Alessia; Hendriksen, Rene S; Lorenzetti, Serena; Onorati, Roberta; Gentile, Gabriele; Dell'Omo, Giacomo; Aarestrup, Frank M; Battisti, Antonio

2011-01-01

The aim of the study was to elucidate the association between the zoonotic pathogen Salmonella and a population of land iguana, Colonophus subcristatus, endemic to Galápagos Islands in Ecuador. We assessed the presence of Salmonella subspecies and serovars and estimated the prevalence of the pathogen in that population. Additionally, we investigated the genetic relatedness among isolates and serovars utilising pulsed field gel electrophoresis (PFGE) on XbaI-digested DNA and determined the antimicrobial susceptibility to a panel of antimicrobials. The study was carried out by sampling cloacal swabs from animals (n = 63) in their natural environment on in the island of Santa Cruz. A high prevalence (62/63, 98.4%) was observed with heterogeneity of Salmonella subspecies and serovars, all known to be associated with reptiles and with reptile-associated salomonellosis in humans. Serotyping revealed 14 different serovars among four Salmonella enterica subspecies: S. enterica subsp. enterica (n = 48), S. enterica subsp. salamae (n = 2), S. enterica subsp. diarizonae (n = 1), and S. enterica subsp. houtenae (n = 7). Four serovars were predominant: S. Poona (n = 18), S. Pomona (n = 10), S. Abaetetuba (n = 8), and S. Newport (n = 5). The S. Poona isolates revealed nine unique XbaI PFGE patterns, with 15 isolates showing a similarity of 70%. Nine S. Pomona isolates had a similarity of 84%. One main cluster with seven (88%) indistinguishable isolates of S. Abaetetuba was observed. All the Salmonella isolates were pan-susceptible to antimicrobials representative of the most relevant therapeutic classes. The high prevalence and absence of clinical signs suggest a natural interaction of the different Salmonella serovars with the host species. The interaction may have been established before any possible exposure of the iguanas and the biocenosis to direct or indirect environmental factors influenced by the use of antimicrobials in agriculture

The Zn finger protein Iguana impacts Hedgehog signaling by promoting ciliogenesis.

PubMed

Glazer, Andrew M; Wilkinson, Alex W; Backer, Chelsea B; Lapan, Sylvain W; Gutzman, Jennifer H; Cheeseman, Iain M; Reddien, Peter W

2010-01-01

Hedgehog signaling is critical for metazoan development and requires cilia for pathway activity. The gene iguana was discovered in zebrafish as required for Hedgehog signaling, and encodes a novel Zn finger protein. Planarians are flatworms with robust regenerative capacities and utilize epidermal cilia for locomotion. RNA interference of Smed-iguana in the planarian Schmidtea mediterranea caused cilia loss and failure to regenerate new cilia, but did not cause defects similar to those observed in hedgehog(RNAi) animals. Smed-iguana gene expression was also similar in pattern to the expression of multiple other ciliogenesis genes, but was not required for expression of these ciliogenesis genes. iguana-defective zebrafish had too few motile cilia in pronephric ducts and in Kupffer's vesicle. Kupffer's vesicle promotes left-right asymmetry and iguana mutant embryos had left-right asymmetry defects. Finally, human Iguana proteins (dZIP1 and dZIP1L) localize to the basal bodies of primary cilia and, together, are required for primary cilia formation. Our results indicate that a critical and broadly conserved function for Iguana is in ciliogenesis and that this function has come to be required for Hedgehog signaling in vertebrates.

Physiological effects of tourism and associated food provisioning in an endangered iguana.

PubMed

Knapp, Charles R; Hines, Kirsten N; Zachariah, Trevor T; Perez-Heydrich, Caro; Iverson, John B; Buckner, Sandra D; Halach, Shelley C; Lattin, Christine R; Romero, L Michael

2013-01-01

Deliberately feeding wildlife is an increasingly popular tourism-related activity despite a limited understanding of long-term impacts on the species being fed. As a result, tourist behaviours that may have adverse impacts on imperiled species have often been encouraged without the necessary evaluation or oversight. Here, we report the responses of Northern Bahamian Rock Iguanas (Cyclura cychlura) to human-visitation pressure and associated food provisioning. We compared a variety of blood chemistry parameters of iguanas subjected to supplemental feeding at popular tourist destinations with iguanas occurring on islands where supplemental feeding does not take place. We demonstrate that male and female iguanas inhabiting tourist-visited islands where supplemental feeding occurs do not differ in body condition or baseline stress and stress response (determined by corticosterone levels) compared with iguanas from non-visited islands. Both males and females from tourist-visited sites experienced a greater incidence of endoparasitic infection and atypical loose faeces. Indicators of dietary nutrition, including glucose, potassium, and uric acid values, also differed for both sexes from tourist-visited and unvisited islands. Male iguanas from visited islands differed significantly from those on non-visited islands in calcium, cholesterol, cobalt, copper, magnesium, packed cell volume, selenium, and triglyceride concentrations, whereas female iguanas from visited islands differed significantly in ionized calcium. Although the interpretation of these differences is challenging, chronic biochemical stressors could compromise individual health over time or decrease survivorship during periods of environmental stress. We suggest protocols that can be adopted throughout the region to ensure that supplemental feeding has fewer impacts on these long-lived iguanas.

Physiological effects of tourism and associated food provisioning in an endangered iguana

PubMed Central

Knapp, Charles R.; Hines, Kirsten N.; Zachariah, Trevor T.; Perez-Heydrich, Caro; Iverson, John B.; Buckner, Sandra D.; Halach, Shelley C.; Lattin, Christine R.; Romero, L. Michael

2013-01-01

Deliberately feeding wildlife is an increasingly popular tourism-related activity despite a limited understanding of long-term impacts on the species being fed. As a result, tourist behaviours that may have adverse impacts on imperiled species have often been encouraged without the necessary evaluation or oversight. Here, we report the responses of Northern Bahamian Rock Iguanas (Cyclura cychlura) to human-visitation pressure and associated food provisioning. We compared a variety of blood chemistry parameters of iguanas subjected to supplemental feeding at popular tourist destinations with iguanas occurring on islands where supplemental feeding does not take place. We demonstrate that male and female iguanas inhabiting tourist-visited islands where supplemental feeding occurs do not differ in body condition or baseline stress and stress response (determined by corticosterone levels) compared with iguanas from non-visited islands. Both males and females from tourist-visited sites experienced a greater incidence of endoparasitic infection and atypical loose faeces. Indicators of dietary nutrition, including glucose, potassium, and uric acid values, also differed for both sexes from tourist-visited and unvisited islands. Male iguanas from visited islands differed significantly from those on non-visited islands in calcium, cholesterol, cobalt, copper, magnesium, packed cell volume, selenium, and triglyceride concentrations, whereas female iguanas from visited islands differed significantly in ionized calcium. Although the interpretation of these differences is challenging, chronic biochemical stressors could compromise individual health over time or decrease survivorship during periods of environmental stress. We suggest protocols that can be adopted throughout the region to ensure that supplemental feeding has fewer impacts on these long-lived iguanas. PMID:27293616

Stress physiology as a predictor of survival in Galapagos marine iguanas

PubMed Central

Romero, L. Michael; Wikelski, Martin

2010-01-01

Although glucocorticoid hormones are considered important physiological regulators for surviving adverse environmental stimuli (stressors), evidence for such a role is sparse and usually extrapolated from glucocorticoid effects under laboratory, short-term and/or non-emergency conditions. Galápagos marine iguanas (Amblyrhynchus cristatus) provide an excellent model for determining the ultimate function of a glucocorticoid response because susceptibility to starvation induced by El Niño conditions is essentially their only major natural stressor. In a prospective study, we captured 98 adult male marine iguanas and assessed four major components of their glucocorticoid response: baseline corticosterone titres; corticosterone responses to acute stressors (capture and handling); the maximal capacity to secrete corticosterone (via adrenocorticotropin injection); and the ability to terminate corticosterone responses (negative feedback). Several months after collecting initial measurements, weak El Niño conditions affected the Galápagos and 23 iguanas died. The dead iguanas were typified by a reduced efficacy of negative feedback (i.e. poorer post-stress suppression of corticosterone release) compared with surviving iguanas. We found no prior differences between dead and alive iguanas in baseline corticosterone concentrations, responses to acute stressors, nor in capacity to respond. These data suggest that a greater ability to terminate a stress response conferred a survival advantage during starvation. PMID:20504812

Comparative evaluation of the cadaveric and computed tomographic features of the coelomic cavity in the green iguana (Iguana iguana), black and white tegu (Tupinambis merianae) and bearded dragon (Pogona vitticeps).

PubMed

Banzato, T; Selleri, P; Veladiano, I A; Zotti, A

2013-12-01

Contrast-enhanced computed tomographic studies of the coelomic cavity in four green iguanas, four black and white tegus and four bearded dragons were performed using a conventional CT scanner. Anatomical reference cross sections were obtained from four green iguana, four black and white tegu and six bearded dragon cadavers; the specimens were stored in a -20°C freezer for 24 h then sliced into 5-mm intervals. The frozen sections were cleaned with water and photographed on both sides. The individual anatomical structures were identified by means of the available literature; these were labelled first on the anatomical images and then matched to the corresponding computed tomography images. The results provide an atlas of the normal cross-sectional and computed tomographic anatomy of the coelomic cavity in the green iguana, the black and white tegu and the bearded dragon, which is useful in the interpretation of any imaging modality. © 2013 Blackwell Verlag GmbH.

Is there an endogenous tidal foraging rhythm in marine iguanas?

PubMed

Wikelski, M; Hau, M

1995-12-01

As strictly herbivorous reptiles, Galápagos marine iguanas graze on algae in the intertidal areas during low tide. Daily foraging rhythms were observed on two islands during 3 years to determine the proximate factors underlying behavioral synchrony with the tides. Marine iguanas walked to their intertidal foraging grounds from far-off resting areas in anticipation of the time of low tide. Foraging activity was restricted to daytime, resulting in a complex bitidal rhythm including conspicuous switches from afternoon foraging to foraging during the subsequent morning when low tide occurred after dusk. The animals anticipated the daily low tide by a maximum of 4 h. The degree of anticipation depended on environmental parameters such as wave action and food supply. "Early foragers" survived in greater numbers than did animals arriving later at foraging sites, a result indicating selection pressure on the timing of anticipation. The timing of foraging trips was better predicted by the daily changes in tabulated low tide than it was by the daily changes in actual exposure of the intertidal foraging flats, suggesting an endogenous nature of the foraging rhythms. Endogenous rhythmicity would also explain why iguanas that had spontaneously fasted for several days nevertheless went foraging at the "right" time of day. A potential lunar component of the foraging rhythmicity of marine iguanas showed up in their assemblage on intertidal rocks during neap tide nights. This may indicate that iguanas possessed information on the semi-monthly rhythms in tide heights. Enclosure experiments showed that bitidal foraging rhythms of iguanas may free run in the absence of direct cues from the intertidal areas and operate independent of the light:dark cycle and social stimuli. Therefore, the existence of a circatidal oscillator in marine iguanas is proposed. The bitidal foraging pattern may result from an interaction of a circadian system with a circatidal system. Food intake or related

Circadian rhythm of body temperature in an ectotherm (Iguana iguana).

PubMed

Tosini, G; Menaker, M

1995-09-01

Ectothermic animals regulate their body temperatures primarily by behavioral adjustment in relation to the thermal characteristics of the environment. Several studies have shown that some vertebrate ectotherms may show a daily pattern of body temperature selection when given a choice of environmental temperature. The pattern of body temperature selection free-runs when the animals are kept in constant darkness, demonstrating the existence of circadian regulation. To test whether there might also be a low amplitude circadian rhythm of body temperature itself, we examined the pattern of body temperature and locomotor activity of the lizard Iguana iguana held in a constant environmental temperature. Both variables were recorded for 3 days in a light:dark cycle and then for 10 days in constant dim light (0.1 lux). Under these conditions the body temperature of the lizard oscillates with a circadian period as does the locomotor behavior. These results demonstrate for the first time that ectothermic animals may display physiologically generated circadian rhythms of body temperature similar to those recorded in endotherms. In some animals the circadian rhythms of body temperature and locomotor activity showed different free-running periods, demonstrating that the body temperature rhythm was not caused by locomotor activity and suggesting internal desyncronization of the two rhythms.

Optimal foraging of a herbivorous lizard, the green iguana in a seasonal environment.

PubMed

van Marken Lichtenbelt, Wouter D

1993-08-01

Food selection was studied in free living green iguanas (Iguana iguana) throughout the year in a semiarid environment, Curaçao (Netherlands Antilles). Food intake was determined by direct observations and converted into biomass intake. Comparison between intake and biomass availability of the various food items revealed that the lizards were selective, and that changes in seasonal food availability led to periodic switching of food plants. The extent to which nutrient constraints determine iguana feeding ecology was investigated. Potential constraints were the requirements for water, digestible crude protein, and metabolizable energy. By using a linear programming model that incorporates characteristics of the food (chemical composition, energy content, item size) and requirements and constraints of the green iguanas (nutrient and energy requirements digestive tract capacity, feeding rate) it was possible to identify which factors determine food choice over the year. During the dry period, when the iguanas had no access to drinking water they consumed flowers to increase water intake, though the amount of flowers consumed was too low to cover maintenance requirements for either energy or protein. After the young leaf flush, following the early rains in May, the biomass increased, free surface water was available during showers, and the linear programming solutions indicate that food selection conformed to the protein maximization criterion. Reproduction in green iguanas shows an annual cycle, in which oviposition takes place at the end of the dry season, when intake is below maintenance levels. Females show a 8-10 month gap between acquisition of most of the protein required for egg synthesis and the act of laying. Thus, as in avian and mammalian herbivores, food availability during a period prior to the energy and protein demanding reproductive season of iguanas determines reproductive success.

Rates of oxygen uptake increase independently of changes in heart rate in late stages of development and at hatching in the green iguana, Iguana iguana.

PubMed

Sartori, Marina R; Abe, Augusto S; Crossley, Dane A; Taylor, Edwin W

2017-03-01

Oxygen consumption (VO 2 ), heart rate (f H ), heart mass (M h ) and body mass (M b ) were measured during embryonic incubation and in hatchlings of green iguana (Iguana iguana). Mean f H and VO 2 were unvarying in early stage embryos. VO 2 increased exponentially during the later stages of embryonic development, doubling by the end of incubation, while f H was constant, resulting in a 2.7-fold increase in oxygen pulse. Compared to late stage embryos, the mean inactive level of VO 2 in hatchlings was 1.7 fold higher, while f H was reduced by half resulting in a further 3.6 fold increase in oxygen pulse. There was an overall negative correlation between mean f H and VO 2 when data from hatchlings was included. Thus, predicting metabolic rate as VO 2 from measurements of f H is not possible in embryonic reptiles. Convective transport of oxygen to supply metabolism during embryonic incubation was more reliably indicated as an index of cardiac output (CO i ) derived from the product of f H and M h . However, a thorough analysis of factors determining rates of oxygen supply during development and eclosion in reptiles will require cannulation of blood vessels that proved impossible in the present study, to determine oxygen carrying capacity by the blood and arteriovenous oxygen content difference (A-V diff), plus patterns of blood flow. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparative evaluation of the cadaveric, radiographic and computed tomographic anatomy of the heads of green iguana (Iguana iguana), common tegu (Tupinambis merianae) and bearded dragon (Pogona vitticeps).

PubMed

Banzato, Tommaso; Selleri, Paolo; Veladiano, Irene A; Martin, Andrea; Zanetti, Emanuele; Zotti, Alessandro

2012-05-11

Radiology and computed tomography are the most commonly available diagnostic tools for the diagnosis of pathologies affecting the head and skull in veterinary practice. Nevertheless, accurate interpretation of radiographic and CT studies requires a thorough knowledge of the gross and the cross-sectional anatomy. Despite the increasing success of reptiles as pets, only a few reports over their normal imaging features are currently available. The aim of this study is to describe the normal cadaveric, radiographic and computed tomographic features of the heads of the green iguana, tegu and bearded dragon. 6 adult green iguanas, 4 tegus, 3 bearded dragons, and, the adult cadavers of: 4 green iguana, 4 tegu, 4 bearded dragon were included in the study. 2 cadavers were dissected following a stratigraphic approach and 2 cadavers were cross-sectioned for each species. These latter specimens were stored in a freezer (-20°C) until completely frozen. Transversal sections at 5 mm intervals were obtained by means of an electric band-saw. Each section was cleaned and photographed on both sides. Radiographs of the head of each subject were obtained. Pre- and post- contrast computed tomographic studies of the head were performed on all the live animals. CT images were displayed in both bone and soft tissue windows. Individual anatomic structures were first recognised and labelled on the anatomic images and then matched on radiographs and CT images. Radiographic and CT images of the skull provided good detail of the bony structures in all species. In CT contrast medium injection enabled good detail of the soft tissues to be obtained in the iguana whereas only the eye was clearly distinguishable from the remaining soft tissues in both the tegu and the bearded dragon. The results provide an atlas of the normal anatomical and in vivo radiographic and computed tomographic features of the heads of lizards, and this may be useful in interpreting any imaging modality involving these

Comparative evaluation of the cadaveric, radiographic and computed tomographic anatomy of the heads of green iguana (Iguana iguana) , common tegu ( Tupinambis merianae) and bearded dragon ( Pogona vitticeps)

PubMed Central

2012-01-01

Background Radiology and computed tomography are the most commonly available diagnostic tools for the diagnosis of pathologies affecting the head and skull in veterinary practice. Nevertheless, accurate interpretation of radiographic and CT studies requires a thorough knowledge of the gross and the cross-sectional anatomy. Despite the increasing success of reptiles as pets, only a few reports over their normal imaging features are currently available. The aim of this study is to describe the normal cadaveric, radiographic and computed tomographic features of the heads of the green iguana, tegu and bearded dragon. Results 6 adult green iguanas, 4 tegus, 3 bearded dragons, and, the adult cadavers of : 4 green iguana, 4 tegu, 4 bearded dragon were included in the study. 2 cadavers were dissected following a stratigraphic approach and 2 cadavers were cross-sectioned for each species. These latter specimens were stored in a freezer (−20°C) until completely frozen. Transversal sections at 5 mm intervals were obtained by means of an electric band-saw. Each section was cleaned and photographed on both sides. Radiographs of the head of each subject were obtained. Pre- and post- contrast computed tomographic studies of the head were performed on all the live animals. CT images were displayed in both bone and soft tissue windows. Individual anatomic structures were first recognised and labelled on the anatomic images and then matched on radiographs and CT images. Radiographic and CT images of the skull provided good detail of the bony structures in all species. In CT contrast medium injection enabled good detail of the soft tissues to be obtained in the iguana whereas only the eye was clearly distinguishable from the remaining soft tissues in both the tegu and the bearded dragon. Conclusions The results provide an atlas of the normal anatomical and in vivo radiographic and computed tomographic features of the heads of lizards, and this may be useful in interpreting any

Median effective dose of isoflurane, sevoflurane, and desflurane in green iguanas.

PubMed

Barter, Linda S; Hawkins, Michelle G; Brosnan, Robert J; Antognini, Joseph F; Pypendop, Bruno H

2006-03-01

To determine the median effective dose (ED(50); equivalent to the minimum alveolar concentration [MAC]) of isoflurane, sevoflurane, and desflurane for anesthesia in iguanas. 6 healthy adult green iguanas. In unmedicated iguanas, anesthesia was induced and maintained with each of the 3 volatile drugs administered on separate days according to a Latin square design. Iguanas were endotracheally intubated, mechanically ventilated, and instrumented for cardiovascular and respiratory measurements. During each period of anesthesia, MAC was determined in triplicate. The mean value of 2 consecutive expired anesthetic concentrations, 1 that just permitted and 1 that just prevented gross purposeful movement in response to supramaximal electrical stimulus, and that were not different by more than 15%, was deemed the MAC. Mean +/- SD values for the third MAC determination for isoflurane, sevoflurane, and desflurane were 1.8 +/- 0.3%, 3.1 +/- 1.0%, and 8.9 +/- 2.1% of atmospheric pressure, respectively. The MAC for all inhaled agents was, on average, 22% greater for the first measurement than for the third measurement. Over time, MACs decreased for all 3 agents. Final MAC measurements were similar to values reported for other species. The decrease in MACs over time may be at least partly explained by limitations of anesthetic uptake and distribution imposed by the reptilian cardiorespiratory system. Hence, for a constant end-tidal anesthetic concentration in an iguana, the plane of anesthesia may deepen over time, which could contribute to increased morbidity during prolonged procedures.

Temporal pattern of foraging and microhabitat use by Galápagos marine iguanas, Amblyrhynchus cristatus.

PubMed

Buttemer, William A; Dawson, William R

1993-10-01

We observed a colony of marine iguanas (Amblyrhynchus cristatus) on Isla Fernandina, Galápagos, Ecuador, while measuring local micrometeorological and tidal conditions. We found size-related differences in foraging mode, with smaller iguanas feeding intertidally during daytime low tides and larger iguanas feeding subtidally. Despite having greater opportunity, subtidal foragers did not time their foraging bouts or exploit their environment in ways that optimized their period at high body temperature. Instead, the foraging schedule of these iguanas served to maximize their rate of rewarming following emergence from the cool sea. Intertidal feeders, by contrast, showed much greater behavioral flexibility in attempting to exploit their thermal environment. We suggest that size-ordered differences in marine iguana thermoregulatory behavior reflect underlying ontogenetic changes in costs and benefits of thermoregulation due to differences in predator pressure, quantity of food and electrolytes taken at each feeding, mode of foraging, and agonistic tendencies.

Cretaceous park of sex determination: sex chromosomes are conserved across iguanas

PubMed Central

Rovatsos, Michail; Pokorná, Martina; Altmanová, Marie; Kratochvíl, Lukáš

2014-01-01

Many poikilothermic vertebrate lineages, especially among amphibians and fishes, possess a rapid turnover of sex chromosomes, while in endotherms there is a notable stability of sex chromosomes. Reptiles in general exhibit variability in sex-determining systems; as typical poikilotherms, they might be expected to have a rapid turnover of sex chromosomes. However, molecular data which would enable the testing of the stability of sex chromosomes are lacking in most lineages. Here, we provide molecular evidence that sex chromosomes are highly conserved across iguanas, one of the most species-rich clade of reptiles. We demonstrate that members of the New World families Iguanidae, Tropiduridae, Leiocephalidae, Phrynosomatidae, Dactyloidae and Crotaphytidae, as well as of the family Opluridae which is restricted to Madagascar, all share homologous sex chromosomes. As our sampling represents the majority of the phylogenetic diversity of iguanas, the origin of iguana sex chromosomes can be traced back in history to the basal splitting of this group which occurred during the Cretaceous period. Iguanas thus show a stability of sex chromosomes comparable to mammals and birds and represent the group with the oldest sex chromosomes currently known among amniotic poikilothermic vertebrates. PMID:24598109

Vertical structure use by the Stout Iguana (Cyclura pinguis) on Guana Island, BVI

USGS Publications Warehouse

Cheek, Christopher A.; Hlavaty, Shay; Perkins, Rebecca N.; Peyton, Mark A.; Ryan, Caitlin N.; Zavaleta, Jennifer C.; Boal, Clint W.; Perry, Gad

2013-01-01

The Stout Iguana (Cyclura pinguis) is a critically endangered species endemic to the Puerto Rico Bank and currently restricted to the British Virgin Islands (BVI). Our study on Guana Island, BVI, focused on vertical structure use. Based on previous incidental observations, we hypothesized that Stout Iguanas use vertical structures and that adults and juveniles use such structures differently. In October 2011, we documented movement and vertical structure use by adult (n = 4) and juvenile (n = 11) iguanas with tracking bobbins. We recorded structure types used, heights attained on structures, distances between structures, and structure sizes. We found that Stout Iguanas used vertical structure more than previously documented. Trees comprised a significantly greater (P < 0.001) proportion of structures used by juveniles than by adults, whereas rocks comprised the greatest proportion of structures used by adults. In addition to differential structure use, juveniles climbed significantly higher (2.4 vs. 0.9 m on average; P < 0.001) than adults. We found no difference in the diameter or distance between structures used by adults and juveniles. Our results suggest that vertical structure use may be an important habitat element for free-ranging juvenile Stout Iguanas. Habitat management that provides vertical structure may be advantageous for the conservation of this species.

Niche expansion, body size, and survival in Galápagos marine iguanas.

PubMed

Wikelski, M; Wrege, Peter H

2000-07-01

Foraging theory predicts that dietary niche breadth should expand as resource availability decreases. However, Galápagos marine iguanas often die during algae shortages (El Niños) although land plants abound where they rest and reproduce. On Seymour Norte island, a subpopulation of iguanas exhibited unique foraging behavior: they consistently included the succulent beach plant B. maritima in their diet. We investigated the consequences of land-plant feeding for body size and survival. Batis-eaters supplemented their algae diet both before and after intertidal zone foraging, and more Batis was eaten during tides unfavorable for intertidal zone foraging (dawn and dusk). Larger, energy-constrained iguanas fed more on land than did smaller animals. Compared to intertidal zone algae, Batis was 39% lower in caloric content (1.6 vs. 2.6 kcal g -1 dry mass), 56% lower in protein (8.3 vs. 18.9% dry mass) and 57% lower in nitrogen (1.3 vs. 3.0% dry mass). In spite of its lower nutrient value, iguanas that supplemented their diet with this plant were able to attain nearly twice the body size of other iguanas on the island. Age estimates indicate that many Batis-eaters survived repeated El Niño episodes during which animals of their relative size-class experienced high mortality on other islands. The larger animals were, however, completely dependent upon this supplementary source of food to maintain condition, and all perished in the 1997-1998 El Niño when high tides inundated and killed Batis on Seymour Norte Island. We hypothesize that Batis feeding developed as a local foraging tradition, and that dietary conservatism and strong foraging site fidelity explain why the inclusion of land plants in the diet has been observed in only a single population. Ultimately, a unique algae-adapted hindgut morphology and physiology may limit a switch from marine to terrestrial diet.

Non-overlapping distributions of feral sheep (Ovis aries) and Stout Iguanas (Cyclura pinguis) on Guana Island, British Virgin Islands

USGS Publications Warehouse

Skipper, Ben R.; Grisham, Blake A.; Kalyvaki, Maria; McGaughey, Kathleen; Mougey, Krista; Navarrete, Laura; Rondeau, Renée; Boal, Clint W.; Perry, Gad

2013-01-01

Stout Iguanas (Cyclura pinguis) remain one of the most critically endangered reptiles in the world. Factors contributing to that status include habitat loss, predation by introduced species, and competition with introduced herbivores. On Guana Island, British Virgin Islands, the presence of feral sheep (Ovis aries) has been a hypothesized detriment to iguanas. Using motion sensitive cameras, we documented the distribution of feral sheep on Guana Island in 2010. We also quantified the impact of feral sheep on ground vegetation by comparing plant abundance at longterm sheep exclosures and areas where sheep were absent to areas where sheep were present. Finally, we compared sheep distribution to iguana distribution on the island. The co-occurrence of sheep and Stout Iguanas was less than expected, indicating possible competition. Although we detected no difference in vegetative cover between areas where sheep were present and absent, the long-term exclosures showed that the exclusion of sheep allowed the abundance of many plant species to increase. Our data support the hypothesis that feral sheep are altering the abundance of ground-level vegetation and limiting iguana distribution on the island.

Evolution of body size in Galapagos marine iguanas.

PubMed

Wikelski, Martin

2005-10-07

Body size is one of the most important traits of organisms and allows predictions of an individual's morphology, physiology, behaviour and life history. However, explaining the evolution of complex traits such as body size is difficult because a plethora of other traits influence body size. Here I review what we know about the evolution of body size in a group of island reptiles and try to generalize about the mechanisms that shape body size. Galapagos marine iguanas occupy all 13 larger islands in this Pacific archipelago and have maximum island body weights between 900 and 12 000g. The distribution of body sizes does not match mitochondrial clades, indicating that body size evolves independently of genetic relatedness. Marine iguanas lack intra- and inter-specific food competition and predators are not size-specific, discounting these factors as selective agents influencing body size. Instead I hypothesize that body size reflects the trade-offs between sexual and natural selection. We found that sexual selection continuously favours larger body sizes. Large males establish display territories and some gain over-proportional reproductive success in the iguanas' mating aggregations. Females select males based on size and activity and are thus responsible for the observed mating skew. However, large individuals are strongly selected against during El Niño-related famines when dietary algae disappear from the intertidal foraging areas. We showed that differences in algae sward ('pasture') heights and thermal constraints on large size are causally responsible for differences in maximum body size among populations. I hypothesize that body size in many animal species reflects a trade-off between foraging constraints and sexual selection and suggest that future research could focus on physiological and genetic mechanisms determining body size in wild animals. Furthermore, evolutionary stable body size distributions within populations should be analysed to better

Evolution of body size in Galapagos marine iguanas

PubMed Central

Wikelski, Martin

2005-01-01

Body size is one of the most important traits of organisms and allows predictions of an individual's morphology, physiology, behaviour and life history. However, explaining the evolution of complex traits such as body size is difficult because a plethora of other traits influence body size. Here I review what we know about the evolution of body size in a group of island reptiles and try to generalize about the mechanisms that shape body size. Galapagos marine iguanas occupy all 13 larger islands in this Pacific archipelago and have maximum island body weights between 900 and 12 000 g. The distribution of body sizes does not match mitochondrial clades, indicating that body size evolves independently of genetic relatedness. Marine iguanas lack intra- and inter-specific food competition and predators are not size-specific, discounting these factors as selective agents influencing body size. Instead I hypothesize that body size reflects the trade-offs between sexual and natural selection. We found that sexual selection continuously favours larger body sizes. Large males establish display territories and some gain over-proportional reproductive success in the iguanas' mating aggregations. Females select males based on size and activity and are thus responsible for the observed mating skew. However, large individuals are strongly selected against during El Niño-related famines when dietary algae disappear from the intertidal foraging areas. We showed that differences in algae sward (‘pasture’) heights and thermal constraints on large size are causally responsible for differences in maximum body size among populations. I hypothesize that body size in many animal species reflects a trade-off between foraging constraints and sexual selection and suggest that future research could focus on physiological and genetic mechanisms determining body size in wild animals. Furthermore, evolutionary stable body size distributions within populations should be analysed to

Changes in globus pallidus with (pre)term kernicterus.

PubMed

Govaert, Paul; Lequin, Maarten; Swarte, Renate; Robben, Simon; De Coo, René; Weisglas-Kuperus, Nynke; De Rijke, Yolanda; Sinaasappel, Maarten; Barkovich, James

2003-12-01

We report serial magnetic resonance (MR) and sonographic behavior of globus pallidus in 5 preterm and 3 term infants with kernicterus and describe the clinical context in very low birth weight preterm infants. On the basis of this information, we suggest means of diagnosis and prevention. Charts and MR and ultrasound images of 5 preterm infants and 3 term infants with suspected bilirubin-associated brain damage were reviewed. Included were preterm infants with severe hearing loss, quadriplegic hypertonia, and abnormal hypersignal of globus pallidus on T2-weighted MR imaging (MRI). In 1 infant who died on day 150, the diagnosis was confirmed during the neonatal period. The others were picked up as outpatients and scanned at 12 or 22 months' corrected age. Three instances of term kernicterus were included for comparison of serial MRI in the neonatal period and early infancy: they were caused by glucose-6-phosphate dehydrogenase deficiency, urosepsis, and dehydration plus fructose 1-6 biphosphatase deficiency. Five preterm infants of 25 to 29 weeks' gestational age presented with total serum bilirubin (TSB) levels below exchange transfusion thresholds commonly advised. Mixed acidosis was present in 3 infants around the TSB peak. The bilirubin/albumin molar ratio was >0.5 in all, in the absence of displacing drugs. All failed to pass bedside hearing screen tests and had severe hearing loss on auditory brain response testing. Symmetrical homogeneous hyperechogenicity of globus pallidus was the alerting feature in 1 infant. Globus pallidus was hyperintense on T1-weighted MR images in this child. The other infants presented with severe developmental delay as a result of dyskinetic quadriplegia and hearing loss. Globus pallidus was normal on T1- but hyperintense on T2-weighted MR images at 12 or 22 months' corrected age. Subthalamic involvement was documented in coronal fluid attenuated inversion recovery MRI in 2 infants. The term infants with classical clinical

In vivo locomotor strain in the hindlimb bones of alligator mississippiensis and iguana iguana: implications for the evolution of limb bone safety factor and non-sprawling limb posture

PubMed

Blob; Biewener

1999-05-01

Limb postures of terrestrial tetrapods span a continuum from sprawling to fully upright; however, most experimental investigations of locomotor mechanics have focused on mammals and ground-dwelling birds that employ parasagittal limb kinematics, leaving much of the diversity of tetrapod locomotor mechanics unexplored. This study reports measurements of in vivo locomotor strain from the limb bones of lizard (Iguana iguana) and crocodilian (Alligator mississippiensis) species, animals from previously unsampled phylogenetic lineages with non-parasagittal limb posture and kinematics. Principal strain orientations and shear strain magnitudes indicate that the limb bones of these species experience considerable torsion during locomotion. This contrasts with patterns commonly observed in mammals, but matches predictions from kinematic observations of axial rotation in lizard and crocodilian limbs. Comparisons of locomotor load magnitudes with the mechanical properties of limb bones in Alligator and Iguana indicate that limb bone safety factors in bending for these species range from 5.5 to 10.8, as much as twice as high as safety factors previously calculated for mammals and birds. Limb bone safety factors in shear (3.9-5.4) for Alligator and Iguana are also moderately higher than safety factors to yield in bending for birds and mammals. Finally, correlations between limb posture and strain magnitudes in Alligator show that at some recording locations limb bone strains can increase during upright locomotion, in contrast to expectations based on size-correlated changes in posture among mammals that limb bone strains should decrease with the use of an upright posture. These data suggest that, in some lineages, strain magnitudes may not have been maintained at constant levels through the evolution of a non-sprawling posture unless the postural change was accompanied by a shift to parasagittal kinematics or by an evolutionary decrease in body size.

Globus pallidus lesions associated with high mountain climbing.

PubMed Central

Jeong, Jee Hyang; Kwon, Jay C.; Chin, Juhee; Yoon, Soo Jin; Na, Duk L.

2002-01-01

Acute mountain sickness (AMS) occurs commonly in hikers who are rapidly exposed to high altitude environments. Despite the numerous reports of AMS, few studies have reported pallidal lesions associated with altitude sickness. A previously healthy 49-yr-old Korean patient, after ascent to 4,700 m, suffered symptoms consistent with AMS. After returning home, the patient showed changes in personality characterized by abulia, indifference, and indecisiveness. T2 weighted brain magnetic resonance imaging showed high signal lesions involving bilateral globus pallidus. Our case suggests that globus pallidus injury should be included in the differential diagnosis of patients with personality or cognitive change after recovery from AMS. PMID:12483018

Neoribates alius Fujikawa, 2007, a junior synonym of Neoribates pallidus Aoki, 1988 (Acari, Oribatida, Parakalummidae).

PubMed

Ermilov, Sergey G; Salavatulin, Vladimir M; Kaga, Wataru; Shimano, Satoshi

2014-09-03

The morphology of adult instars of two oribatid mites of the genus Neoribates, N. pallidus Aoki, 1988 and N. alius Fujikawa, 2007, is analyzed. Comparisons were based on holotype and paratypes (for N. alius) and specimens identified by the original author (for N. pallidus). Both species were described from Japan. Neoribates alius is recognized as a junior subjective synonym of N. pallidus.

Characterization of Thermophilic Halotolerant Aeribacillus pallidus TD1 from Tao Dam Hot Spring, Thailand

PubMed Central

Yasawong, Montri; Areekit, Supatra; Pakpitchareon, Arda; Santiwatanakul, Somchai; Chansiri, Kosum

2011-01-01

The bacterial strain TD1 was isolated from Tao Dam hot spring in Thailand. Strain TD1 was Gram positive, rod-shaped, aerobic, motile, and endospore forming. The cell was 2.0–40 μm in length and about 0.4 μm in diameter. The optimum growth occurred at 55–60 °C and at pH 7–8. Strain TD1 was able to grow on medium containing up to 10% NaCl. The DNA G+C content was 38.9 mol%. The cellular fatty acid content was mainly C16:0, which comprised 25.04% of the total amount of cellular fatty acid. 16S rDNA showed 99% identity to Aeribacillus pallidus DSM 3670T. Bayesian tree analysis strongly supported the idea that strain TD1 is affiliated with genus Aeribacillus, as Aeribacillus pallidus strain TD1. Although the 16S rDNA of A. pallidus strain TD1 is similar to that of A. pallidus DSM 3670T, some physiological properties and the cellular fatty acid profiles differ significantly. A. pallidus strain TD1 can produce extracellular pectate lyase, which has not been reported elsewhere for other bacterial strains in the genus Aeribacillus. A. pallidus strain TD1 may be a good candidate as a pectate lyase producer, which may have useful industrial applications. PMID:21954359

Function of muscle-type lactate dehydrogenase and citrate synthase of the Galápagos marine iguana, Amblyrhynchus cristatus, in relation to temperature.

PubMed

Fields, Peter A; Strothers, Chad M; Mitchell, Mark A

2008-05-01

The Galápagos marine iguana, Amblyrhynchus cristatus, is unique among lizards in foraging subtidally, leading to activity across a broad range of ambient temperatures ( approximately 14-40 degrees C). To determine whether the marine iguana shows any biochemical changes consistent with maintaining enzyme function at both warm and cold body temperatures, we examined the function of the aerobic enzyme citrate synthase (CS) and the muscle isoform of the anaerobic enzyme lactate dehydrogenase (A(4)-LDH) in A. cristatus and a confamilial species, Iguana iguana, from 14 to 46 degrees C. We also deduced amino acid sequences from cDNA of each enzyme. In CS, despite two amino acid substitutions, we found no difference in the apparent Michaelis-Menten constant K(m) of oxaloacetate at any temperature, indicating that the substrate affinity of CS in A. cristatus has not adapted to changes in thermal environment. In A(4)-LDH, we used site-directed mutagenesis to show that the substitutions T9A and I283V (A. cristatus --> I. iguana) individually have no effect on kinetics, but together significantly decrease the K(m) of pyruvate and catalytic rate constant (k(cat)) of the A. cristatus ortholog. Thus, our data show that A. cristatus A(4)-LDH has not become cold adapted in response to this species' aquatic foraging behavior, and instead may be consistent with moderate warm adaptation with respect to the I. iguana ortholog.

Spatial Ecology of the Critically Endangered Fijian Crested Iguana, Brachylophus vitiensis, in an Extremely Dense Population: Implications for Conservation

PubMed Central

Morrison, Suzanne F.; Biciloa, Pita; Harlow, Peter S.; Keogh, J. Scott

2013-01-01

The Critically Endangered Fijian crested iguana, Brachylophus vitiensis, occurs at extreme density at only one location, with estimates of >10,000 iguanas living on the 70 hectare island of Yadua Taba in Fiji. We conducted a mark and recapture study over two wet seasons, investigating the spatial ecology and intraspecific interactions of the strictly arboreal Fijian crested iguana. This species exhibits moderate male-biased sexual size dimorphism, which has been linked in other lizard species to territoriality, aggression and larger male home ranges. We found that male Fijian crested iguanas exhibit high injury levels, indicative of frequent aggressive interactions. We did not find support for larger home range size in adult males relative to adult females, however male and female residents were larger than roaming individuals. Males with established home ranges also had larger femoral pores relative to body size than roaming males. Home range areas were small in comparison to those of other iguana species, and we speculate that the extreme population density impacts considerably on the spatial ecology of this population. There was extensive home range overlap within and between sexes. Intersexual overlap was greater than intrasexual overlap for both sexes, and continuing male-female pairings were observed among residents. Our results suggest that the extreme population density necessitates extensive home range overlap even though the underlying predictors of territoriality, such as male biased sexual size dimorphism and high aggression levels, remain. Our findings should be factored in to conservation management efforts for this species, particularly in captive breeding and translocation programs. PMID:24019902

Spatial ecology of the critically endangered Fijian crested iguana, Brachylophus vitiensis, in an extremely dense population: implications for conservation.

PubMed

Morrison, Suzanne F; Biciloa, Pita; Harlow, Peter S; Keogh, J Scott

2013-01-01

The Critically Endangered Fijian crested iguana, Brachylophus vitiensis, occurs at extreme density at only one location, with estimates of >10,000 iguanas living on the 70 hectare island of Yadua Taba in Fiji. We conducted a mark and recapture study over two wet seasons, investigating the spatial ecology and intraspecific interactions of the strictly arboreal Fijian crested iguana. This species exhibits moderate male-biased sexual size dimorphism, which has been linked in other lizard species to territoriality, aggression and larger male home ranges. We found that male Fijian crested iguanas exhibit high injury levels, indicative of frequent aggressive interactions. We did not find support for larger home range size in adult males relative to adult females, however male and female residents were larger than roaming individuals. Males with established home ranges also had larger femoral pores relative to body size than roaming males. Home range areas were small in comparison to those of other iguana species, and we speculate that the extreme population density impacts considerably on the spatial ecology of this population. There was extensive home range overlap within and between sexes. Intersexual overlap was greater than intrasexual overlap for both sexes, and continuing male-female pairings were observed among residents. Our results suggest that the extreme population density necessitates extensive home range overlap even though the underlying predictors of territoriality, such as male biased sexual size dimorphism and high aggression levels, remain. Our findings should be factored in to conservation management efforts for this species, particularly in captive breeding and translocation programs.

Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange

PubMed Central

Porter, William Ruger; Witmer, Lawrence M.

2015-01-01

Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body) as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange). Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana) was investigated using a differential-contrast, dual-vascular injection (DCDVI) technique and high-resolution X-ray microcomputed tomography (μCT). Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory tissue temperature

Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange.

PubMed

Porter, William Ruger; Witmer, Lawrence M

2015-01-01

Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body) as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange). Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana) was investigated using a differential-contrast, dual-vascular injection (DCDVI) technique and high-resolution X-ray microcomputed tomography (μCT). Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory tissue temperature

From a thriving past to an uncertain future: Zooarchaeological evidence of two millennia of human impact on a large emblematic lizard (Iguana delicatissima) on the Guadeloupe Islands (French West Indies)

NASA Astrophysics Data System (ADS)

Bochaton, C.; Bailon, S.; Ineich, I.; Breuil, M.; Tresset, A.; Grouard, S.

2016-10-01

Among the lizards in the Lesser Antillean Islands, iguanas are undoubtedly the most emblematic, especially the endemic species, Iguana delicatissima. However, although much effort is currently made for the conservation of this species as a result of the present biodiversity crisis, nearly nothing is known of the history of this animal on these islands during the last millennia. Here we present the first data relating to the distribution, morphology, and interaction of past iguanas with human populations in the Lesser Antilles. To do so, we review the archaeological Iguana remains collected over the past 15 years on the Guadeloupe Islands. Our results show that the only Iguana species occurring in pre-Columbian archaeological deposits is Iguana delicatissima. Moreover, we demonstrate that this species occurred on all the islands of Guadeloupe during pre-Columbian times and then suddenly became extinct between 1960 and 1990 on most of these islands. We also confirm the modern introduction of I. iguana to the Guadeloupe Islands. In addition, zooarchaeological research demonstrates that pre-Columbian human populations occasionally used iguanas as a source of food, but with no apparent impact on the native population. However, the first data relating to past size variations of I. delicatissima on the Guadeloupe Islands indicate that archaeological iguanas were much larger than the largest remnant modern specimens and that a marked decrease in body length (more than 20%) occurred in these lizards after contact with European populations. This evidence of widespread extinction and morphological change during modern times is another demonstration of the extensive effects of disturbance and selection induced by modern human societies on endemic insular faunas.

Hybridization masks speciation in the evolutionary history of the Galápagos marine iguana

PubMed Central

MacLeod, Amy; Rodríguez, Ariel; Vences, Miguel; Orozco-terWengel, Pablo; García, Carolina; Trillmich, Fritz; Gentile, Gabriele; Caccone, Adalgisa; Quezada, Galo; Steinfartz, Sebastian

2015-01-01

The effects of the direct interaction between hybridization and speciation—two major contrasting evolutionary processes—are poorly understood. We present here the evolutionary history of the Galápagos marine iguana (Amblyrhynchus cristatus) and reveal a case of incipient within-island speciation, which is paralleled by between-island hybridization. In-depth genome-wide analyses suggest that Amblyrhynchus diverged from its sister group, the Galápagos land iguanas, around 4.5 million years ago (Ma), but divergence among extant populations is exceedingly young (less than 50 000 years). Despite Amblyrhynchus appearing as a single long-branch species phylogenetically, we find strong population structure between islands, and one case of incipient speciation of sister lineages within the same island—ostensibly initiated by volcanic events. Hybridization between both lineages is exceedingly rare, yet frequent hybridization with migrants from nearby islands is evident. The contemporary snapshot provided by highly variable markers indicates that speciation events may have occurred throughout the evolutionary history of marine iguanas, though these events are not visible in the deeper phylogenetic trees. We hypothesize that the observed interplay of speciation and hybridization might be a mechanism by which local adaptations, generated by incipient speciation, can be absorbed into a common gene pool, thereby enhancing the evolutionary potential of the species as a whole. PMID:26041359

A new species of iguana Brachylophus Cuvier 1829 (Sauria: Iguania: Iguanidae) from Gau Island, Fiji Islands

USGS Publications Warehouse

Fisher, Robert N.; Niukula, Jone; Watling, Dick; Harlow, Peter S.

2017-01-01

The south Pacific iguanas (Brachylophus) currently have three recognized living species in Fiji.  Recent surveys have uncovered more specific variation (morphological and genetic) within the genus and have better defined the geographic ranges of the named species.  One of these recent discoveries is a strikingly different iguana from all other island populations in Fiji which is restricted to Gau Island of the Lomaiviti Province.  Gau is the fifth largest island in Fiji and maintains excellent upland forests in the higher elevations.  We describe this population from Gau Island as a new species, Brachylophus gau sp. nov., in recognition of its type locality.

Ecological and evolutionary influences on body size and shape in the Galápagos marine iguana (Amblyrhynchus cristatus).

PubMed

Chiari, Ylenia; Glaberman, Scott; Tarroso, Pedro; Caccone, Adalgisa; Claude, Julien

2016-07-01

Oceanic islands are often inhabited by endemic species that have undergone substantial morphological evolutionary change due to processes of multiple colonizations from various source populations, dispersal, and local adaptation. Galápagos marine iguanas are an example of an island endemic exhibiting high morphological diversity, including substantial body size variation among populations and sexes, but the causes and magnitude of this variation are not well understood. We obtained morphological measurements from marine iguanas throughout their distribution range. These data were combined with genetic and local environmental data from each population to investigate the effects of evolutionary history and environmental conditions on body size and shape variation and sexual dimorphism. Our results indicate that body size and shape are highly variable among populations. Sea surface temperature and island perimeter, but not evolutionary history as depicted by phylogeographic patterns in this species, explain variation in body size among populations. Conversely, evolutionary history, but not environmental parameters or island size, was found to influence variation in body shape among populations. Finally, in all populations except one, we found strong sexual dimorphism in body size and shape in which males are larger, with higher heads than females, while females have longer heads than males. Differences among populations suggest that plasticity and/or genetic adaptation may shape body size and shape variation in marine iguanas. This study will help target future investigations to address the contribution of plasticity versus genetic adaptation on size and shape variation in marine iguanas.

A new species of iguana Brachylophus Cuvier 1829 (Sauria: Iguania: Iguanidae) from Gau Island, Fiji Islands.

PubMed

Fisher, Robert N; Niukula, Jone; Watling, Dick; Harlow, Peter S

2017-06-06

The south Pacific iguanas (Brachylophus) currently have three recognized living species in Fiji.  Recent surveys have uncovered more specific variation (morphological and genetic) within the genus and have better defined the geographic ranges of the named species.  One of these recent discoveries is a strikingly different iguana from all other island populations in Fiji which is restricted to Gau Island of the Lomaiviti Province.  Gau is the fifth largest island in Fiji and maintains excellent upland forests in the higher elevations.  We describe this population from Gau Island as a new species, Brachylophus gau sp. nov., in recognition of its type locality.

Segmentation of the Globus Pallidus Internus Using Probabilistic Diffusion Tractography for Deep Brain Stimulation Targeting in Parkinson Disease.

PubMed

Middlebrooks, E H; Tuna, I S; Grewal, S S; Almeida, L; Heckman, M G; Lesser, E R; Foote, K D; Okun, M S; Holanda, V M

2018-06-01

Although globus pallidus internus deep brain stimulation is a widely accepted treatment for Parkinson disease, there is persistent variability in outcomes that is not yet fully understood. In this pilot study, we aimed to investigate the potential role of globus pallidus internus segmentation using probabilistic tractography as a supplement to traditional targeting methods. Eleven patients undergoing globus pallidus internus deep brain stimulation were included in this retrospective analysis. Using multidirection diffusion-weighted MR imaging, we performed probabilistic tractography at all individual globus pallidus internus voxels. Each globus pallidus internus voxel was then assigned to the 1 ROI with the greatest number of propagated paths. On the basis of deep brain stimulation programming settings, the volume of tissue activated was generated for each patient using a finite element method solution. For each patient, the volume of tissue activated within each of the 10 segmented globus pallidus internus regions was calculated and examined for association with a change in the Unified Parkinson Disease Rating Scale, Part III score before and after treatment. Increasing volume of tissue activated was most strongly correlated with a change in the Unified Parkinson Disease Rating Scale, Part III score for the primary motor region (Spearman r = 0.74, P = .010), followed by the supplementary motor area/premotor cortex (Spearman r = 0.47, P = .15). In this pilot study, we assessed a novel method of segmentation of the globus pallidus internus based on probabilistic tractography as a supplement to traditional targeting methods. Our results suggest that our method may be an independent predictor of deep brain stimulation outcome, and evaluation of a larger cohort or prospective study is warranted to validate these findings. © 2018 by American Journal of Neuroradiology.

Blood gases, biochemistry and haematology of Galápagos marine iguanas (Amblyrhynchus cristatus)

PubMed Central

Lewbart, Gregory A.; Hirschfeld, Maximilian; Brothers, J. Roger; Muñoz-Pérez, Juan Pablo; Denkinger, Judith; Vinueza, Luis; García, Juan; Lohmann, Kenneth J.

2015-01-01

The marine iguana, Amblyrhynchus cristatus, is an iconic lizard endemic to the Galápagos Islands of Ecuador, but surprisingly little information exists on baseline health parameters for this species. We analysed blood samples drawn from 35 marine iguanas captured at three locations on San Cristóbal Island. A portable blood analyser (iSTAT) was used to obtain near-immediate field results for pH, lactate, partial pressure of O2, partial pressure of CO2, bicarbonate (HCO3−), percentage O2 saturation, haematocrit, haemoglobin, sodium, potassium, ionized calcium and glucose. Parameter values affected by temperature were auto-corrected by the iSTAT. Standard laboratory haematology techniques were employed for differential white blood cell counts and haematocrit determination; resulting values were also compared with the haematocrit values generated by the iSTAT. Body temperature, heart rate, respiratory rate and body measurements were also recorded. Body length was positively correlated with several blood chemistry values (HCO3− and glucose) and two haematology parameters (haemoglobin and manually determined haematocrit). A notable finding was the unusually high blood sodium level; the mean value of 178 mg/dl is among the highest known for any reptile. This value is likely to be a conservative estimate because some samples exceeded the maximal value the iSTAT can detect. For haematocrit determination, the iSTAT blood analyser yielded results significantly lower than those obtained with high-speed centrifugation. The values reported in this study provide baseline data that may be useful in comparisons among populations and in detecting changes in health status among marine iguanas affected by natural disturbances or anthropogenic threats. The findings might also be helpful in future efforts to demonstrate associations between specific biochemical parameters and disease. PMID:27293719

Behavior of juvenile lizards (Iguana iguana) in a conflict between temperature regulation and palatable food.

PubMed

Balasko, M; Cabanac, M

1998-01-01

Juvenile green iguanas were placed in a situation of conflict between two motivations: a thermoregulatory drive and the attraction of a palatable bait. To be able to reach the bait (lettuce), they had to leave a warm refuge, provided with standard food, and venture into a cold environment. In experiment 1 the time interval between sessions with bait, ranging from 1 to 8 days, had no effect on the duration of stay on the bait. This result shows that the lettuce was not a necessary food, deprivation of which would have had to be compensated for. In experiment 2 as the ambient temperature at the bait decreased the lizards spent less time feeding on lettuce, and they visited the bait less frequently. This result shows that the lizards traded off the palatability of the bait with the disadvantage of the cold. These findings support the hypothesis that a common currency makes it possible for lizards to compare two sensory modalities.

Cycloartane glycosides from leaves of Oxyanthus pallidus.

PubMed

Tigoufack, Ignas Bertrand Nzedong; Ngnokam, David; Tapondjou, Leon Azefack; Harakat, Dominique; Voutquenne, Laurence

2010-12-01

From the MeOH extract of leaves of Oxyanthus pallidus, three cycloartane glycosides, named pallidiosides A-C, were isolated together with two known compounds, oleanolic acid and 3-O-β-D-glucopyranosyl-β-sitosterol. The structures of pallidiosides A-C were assigned on the basis of spectral studies and comparison with published literature data. The known compounds were identified by means of Co TLC and confirmed by their physical constants. Copyright © 2010 Elsevier Ltd. All rights reserved.

Phylogenetic Evidence for Lateral Gene Transfer in the Intestine of Marine Iguanas

PubMed Central

Nelson, David M.; Cann, Isaac K. O.; Altermann, Eric; Mackie, Roderick I.

2010-01-01

Background Lateral gene transfer (LGT) appears to promote genotypic and phenotypic variation in microbial communities in a range of environments, including the mammalian intestine. However, the extent and mechanisms of LGT in intestinal microbial communities of non-mammalian hosts remains poorly understood. Methodology/Principal Findings We sequenced two fosmid inserts obtained from a genomic DNA library derived from an agar-degrading enrichment culture of marine iguana fecal material. The inserts harbored 16S rRNA genes that place the organism from which they originated within Clostridium cluster IV, a well documented group that habitats the mammalian intestinal tract. However, sequence analysis indicates that 52% of the protein-coding genes on the fosmids have top BLASTX hits to bacterial species that are not members of Clostridium cluster IV, and phylogenetic analysis suggests that at least 10 of 44 coding genes on the fosmids may have been transferred from Clostridium cluster XIVa to cluster IV. The fosmids encoded four transposase-encoding genes and an integrase-encoding gene, suggesting their involvement in LGT. In addition, several coding genes likely involved in sugar transport were probably acquired through LGT. Conclusion Our phylogenetic evidence suggests that LGT may be common among phylogenetically distinct members of the phylum Firmicutes inhabiting the intestinal tract of marine iguanas. PMID:20520734

Effect of tidal cycle and food intake on the baseline plasma corticosterone rhythm in intertidally foraging marine iguanas.

PubMed

Woodley, Sarah K; Painter, Danika L; Moore, Michael C; Wikelski, Martin; Romero, L Michael

2003-06-15

In most species, plasma levels of baseline glucocorticoids such as corticosterone (B) have a circadian rhythm. This rhythm can be entrained by both photoperiod and food intake and is related to aspects of energy intake and metabolism. Marine iguanas (Amblyrhynchus cristatus) offer a unique opportunity to better understand the relative importance of the light:dark cycle versus food intake in influencing the rhythm in baseline B in a natural system. Compared to other species, food intake is not as strictly determined by the phase of the light:dark cycle. Animals feed in the intertidal zone so feeding activity is heavily influenced by the tidal cycle. We measured baseline plasma B levels in free-living iguanas over several 24-h periods that varied in the timing of low tide/foraging activity. We found that baseline B levels were higher during the day relative to night. However, when low tide occurred during the day, baseline B levels dropped coincident with the timing of low tide. Whether the baseline B rhythm (including the drop during foraging) is an endogenous rhythm with a circatidal component, or is simply a result of feeding and associated physiological changes needs to be tested. Together, these data suggest that the baseline B rhythm in marine iguanas is influenced by the tidal cycle/food intake as well as the light:dark cycle.

Uneven frequency of Vibrio alginolyticus-group isolates among different populations of Galápagos marine iguana (Amblyrhynchus cristatus).

PubMed

Thaller, Maria C; Ciambotta, Marco; Sapochetti, Manuela; Migliore, Luciana; Tapia, Whashington; Cedeño, Virna; Gentile, Gabriele

2010-02-01

The presence of Vibrio isolates was investigated in cloacal swabs from the Galápagos marine iguana (Amblyrhyncus cristatus). Such unique iguana is endemic to the Galápagos Archipelago, it is listed as vulnerable in the IUCN Red List (2009), and is strictly protected by CITES and Ecuador laws. Our results revealed an uneven isolation frequency of vibrios from animals living in different settings: maximal among the Santa Fe population, scarce at Bahía Tortuga but practically absent in the samples from Puerto Ayora and Plaza Sur. A 16S sequencing confirmed that the isolates belonged to the genus Vibrio, placing them within the V. alginolyticus group; the biochemical identification was, indeed, consistent with V. alginolyticus features. The reason of the observed discrepancy is not clear, but could be either linked to a higher pollution in the inhabited or more touristic places or to differential influence of chemical and physical parameters at a local scale. As V. alginolyticus is an opportunistic pathogen for man and it is known to cause disease in sea-living animals, the ability of these vibrios to enter and persist to a certain extent in the marine iguana gut should be regarded as a risk for health of both the animals and the human personnel involved in monitoring activities. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

Nrxn3 upregulation in the globus pallidus of mice developing cocaine addiction

PubMed Central

Kelai, Sabah; Maussion, Gilles; Noble, Florence; Boni, Claudette; Ramoz, Nicolas; Moalic, Jean-Marie; Peuchmaur, Michel; Gorwood, Philip; Simonneau, Michel

2008-01-01

Dysfunctions affecting the connections of basal ganglia lead to major neurological and psychiatric disorders. We investigated levels of mRNA for three neurexins (Nrxn) and three neuroligins (Nlgn) in the globus pallidus, subthalamic nucleus, and substantia nigra, in control conditions and after short-term exposure to cocaine. The expression of Nrxn2β and Nlgn3 in the substantia nigra and Nlgn1in the subthalamic nucleus depended on genetic background. The development of short-term cocaine appetence induced an increase in Nrxn3β expression in the globus pallidus. Human NRXN3 has recently been linked to several addictions. Thus, NRXN3 adhesion molecules may play an important role in the synaptic plasticity of neurons involved in the indirect pathways of basal ganglia, in which they regulate reward-related learning. PMID:18418251

Nrxn3 upregulation in the globus pallidus of mice developing cocaine addiction.

PubMed

Kelai, Sabah; Maussion, Gilles; Noble, Florence; Boni, Claudette; Ramoz, Nicolas; Moalic, Jean-Marie; Peuchmaur, Michel; Gorwood, Philip; Simonneau, Michel

2008-05-07

Dysfunctions affecting the connections of basal ganglia lead to major neurological and psychiatric disorders. We investigated levels of mRNA for three neurexins (Nrxn) and three neuroligins (Nlgn) in the globus pallidus, subthalamic nucleus, and substantia nigra, in control conditions and after short-term exposure to cocaine. The expression of Nrxn2beta and Nlgn3 in the substantia nigra and Nlgn1 in the subthalamic nucleus depended on genetic background. The development of short-term cocaine appetence induced an increase in Nrxn3beta expression in the globus pallidus. Human NRXN3 has recently been linked to several addictions. Thus, NRXN3 adhesion molecules may play an important role in the synaptic plasticity of neurons involved in the indirect pathways of basal ganglia, in which they regulate reward-related learning.

Age-dependent, negative heterozygosity-fitness correlations and local effects in an endangered Caribbean reptile, Iguana delicatissima.

PubMed

Judson, Jessica L Martin; Knapp, Charles R; Welch, Mark E

2018-02-01

Inbreeding depression can have alarming impacts on threatened species with small population sizes. Assessing inbreeding has therefore become an important focus of conservation research. In this study, heterozygosity-fitness correlations (HFCs) were measured by genotyping 7 loci in 83 adult and 184 hatchling Lesser Antillean Iguanas, Iguana delicatissima, at a communal nesting site in Dominica to assess the role of inbreeding depression on hatchling fitness and recruitment to the adult population in this endangered species. We found insignificant correlations between multilocus heterozygosity and multiple fitness proxies in hatchlings and adults. Further, multilocus heterozygosity did not differ significantly between hatchlings and adults, which suggests that the survivorship of homozygous hatchlings does not differ markedly from that of their heterozygous counterparts. However, genotypes at two individual loci were correlated with hatching date, a finding consistent with the linkage between specific marker loci and segregating deleterious recessive alleles. These results provide only modest evidence that inbreeding depression influences the population dynamics of I. delicatissima on Dominica.

Biofilm characteristics and evaluation of the sanitation procedures of thermophilic Aeribacillus pallidus E334 biofilms.

PubMed

Kilic, Tugba; Karaca, Basar; Ozel, Beste Piril; Ozcan, Birgul; Cokmus, Cumhur; Coleri Cihan, Arzu

2017-04-01

The ability of Aeribacillus pallidus E334 to produce pellicle and form a biofilm was studied. Optimal biofilm formation occurred at 60 °C, pH 7.5 and 1.5% NaCl. Extra polymeric substances (EPS) were composed of proteins and eDNA (21.4 kb). E334 formed biofilm on many surfaces, but mostly preferred polypropylene and glass. Using CLSM analysis, the network-like structure of the EPS was observed. The A. pallidus biofilm had a novel eDNA content. DNaseI susceptibility (86.8% removal) of eDNA revealed its importance in mature biofilms, but the purified eDNA was resistant to DNaseI, probably due to its extended folding outside the matrix. Among 15 cleaning agents, biofilms could be removed with alkaline protease and sodium dodecyl sulphate (SDS). The removal of cells from polypropylene and biomass on glass was achieved with combined SDS/alkaline protease treatment. Strong A. pallidus biofilms could cause risks for industrial processes and abiotic surfaces must be taken into consideration in terms of sanitation procedures.

Cycloartanes from Oxyanthus pallidus and derivatives with analgesic activities.

PubMed

Piegang, Basile Nganmegne; Tigoufack, Ignas Bertrand Nzedong; Ngnokam, David; Achounna, Angèle Sorel; Watcho, Pierre; Greffrath, Wolfgang; Treede, Rolf-Detlef; Nguelefack, Télesphore Benoît

2016-03-09

The leaves of Oxyanthus pallidus Hiern (Rubiaceae) are extensively used in the west region of Cameroon as analgesic. These leaves are rich in cycloartanes, a subclass of triterpenes known to possess analgesic and anti-inflammatory properties. The present study aimed at evaluating the analgesic properties of three cycloartanes isolated from Oxyanthus pallidus leaves as well as their aglycones and acetylated derivatives. Three cycloartanes OP3, OP5 and OP6 obtained by successive chromatography of the crude methanol extract of the leaves were hydrolysed to yield respective aglycone AOP1, AOP2, AOP3 and acetylated to HOP1, HOP2 and HOP3 respectively. Formalin-induced pain model was used to evaluate the acute anti-nociceptive properties of these cycloartanes (5 mg/kg, p.o) in mice and to determine the structure-activity relationship. Acute (24 h) and chronic (10 days) anti-hyperalgesic and anti-inflammatory activities of OP5 were evaluated at the doses of 2.5 and 5 mg/kg/day administered orally. OP6 was also evaluated in acute experiments. The antioxidant and hepato-protective activities of OP5 were evaluated at the end of the chronic treatment. The mixture and the individual isolated cycloartanes significantly inhibited both phases of formalin-induced pain with percentage inhibition ranging from 13 to 78%. Acid hydrolysis did not significantly affect their antinociceptive activities while acetylation significantly reduced the effects of these compounds during the second phase of pain. OP5 and OP6 induced acute anti-hyperalgesic activity in formalin-induced mechanical hyperalgesia but not an anti-inflammatory effect. Repeated administration of OP5 for 10 days did not induce any anti-hyperalgesic effect. The evaluation of in vivo antioxidant properties showed that OP5 significantly reduced malondialdehyde and increased superoxide dismutase levels in liver without significantly affecting other oxidative stress and hepatotoxic parameters. Chronic administration of OP5 did

Inferred vs Realized Patterns of Gene Flow: An Analysis of Population Structure in the Andros Island Rock Iguana

PubMed Central

Colosimo, Giuliano; Knapp, Charles R.; Wallace, Lisa E.; Welch, Mark E.

2014-01-01

Ecological data, the primary source of information on patterns and rates of migration, can be integrated with genetic data to more accurately describe the realized connectivity between geographically isolated demes. In this paper we implement this approach and discuss its implications for managing populations of the endangered Andros Island Rock Iguana, Cyclura cychlura cychlura. This iguana is endemic to Andros, a highly fragmented landmass of large islands and smaller cays. Field observations suggest that geographically isolated demes were panmictic due to high, inferred rates of gene flow. We expand on these observations using 16 polymorphic microsatellites to investigate the genetic structure and rates of gene flow from 188 Andros Iguanas collected across 23 island sites. Bayesian clustering of specimens assigned individuals to three distinct genotypic clusters. An analysis of molecular variance (AMOVA) indicates that allele frequency differences are responsible for a significant portion of the genetic variance across the three defined clusters (Fst =  0.117, p0.01). These clusters are associated with larger islands and satellite cays isolated by broad water channels with strong currents. These findings imply that broad water channels present greater obstacles to gene flow than was inferred from field observation alone. Additionally, rates of gene flow were indirectly estimated using BAYESASS 3.0. The proportion of individuals originating from within each identified cluster varied from 94.5 to 98.7%, providing further support for local isolation. Our assessment reveals a major disparity between inferred and realized gene flow. We discuss our results in a conservation perspective for species inhabiting highly fragmented landscapes. PMID:25229344

Progressive colonization and restricted gene flow shape island-dependent population structure in Galápagos marine iguanas (Amblyrhynchus cristatus)

PubMed Central

2009-01-01

Background Marine iguanas (Amblyrhynchus cristatus) inhabit the coastlines of large and small islands throughout the Galápagos archipelago, providing a rich system to study the spatial and temporal factors influencing the phylogeographic distribution and population structure of a species. Here, we analyze the microevolution of marine iguanas using the complete mitochondrial control region (CR) as well as 13 microsatellite loci representing more than 1200 individuals from 13 islands. Results CR data show that marine iguanas occupy three general clades: one that is widely distributed across the northern archipelago, and likely spread from east to west by way of the South Equatorial current, a second that is found mostly on the older eastern and central islands, and a third that is limited to the younger northern and western islands. Generally, the CR haplotype distribution pattern supports the colonization of the archipelago from the older, eastern islands to the younger, western islands. However, there are also signatures of recurrent, historical gene flow between islands after population establishment. Bayesian cluster analysis of microsatellite genotypes indicates the existence of twenty distinct genetic clusters generally following a one-cluster-per-island pattern. However, two well-differentiated clusters were found on the easternmost island of San Cristóbal, while nine distinct and highly intermixed clusters were found on youngest, westernmost islands of Isabela and Fernandina. High mtDNA and microsatellite genetic diversity were observed for populations on Isabela and Fernandina that may be the result of a recent population expansion and founder events from multiple sources. Conclusions While a past genetic study based on pure FST analysis suggested that marine iguana populations display high levels of nuclear (but not mitochondrial) gene flow due to male-biased dispersal, the results of our sex-biased dispersal tests and the finding of strong genetic

Chemical composition, antibacterial and antioxidant activities of the essential oils from Thymus satureioides and Thymus pallidus.

PubMed

Ichrak, Ghalbane; Rim, Belaqziz; Loubna, Ait Said; Khalid, Oufdou; Abderrahmane, Romane; Said, El Messoussi

2011-10-01

This study was designed to examine the in vitro antibacterial and antioxidant activities of the essential oils (EOs) of Thymus satureioides (T.s) and T. pallidus (T.p). EOs were isolated by steam distillation and analyzed by capillary gas chromatography and gas chromatography coupled to mass spectrometry (GC-MS). The major constituents of the volatile fraction of T. satureioides were bomeol (29.5%), carvacrol (9.1%), and beta-caryophyllene (8.2%), while those of T. pallidus were camphor (29.8%), dihydrocarvone (17.6%), bomeol (7.6%) and camphene (7.5%). The essential oils were tested against a panel of Gram+ and Gram- bacteria by using agar diffusion and broth dilution methods. The data indicated that the Gram-positive Bacillus subtilis was the most sensitive strain producing an average inhibition zone of 51.7 mm. Furthermore, Pseudomonas aeruginosa, known as a resistant strain, was also sensitive. The samples were also subjected to screening for their possible antioxidant activity by using the 2,2-diphenyl-l-picrylhydrazyl (DPPH) assay. The IC50 values of the oil of T. satureioides and T. pallidus were 0.32 and 11.6 mg/mL, respectively.

Hyperkinetic movement disorder in a child treated by globus pallidus stimulation.

PubMed

Sato, Ken; Nakagawa, Eiji; Saito, Yoshiaki; Komaki, Hirofumi; Sakuma, Hiroshi; Sugai, Kenji; Sasaki, Masayuki; Kaido, Takanobu; Nakama, Hideyuki; Otsuki, Taisuke

2009-06-01

We report herein the case of a 9-year-old girl with life-threatening hyperkinetic involuntary movement of unknown etiology. Medical treatment was ineffective for her stereotypy and choreoathetotic/ballistic movements, but bilateral stimulation of the globus pallidus immediately alleviated these symptoms. Pallidal deep-brain stimulation may be considered the therapy of choice for children with intractable hyperkinetic movement disorders.

Mean diffusivity of globus pallidus associated with verbal creativity measured by divergent thinking and creativity‐related temperaments in young healthy adults

PubMed Central

Taki, Yasuyuki; Sekiguchi, Atsushi; Hashizume, Hiroshi; Nouchi, Rui; Sassa, Yuko; Kotozaki, Yuka; Miyauchi, Carlos Makoto; Yokoyama, Ryoichi; Iizuka, Kunio; Nakagawa, Seishu; Nagase, Tomomi; Kunitoki, Keiko; Kawashima, Ryuta

2015-01-01

Abstract Recent investigations revealed mean diffusivity (MD) in gray matter and white matter areas is correlated with individual cognitive differences in healthy subjects and show unique properties and sensitivity that other neuroimaging tools donot have. In this study, we tested the hypothesis that the MD in the dopaminergic system is associated with individual differences in verbal creativity measured by divergent thinking (VCDT) and novelty seeking based on prior studies suggesting associations between these and dopaminergic functions. We examined this issue in a large sample of right‐handed healthy young adults. We used analyses of MD and a psychological measure of VCDT, as well as personality measures of the Temperament and Character Inventory (TCI). Our results revealed associations between higher VCDT and lower MD in the bilateral globus pallidus. Furthermore, not only higher novelty seeking, but also lower harm avoidance, higher self‐directedness, and higher self‐transcendence were robustly associated with lower MD in the right globus pallidus, whereas higher persistence was associated with lower MD in the left globus pallidus. These personality variables were also associated with VCDT. The globus pallidus receives the dopaminergic input from the substantia nigra and plays a key role in motivation which is critically linked to dopamine. These results suggested the MD in the globus pallidus, underlie the association between VCDT and multiple personalities in TCI including novelty seeking. Hum Brain Mapp 36:1808–1827, 2015. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. PMID:25627674

Invasive black spiny-tailed iguanas (Ctenosaura similis) on Gasparilla Island, Florida, USA.

PubMed

Avery, Michael L; Tillman, Eric A; Spurfeld, Conny; Engeman, Richard M; Maciejewski, Kelin P; Brown, Jessica D; Fetzer, Emily A

2014-11-01

The native range of Ctenosaura similis extends from southern Mexico through Panama. From an initial introduction of 3 animals in 1979, the species now numbers in the thousands on Gasparilla Island in southwest Florida. In response to complaints of property damage from residents and threats to native species, local officials and the US Department of Agriculture Wildlife Services began a removal program in 2008. Through 2011, trappers removed 9467 ctenosaurs. The number removed declined from 32 iguanas/day in 2008 to 1.9 iguanas/day in 2011 despite no easing of the control effort. We necropsied 2757 ctenosaurs to document aspects of their natural history. Females outnumbered males overall, although the largest size class (>300 mm snout-vent length) included 32 males and just 2 females. Reproduction was seasonal. We found oviducal eggs in females from early Apr to early Jun, approximately 2 months later than C. similis in its native range. We trapped hatchlings from late Jul to early Oct coincident with the summer rainy season. Clutch size increased with female body size, with 62 being the largest clutch size recorded. In general, the biology of the invasive population on Gasparilla Island resembles native C. similis populations in Central America, except for the lack of large individuals. We suggest that shorter day length and colder temperatures create environmental conditions that are suboptimal for individual growth compared to those in the native range. © 2013 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Variation in the thermal ecology of an endemic iguana from Mexico reduces its vulnerability to global warming.

PubMed

Valenzuela-Ceballos, Sara; Castañeda, Gamaliel; Rioja-Paradela, Tamara; Carrillo-Reyes, Arturo; Bastiaans, Elizabeth

2015-02-01

The persistence of reptile populations in a specific location is influenced by individuals' capacity to regulate their body temperatures, among other factors. Anthropogenic climate change may pose a risk to the survival of ectothermic animals due to their dependence on external heat sources to thermoregulate. In this study, we calculated indices of thermal habitat quality, thermoregulatory precision, and thermoregulatory effectiveness for the endemic spiny-tailed iguana Ctenosaura oaxacana. We evaluated these indices and the thermoregulatory behavior of the iguanas in the four types of vegetation that provide the most favorable conditions for thermoregulation. We also performed our experiments during both the wet and dry seasons to capture the full range of thermal conditions available to C. oaxacana over the course of a year. Finally, we evaluated the potential niche for the iguana in the years 2020, 2050, and 2080. Thermoregulation depends on both seasonal and environmental factors in this species. We found that thermoregulation effectiveness in both wet and dry seasons depends not only on the thermal conditions of the immediate environment, but also on the cover vegetation and habitat structure available across the range of habitats the species uses. Thus, heterogeneous habitats with dispersed vegetation may be most suitable for this species' thermoregulatory strategy. Likewise, niche modeling results suggested that suitable habitat for our study species may continue to be available for the next few decades, despite global warming tendencies, as long as cover vegetation remains unaltered. Our results suggest that thermoregulation is a complex process that cannot be generalized for all ectothermic species inhabiting a given region. We also found that temperature changes are not the only factor one must consider when estimating the risk of species loss. To understand the necessary thermal conditions and extinction risk for any ectothermic species, it is necessary

The External Globus Pallidus: Progress and Perspectives

PubMed Central

Hegeman, Daniel J.; Hong, Ellie S.; Hernández, Vivian M.; Chan, C. Savio

2016-01-01

The external globus pallidus (GPe) of the basal ganglia is in a unique and powerful position to influence processing of motor information by virtue of its widespread projections to all basal ganglia nuclei. Despite the clinical importance of the GPe in common motor disorders such as Parkinson’s disease, we have only limited information about its cellular composition and organizational principles. In this review, we describe recent advances in our understanding of the diversity in the molecular profile, anatomy, physiology, and corresponding behavior during movement of GPe neurons. Importantly, we attempt to build consensus and highlight commonalities of the cellular classification based on existing but contentious literature. Additionally, we provide an analysis of the literature concerning the intricate reciprocal loops formed between the GPe and major synaptic partners, including both the striatum and the subthalamic nucleus. In conclusion, the GPe has emerged as a crucial node in the basal ganglia macrocircuit. While subtleties in the cellular makeup and synaptic connection of the GPe create new challenges, modern research tools have shown promise in untangling such complexity and will provide better understanding of the roles of the GPe in encoding movements and their associated pathologies. PMID:26841063

Genome Sequence of Aeribacillus pallidus Strain GS3372, an Endospore-Forming Bacterium Isolated in a Deep Geothermal Reservoir

PubMed Central

Filippidou, Sevasti; Jaussi, Marion; Junier, Thomas; Wunderlin, Tina; Jeanneret, Nicole; Regenspurg, Simona; Li, Po-E; Lo, Chien-Chi; McMurry, Kim; Gleasner, Cheryl D.; Vuyisich, Momchilo; Chain, Patrick S.

2015-01-01

The genome of strain GS3372 is the first publicly available strain of Aeribacillus pallidus. This endospore-forming thermophilic strain was isolated from a deep geothermal reservoir. The availability of this genome can contribute to the clarification of the taxonomy of the closely related Anoxybacillus, Geobacillus, and Aeribacillus genera. PMID:26316637

Genome Sequence of Aeribacillus pallidus Strain GS3372, an Endospore-Forming Bacterium Isolated in a Deep Geothermal Reservoir.

PubMed

Filippidou, Sevasti; Jaussi, Marion; Junier, Thomas; Wunderlin, Tina; Jeanneret, Nicole; Regenspurg, Simona; Li, Po-E; Lo, Chien-Chi; Johnson, Shannon; McMurry, Kim; Gleasner, Cheryl D; Vuyisich, Momchilo; Chain, Patrick S; Junier, Pilar

2015-08-27

The genome of strain GS3372 is the first publicly available strain of Aeribacillus pallidus. This endospore-forming thermophilic strain was isolated from a deep geothermal reservoir. The availability of this genome can contribute to the clarification of the taxonomy of the closely related Anoxybacillus, Geobacillus, and Aeribacillus genera. Copyright © 2015 Filippidou et al.

The external globus pallidus: progress and perspectives.

PubMed

Hegeman, Daniel J; Hong, Ellie S; Hernández, Vivian M; Chan, C Savio

2016-05-01

The external globus pallidus (GPe) of the basal ganglia is in a unique and powerful position to influence processing of motor information by virtue of its widespread projections to all basal ganglia nuclei. Despite the clinical importance of the GPe in common motor disorders such as Parkinson's disease, there is only limited information about its cellular composition and organizational principles. In this review, recent advances in the understanding of the diversity in the molecular profile, anatomy, physiology and corresponding behaviour during movement of GPe neurons are described. Importantly, this study attempts to build consensus and highlight commonalities of the cellular classification based on existing but contentious literature. Additionally, an analysis of the literature concerning the intricate reciprocal loops formed between the GPe and major synaptic partners, including both the striatum and the subthalamic nucleus, is provided. In conclusion, the GPe has emerged as a crucial node in the basal ganglia macrocircuit. While subtleties in the cellular makeup and synaptic connection of the GPe create new challenges, modern research tools have shown promise in untangling such complexity, and will provide better understanding of the roles of the GPe in encoding movements and their associated pathologies. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Basic ecology of the Oaxacan Spiny-tailed Iguana Ctenosaura oaxacana (Squamata: Iguanidae), in Oaxaca, Mexico.

PubMed

Rioja, Tamara; Carrillo-Reyes, Arturo; Espinoza-Medinilla, Eduardo; López-Mendoza, Sergio

2012-12-01

The Oaxacan Spiny-tailed Iguana Ctenosaura oaxacana is a restricted species to the Isthmus of Tehuantepec in Southern Oaxaca, Mexico. This reptile is one of the less known iguanid species. We census-tracked a population in the South ofNiltepec, Oaxaca, Mexico from May 2010 to April 2011. Throughout one year, a total of 10 line transects were situated and recorded in the study area to determine relative abundance and density, and habitat type use (dry forest, Nanchal, grassland, riparian vegetation, and mangrove) by the species. This study reports a new C. oaxacana population on the Southeastern limit of species range. Although this species has a very restricted distribution and is in danger of extinction, C. oaxacana has a high population density when compared to other Ctenosaura species. A total of 108 individuals were recorded throughout the study. Dry forest (33.75ind/ha) and Nanchal (18.75ind/ha) were the habitats with higher densities. Comparisons between habitat types showed no significant differences between dry forest and Nanchal (W=15, p=0.0808). Results between seasons were similar. The Oaxacan Spiny tailed Iguana preferred first the dry forest, and then Nanchal, while avoided grassland, riparian vegetation, and mangroves. There was no difference in habitat use between males and females. Mean perch heights were 1.23 +/- 0.32 (n=30) in Nanchal, 2.11 +/- 0.30 (n=9) in grassland, 1.90 +/- 0.56 (n=54) in dry forest, 1.91 +/- 0.28 (n=9) in mangrove and 2.30 +/- 0.37 (n=6) in riparian vegetation. Species observed as refuge and perch were B. crassifolia (Nanchal); C. alata (grassland); Tabebuia sp., Genipa americana, G. sepium, Acacia sp., Ficus sp. and Haematoxylon sp. (dry forest); G. sepium, Acacia sp. and Guazuma ulmifolia (riparian vegetation); and C. erecta (mangrove). Live trees hollows and branches were used by species. Main threats to the species are excessive hunting and habitat loss. Furthermore, grassland fires are still common in the study area

Phylogeography and Ecological Niche Modeling of the Desert Iguana (Dipsosaurus dorsalis, Baird & Girard 1852) in the Baja California Peninsula.

PubMed

Valdivia-Carrillo, Tania; García-De León, Francisco J; Blázquez, Ma Carmen; Gutiérrez-Flores, Carina; González Zamorano, Patricia

2017-09-01

Understanding the factors that explain the patterns of genetic structure or phylogeographic breaks at an intraspecific level is key to inferring the mechanisms of population differentiation in its early stages. These topics have been well studied in the Baja California region, with vicariance and the dispersal ability of individuals being the prevailing hypothesis for phylogeographic breaks. In this study, we evaluated the phylogeographic patterns in the desert iguana (Dipsosaurus dorsalis), a species with a recent history in the region and spatial variation in life history traits. We analyzed a total of 307 individuals collected throughout 19 localities across the Baja California Peninsula with 15 microsatellite DNA markers. Our data reveal the existence of 3 geographically discrete genetic populations with moderate gene flow and an isolation-by-distance pattern presumably produced by the occurrence of a refugium in the Cape region during the Pleistocene Last Glacial Maximum. Bayesian methods and ecological niche modeling were used to assess the relationship between population genetic structure and present and past climatic preferences of the desert iguana. We found that the present climatic heterogeneity of the Baja California Peninsula has a marked influence on the population genetic structure of the species, suggesting that there are alternative explanations besides vicariance. The information obtained in this study provides data allowing a better understanding of how historical population processes in the Baja California Peninsula can be understood from an ecological perspective. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Left globus pallidus abnormality in never-medicated patients with schizophrenia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Early, T.S.; Reiman, E.M.; Raichle, M.E.

1987-01-01

Schizophrenia is a severe psychiatric disorder characterized by onset in young adulthood, the occurrence of hallucinations and delusions, and the development of enduring psychosocial disability. The pathophysiology of this disorder remains unknown. Studies of cerebral blood flow and metabolism designed to identify brain abnormalities in schizophrenia have been limited by inadequate methods of anatomical localization and the possibility of persistent medication effects. The authors have now used positron emission tomography and a validated method of anatomical localization in an attempt to identify abnormalities of regional cerebral blood flow in newly diagnosed never-medicated patients with schizophrenia. An exploratory study of 5more » patients and 10 normal control subjects identified abnormally high blood flow in the left globus pallidus of patients with schizophrenia. A replication study of 5 additional patients and 10 additional control subjects confirmed this finding. No other abnormalities were found.« less

Assessing ecological and molecular divergence between the closely related species Hydrolagus pallidus and H. affinis (Chimaeridae).

PubMed

Violi, B; Gaither, M R; Burns, F; Rus Hoelzel, A; Neat, F

2018-04-01

This study investigated taxonomic validity of the pale ghost shark Hydrolagus pallidus Hardy & Stehmann, 1990, which was described as a species distinct from the smalleyed rabbitfish H. affinis (de Brito Capello 1868). While few morphological characters distinguish the two taxa, a striking difference in sex ratio and fixed differences (1·1-1·6% divergence) in the cytochrome oxidase subunit I barcoding gene support the recognition of both species. © 2018 The Fisheries Society of the British Isles.

Molecular and morphological analysis of the critically endangered Fijian iguanas reveals cryptic diversity and a complex biogeographic history

USGS Publications Warehouse

Keogh, J.S.; Edwards, D.L.; Fisher, R.N.; Harlow, P.S.

2008-01-01

The Pacific iguanas of the Fijian and Tongan archipelagos are a biogeographic enigma in that their closest relatives are found only in the New World. They currently comprise two genera and four species of extinct and extant taxa. The two extant species, Brachylophus fasciatus from Fiji, Tonga, and Vanuatu and Brachylophus vitiensis from western Fiji, are of considerable conservation concern with B. vitiensis listed as critically endangered. A recent molecular study has shown that Brachylophus comprised three evolutionarily significant units. To test these conclusions and to reevaluate the phylogenetic and biogeographic relationships within Brachylophus, we generated an mtDNA dataset consisting of 1462 base pairs for 61 individuals from 13 islands, representing both Brachylophus species. Unweighted parsimony analyses and Bayesian analyses produced a well-resolved phylogenetic hypothesis supported by high bootstrap values and posterior probabilities within Brachylophus. Our data reject the monophyly of specimens previously believed to comprise B. fasciatus. Instead, our data demonstrate that living Brachylophus comprise three robust and well-supported clades that do not correspond to current taxonomy. One of these clades comprises B. fasciatus from the Lau group of Fiji and Tonga (type locality for B. fasciatus), while a second comprises putative B. fasciatus from the central regions of Fiji, which we refer to here as B. n. sp. Animals in this clade form the sister group to B. vitiensis rather than other B. fasciatus. We herein describe this clade as a new species of Brachylophus based on molecular and morphological data. With only one exception, every island is home to one or more unique haplotypes. We discuss alternative biogeographic hypotheses to explain their distribution in the Pacific and the difficulties of distinguishing these. Together, our molecular and taxonomic results have important implications for future conservation initiatives for the Pacific

Carriage of antibiotic-resistant enteric bacteria varies among sites in Galapagos reptiles.

PubMed

Wheeler, Emily; Hong, Pei-Ying; Bedon, Lenin Cruz; Mackie, Roderick I

2012-01-01

Increased overlap between humans and wildlife populations has increased the risk for novel disease emergence. Detecting contacts with a high risk for transmission of pathogens requires the identification of dependable measures of microbial exchange. We evaluated antibiotic resistance as a molecular marker for the intensity of human-wildlife microbial connectivity in the Galápagos Islands. We isolated Escherichia coli and Salmonella enterica from the feces of land iguanas (Conolophus sp.), marine iguanas (Amblyrhynchus cristatus), giant tortoises (Geochelone nigra), and seawater, and tested these bacteria with the use of the disk diffusion method for resistance to 10 antibiotics. Antibiotic-resistant bacteria were found in reptile feces from two tourism sites (Isla Plaza Sur and La Galapaguera on Isla San Cristóbal) and from seawater close to a public use beach near Puerto Baquerizo Moreno on Isla San Cristóbal. No resistance was detected at two protected beaches on more isolated islands (El Miedo on Isla Santa Fe and Cape Douglas on Isla Fernandina) and at a coastal tourism site (La Lobería on Isla San Cristóbal). Eighteen E. coli isolates from three locations, all sites relatively proximate to a port town, were resistant to ampicillin, doxycycline, tetracycline, and trimethoprin/sulfamethoxazole. In contrast, only five S. enterica isolates showed a mild decrease in susceptibility to doxycycline and tetracycline from these same sites (i.e., an intermediate resistance phenotype), but no clinical resistance was detected in this bacterial species. These findings suggest that reptiles living in closer proximity to humans potentially have higher exposure to bacteria of human origin; however, it is not clear from this study to what extent this potential exposure translates to ongoing exchange of bacterial strains or genetic traits. Resistance patterns and bacterial exchange in this system warrant further investigation to understand better how human associations

[Treatment of early-onset generalized dystonia by chronic bilateral stimulation of the internal globus pallidus. Apropos of a case].

PubMed

Coubes, P; Echenne, B; Roubertie, A; Vayssière, N; Tuffery, S; Humbertclaude, V; Cambonie, G; Claustres, M; Frerebeau, P

1999-05-01

Dystonia musculorum deformans is an inherited severe disease, with a wide clinical polymorphism. The most severe clinical forms with early onset carry a high risk of life-threatening complications. In the absence of any efficient medical treatment, bilateral pallidotomy has previously been reported to be of value in the management of this disease. We report the first clinical case of a severe early-onset generalized dystonia dramatically improved by a bilateral stimulation of the internal globus pallidus. In November 1996, we proposed this neurosurgical procedure for a 8-year-old girl, who had suffered since the age of 3 from severe generalized dystonia, and who progressively became totally dependent and bedridden. She had been under sedation and permanent controlled respiratory assistance for the last two months. The etiology of the disease remained unknown (the DYT1 mutation was absent). Under general anesthesia, we bilaterally implanted a four-contacts electrode in the internal globus pallidus, using the Leksell's stereotactic frame and a 1.5 tesla MRI control. A dramatic improvement was noted 6 weeks later and led us to connect the two electrodes to neurostimulators inserted under the abdominal skin.

The globus pallidus pars interna in goal-oriented and routine behaviors: Resolving a long-standing paradox.

PubMed

Piron, Camille; Kase, Daisuke; Topalidou, Meropi; Goillandeau, Michel; Orignac, Hugues; N'Guyen, Tho-Haï; Rougier, Nicolas; Boraud, Thomas

2016-08-01

There is an apparent contradiction between experimental data showing that the basal ganglia are involved in goal-oriented and routine behaviors and clinical observations. Lesion or disruption by deep brain stimulation of the globus pallidus interna has been used for various therapeutic purposes ranging from the improvement of dystonia to the treatment of Tourette's syndrome. None of these approaches has reported any severe impairment in goal-oriented or automatic movement. To solve this conundrum, we trained 2 monkeys to perform a variant of a 2-armed bandit-task (with different reward contingencies). In the latter we alternated blocks of trials with choices between familiar rewarded targets that elicit routine behavior and blocks with novel pairs of targets that require an intentional learning process. Bilateral inactivation of the globus pallidus interna, by injection of muscimol, prevents animals from learning new contingencies while performance remains intact, although slower for the familiar stimuli. We replicate in silico these data by adding lateral competition and Hebbian learning in the cortical layer of the theoretical model of the cortex-basal ganglia loop that provided the framework of our experimental approach. The basal ganglia play a critical role in the deliberative process that underlies learning but are not necessary for the expression of routine movements. Our approach predicts that after pallidotomy or during stimulation, patients should have difficulty with complex decision-making processes or learning new goal-oriented behaviors. © 2016 Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

Isolation and characterization of 23 polymorphic microsatellite loci for a West Indian iguana (Cyclura pinguis) from the British Virgin Islands.

PubMed

Lau, Jennie; Alberts, Allison C; Chemnick, Leona G; Gerber, Glenn P; Jones, Kenneth C; Mitchell, Adele A; Ryder, Oliver A

2009-09-01

Twenty-three polymorphic microsatellite markers were identified and characterized for Cyclura pinguis, a critically endangered species of lizard (Sauria: Iguanidae) native to Anegada Island in the British Virgin Islands. We examined variation at these loci for 39 C. pinguis, finding up to five alleles per locus and an average expected heterozygosity of 0.55. Allele frequency estimates for these microsatellite loci will be used to characterize genetic diversity of captive and wild C. pinguis populations and to estimate relatedness among adult iguanas at the San Diego Zoo that form the nucleus of a captive breeding programme for this critically endangered species. © 2009 Blackwell Publishing Ltd.

A multilevel approach to examining cephalopod growth using Octopus pallidus as a model.

PubMed

Semmens, Jayson; Doubleday, Zoë; Hoyle, Kate; Pecl, Gretta

2011-08-15

Many aspects of octopus growth dynamics are poorly understood, particularly in relation to sub-adult or adult growth, muscle fibre dynamics and repro-somatic investment. The growth of 5 month old Octopus pallidus cultured in the laboratory was investigated under three temperature regimes over a 12 week period: seasonally increasing temperatures (14-18°C); seasonally decreasing temperatures (18-14°C); and a constant temperature mid-way between seasonal peaks (16°C). Differences in somatic growth at the whole-animal level, muscle tissue structure and rate of gonad development were investigated. Continuous exponential growth was observed, both at a group and at an individual level, and there was no detectable effect of temperature on whole-animal growth rate. Juvenile growth rate (from 1 to 156 days) was also monitored prior to the controlled experiment; exponential growth was observed, but at a significantly faster rate than in the older experimental animals, suggesting that O. pallidus exhibit a double-exponential two-phase growth pattern. There was considerable variability in size-at-age even between individuals growing under identical thermal regimes. Animals exposed to seasonally decreasing temperatures exhibited a higher rate of gonad development compared with animals exposed to increasing temperatures; however, this did not coincide with a detectable decline in somatic growth rate or mantle condition. The ongoing production of new mitochondria-poor and mitochondria-rich muscle fibres (hyperplasia) was observed, indicated by a decreased or stable mean muscle fibre diameter concurrent with an increase in whole-body size. Animals from both seasonal temperature regimes demonstrated higher rates of new mitochondria-rich fibre generation relative to those from the constant temperature regime, but this difference was not reflected in a difference in growth rate at the whole-body level. This is the first study to record ongoing hyperplasia in the muscle tissue of an

Roosting ecology of the pallid bat, Antrozous pallidus

USGS Publications Warehouse

Vaughan, Terry A.; O'Shea, Thomas J.

1976-01-01

Daytime roosting behavior of pallid bats (Antrozous pallidus) was studied in central Arizona. Bats were present in the area from March or April until November and roosted in cliffs in colonies generally including 20 or more individuals. Pallid bats were highly selective in their choice of roost sites and minimized diurnal energy output by adaptive hypothermia and behavioral thermo-regulation. In spring and autumn the bats roosted in vertical crevices responsive to changes in ambient temperatures. Here temperatures remained low and the bats were torpid for much of the day, but when the crevices became heated in the late afternoon the bats were passively warmed prior to emergence. Deep, horizontal crevices were preferred in summer; cliffs function as massive heat sinks, and in summer crevice temperatures remained moderate and relatively stable. Throughout most of the day both the deep parts of the crevices and the body temperatures of the bats remained close to 30ºC; at this body temperature pallid bats have unexpectedly low metabolic rates (Trune, 1974). By adjusting their positions and closeness to other bats in the thermal gradient within the crevice, bats dissipate heat early in the day, maintain a low metabolic rate through most of the fat and elevate the body temperature prior to emergence in the evening. Of vital important to pallid bats in the summer are social behaviors that promote communal roosting at "traditional" crevices.

Cryptic gentes revealed in pallid cuckoos Cuculus pallidus using reflectance spectrophotometry

PubMed Central

Starling, M; Heinsohn, R; Cockburn, A; Langmore, N.E

2006-01-01

Many cuckoo species lay eggs that match those of their hosts, which can significantly reduce rejection of their eggs by the host species. However, egg mimicry is problematic for generalist cuckoos that parasitize several host species with different egg types. Some generalist cuckoos have overcome this problem by evolving several host-specific races (gentes), each with its own, host-specific egg type. It is unknown how generalist cuckoos lacking gentes are able to avoid egg rejection by hosts. Here we use reflectance spectrophotometry (300–700 nm) on museum egg collections to test for host-specific egg types in an Australian generalist cuckoo reported to have a single egg type. We show that the colour of pallid cuckoo (Cuculus pallidus) eggs differed between four host species, and that their eggs closely mimicked the eggs of the host they parasitized. These results reveal that pallid cuckoos have host-specific egg types that have not been detected by human observation, and indicate that gentes could be more common than previously realized. PMID:16822754

Distinct changes in evoked and resting globus pallidus activity in early and late Parkinson's disease experimental models.

PubMed

Zold, Camila L; Larramendy, Celia; Riquelme, Luis A; Murer, M Gustavo

2007-09-01

The main clinical manifestations of Parkinson's disease are caused by alterations of basal ganglia activity that are tied in with the progressive loss of mesencephalic dopaminergic neurons. Recent theoretical and modeling studies have suggested that changes in resting neuronal activity occurred later in the course of the disease than those evoked by phasic cortical input. However, there is no empirical support for this proposal. Here we report a marked increase in the responsiveness of globus pallidus neurons to electrical motor cortex stimulation, in the absence of noticeable changes in resting activity, in anesthetized rats that had consistently shown a deficit in forelimb use during behavioral testing before the experiments, and had approximately 45% dopamine neurons spared in the substantia nigra. Pallidal neurons were also over-responsive to motor cortex stimulation and lost spatial selectivity for cortical inputs in rats with extensive nigrostriatal damage. After partial lesions, over-responsiveness was mainly due to an increased proportion of neurons showing excitatory responses, while extensive lesions led to an increased likelihood of inhibitory responding neurons. Changes in resting neuronal activity, comprising pauses disrupting tonic discharge, occurred across different global brain states, including an activated condition which shares similarities with natural patterns of cortical activity seen in awake states and rapid eye-movement sleep, but only after massive nigrostriatal degeneration. These results suggest that a loss of functional segregation and an abnormal temporal encoding of phasic cortical inputs by globus pallidus neurons may contribute to inducing early motor impairment in Parkinson's disease.

Body size, performance and fitness in galapagos marine iguanas.

PubMed

Wikelski, Martin; Romero, L Michael

2003-07-01

Complex organismal traits such as body size are influenced by innumerable selective pressures, making the prediction of evolutionary trajectories for those traits difficult. A potentially powerful way to predict fitness in natural systems is to study the composite response of individuals in terms of performance measures, such as foraging or reproductive performance. Once key performance measures are identified in this top-down approach, we can determine the underlying physiological mechanisms and gain predictive power over long-term evolutionary processes. Here we use marine iguanas as a model system where body size differs by more than one order of magnitude between island populations. We identified foraging efficiency as the main performance measure that constrains body size. Mechanistically, foraging performance is determined by food pasture height and the thermal environment, influencing intake and digestion. Stress hormones may be a flexible way of influencing an individual's response to low-food situations that may be caused by high population density, famines, or anthropogenic disturbances like oil spills. Reproductive performance, on the other hand, increases with body size and is mediated by higher survival of larger hatchlings from larger females and increased mating success of larger males. Reproductive performance of males may be adjusted via plastic hormonal feedback mechanisms that allow individuals to assess their social rank annually within the current population size structure. When integrated, these data suggest that reproductive performance favors increased body size (influenced by reproductive hormones), with an overall limit imposed by foraging performance (influenced by stress hormones). Based on our mechanistic understanding of individual performances we predicted an evolutionary increase in maximum body size caused by global warming trends. We support this prediction using specimens collected during 1905. We also show in a common

Human disturbance alters endocrine and immune responses in the Galapagos marine iguana (Amblyrhynchus cristatus)

PubMed Central

French, Susannah S; DeNardo, Dale F.; Greives, Timothy J.; Strand, Christine R.; Demas, Gregory E.

2010-01-01

Anthropogenic disturbance is a relevant and widespread facilitator of environmental change and there is clear evidence that it impacts natural populations. While population-level responses to major anthropogenic changes have been well studied, individual physiological responses to mild disturbance can be equally critical to the long-term survival of a species, yet they remain largely unexamined. The current study investigated the impact of seemingly low-level anthropogenic disturbance (ecotourism) on stress responsiveness and specific fitness-related immune measures in different breeding stages of the marine iguana (Amblyrhynchus cristatus). Specifically, we found stress-induced elevations in plasma corticosterone among tourist-exposed populations relative to undisturbed populations. We also found changes in multiple immunological responses associated with stress-related effects of human disturbance, including bacterial killing ability, cutaneous wound healing, and hemolytic complement activity, and the responses varied according to reproductive state. By identifying health-related consequences of human disturbance, this study provides critical insight into the conservation of a well-known species that has a very distinct ecology. The study also broadens the foundation of knowledge needed to understand the global significance of various levels of human disturbance. PMID:20708010

Genetic diversity and structure in the Endangered Allen Cays Rock Iguana, Cyclura cychlura inornata

PubMed Central

Aplasca, Andrea C.; Iverson, John B.; Welch, Mark E.; Colosimo, Giuliano

2016-01-01

The Endangered Allen Cays Rock Iguana (Cyclura cychlura inornata) is endemic to the Allen Cays, a tiny cluster of islands in the Bahamas. Naturally occurring populations exist on only two cays (<4 ha each). However, populations of unknown origin were recently discovered on four additional cays. To investigate patterns of genetic variation among these populations, we analyzed nuclear and mitochondrial markers for 268 individuals. Analysis of three mitochondrial gene regions (2,328 bp) and data for eight nuclear microsatellite loci indicated low genetic diversity overall. Estimates of effective population sizes based on multilocus genotypes were also extremely low. Despite low diversity, significant population structuring and variation in genetic diversity measures were detected among cays. Genetic data confirm the source population for an experimentally translocated population while raising concerns regarding other, unauthorized, translocations. Reduced heterozygosity is consistent with a documented historical population decline due to overharvest. This study provides the first range-wide genetic analysis of this subspecies. We suggest strategies to maximize genetic diversity during ongoing recovery including additional translocations to establish assurance populations and additional protective measures for the two remaining natural populations. PMID:26989628

The quaternary structure of the amidase from Geobacillus pallidus RAPc8 is revealed by its crystal packing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agarkar, Vinod B.; Kimani, Serah W.; Cowan, Donald A.

2006-12-01

The amidase from G. pallidus RAPc8, a moderate thermophile, converts amides to the corresponding acids and ammonia and has application as an industrial catalyst. RAPc8 amidase has been cloned, expressed and purified, and then crystallized using the hanging-drop vapour-diffusion method. The amidase from Geobacillus pallidus RAPc8, a moderate thermophile, is a member of the nitrilase enzyme superfamily. It converts amides to the corresponding acids and ammonia and has application as an industrial catalyst. RAPc8 amidase has been cloned and functionally expressed in Escherichia coli and has been purified by heat treatment and a number of chromatographic steps. The enzyme wasmore » crystallized using the hanging-drop vapour-diffusion method. Crystals produced in the presence of 1.2 M sodium citrate, 400 mM NaCl, 100 mM sodium acetate pH 5.6 were selected for X-ray diffraction studies. A data set having acceptable statistics to 1.96 Å resolution was collected under cryoconditions using an in-house X-ray source. The space group was determined to be primitive cubic P4{sub 2}32, with unit-cell parameter a = 130.49 (±0.05) Å. The structure was solved by molecular replacement using the backbone of the hypothetical protein PH0642 from Pyrococcus horikoshii (PDB code 1j31) with all non-identical side chains substituted with alanine as a probe. There is one subunit per asymmetric unit. The subunits are packed as trimers of dimers with D3 point-group symmetry around the threefold axis in such a way that the dimer interface seen in the homologues is preserved.« less

Characterization and distribution of GHRH, PACAP, TRH, SST and IGF1 mRNAs in the green iguana.

PubMed

Ávila-Mendoza, José; Pérez-Rueda, Ernesto; Urban-Sosa, Valeria; Carranza, Martha; Martínez-Moreno, Carlos G; Luna, Maricela; Arámburo, Carlos

2018-01-01

The somatotropic axis (SA) regulates numerous aspects of vertebrate physiology such as development, growth, and metabolism and has influence on several tissues including neural, immune, reproductive and gastric tract. Growth hormone (GH) is a key component of SA, it is synthesized and released mainly by pituitary somatotrophs, although now it is known that virtually all tissues can express GH, which, in addition to its well-described endocrine roles, also has autocrine/paracrine/intracrine actions. In the pituitary, GH expression is regulated by several hypothalamic neuropeptides including GHRH, PACAP, TRH and SST. GH, in turn, regulates IGF1 synthesis in several target tissues, adding complexity to the system since GH effects can be exerted either directly or mediated by IGF1. In reptiles, little is known about the SA components and their functional interactions. The aim of this work was to characterize the mRNAs of the principal SA components in the green iguana and to develop the tools that allow the study of the structural and functional evolution of this system in reptiles. By employing RT-PCR and RACE, the cDNAs encoding for GHRH, PACAP, TRH, SST and IGF1 were amplified and sequenced. Results showed that these cDNAs coded for the corresponding protein precursors of 154, 170, 243, 113, and 131 amino acids, respectively. Of these, GHRH, PACAP, SST and IGF1 precursors exhibited a high structural conservation with respect to its counterparts in other vertebrates. On the other hand, iguana's TRH precursor showed 7 functional copies of mature TRH (pyr-QHP-NH 2 ), as compared to 4 and 6 copies of TRH in avian and mammalian proTRH sequences, respectively. It was found that in addition to its primary production site (brain for GHRH, PACAP, TRH and SST, and liver for IGF1), they were also expressed in other peripheral tissues, i.e. testes and ovaries expressed all the studied mRNAs, whereas TRH and IGF1 mRNAs were observed ubiquitously in all tissues considered. These

Isolation and characterization of polymorphic microsatellite markers in the black spiny tailed iguana (Ctenosaura pectinata) and their cross-utility in other Ctenosaura.

PubMed

Zarza, Eugenia; Pereyra, Ricardo T; Reynoso, Victor H; Emerson, Brent C

2009-01-01

We isolated and characterized 10 polymorphic microsatellite loci from the Mexican black iguana (Ctenosaura pectinata) and assessed levels of polymorphism in sampling sites located in the northern areas of the species' distribution range. Two to 19 alleles per locus and observed heterozygosity ranging from 0.15 to 0.96 were detected. These markers will be useful to describe population genetic structure, the extent of gene flow in contact zones, to study the mating system of the species and to address conservation genetics issues. Additionally, we evaluated the potential utility of these markers for studies of other species within the genus Ctenosaura (i.e. C. hemilopha, C. similis and C. oaxacana). © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd.

Parvalbumin+ Neurons and Npas1+ Neurons Are Distinct Neuron Classes in the Mouse External Globus Pallidus

PubMed Central

Hernández, Vivian M.; Hegeman, Daniel J.; Cui, Qiaoling; Kelver, Daniel A.; Fiske, Michael P.; Glajch, Kelly E.; Pitt, Jason E.; Huang, Tina Y.; Justice, Nicholas J.

2015-01-01

Compelling evidence suggests that pathological activity of the external globus pallidus (GPe), a nucleus in the basal ganglia, contributes to the motor symptoms of a variety of movement disorders such as Parkinson's disease. Recent studies have challenged the idea that the GPe comprises a single, homogenous population of neurons that serves as a simple relay in the indirect pathway. However, we still lack a full understanding of the diversity of the neurons that make up the GPe. Specifically, a more precise classification scheme is needed to better describe the fundamental biology and function of different GPe neuron classes. To this end, we generated a novel multicistronic BAC (bacterial artificial chromosome) transgenic mouse line under the regulatory elements of the Npas1 gene. Using a combinatorial transgenic and immunohistochemical approach, we discovered that parvalbumin-expressing neurons and Npas1-expressing neurons in the GPe represent two nonoverlapping cell classes, amounting to 55% and 27% of the total GPe neuron population, respectively. These two genetically identified cell classes projected primarily to the subthalamic nucleus and to the striatum, respectively. Additionally, parvalbumin-expressing neurons and Npas1-expressing neurons were distinct in their autonomous and driven firing characteristics, their expression of intrinsic ion conductances, and their responsiveness to chronic 6-hydroxydopamine lesion. In summary, our data argue that parvalbumin-expressing neurons and Npas1-expressing neurons are two distinct functional classes of GPe neurons. This work revises our understanding of the GPe, and provides the foundation for future studies of its function and dysfunction. SIGNIFICANCE STATEMENT Until recently, the heterogeneity of the constituent neurons within the external globus pallidus (GPe) was not fully appreciated. We addressed this knowledge gap by discovering two principal GPe neuron classes, which were identified by their nonoverlapping

Parvalbumin+ Neurons and Npas1+ Neurons Are Distinct Neuron Classes in the Mouse External Globus Pallidus.

PubMed

Hernández, Vivian M; Hegeman, Daniel J; Cui, Qiaoling; Kelver, Daniel A; Fiske, Michael P; Glajch, Kelly E; Pitt, Jason E; Huang, Tina Y; Justice, Nicholas J; Chan, C Savio

2015-08-26

Compelling evidence suggests that pathological activity of the external globus pallidus (GPe), a nucleus in the basal ganglia, contributes to the motor symptoms of a variety of movement disorders such as Parkinson's disease. Recent studies have challenged the idea that the GPe comprises a single, homogenous population of neurons that serves as a simple relay in the indirect pathway. However, we still lack a full understanding of the diversity of the neurons that make up the GPe. Specifically, a more precise classification scheme is needed to better describe the fundamental biology and function of different GPe neuron classes. To this end, we generated a novel multicistronic BAC (bacterial artificial chromosome) transgenic mouse line under the regulatory elements of the Npas1 gene. Using a combinatorial transgenic and immunohistochemical approach, we discovered that parvalbumin-expressing neurons and Npas1-expressing neurons in the GPe represent two nonoverlapping cell classes, amounting to 55% and 27% of the total GPe neuron population, respectively. These two genetically identified cell classes projected primarily to the subthalamic nucleus and to the striatum, respectively. Additionally, parvalbumin-expressing neurons and Npas1-expressing neurons were distinct in their autonomous and driven firing characteristics, their expression of intrinsic ion conductances, and their responsiveness to chronic 6-hydroxydopamine lesion. In summary, our data argue that parvalbumin-expressing neurons and Npas1-expressing neurons are two distinct functional classes of GPe neurons. This work revises our understanding of the GPe, and provides the foundation for future studies of its function and dysfunction. Until recently, the heterogeneity of the constituent neurons within the external globus pallidus (GPe) was not fully appreciated. We addressed this knowledge gap by discovering two principal GPe neuron classes, which were identified by their nonoverlapping expression of the

Salmonella Strains Isolated from Galápagos Iguanas Show Spatial Structuring of Serovar and Genomic Diversity

PubMed Central

Lankau, Emily W.; Cruz Bedon, Lenin; Mackie, Roderick I.

2012-01-01

It is thought that dispersal limitation primarily structures host-associated bacterial populations because host distributions inherently limit transmission opportunities. However, enteric bacteria may disperse great distances during food-borne outbreaks. It is unclear if such rapid long-distance dispersal events happen regularly in natural systems or if these events represent an anthropogenic exception. We characterized Salmonella enterica isolates from the feces of free-living Galápagos land and marine iguanas from five sites on four islands using serotyping and genomic fingerprinting. Each site hosted unique and nearly exclusive serovar assemblages. Genomic fingerprint analysis offered a more complex model of S. enterica biogeography, with evidence of both unique strain pools and of spatial population structuring along a geographic gradient. These findings suggest that even relatively generalist enteric bacteria may be strongly dispersal limited in a natural system with strong barriers, such as oceanic divides. Yet, these differing results seen on two typing methods also suggests that genomic variation is less dispersal limited, allowing for different ecological processes to shape biogeographical patterns of the core and flexible portions of this bacterial species' genome. PMID:22615968

Neuronal activity in the globus pallidus internus in patients with tics.

PubMed

Zhuang, P; Hallett, M; Zhang, X; Li, J; Zhang, Y; Li, Y

2009-10-01

To explore the role of neuronal activity in the globus pallidus internus (GPi) in the generation of tic movements. 8 patients with Tourette's syndrome with medically intractable tics who underwent a unilateral pallidotomy for severe tics were studied. They ranged in age from 17 to 24 years; disease duration was 7-19 years. Microelectrode recording was performed in the GPi. The electromyogram (EMG) was simultaneously recorded in muscle groups appropriate for the patient's tics. The relationship between neuronal firing pattern and the EMG was studied. 232 neurons were recorded during tics from eight trajectories. Of these neurons, in addition to decreased neuronal firing rate and irregular firing pattern, 105 (45%) were tic related showing either a burst of activity or a pause in ongoing tonic activity. They could be synchronous (n = 75), earlier than EMG onset (n = 27) or following EMG onset (n = 3). The GPi neuronal bursts preceded EMG onset with decreased (n = 6) or increased activity (n = 21). The initial change in neural activity occurred about 50 ms to 2 s before the EMG onset. Although the data are descriptive and preliminary, the tic related neuronal activity observed in GPi appears to indicate that the basal ganglia motor circuit is involved in tic movements. The early neuronal activity seen in GPi may reflect premonitory sensations that precede a tic.

Field evoked potentials in the globus pallidus of non-human primates.

PubMed

Prescott, Ian A; Marino, Robert A; Levy, Ron

2017-07-01

Stimulation-induced field evoked potentials (fEPs) have been described in the basal ganglia output nuclei of patients with Parkinson's disease and dystonia. The aim of this study was to ascertain whether fEPs were inducible in the external (GPe) and internal (GPi) segments of the globus pallidus in normal non-human primates (NHPs). Microelectrode recording and stimulation was performed in the GPe and GPi of 2 healthy NHPs. Stimulus response curves of the fEP response to changing pulse width and amplitude examined strength-duration relationships and allowed for calculation of fEP chronaxie in the GPe and GPi. Traditional localization techniques were also used, including comparison of neuronal firing rates, optic tract activation, and internal capsule activation. Notable differences were seen in the fEPs found in GPe compared to the fEPs found in GPi. The GPe fEP had a smaller chronaxie time and larger positive deflection amplitude compared to GPi. In addition, an earlier negative deflection was identified in both nuclei and a late negative deflection was observed in the GPe in contrast to reported fEPs in patients with movement disorders. fEPs proved valuable as an ancillary method in localizing the GPe and GPi in NHPs and may be useful in the operating room during human GPi deep brain stimulation or pallidotomy procedures. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Chemical and behavioral studies of femoral gland secretions in iguanid lizards.

PubMed

Alberts, A C

1993-01-01

Comparative studies on the chemistry and behavioral significance of femoral gland secretions in desert iguanas (Dipsosaurus dorsalis) and green iguanas (Iguana iguana) are reviewed. Field and laboratory studies suggest that femoral gland secretions function in conspecific recognition and range marking. In desert iguanas, secretions are of low volatility and may be detected initially using long-range ultraviolet visual cues. In contrast, green iguana secretions contain a diversity of volatile lipids and appear to be localized by chemoreception. Interspecific differences in femoral gland chemistry may reflect adaptations to the diverse climatic conditions of arid desert and tropical forest environments.

Ethanol-Sensitive Pacemaker Neurons in the Mouse External Globus Pallidus

PubMed Central

Abrahao, Karina P; Chancey, Jessica H; Chan, C Savio; Lovinger, David M

2017-01-01

Although ethanol is one of the most widely used drugs, we still lack a full understanding of which neuronal subtypes are affected by this drug. Pacemaker neurons exert powerful control over brain circuit function, but little is known about ethanol effects on these types of neurons. Neurons in the external globus pallidus (GPe) generate pacemaker activity that controls basal ganglia, circuitry associated with habitual and compulsive drug use. We performed patch-clamp recordings from GPe neurons and found that bath application of ethanol dose-dependently decreased the firing rate of low-frequency GPe neurons, but did not alter the firing of high-frequency neurons. GABA or glutamate receptor antagonists did not block the ethanol effect. The GPe is comprised of a heterogeneous population of neurons. We used Lhx6-EGFP and Npas1-tdTm mice strains to identify low-frequency neurons. Lhx6 and Npas1 neurons exhibited decreased firing with ethanol, but only Npas1 neurons were sensitive to 10 mM ethanol. Large-conductance voltage and Ca2+-activated K+ (BK) channel have a key role in the ethanol effect on GPe neurons, as the application of BK channel inhibitors blocked the ethanol-induced firing decrease. Ethanol also increased BK channel open probability measured in single-channel recordings from Npas1-tdTm neurons. In addition, in vivo electrophysiological recordings from GPe showed that ethanol decreased the firing of a large subset of low-frequency neurons. These findings indicate how selectivity of ethanol effects on pacemaker neurons can occur, and enhance our understanding of the mechanisms contributing to acute ethanol effects on the basal ganglia. PMID:27827370

Reptile-associated ticks from Dominica and the Bahamas with notes on hyperparasitic erythraeid mites.

PubMed

Durden, Lance A; Knapp, Charles R; Beati, Lorenza; Dold, Stephanie

2015-02-01

Ticks were collected or recorded from 522 individual reptiles on Dominica and from 658 reptiles from the Bahamas. Two species of ticks were collected on Dominica: Amblyomma antillorum and Amblyomma rotundatum. Similarly, 2 species were collected in the Bahamas: Amblyomma albopictum and Amblyomma torrei. On Dominica, A. antillorum was recorded from 517 Lesser Antillean iguanas (Iguana delicatissima), 2 boa constrictors (Boa nebulosa), 1 Antilles snake (Alsophis sibonius), and 1 Dominican ground lizard (Ameiva fuscata), whereas A. rotundatum was recorded from 1 Lesser Antillean skink (Mabuya mabouya). In the Bahamas, A. albopictum was recorded from 131 Andros iguanas (Cyclura cychlura cychlura), 271 Exuma Island iguanas (Cyclura cychlura figginsi), and 1 Andros curlytail lizard (Leiocephalus carinatus coryi), whereas A. torrei was recorded from 255 Exuma Island iguanas. In the Bahamas, A. albopictum parasitized iguanas on Andros Island and the central Exuma Islands, and A. torrei parasitized iguanas in the southern Exumas. An exception to this trend was that A. torrei was collected from iguanas on Pasture Cay in the central Exumas, an anomaly that is explained by the fact that iguanas (with attached ticks) on Pasture Cay were introduced by humans in the past from islands further south. External hyperparasitic larval erythraeid mites ( Leptus sp.) were recorded from A. torrei in the Bahamas.

Properties of Neurons in External Globus Pallidus Can Support Optimal Action Selection

PubMed Central

Bogacz, Rafal; Martin Moraud, Eduardo; Abdi, Azzedine; Magill, Peter J.; Baufreton, Jérôme

2016-01-01

The external globus pallidus (GPe) is a key nucleus within basal ganglia circuits that are thought to be involved in action selection. A class of computational models assumes that, during action selection, the basal ganglia compute for all actions available in a given context the probabilities that they should be selected. These models suggest that a network of GPe and subthalamic nucleus (STN) neurons computes the normalization term in Bayes’ equation. In order to perform such computation, the GPe needs to send feedback to the STN equal to a particular function of the activity of STN neurons. However, the complex form of this function makes it unlikely that individual GPe neurons, or even a single GPe cell type, could compute it. Here, we demonstrate how this function could be computed within a network containing two types of GABAergic GPe projection neuron, so-called ‘prototypic’ and ‘arkypallidal’ neurons, that have different response properties in vivo and distinct connections. We compare our model predictions with the experimentally-reported connectivity and input-output functions (f-I curves) of the two populations of GPe neurons. We show that, together, these dichotomous cell types fulfil the requirements necessary to compute the function needed for optimal action selection. We conclude that, by virtue of their distinct response properties and connectivities, a network of arkypallidal and prototypic GPe neurons comprises a neural substrate capable of supporting the computation of the posterior probabilities of actions. PMID:27389780

Rat globus pallidus neurons: functional classification and effects of dopamine depletion.

PubMed

Karain, Brad; Xu, Dan; Bellone, John A; Hartman, Richard E; Shi, Wei-Xing

2015-01-01

The rat globus pallidus (GP) is homologous to the primate GP externus. Studies with injectable anesthetics suggest that GP neurons can be classified into Type-I and Type-II cells based on extracellularly recorded spike shape, or positively coupled (PC), negatively coupled (NC), and uncoupled (UC) cells based on functional connectivity with the cortex. In this study, we examined the electrophysiology of rat GP neurons using the inhalational anesthetic isoflurane which offers more constant and easily regulated levels of anesthesia than injectable anesthetics. In 130 GP neurons recorded using small-tip glass electrodes (<1 μm), all but one fired Type-II spikes (positive/negative waveform). Type-I cells were unlikely to be inhibited by isoflurane since all GP neurons also fired Type-II spikes under ketamine-induced anesthesia. When recorded with large-tip electrodes (∼2 μm), however, over 70% of GP neurons exhibited Type-I spikes (negative/positive waveform). These results suggest that the spike shape, recorded extracellularly, varies depending on the electrode used and is not reliable in distinguishing Type-I and Type-II neurons. Using dual-site recording, 40% of GP neurons were identified as PC cells, 17.5% NC cells, and 42.5% UC cells. The three subtypes also differed significantly in firing rate and pattern. Lesions of dopamine neurons increased the number of NC cells, decreased that of UC cells, and significantly shifted the phase relationship between PC cells and the cortex. These results support the presence of GP neuron subtypes and suggest that each subtype plays a different role in the pathophysiology of Parkinson's disease. Synapse 69:41-51, 2015. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

Prototypic and Arkypallidal Neurons in the Dopamine-Intact External Globus Pallidus

PubMed Central

Abdi, Azzedine; Mallet, Nicolas; Mohamed, Foad Y.; Sharott, Andrew; Dodson, Paul D.; Nakamura, Kouichi C.; Suri, Sana; Avery, Sophie V.; Larvin, Joseph T.; Garas, Farid N.; Garas, Shady N.; Vinciati, Federica; Morin, Stéphanie; Bezard, Erwan

2015-01-01

Studies in dopamine-depleted rats indicate that the external globus pallidus (GPe) contains two main types of GABAergic projection cell; so-called “prototypic” and “arkypallidal” neurons. Here, we used correlative anatomical and electrophysiological approaches in rats to determine whether and how this dichotomous organization applies to the dopamine-intact GPe. Prototypic neurons coexpressed the transcription factors Nkx2-1 and Lhx6, comprised approximately two-thirds of all GPe neurons, and were the major GPe cell type innervating the subthalamic nucleus (STN). In contrast, arkypallidal neurons expressed the transcription factor FoxP2, constituted just over one-fourth of GPe neurons, and innervated the striatum but not STN. In anesthetized dopamine-intact rats, molecularly identified prototypic neurons fired at relatively high rates and with high regularity, regardless of brain state (slow-wave activity or spontaneous activation). On average, arkypallidal neurons fired at lower rates and regularities than prototypic neurons, and the two cell types could be further distinguished by the temporal coupling of their firing to ongoing cortical oscillations. Complementing the activity differences observed in vivo, the autonomous firing of identified arkypallidal neurons in vitro was slower and more variable than that of prototypic neurons, which tallied with arkypallidal neurons displaying lower amplitudes of a “persistent” sodium current important for such pacemaking. Arkypallidal neurons also exhibited weaker driven and rebound firing compared with prototypic neurons. In conclusion, our data support the concept that a dichotomous functional organization, as actioned by arkypallidal and prototypic neurons with specialized molecular, structural, and physiological properties, is fundamental to the operations of the dopamine-intact GPe. PMID:25926446

Distinct Developmental Origins Manifest in the Specialized Encoding of Movement by Adult Neurons of the External Globus Pallidus

PubMed Central

Dodson, Paul D.; Larvin, Joseph T.; Duffell, James M.; Garas, Farid N.; Doig, Natalie M.; Kessaris, Nicoletta; Duguid, Ian C.; Bogacz, Rafal; Butt, Simon J.B.; Magill, Peter J.

2015-01-01

Summary Transcriptional codes initiated during brain development are ultimately realized in adulthood as distinct cell types performing specialized roles in behavior. Focusing on the mouse external globus pallidus (GPe), we demonstrate that the potential contributions of two GABAergic GPe cell types to voluntary action are fated from early life to be distinct. Prototypic GPe neurons derive from the medial ganglionic eminence of the embryonic subpallium and express the transcription factor Nkx2-1. These neurons fire at high rates during alert rest, and encode movements through heterogeneous firing rate changes, with many neurons decreasing their activity. In contrast, arkypallidal GPe neurons originate from lateral/caudal ganglionic eminences, express the transcription factor FoxP2, fire at low rates during rest, and encode movements with robust increases in firing. We conclude that developmental diversity positions prototypic and arkypallidal neurons to fulfil distinct roles in behavior via their disparate regulation of GABA release onto different basal ganglia targets. PMID:25843402

Glycinergic inhibition of BAT sympathetic premotor neurons in rostral raphe pallidus.

PubMed

Conceição, Ellen Paula Santos da; Madden, Christopher J; Morrison, Shaun F

2017-06-01

The rostral raphe pallidus (rRPa) contains sympathetic premotor neurons controlling thermogenesis in brown adipose tissue (BAT). We sought to determine whether a tonic activation of glycine A receptors (Gly A R) in the rRPa contributes to the inhibitory regulation of BAT sympathetic nerve activity (SNA) and of cardiovascular parameters in anesthetized rats. Nanoinjection of the Gly A R antagonist, strychnine (STR), into the rRPa of intact rats increased BAT SNA (peak: +495%), BAT temperature (T BAT , +1.1°C), expired CO 2 , (+0.4%), core body temperature (T CORE , +0.2°C), mean arterial pressure (MAP, +4 mmHg), and heart rate (HR, +57 beats/min). STR into rRPa in rats with a postdorsomedial hypothalamus transection produced similar increases in BAT thermogenic and cardiovascular parameters. Glycine nanoinjection into the rRPa evoked a potent inhibition of the cooling-evoked increases in BAT SNA (nadir: -74%), T BAT (-0.2°C), T CORE (-0.2°C), expired CO 2 (-0.2%), MAP (-8 mmHg), and HR (-22 beats/min) but had no effect on the increases in these variables evoked by STR nanoinjection into rRPa. Nanoinjection of GABA into the rRPa inhibited the STR-evoked BAT SNA (nadir: -86%) and reduced the expired CO 2 (-0.4%). Blockade of glutamate receptors in rRPa reduced the STR-evoked increases in BAT SNA (nadir: -61%), T BAT (-0.5°C), expired CO 2 (-0.3%), MAP (-9 mmHg), and HR (-33 beats/min). We conclude that a tonically active glycinergic input to the rRPa contributes to the inhibitory regulation of the discharge of BAT sympathetic premotor neurons and of BAT thermogenesis and energy expenditure. Copyright © 2017 the American Physiological Society.

Role of urea in the postprandial urine concentration cycle of the insectivorous bat Antrozous pallidus.

PubMed

Bassett, John E

2004-02-01

Insectivorous bats, which feed once daily, produce maximally concentrated urine only after feeding. The role of urea as an osmolyte in this process was investigated in pallid bats (Antrozous pallidus) in the laboratory. Following a 24-h fast, plasma and urine were sampled before and 2 h after feeding in postprandial (PP) animals and before and 2 h after similar treatment without feeding in nonfed (NF) animals. Food consumption by PP animals and handling of NF animals had no effect on blood water content as measured by hematocrit and plasma oncotic pressure. Food consumption increased both plasma osmolality (P(osm)) and plasma urea (P(urea)) by as much as 15%. Food consumption also increased urine osmolality (U(osm)) and urine urea (U(urea)) by 50-100%. Feeding increased U(osm) regardless of changes in P(osm), and elevation of U(osm) resulted primarily from increased U(urea). In NF bats, P(osm) and P(urea) were unchanged, while U(osm) and U(urea) increased by as much as 25%. Again, increased U(osm) resulted primarily from increased U(urea). The PP urine concentration cycle of pallid bats resulted from increased urea excretion in response to apparent rapid urea synthesis. Bats rapidly metabolized protein and excreted urea following feeding when body water was most plentiful.

Diversification in the northern neotropics: mitochondrial and nuclear DNA phylogeography of the iguana Ctenosaura pectinata and related species.

PubMed

Zarza, Eugenia; Reynoso, Victor H; Emerson, Brent C

2008-07-01

While Quaternary climatic changes are considered by some to have been a major factor promoting speciation within the neotropics, others suggest that much of the neotropical species diversity originated before the Pleistocene. Using mitochondrial and nuclear sequence data, we evaluate the relative importance of Pleistocene and pre-Pleistocene events within the evolutionary history of the Mexican iguana Ctenosaura pectinata, and related species. Results support the existence of cryptic lineages with strong mitochondrial divergence (> 4%) among them. Some of these lineages form zones of secondary contact, with one of them hybridizing with C. hemilopha. Evolutionary network analyses reveal the oldest populations of C. pectinata to be those of the northern and southern Mexican coastal regions. Inland and mid-latitudinal coastal populations are younger in age as a consequence of a history of local extinction within these regions followed by re-colonization. Estimated divergence times suggest that C. pectinata originated during the Pliocene, whereas geographically distinct mitochondrial DNA lineages first started to diverge during the Pliocene, with subsequent divergence continuing through the Pleistocene. Our results highlight the influence of both Pliocene and Pleistocene events in shaping the geographical distribution of genetic variation within neotropical lowland organisms. Areas of high genetic diversity in southern Mexico were detected, this finding plus the high levels of genetic diversity within C. pectinata, have implications for the conservation of this threatened species.

Localization and function of GABA transporters in the globus pallidus of parkinsonian monkeys

PubMed Central

Galvan, Adriana; Hu, Xing; Smith, Yoland; Wichmann, Thomas

2010-01-01

The GABA transporters GAT-1 and GAT-3 are abundant in the external and internal segments of the globus pallidus (GPe and GPi, respectively). We have shown that pharmacological blockade of either of these transporters results in decreased neuronal firing, and in elevated levels of extracellular GABA in normal monkeys. We now studied whether the electrophysiologic and biochemical effects of local intra-pallidal injections of GAT-1 and GAT-3 blockers, or the subcellular localization of these transporters, are altered in monkeys rendered parkinsonian by the administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The subcellular localization of the transporters in GPe and GPi, studied with electron microscopy immunoperoxidase, was similar to that found in normal animals: i.e., GAT-3 immunoreactivity was mostly confined to glial processes, while GAT-1 labeling was expressed in unmyelinated axons and glial processes. A combined injection/recording device was used to record extracellular activity of single neurons in GPe and GPi, before, during and after administration of small volumes (1 μl) of either the GAT-1 inhibitor, SKF-89976A hydrochloride (720 ng), or the GAT-3 inhibitor, (S)-SNAP-5114 (500 ng). In GPe, the effects of GAT-1 or GAT-3 blockade were similar to those seen in normal monkeys. However, unlike the findings in the normal state, the firing of most neurons was not affected by blockade of either transporter in GPi. These results suggest that, after dopaminergic depletion, the functions of GABA transporters are altered in GPi; without major changes in their subcellular localization. PMID:20138865

Arizona bark scorpion venom resistance in the pallid bat, Antrozous pallidus

PubMed Central

Hopp, Bradley H.; Arvidson, Ryan S.; Adams, Michael E.; Razak, Khaleel A.

2017-01-01

The pallid bat (Antrozous pallidus), a gleaning bat found in the western United States and Mexico, hunts a wide variety of ground-dwelling prey, including scorpions. Anecdotal evidence suggests that the pallid bat is resistant to scorpion venom, but no systematic study has been performed. Here we show with behavioral measures and direct injection of venom that the pallid bat is resistant to venom of the Arizona bark scorpion, Centruroides sculpturatus. Our results show that the pallid bat is stung multiple times during a hunt without any noticeable effect on behavior. In addition, direct injection of venom at mouse LD50 concentrations (1.5 mg/kg) has no effect on bat behavior. At the highest concentration tested (10 mg/kg), three out of four bats showed no effects. One of the four bats showed a transient effect suggesting that additional studies are required to identify potential regional variation in venom tolerance. Scorpion venom is a cocktail of toxins, some of which activate voltage-gated sodium ion channels, causing intense pain. Dorsal root ganglia (DRG) contain nociceptive neurons and are principal targets of scorpion venom toxins. To understand if mutations in specific ion channels contribute to venom resistance, a pallid bat DRG transcriptome was generated. As sodium channels are a major target of scorpion venom, we identified amino acid substitutions present in the pallid bat that may lead to venom resistance. Some of these substitutions are similar to corresponding amino acids in sodium channel isoforms responsible for reduced venom binding activity. The substitution found previously in the grasshopper mouse providing venom resistance to the bark scorpion is not present in the pallid bat, indicating a potentially novel mechanism for venom resistance in the bat that remains to be identified. Taken together, these results indicate that the pallid bat is resistant to venom of the bark scorpion and altered sodium ion channel function may partly underlie

Arizona bark scorpion venom resistance in the pallid bat, Antrozous pallidus.

PubMed

Hopp, Bradley H; Arvidson, Ryan S; Adams, Michael E; Razak, Khaleel A

2017-01-01

The pallid bat (Antrozous pallidus), a gleaning bat found in the western United States and Mexico, hunts a wide variety of ground-dwelling prey, including scorpions. Anecdotal evidence suggests that the pallid bat is resistant to scorpion venom, but no systematic study has been performed. Here we show with behavioral measures and direct injection of venom that the pallid bat is resistant to venom of the Arizona bark scorpion, Centruroides sculpturatus. Our results show that the pallid bat is stung multiple times during a hunt without any noticeable effect on behavior. In addition, direct injection of venom at mouse LD50 concentrations (1.5 mg/kg) has no effect on bat behavior. At the highest concentration tested (10 mg/kg), three out of four bats showed no effects. One of the four bats showed a transient effect suggesting that additional studies are required to identify potential regional variation in venom tolerance. Scorpion venom is a cocktail of toxins, some of which activate voltage-gated sodium ion channels, causing intense pain. Dorsal root ganglia (DRG) contain nociceptive neurons and are principal targets of scorpion venom toxins. To understand if mutations in specific ion channels contribute to venom resistance, a pallid bat DRG transcriptome was generated. As sodium channels are a major target of scorpion venom, we identified amino acid substitutions present in the pallid bat that may lead to venom resistance. Some of these substitutions are similar to corresponding amino acids in sodium channel isoforms responsible for reduced venom binding activity. The substitution found previously in the grasshopper mouse providing venom resistance to the bark scorpion is not present in the pallid bat, indicating a potentially novel mechanism for venom resistance in the bat that remains to be identified. Taken together, these results indicate that the pallid bat is resistant to venom of the bark scorpion and altered sodium ion channel function may partly underlie

A review of the nutritional content and technological parameters of indigenous sources of meat in South America.

PubMed

Saadoun, A; Cabrera, M C

2008-11-01

Meat yields, proximate compositions, fatty acids compositions and technological parameters are reviewed for species which might be further developed as indigenous sources of meat in South America. These include the alpaca (Lama pacos), capybara (Hydrochoerus hydrochaeris), guanaco (Lama guanicoe), llama (Lama glama), nutria (Myocastor coypus), collared peccary (Tayassu tajacu), greater rhea (Rhea americana), lesser rhea (Rhea pennata), yacare (Caiman crocodilus yacare), tegu lizard (Tupinambis merianae) and green iguana (Iguana iguana).

Gadolinium Accumulation in the Deep Cerebellar Nuclei and Globus Pallidus After Exposure to Linear but Not Macrocyclic Gadolinium-Based Contrast Agents in a Retrospective Pig Study With High Similarity to Clinical Conditions.

PubMed

Boyken, Janina; Frenzel, Thomas; Lohrke, Jessica; Jost, Gregor; Pietsch, Hubertus

2018-05-01

The aim of this retrospective study was to determine the gadolinium (Gd) concentration in different brain areas in a pig cohort that received repeated administration of Gd-based contrast agents (GBCAs) at standard doses over several years, comparable with a clinical setting. Brain tissue was collected from 13 Göttingen mini pigs that had received repeated intravenous injections of gadopentetate dimeglumine (Gd-DTPA; Magnevist) and/or gadobutrol (Gadovist). The animals have been included in several preclinical imaging studies since 2008 and received cumulative Gd doses ranging from 7 to 129 mmol per animal over an extended period. Two animals with no history of administration of GBCA were included as controls. Brain autopsies were performed not earlier than 8 and not later than 38 months after the last GBCA application. Tissues from multiple brain areas including cerebellar and cerebral deep nuclei, cerebellar and cerebral cortex, and pons were analyzed for Gd using inductively coupled plasma mass spectrometry. Of the 13 animals, 8 received up to 48 injections of gadobutrol and Gd-DTPA and 5 received up to 29 injections of gadobutrol only. In animals that had received both Gd-DTPA and gadobutrol, a median (interquartile range) Gd concentration of 1.0 nmol/g tissue (0.44-1.42) was measured in the cerebellar nuclei and 0.53 nmol/g (0.29-0.62) in the globus pallidus. The Gd concentration in these areas in gadobutrol-only animals was 50-fold lower with median concentrations of 0.02 nmol/g (0.01-0.02) for cerebellar nuclei and 0.01 nmol/g (0.01-0.01) for globus pallidus and was comparable with control animals with no GBCA history. Accordingly, in animals that received both GBCAs, the amount of residual Gd correlated with the administered dose of Gd-DTPA (P ≤ 0.002) but not with the total Gd dose, consisting of Gd-DTPA and gadobutrol. The Gd concentration in cortical tissue and in the pons was very low (≤0.07 nmol/g tissue) in all animals analyzed. Multiple exposure

Modeling Laterality of the Globus Pallidus Internus in Patients With Parkinson's Disease.

PubMed

Sharim, Justin; Yazdi, Daniel; Baohan, Amy; Behnke, Eric; Pouratian, Nader

2017-04-01

Neurosurgical interventions such as deep brain stimulation surgery of the globus pallidus internus (GPi) play an important role in the treatment of medically refractory Parkinson's disease (PD), and require high targeting accuracy. Variability in the laterality of the GPi across patients with PD has not been well characterized. The aim of this report is to identify factors that may contribute to differences in position of the motor region of GPi. The charts and operative reports of 101 PD patients following deep brain stimulation surgery (70 males, aged 11-78 years) representing 201 GPi were retrospectively reviewed. Data extracted for each subject include age, gender, anterior and posterior commissures (AC-PC) distance, and third ventricular width. Multiple linear regression, stepwise regression, and relative importance of regressors analysis were performed to assess the predictive ability of these variables on GPi laterality. Multiple linear regression for target vs. third ventricular width, gender, AC-PC distance, and age were significant for normalized linear regression coefficients of 0.333 (p < 0.0001), 0.206 (p = 0.00219), 0.168 (p = 0.0119), and 0.159 (p = 0.0136), respectively. Third ventricular width, gender, AC-PC distance, and age each account for 44.06% (21.38-65.69%, 95% CI), 20.82% (10.51-35.88%), 21.46% (8.28-37.05%), and 13.66% (2.62-28.64%) of the R 2 value, respectively. Effect size calculation was significant for a change in the GPi laterality of 0.19 mm per mm of ventricular width, 0.11 mm per mm of AC-PC distance, 0.017 mm per year in age, and 0.54 mm increase for male gender. This variability highlights the limitations of indirect targeting alone, and argues for the continued use of MRI as well as intraoperative physiological testing to account for such factors that contribute to patient-specific variability in GPi localization. © 2016 International Neuromodulation Society.

Neuronal Responses in the Globus Pallidus during Subthalamic Nucleus Electrical Stimulation in Normal and Parkinson's Disease Model Rats

PubMed Central

Ryu, Sang Baek; Bae, Eun Kyung; Kim, Jinhyung; Hwang, Yong Sup; Im, Changkyun; Chang, Jin Woo; Shin, Hyung-Cheul

2013-01-01

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been widely used as a treatment for the movement disturbances caused by Parkinson's disease (PD). Despite successful application of DBS, its mechanism of therapeutic effect is not clearly understood. Because PD results from the degeneration of dopamine neurons that affect the basal ganglia (BG) network, investigation of neuronal responses of BG neurons during STN DBS can provide informative insights for the understanding of the mechanism of therapeutic effect. However, it is difficult to observe neuronal activity during DBS because of large stimulation artifacts. Here, we report the observation of neuronal activities of the globus pallidus (GP) in normal and PD model rats during electrical stimulation of the STN. A custom artifact removal technique was devised to enable monitoring of neural activity during stimulation. We investigated how GP neurons responded to STN stimulation at various stimulation frequencies (10, 50, 90 and 130 Hz). It was observed that activities of GP neurons were modulated by stimulation frequency of the STN and significantly inhibited by high frequency stimulation above 50 Hz. These findings suggest that GP neuronal activity is effectively modulated by STN stimulation and strongly dependent on the frequency of stimulation. PMID:23946689

Among-Individual Variation in Desert Iguanas (Squamata: Dipsosaurus dorsalis): Endurance Capacity Is Positively Related to Home Range Size.

PubMed

Singleton, Jennifer M; Garland, Theodore

Among species of lizards, endurance capacity measured on a motorized treadmill is positively related to daily movement distance and time spent moving, but few studies have addressed such relationships at the level of individual variation within a sex and age category in a single population. Both endurance capacity and home range size show substantial individual variation in lizards, rendering them suitable for such studies. We predicted that these traits would be positively related because endurance capacity is one of the factors that has the potential to limit home range size. We measured the endurance capacity and home range size of adult male desert iguanas (Dipsosaurus dorsalis). Lizards were field captured for measurements of endurance, and home range data were gathered using visual identification of previously marked individuals. Endurance was significantly repeatable between replicate trials, conducted 1-17 d apart ([Formula: see text] for log-transformed values, [Formula: see text], [Formula: see text]). The log of the higher of two endurance trials was positively but not significantly related to log body mass. The log of home range area was positively but not significantly related to log body mass, the number of sightings, or the time span from first to last sighting. As predicted, log endurance was positively correlated with log home range area ([Formula: see text], [Formula: see text], one-tailed [Formula: see text]; for body-mass residual endurance values: [Formula: see text], one-tailed [Formula: see text]). These results suggest that endurance capacity may have a permissive effect on home range size. Alternatively, individuals with larger home ranges may experience training effects (phenotypic plasticity) that increase their endurance.

An orexinergic projection from perifornical hypothalamus to raphe pallidus increases rat brown adipose tissue thermogenesis.

PubMed

Tupone, Domenico; Madden, Christopher J; Cano, Georgina; Morrison, Shaun F

2011-11-02

Orexin (hypocretin) neurons, located exclusively in the PeF-LH, which includes the perifornical area (PeF), the lateral hypothalamus (LH), and lateral portions of the medial hypothalamus, have widespread projections and influence many physiological functions, including the autonomic regulation of body temperature and energy metabolism. Narcolepsy is characterized by the loss of orexin neurons and by disrupted sleep, but also by dysregulation of body temperature and by a strong tendency for obesity. Heat production (thermogenesis) in brown adipose tissue (BAT) contributes to the maintenance of body temperature and, through energy consumption, to body weight regulation. We identified a neural substrate for the influence of orexin neurons on BAT thermogenesis in rat. Nanoinjection of orexin-A (12 pmol) into the rostral raphe pallidus (rRPa), the site of BAT sympathetic premotor neurons, produced large, sustained increases in BAT sympathetic outflow and in BAT thermogenesis. Activation of neurons in the PeF-LH also enhanced BAT thermogenesis over a long time course. Combining viral retrograde tracing from BAT, or cholera toxin subunit b tracing from rRPa, with orexin immunohistochemistry revealed synaptic connections to BAT from orexin neurons in PeF-LH and from rRPa neurons with closely apposed, varicose orexin fibers, as well as a direct, orexinergic projection from PeF-LH to rRPa. These results indicate a potent modulation of BAT thermogenesis by orexin released from the terminals of orexin neurons in PeF-LH directly into the rRPa and provide a potential mechanism contributing to the disrupted regulation of body temperature and energy metabolism in the absence of orexin.

An appraisal of the use of an infrared digital monitoring system for long-term measurement of heart rate in reptilian embryos.

PubMed

Sartori, Marina R; Taylor, Edwin W; Abe, Augusto S; Crossley, Dane A

2015-10-01

Measurement of heart rate (fH) in embryonic reptiles has previously imposed some degree of invasive treatment on the developing embryo. Recently a non-invasive technique of fH detection from intact eggs was developed for commercial avian breeders and has since been used in biological research. This device uses infrared light, enabling it to detect heartbeats in very early embryos. However, infrared light is a source of heat and extended enclosure of an egg in the device is likely to affect temperature with consequent effects on physiological processes, including fH. We studied the effect of use of the monitor on the temperature of eggs and on fH in two species of reptiles, the snapping turtle (Chelydra serpentina) and the green iguana (Iguana iguana). Egg temperature increased from a room temperature of 27-28 °C, by 26% in turtles and 14% in iguanas over 1h of enclosure, resulting in an increase in fH of 76-81% in turtles and 35-50% iguanas. These effects on fH can either be avoided by brief enclosure of each egg in the monitor or measured and accounted for during the design of long-term experiments. Copyright © 2015 Elsevier Inc. All rights reserved.

Movement-Related Discharge in the Macaque Globus Pallidus during High-Frequency Stimulation of the Subthalamic Nucleus

PubMed Central

Zimnik, Andrew J.; Nora, Gerald J.; Desmurget, Michel

2015-01-01

Deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) has largely replaced ablative therapies for Parkinson's disease. Because of the similar efficacies of the two treatments, it has been proposed that DBS acts by creating an “informational lesion,” whereby pathologic neuronal firing patterns are replaced by low-entropy, stimulus-entrained firing patterns. The informational lesion hypothesis, in its current form, states that DBS blocks the transmission of all information from the basal ganglia, including both pathologic firing patterns and normal, task-related modulations in activity. We tested this prediction in two healthy rhesus macaques by recording single-unit spiking activity from the globus pallidus (232 neurons) while the animals completed choice reaction time reaching movements with and without STN-DBS. Despite strong effects of DBS on the activity of most pallidal cells, reach-related modulations in firing rate were equally prevalent in the DBS-on and DBS-off states. This remained true even when the analysis was restricted to cells affected significantly by DBS. In addition, the overall form and timing of perimovement modulations in firing rate were preserved between DBS-on and DBS-off states in the majority of neurons (66%). Active movement and DBS had largely additive effects on the firing rate of most neurons, indicating an orthogonal relationship in which both inputs contribute independently to the overall firing rate of pallidal neurons. These findings suggest that STN-DBS does not act as an indiscriminate informational lesion but rather as a filter that permits task-related modulations in activity while, presumably, eliminating the pathological firing associated with parkinsonism. PMID:25740526

Axial complex and associated structures of the sea urchin Strongylocentrotus pallidus (Sars, G.O. 1871) (Echinodermata: Echinoidea).

PubMed

Ezhova, Olga Vladimirovna; Malakhov, Vladimir Vasil'yevich; Egorova, Ekaterina Alekseevna

2018-06-01

Studies of echinoid microscopic anatomy over the last two centuries have created a number of inaccuracies and mistakes that have accumulated in the descriptions of the intricate organization of the coelomic system of Echinoidea. To clarify the situation, we reconstructed the axial complex and radial complex of the echinoid Strongylocentrotus pallidus. The water ring is located between the perivisceral coelom and the perioral coelom. The oral haemal ring lies between the coelothelia of the water-vascular, perivisceral, and perioral rings. The axial part of the axial organ communicates with the oral haemal ring in interradius CD, but the axial coelom does not form the axocoelomic perihaemal ring. The ventral intestinal haemal vessel originates from the oral haemal ring in radius A, and then branches into a network of capillaries, from which the dorsal intestinal vessel starts. The pericardial coelom envelopes the pericardial part of the axial organ, the lacunae of which communicate with the haemocoel of the body wall and with the axial part of the axial organ. The genital haemal ring and the dorsal intestinal vessel communicate with the axial organ. The genital coelom passes in the CD interradius on the side opposite to the hindgut. There is a somatocoelomic perihaemal ring, which sends a pair of coelomic outgrowths into each radius, accompanied by a radial haemal vessel in the oral part. The mistakes and inaccuracies of early descriptions of the echinoid axial complex are listed. The axial complex and associated structures of sea urchins are compared with other eleutherozoans. © 2018 Wiley Periodicals, Inc.

Transgenic Mouse Lines Subdivide External Segment of the Globus Pallidus (GPe) Neurons and Reveal Distinct GPe Output Pathways

PubMed Central

Mastro, Kevin J.; Bouchard, Rachel S.; Holt, Hiromi A. K.

2014-01-01

Cell-type diversity in the brain enables the assembly of complex neural circuits, whose organization and patterns of activity give rise to brain function. However, the identification of distinct neuronal populations within a given brain region is often complicated by a lack of objective criteria to distinguish one neuronal population from another. In the external segment of the globus pallidus (GPe), neuronal populations have been defined using molecular, anatomical, and electrophysiological criteria, but these classification schemes are often not generalizable across preparations and lack consistency even within the same preparation. Here, we present a novel use of existing transgenic mouse lines, Lim homeobox 6 (Lhx6)–Cre and parvalbumin (PV)–Cre, to define genetically distinct cell populations in the GPe that differ molecularly, anatomically, and electrophysiologically. Lhx6–GPe neurons, which do not express PV, are concentrated in the medial portion of the GPe. They have lower spontaneous firing rates, narrower dynamic ranges, and make stronger projections to the striatum and substantia nigra pars compacta compared with PV–GPe neurons. In contrast, PV–GPe neurons are more concentrated in the lateral portions of the GPe. They have narrower action potentials, deeper afterhyperpolarizations, and make stronger projections to the subthalamic nucleus and parafascicular nucleus of the thalamus. These electrophysiological and anatomical differences suggest that Lhx6–GPe and PV–GPe neurons participate in different circuits with the potential to contribute to different aspects of motor function and dysfunction in disease. PMID:24501350

Characterization of a Nonclassical Class I MHC Gene in a Reptile, the Galápagos Marine Iguana (Amblyrhynchus cristatus)

PubMed Central

Glaberman, Scott; Du Pasquier, Louis; Caccone, Adalgisa

2008-01-01

Squamates are a diverse order of vertebrates, representing more than 7,000 species. Yet, descriptions of full-length major histocompatibility complex (MHC) genes in this group are nearly absent from the literature, while the number of MHC studies continues to rise in other vertebrate taxa. The lack of basic information about MHC organization in squamates inhibits investigation into the relationship between MHC polymorphism and disease, and leaves a large taxonomic gap in our understanding of amniote MHC evolution. Here, we use both cDNA and genomic sequence data to characterize a class I MHC gene (Amcr-UA) from the Galápagos marine iguana, a member of the squamate subfamily Iguaninae. Amcr-UA appears to be functional since it is expressed in the blood and contains many of the conserved peptide-binding residues that are found in classical class I genes of other vertebrates. In addition, comparison of Amcr-UA to homologous sequences from other iguanine species shows that the antigen-binding portion of this gene is under purifying selection, rather than balancing selection, and therefore may have a conserved function. A striking feature of Amcr-UA is that both the cDNA and genomic sequences lack the transmembrane and cytoplasmic domains that are necessary to anchor the class I receptor molecule into the cell membrane, suggesting that the product of this gene is secreted and consequently not involved in classical class I antigen-presentation. The truncated and conserved character of Amcr-UA lead us to define it as a nonclassical gene that is related to the few available squamate class I sequences. However, phylogenetic analysis placed Amcr-UA in a basal position relative to other published classical MHC genes from squamates, suggesting that this gene diverged near the beginning of squamate diversification. PMID:18682845

Amblyomma dissimile Koch (Acari: Ixodidae) attacking Primolius maracana Vieillot (Psittaciformes: Psittacidae) in the Amazon region, State of Pará, Brazil.

PubMed

Scofield, A; Bahia, M; Martins, A L; Góes-Cavalcante, G; Martins, T F; Labruna, M B

2011-01-01

The tick Amblyomma dissimile Koch feeds preferentially on reptiles (Squamata), although amphibians (Anura) also seem to be important hosts. We report an A. dissimile nymph infesting a blue-winged macaw, Primolius maracana, held in captivity in the Mangal das Garças Park, State of Pará, Brazil. Environmental observations suggest that free-living iguanas (Iguana iguana), which used to walk on the bird enclosure in the park, were the source of the A. dissimile tick that infested the blue-winged macaw. We provide the second world record of a bird host for A. dissimile, and the first bird record for this species in South America.

Altered neuronal activity in the primary motor cortex and globus pallidus after dopamine depletion in rats.

PubMed

Wang, Min; Li, Min; Geng, Xiwen; Song, Zhimin; Albers, H Elliott; Yang, Maoquan; Zhang, Xiao; Xie, Jinlu; Qu, Qingyang; He, Tingting

2015-01-15

The involvement of dopamine (DA) neuron loss in the etiology of Parkinson's disease has been well documented. The neural mechanisms underlying the effects of DA loss and the resultant motor dysfunction remain unknown. To gain insights into how loss of DA disrupts the electrical processes in the cortico-subcortical network, the present study explores the effects of DA neuron depletion on electrical activity in the primary motor cortex (M1), on the external and the internal segment of the globus pallidus (GPe and GPi respectively), and on their temporal relationships. Comparison of local field potentials (LFPs) in these brain regions from unilateral hemispheric DA neuron depleted rats and neurologically intact rats revealed that the spectrum power of LFPs in 12-70Hz (for M1, and GPe) and in 25-40Hz (for GPi) was significantly greater in the DA depleted rats than that in the control group. These changes were associated with a shortening of latency in LFP activities between M1 and GPe, from several hundred milliseconds in the intact animals to close to zero in the DA depleted animals. LFP oscillations in M1 were significantly more synchronized with those in GPe in the DA depleted rats compared with those in the control rats. By contrast, the synchronization of oscillation in LFP activities between M1 and GPi did not differ between the DA depleted and intact rats. Not surprisingly, rats that had DA neuron depletion spent more time along the ladder compared with the control rats. These data suggest that enhanced oscillatory activity and increased synchronization of LFPs may contribute to movement impairment in the rat model of Parkinson's disease. Copyright © 2014 Elsevier B.V. All rights reserved.

High-frequency stimulation of the globus pallidus interna nucleus modulates GFRα1 gene expression in the basal ganglia.

PubMed

Ho, Duncun Xun Kiat; Tan, Yong Chee; Tan, Jiayi; Too, Heng Phon; Ng, Wai Hoe

2014-04-01

Deep brain stimulation (DBS) is an established therapy for movement disorders such as Parkinson's disease (PD). Although the efficacy of DBS is clear, its precise molecular mechanism remains unknown. The glial cell line derived factor (GDNF) family of ligands has been shown to confer neuroprotective effects on dopaminergic neurons, and putaminal infusion of GDNF have been investigated in PD patients with promising results. Despite the potential therapeutic role of GDNF in alleviating motor symptoms, there is no data on the effects of electrical stimulation on GDNF-family receptor (GFR) expression in the basal ganglia structures. Here, we report the effects of electrical stimulation on GFRα1 isoforms, particularly GFRα1a and GFRα1b. Wistar rats underwent 2 hours of high frequency stimulation (HFS) at the globus pallidus interna nucleus. A control group was subjected to a similar procedure but without stimulation. The HFS group, sacrificed 24 hours after treatment, had a threefold decrease in mRNA expression level of GFRα1b (p=0.037), but the expression level reverted to normal 72 hours after stimulation. Our preliminary data reveal the acute effects of HFS on splice isoforms of GFRα1, and suggest that HFS may modulate the splice isoforms of GFRα1a and GFRα1b to varying degrees. Going forward, elucidating the interactions between HFS and GFR may shed new insights into the complexity of GDNF signaling in the nervous system and lead to better design of clinical trials using these signaling pathways to halt disease progression in PD and other neurodegenerative diseases. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dendritic sodium channels promote active decorrelation and reduce phase locking to parkinsonian input oscillations in model globus pallidus neurons

PubMed Central

Edgerton, Jeremy R.; Jaeger, Dieter

2011-01-01

Correlated firing among populations of neurons is present throughout the brain and is often rhythmic in nature, observable as an oscillatory fluctuation in the local field potential. Although rhythmic population activity is believed to be critical for normal function in many brain areas, synchronized neural oscillations are associated with disease states in other cases. In the globus pallidus (GP in rodents, homolog of the primate GPe), pairs of neurons generally have uncorrelated firing in normal animals despite an anatomical organization suggesting that they should receive substantial common input. By contrast, correlated and rhythmic GP firing is observed in animal models of Parkinson's disease (PD). Based in part on these findings it has been proposed that an important part of basal ganglia function is active decorrelation, whereby redundant information is compressed. Mechanisms that implement active decorrelation, and changes that cause it to fail in PD, are subjects of great interest. Rat GP neurons express fast, transient voltage-dependent sodium channels (NaF channels) in their dendrites, with the expression level being highest near asymmetric synapses. We recently showed that the dendritic NaF density strongly influences the responsiveness of model GP neurons to synchronous excitatory inputs. In the present study we use rat GP neuron models to show that dendritic NaF channel expression is a potential cellular mechanism of active decorrelation. We further show that model neurons with lower dendritic NaF channel expression have a greater tendency to phase lock with oscillatory synaptic input patterns like those observed in PD. PMID:21795543

T1 Shortening in the Globus Pallidus after Multiple Administrations of Gadobutrol: Assessment with a Multidynamic Multiecho Sequence.

PubMed

Kang, Koung Mi; Choi, Seung Hong; Hwang, Moonjung; Yun, Tae Jin; Kim, Ji-Hoon; Sohn, Chul-Ho

2018-04-01

Purpose To determine the association between the administration of the macrocyclic contrast medium gadobutrol and T1 relaxation time in the brains of patients with normal renal function by using multidynamic multiecho (MDME) magnetic resonance (MR) imaging sequences. Materials and Methods The institutional review board approved this retrospective study, and the need to obtain written informed consent was waived. This study included 46 patients (revealed by an electronic medical record search) who had received one or more gadobutrol injections and a maximum of one MR imaging contrast medium injection other than gadobutrol before MDME sequence acquisition. One radiologist performed quantitative analyses of regions of interest on quantitative T1 maps twice to cover the normal-appearing globus pallidus (GP), frontal white matter, frontal cortex, and thalamus. The number of administrations and the cumulative dose of gadobutrol, age, intervals between administrations, sex, and treatment were investigated. Univariable and multivariable linear regression analyses of the T1 values in four brain regions and the GP-to-thalamus signal intensity (SI) ratio were performed. P values of less than the Bonferroni-corrected value of .01 were considered to indicate significant differences. Results Intraobserver reproducibility was good to excellent (intraclass correlation coefficients, 0.62-0.81). Because of high multicollinearity between the number of gadobutrol administrations and accumulated dose (r = 0.96, P < .001), the number of gadobutrol administrations was considered in the regression analyses. T1 shortening in the GP was independently associated with the number of gadobutrol administrations (P = .002). T1 in the other brain regions and the GP-to-thalamus SI ratio were not significantly associated with the number of gadobutrol administrations (P > .01). Conclusion Multiple exposures to gadobutrol are associated with T1 shortening in the GP. © RSNA, 2017 Online supplemental

Deep Brain Stimulation of the Internal Globus Pallidus Improves Response Initiation and Proactive Inhibition in Patients With Parkinson’s Disease

PubMed Central

Pan, Yixin; Wang, Linbin; Zhang, Yingying; Zhang, Chencheng; Qiu, Xian; Tan, Yuyan; Zhou, Haiyan; Sun, Bomin; Li, Dianyou

2018-01-01

Background: Impulse control disorder is not uncommon in patients with Parkinson’s disease (PD) who are treated with dopamine replacement therapy and subthalamic deep brain stimulation (DBS). Internal globus pallidus (GPi)-DBS is increasingly used, but its role in inhibitory control has rarely been explored. In this study, we evaluated the effect of GPi-DBS on inhibitory control in PD patients. Methods: A stop-signal paradigm was used to test response initiation, proactive inhibition, and reactive inhibition. The subjects enrolled in the experiment were 27 patients with PD, of whom 13 had received only drug treatment and 14 had received bilateral GPi-DBS in addition to conventional medical treatment and 15 healthy individuals. Results: Our results revealed that with GPi-DBS on, patients with PD showed significantly faster responses than the other groups in trials where it was certain that no stop signal would be presented. Proactive inhibition was significantly different in the surgical patients with GPi-DBS on versus when GPi-DBS was off, in surgical patients with GPi-DBS on versus drug-treated patients, and in healthy controls versus drug-treated patients. Correlation analyses revealed that when GPi-DBS was on, there was a statistically significant moderate positive relationship between proactive inhibition and dopaminergic medication. Conclusion: GPi-DBS may lead to an increase in response initiation speed and improve the dysfunctional proactive inhibitory control observed in PD patients. Our results may help us to understand the role of the GPi in cortical-basal ganglia circuits. PMID:29681869

Editor's Highlight: Lower Fractional Anisotropy in the Globus Pallidus of Asymptomatic Welders, a Marker for Long-Term Welding Exposure.

PubMed

Lee, Eun-Young; Flynn, Michael R; Du, Guangwei; Lewis, Mechelle M; Herring, Amy H; Van Buren, Eric; Van Buren, Scott; Kong, Lan; Mailman, Richard B; Huang, Xuemei

2016-09-01

Welding fumes contain several metals including manganese (Mn), iron (Fe), and copper (Cu) that at high exposure may co-influence welding-related neurotoxicity. The relationship between brain accumulation of these metals and neuropathology, especially in welders with subclinical exposure levels, is unclear. This study examined the microstructural integrity of basal ganglia (BG) regions in asymptomatic welders using diffusion tensor imaging (DTI). Subjects with (n = 43) and without (age- and gender-matched controls; n = 31) history of welding were studied. Occupational questionnaires estimated short-term (HrsW; welding hours and E90; cumulative exposure, past 90 days) and long-term (YrsW; total years welding and ELT; cumulative exposure, lifetime) exposure. Whole blood metal levels (Mn, Fe, and Cu) were obtained. Brain MRI pallidal index (PI), R1 (1/T1), and R2* (1/T2*) were measured to estimate Mn and Fe accumulation in BG [caudate, putamen, and globus pallidus (GP)]. DTI was used to assess BG microstructural differences, and related with exposure measurements. When compared with controls, welders had significantly lower fractional anisotropy (FA) in the GP. In welders, GP FA values showed non-linear relationships to YrsW, blood Mn, and PI. GP FA decreased after a critical level of YrsW or Mn was reached, whereas it decreased with increasing PI values until plateauing at the highest PI values. GP FA, however, did not show any relationship with short-term exposure measurements (HrsW, E90), blood Cu and Fe, or R(2)* values. GP FA captured microstructural changes associated with chronic low-level Mn exposure, and may serve as a biomarker for neurotoxicity in asymptomatic welders. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Editor’s Highlight: Lower Fractional Anisotropy in the Globus Pallidus of Asymptomatic Welders, a Marker for Long-Term Welding Exposure

PubMed Central

Lee, Eun-Young; Flynn, Michael R.; Du, Guangwei; Lewis, Mechelle M.; Herring, Amy H.; Van Buren, Eric; Van Buren, Scott; Kong, Lan; Mailman, Richard B.; Huang, Xuemei

2016-01-01

Introduction: Welding fumes contain several metals including manganese (Mn), iron (Fe), and copper (Cu) that at high exposure may co-influence welding-related neurotoxicity. The relationship between brain accumulation of these metals and neuropathology, especially in welders with subclinical exposure levels, is unclear. This study examined the microstructural integrity of basal ganglia (BG) regions in asymptomatic welders using diffusion tensor imaging (DTI). Methods: Subjects with (n = 43) and without (age- and gender-matched controls; n = 31) history of welding were studied. Occupational questionnaires estimated short-term (HrsW; welding hours and E90; cumulative exposure, past 90 days) and long-term (YrsW; total years welding and ELT; cumulative exposure, lifetime) exposure. Whole blood metal levels (Mn, Fe, and Cu) were obtained. Brain MRI pallidal index (PI), R1 (1/T1), and R2* (1/T2*) were measured to estimate Mn and Fe accumulation in BG [caudate, putamen, and globus pallidus (GP)]. DTI was used to assess BG microstructural differences, and related with exposure measurements. Results: When compared with controls, welders had significantly lower fractional anisotropy (FA) in the GP. In welders, GP FA values showed non-linear relationships to YrsW, blood Mn, and PI. GP FA decreased after a critical level of YrsW or Mn was reached, whereas it decreased with increasing PI values until plateauing at the highest PI values. GP FA, however, did not show any relationship with short-term exposure measurements (HrsW, E90), blood Cu and Fe, or R2* values. Conclusion: GP FA captured microstructural changes associated with chronic low-level Mn exposure, and may serve as a biomarker for neurotoxicity in asymptomatic welders. PMID:27466214

Diet-tissue stable isotope (Δ(13)C and Δ(15)N) discrimination factors for multiple tissues from terrestrial reptiles.

PubMed

Steinitz, Ronnie; Lemm, Jeffrey M; Pasachnik, Stesha A; Kurle, Carolyn M

2016-01-15

Stable isotope analysis is a powerful tool for reconstructing trophic interactions to better understand drivers of community ecology. Taxon-specific stable isotope discrimination factors contribute to the best use of this tool. We determined the first Δ(13)C and Δ(15)N values for Rock Iguanas (Cyclura spp.) to better understand isotopic fractionation and estimate wild reptile foraging ecology. The Δ(13)C and Δ(15)N values between diet and skin, blood, and scat were determined from juvenile and adult iguanas held for 1 year on a known diet. We measured relationships between iguana discrimination factors and size/age and quantified effects of lipid extraction and acid treatment on stable isotope values from iguana tissues. Isotopic and elemental compositions were determined by Dumas combustion using an elemental analyzer coupled to an isotope ratio mass spectrometer using standards of known composition. The Δ(13)C and Δ(15)N values ranged from -2.5 to +6.5‰ and +2.2 to +7.5‰, respectively, with some differences among tissues and between juveniles and adults. The Δ(13)C values from blood and skin differed among species, but not the Δ(15)N values. The Δ(13)C values from blood and skin and Δ(15)N values from blood were positively correlated with size/age. The Δ(13)C values from scat were negatively correlated with size (not age). Treatment with HCl (scat) and lipid extraction (skin) did not affect the isotope values. These results should aid in the understanding of processes driving stable carbon and nitrogen isotope discrimination factors in reptiles. We provide estimates of Δ(13)C and Δ(15)N values and linear relationships between iguana size/age and discrimination factors for the best interpretation of wild reptile foraging ecology. Copyright © 2015 John Wiley & Sons, Ltd.

First reports of ectoparasites collected from wild-caught exotic reptiles in Florida.

PubMed

Corn, Joseph L; Mertins, James W; Hanson, Britta; Snow, Skip

2011-01-01

We collected ectoparasites from 27 of 51 wild-caught, free-ranging exotic reptiles examined in Florida from 2003 to 2008. Sampled animals represented eight species, five of which yielded ectoparasites. Reported new parasite distribution records for the United States include the following: the first collection of the African tick Amblyomma latum (Koch) from a wild-caught animal [ball python, Python regius (Shaw)] in the United States; the first collection of the lizard scale mite Hirstiella stamii (Jack) from any wild-caught animal [green iguana, Iguana iguana (L.)]; and the first collection of the lizard scale mite Geckobia hemidactyli (Lawrence) in the continental United States from a wild-caught tropical house gecko, Hemidactylus mabouia (Moreau de Jonnès). We also report the first collections of the Neotropical ticks Amblyomma rotundatum (Koch) and Amblyomma dissimile (Koch) from wild-caught Burmese pythons, Python molurus bivittatus (Kuhl); the first collections of A. dissimile from a wild-caught African savannah monitor, Varanus exanthematicus (Bosc); and from wild-caught green iguanas in the United States; and the first collections of the native chiggers Eutrombicula splendens (Ewing) and Eutrombicula cinnabaris (Ewing) from wild-caught Burmese pythons. These reports may only suggest the diversity of reptile ectoparasites introduced and established in Florida and the new host-parasite relationships that have developed among exotic and native ectoparasites and established exotic reptiles.

Meta-analysis comparing deep brain stimulation of the globus pallidus and subthalamic nucleus to treat advanced Parkinson disease.

PubMed

Liu, Yi; Li, Weina; Tan, Changhong; Liu, Xi; Wang, Xin; Gui, Yuejiang; Qin, Lu; Deng, Fen; Hu, Changlin; Chen, Lifen

2014-09-01

Deep brain stimulation (DBS) is the surgical procedure of choice for patients with advanced Parkinson disease (PD). The globus pallidus internus (GPi) and the subthalamic nucleus (STN) are commonly targeted by this procedure. The purpose of this meta-analysis was to compare the efficacy of DBS in each region. MEDLINE/PubMed, EMBASE, Web of Knowledge, and the Cochrane Library were searched for English-language studies published before April 2013. of studies investigating the efficacy and clinical outcomes of DBS of the GPi and STN for PD were analyzed. Six eligible trials containing a total of 563 patients were included in the analysis. Deep brain stimulation of the GPi or STN equally improved motor function, measured by the Unified Parkinson's Disease Rating Scale Section III (UPDRSIII) (motor section, for patients in on- and off-medication phases), within 1 year postsurgery. The change score for the on-medication phase was 0.68 (95% CI - 2.12 to 3.47, p > 0.05; 5 studies, 518 patients) and for the off-medication phase was 1.83 (95% CI - 3.12 to 6.77, p > 0.05; 5 studies, 518 patients). The UPDRS Section II (activities of daily living) scores for patients on medication improved equally in both DBS groups (p = 0.97). STN DBS allowed medication dosages to be reduced more than GPi DBS (95% CI 129.27-316.64, p < 0.00001; 5 studies, 540 patients). Psychiatric symptoms, measured by Beck Depression Inventory, 2nd edition scores, showed greater improvement from baseline after GPi DBS than after STN DBS (standardized mean difference -2.28, 95% CI -3.73 to -0.84, p = 0.002; 3 studies, 382 patients). GPi and STN DBS improve motor function and activities of daily living for PD patients. Differences in therapeutic efficacy for PD were not observed between the 2 procedures. STN DBS allowed greater reduction in medication for patients, whereas GPi DBS provided greater relief from psychiatric symptoms. An understanding of other symptomatic aspects of targeting each region and long

Systemic blockade of dopamine D2-like receptors increases high-voltage spindles in the globus pallidus and motor cortex of freely moving rats.

PubMed

Yang, Chen; Ge, Shun-Nan; Zhang, Jia-Rui; Chen, Lei; Yan, Zhi-Qiang; Heng, Li-Jun; Zhao, Tian-Zhi; Li, Wei-Xin; Jia, Dong; Zhu, Jun-Ling; Gao, Guo-Dong

2013-01-01

High-voltage spindles (HVSs) have been reported to appear spontaneously and widely in the cortical-basal ganglia networks of rats. Our previous study showed that dopamine depletion can significantly increase the power and coherence of HVSs in the globus pallidus (GP) and motor cortex of freely moving rats. However, it is unclear whether dopamine regulates HVS activity by acting on dopamine D₁-like receptors or D₂-like receptors. We employed local-field potential and electrocorticogram methods to simultaneously record the oscillatory activities in the GP and primary motor cortex (M1) in freely moving rats following systemic administration of dopamine receptor antagonists or saline. The results showed that the dopamine D₂-like receptor antagonists, raclopride and haloperidol, significantly increased the number and duration of HVSs, and the relative power associated with HVS activity in the GP and M1 cortex. Coherence values for HVS activity between the GP and M1 cortex area were also significantly increased by dopamine D₂-like receptor antagonists. On the contrary, the selective dopamine D₁-like receptor antagonist, SCH23390, had no significant effect on the number, duration, or relative power of HVSs, or HVS-related coherence between M1 and GP. In conclusion, dopamine D₂-like receptors, but not D₁-like receptors, were involved in HVS regulation. This supports the important role of dopamine D₂-like receptors in the regulation of HVSs. An siRNA knock-down experiment on the striatum confirmed our conclusion.

Dermatomycosis in a pet inland bearded dragon (Pogona vitticeps) caused by a Chrysosporium species related to Nannizziopsis vriesii.

PubMed

Abarca, M L; Martorell, J; Castellá, G; Ramis, A; Cabañes, F J

2009-08-01

A Chrysosporium sp. related to Nannizziopsis vriesii was isolated in pure culture from squames and biopsies of facial lesions in a pet inland bearded dragon (Pogona vitticeps) in Spain. The presence in histological sections of morphologically consistent fungal elements strongly incriminates this fungus as the aetiological agent of infection. Lesions regressed following treatment with oral ketoconazole and topical chlorhexidine and terbinafine until the lizard was lost to follow up 1 month later. The ITS-5.8S rRNA gene of the isolate was sequenced and a search on the GenBank database revealed a high match with the sequences of two Chrysosporium sp. strains recently isolated from green iguanas (Iguana iguana) with dermatomycosis, also in Spain. Phylogenetic analysis of the sequences revealed that all these strains are related to N. vriesii. This is the first report of dermatomycoses caused by a Chrysosporium species related to N. vriesii in a bearded dragon outside North America.

Reversible inactivation of rostral nucleus raphe pallidus attenuates acute autonomic responses but not their habituation to repeated audiogenic stress in rats.

PubMed

Nyhuis, Tara J; Masini, Cher V; Taufer, Kirsten L; Day, Heidi E W; Campeau, Serge

2016-01-01

The medullary nucleus raphe pallidus (RPa) mediates several autonomic responses evoked by acute stress exposure, including tachycardia and hyperthermia. The present study assessed whether the RPa contributes to the decline/habituation of these responses observed during repeated audiogenic stress. Adult male rats were implanted with cannulae aimed at the RPa, and abdominal E-mitters that wirelessly acquire heart rate and core body temperature. After surgical recovery, animals were injected with muscimol or vehicle (aCSF) in the RPa region, followed by 30 min of 95-dBA loud noise or no noise control exposures on 3 consecutive days at 24-h intervals. Forty-eight hours after the third exposure, animals were exposed to an additional, but injection-free, loud noise or no noise test to assess habituation of hyperthermia and tachycardia. Three days later, rats were restrained for 30-min to evaluate their ability to display normal acute autonomic responses following the repeated muscimol injection regimen. The results indicated that the inhibition of cellular activity induced by the GABAA-receptor agonist muscimol centered in the RPa region reliably attenuated acute audiogenic stress-evoked tachycardia and hyperthermia, compared with vehicle-injected rats. Animals in the stress groups exhibited similar attenuated tachycardia and hyperthermia during the injection-free fourth audiogenic stress exposure, and displayed similar and robust increases in these responses to the subsequent restraint test. These results suggest that cellular activity in neurons of the RPa region is necessary for the expression of acute audiogenic stress-induced tachycardia and hyperthermia, but may not be necessary for the acquisition of habituated tachycardic responses to repeated stress.

Reversible inactivation of rostral nucleus raphe pallidus attenuates acute autonomic responses but not their habituation to repeated audiogenic stress in rats

PubMed Central

Nyhuis, Tara J.; Masini, Cher V.; Taufer, Kirsten L.; Day, Heidi E.W.; Campeau, Serge

2016-01-01

The medullary nucleus raphe pallidus (RPa) mediates several autonomic responses evoked by acute stress exposure, including tachycardia and hyperthermia. The present study assessed whether the RPa contributes to the decline/habituation of these responses observed during repeated audiogenic stress. Adult male rats were implanted with cannulae aimed at the RPa, and abdominal E-mitters that wirelessly acquire heart rate and core body temperature. After surgical recovery, animals were injected with muscimol or vehicle (aCSF) in the RPa region, followed by 30 minutes of 95-dBA loud noise or no noise control exposures on 3 consecutive days at 24-hr intervals. Forty-eight hours after the third exposure, animals were exposed to an additional, but injection-free, loud noise or no noise test to assess habituation of hyperthermia and tachycardia. Three days later, rats were restrained for 30-minutes to evaluate their ability to display normal acute autonomic responses following the repeated muscimol injection regimen. The results indicated that the inhibition of cellular activity induced by the GABAA-receptor agonist muscimol centered in the RPa region reliably attenuated acute audiogenic stress-evoked tachycardia and hyperthermia, compared with vehicle-injected rats. Animals in the stress groups exhibited similarly attenuated tachycardia and hyperthermia during the injection-free fourth audiogenic stress exposure, and displayed similar and robust increases in these responses to the subsequent restraint test. These results suggest that cellular activity in neurons of the RPa region is necessary for the expression of acute audiogenic stress-induced tachycardia and hyperthermia, but may not be necessary for the acquisition of habituated tachycardic responses to repeated stress. PMID:26998558

Localization of Basal Ganglia and Thalamic Damage in Dyskinetic Cerebral Palsy.

PubMed

Aravamuthan, Bhooma R; Waugh, Jeff L

2016-01-01

Dyskinetic cerebral palsy affects 15%-20% of patients with cerebral palsy. Basal ganglia injury is associated with dyskinetic cerebral palsy, but the patterns of injury within the basal ganglia predisposing to dyskinetic cerebral palsy are unknown, making treatment difficult. For example, deep brain stimulation of the globus pallidus interna improves dystonia in only 40% of patients with dyskinetic cerebral palsy. Basal ganglia injury heterogeneity may explain this variability. To investigate this, we conducted a qualitative systematic review of basal ganglia and thalamic damage in dyskinetic cerebral palsy. Reviews and articles primarily addressing genetic or toxic causes of cerebral palsy were excluded yielding 22 studies (304 subjects). Thirteen studies specified the involved basal ganglia nuclei (subthalamic nucleus, caudate, putamen, globus pallidus, or lentiform nuclei, comprised by the putamen and globus pallidus). Studies investigating the lentiform nuclei (without distinguishing between the putamen and globus pallidus) showed that all subjects (19 of 19) had lentiform nuclei damage. Studies simultaneously but independently investigating the putamen and globus pallidus also showed that all subjects (35 of 35) had lentiform nuclei damage (i.e., putamen or globus pallidus damage); this was followed in frequency by damage to the putamen alone (70 of 101, 69%), the subthalamic nucleus (17 of 25, 68%), the thalamus (88 of 142, 62%), the globus pallidus (7/35, 20%), and the caudate (6 of 47, 13%). Globus pallidus damage was almost always coincident with putaminal damage. Noting consistent involvement of the lentiform nuclei in dyskinetic cerebral palsy, these results could suggest two groups of patients with dyskinetic cerebral palsy: those with putamen-predominant damage and those with panlenticular damage involving both the putamen and the globus pallidus. Differentiating between these groups could help predict response to therapies such as deep brain

Dopamine depletion increases the power and coherence of high-voltage spindles in the globus pallidus and motor cortex of freely moving rats.

PubMed

Ge, Shunnan; Yang, Chen; Li, Min; Li, Jiang; Chang, Xiaozan; Fu, Jian; Chen, Lei; Chang, Chongwang; Wang, Xuelian; Zhu, Junling; Gao, Guodong

2012-07-17

Studies on patients with Parkinson's disease and in animal models have observed enhanced synchronization of oscillations in several frequency bands within and between the cortical-basal ganglia (BG) structures. Recent research has also shown that synchronization of high-voltage spindles (HVSs) in the cortex, striatum and substantia nigra pars reticulate is increased by dopamine depletion. However, more evidence is needed to determine whether HVS activity in the whole cortex-BG network represents homologous alteration following dopamine depletion. As the globus pallidus (GP) is in a central position to propagate and synchronize oscillations in the cortical-BG circuits, we employed local-field potentials and electrocorticogram to simultaneously record oscillations in the GP and primary (M1) and secondary (M2) motor cortices on freely moving 6-hydroxydopamine (6-OHDA) lesioned and control rats. Results showed that HVS episodes recorded from GP, and M2 and M1 cortex areas were more numerous and longer in 6-OHDA lesioned rats compared to controls. Relative power associated with HVS activity in the GP, and M2 and M1 cortices of 6-OHDA lesioned rats was significantly greater than that for control rats. Coherence values for HVS activity between the GP, and M2 and M1 cortex areas were significantly increased by dopamine depletion. Time lag between the M1 cortex HVS and GP HVS was significantly shorter for dopamine depleted than normal rats. Findings indicate a crucial rule for dopamine in the regulation of HVS activity in the whole cortical-BG circuit, and suggest a close relationship between abnormally synchronized HVS oscillations in the cortex-BG network and Parkinson's disease. Copyright © 2012 Elsevier B.V. All rights reserved.

Cognition and Depression Following Deep Brain Stimulation of the Subthalamic Nucleus and Globus Pallidus Pars Internus in Parkinson's Disease: A Meta-Analysis.

PubMed

Combs, Hannah L; Folley, Bradley S; Berry, David T R; Segerstrom, Suzanne C; Han, Dong Y; Anderson-Mooney, Amelia J; Walls, Brittany D; van Horne, Craig

2015-12-01

Parkinson's disease (PD) is a common, degenerative disorder of the central nervous system. Individuals experience predominantly extrapyramidal symptoms including resting tremor, rigidity, bradykinesia, gait abnormalities, cognitive impairment, depression, and neurobehavioral concerns. Cognitive impairments associated with PD are diverse, including difficulty with attention, processing speed, executive functioning, memory recall, visuospatial functions, word-retrieval, and naming. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or globus pallidus internus (GPi) is FDA approved and has been shown to be effective in reducing motor symptoms of PD. Studies have found that stimulating STN and GPi are equally effective at improving motor symptoms and dyskinesias; however, there has been discrepancy as to whether the cognitive, behavioral, and mood symptoms are affected differently between the two targets. The present study used random-effects meta-analytic models along with a novel p-curve analytic procedure to compare the potential cognitive and emotional impairments associated with STN-DBS in the current literature to those associated with GPi-DBS. Forty-one articles were reviewed with an aggregated sample size of 1622 patients. Following STN-DBS, small declines were found in psychomotor speed, memory, attention, executive functions, and overall cognition; and moderate declines were found in both semantic and phonemic fluency. However, GPi-DBS resulted in fewer neurocognitive declines than STN-DBS (small declines in attention and small-moderate declines in verbal fluency). With regards to its effect on depression symptomatology, both GPi-DBS and STN-DBS resulted in lower levels of depressive symptoms post-surgery. From a neurocognitive standpoint, both GPi-DBS and STN-DBS produce subtle cognitive declines but appears to be relatively well tolerated.

Plasma lipid concentrations for some Brazilian lizards.

PubMed

Gillett, M P; Lima, V L; Costa, J C; Sibrian, A M

1979-01-01

1. Plasma concentrations of cholesterol, cholesteryl esters, phospholipids and triglycerides were determined for ten species of Brazilian lizards, Iguana iguana, Tropidurus torquatos and T. semitaeniatus (Iguanidae), Tupinambis teguixin, Ameiva ameiva and Cnemidophorus ocellifer (Teiidae), Mabuya maculata (Scincidae), Hemidactylus mabouia (Gekkonidae), Amphisbaenia vermicularis and Leposternon polystegum (Amphisbaenidae). 2. Considerable inter- and intra-species variations in plasma lipid concentrations were observed. 3. The percentage of total cholesterol esterified and the individual phospholipid composition of plasma were relatively constant for each species. 4. Over 60% of the cholesteryl esters present in plasma from three species each of iguanid and teiid lizards were polyenoic.

Altered Effective Connectivity Network of the Basal Ganglia in Low-Grade Hepatic Encephalopathy: A Resting-State fMRI Study with Granger Causality Analysis

PubMed Central

Zhong, Jianhui; Zhang, Zhiqiang; Ni, Ling; Jiao, Qing; Liao, Wei; Zheng, Gang; Lu, Guangming

2013-01-01

Background The basal ganglia often show abnormal metabolism and intracranial hemodynamics in cirrhotic patients with hepatic encephalopathy (HE). Little is known about how the basal ganglia affect other brain system and is affected by other brain regions in HE. The purpose of this study was to investigate whether the effective connectivity network associated with the basal ganglia is disturbed in HE patients by using resting-state functional magnetic resonance imaging (rs-fMRI). Methodology/Principal Findings Thirty five low-grade HE patients and thirty five age- and gender- matched healthy controls participated in the rs-fMRI scans. The effective connectivity networks associated with the globus pallidus, the primarily affected region within basal ganglia in HE, were characterized by using the Granger causality analysis and compared between HE patients and healthy controls. Pearson correlation analysis was performed between the abnormal effective connectivity and venous blood ammonia levels and neuropsychological performances of all HE patients. Compared with the healthy controls, patients with low-grade HE demonstrated mutually decreased influence between the globus pallidus and the anterior cingulate cortex (ACC), cuneus, bi-directionally increased influence between the globus pallidus and the precuneus, and either decreased or increased influence from and to the globus pallidus in many other frontal, temporal, parietal gyri, and cerebellum. Pearson correlation analyses revealed that the blood ammonia levels in HE patients negatively correlated with effective connectivity from the globus pallidus to ACC, and positively correlated with that from the globus pallidus to precuneus; and the number connectivity test scores in patients negatively correlated with the effective connectivity from the globus pallidus to ACC, and from superior frontal gyrus to globus pallidus. Conclusions/Significance Low-grade HE patients had disrupted effective connectivity network of

Visualization of the internal globus pallidus: sequence and orientation for deep brain stimulation using a standard installation protocol at 3.0 Tesla.

PubMed

Nölte, Ingo S; Gerigk, Lars; Al-Zghloul, Mansour; Groden, Christoph; Kerl, Hans U

2012-03-01

Deep-brain stimulation (DBS) of the internal globus pallidus (GPi) has shown remarkable therapeutic benefits for treatment-resistant neurological disorders including dystonia and Parkinson's disease (PD). The success of the DBS is critically dependent on the reliable visualization of the GPi. The aim of the study was to evaluate promising 3.0 Tesla magnetic resonance imaging (MRI) methods for pre-stereotactic visualization of the GPi using a standard installation protocol. MRI at 3.0 T of nine healthy individuals and of one patient with PD was acquired (FLAIR, T1-MPRAGE, T2-SPACE, T2*-FLASH2D, susceptibility-weighted imaging mapping (SWI)). Image quality and visualization of the GPi for each sequence were assessed by two neuroradiologists independently using a 6-point scale. Axial, coronal, and sagittal planes of the T2*-FLASH2D images were compared. Inter-rater reliability, contrast-to-noise ratios (CNR) and signal-to-noise ratios (SNR) for the GPi were determined. For illustration, axial T2*-FLASH2D images were fused with a section schema of the Schaltenbrand-Wahren stereotactic atlas. The GPi was best and reliably visualized in axial and to a lesser degree on coronal T2*-FLASH2D images. No major artifacts in the GPi were observed in any of the sequences. SWI offered a significantly higher CNR for the GPi compared to standard T2-weighted imaging using the standard parameters. The fusion of the axial T2*-FLASH2D images and the atlas projected the GPi clearly in the boundaries of the section schema. Using a standard installation protocol at 3.0 T T2*-FLASH2D imaging (particularly axial view) provides optimal and reliable delineation of the GPi.

Retention of Gadolinium-Based Contrast Agents in Multiple Sclerosis: Retrospective Analysis of an 18-Year Longitudinal Study.

PubMed

Forslin, Y; Shams, S; Hashim, F; Aspelin, P; Bergendal, G; Martola, J; Fredrikson, S; Kristoffersen-Wiberg, M; Granberg, T

2017-07-01

Gadolinium-based contrast agents have been associated with lasting high T1-weighted signal intensity in the dentate nucleus and globus pallidus, with histopathologically confirmed gadolinium retention. We aimed to longitudinally investigate the relationship of multiple gadolinium-based contrast agent administrations to the Signal Intensity Index in the dentate nucleus and globus pallidus and any associations with cognitive function in multiple sclerosis. The Signal Intensity Index in the dentate nucleus and globus pallidus was retrospectively evaluated on T1-weighted MR imaging in an 18-year longitudinal cohort study of 23 patients with MS receiving multiple gadolinium-based contrast agent administrations and 23 healthy age- and sex-matched controls. Participants also underwent comprehensive neuropsychological testing. Patients with MS had a higher Signal Intensity Index in the dentate nucleus ( P < .001), but not in the globus pallidus ( P = .19), compared with non-gadolinium-based contrast agent-exposed healthy controls by an unpaired t test. Increasing numbers of gadolinium-based contrast agent administrations were associated with an increased Signal Intensity Index in the dentate nucleus (β = 0.45, P < .001) and globus pallidus (β = 0.60, P < .001). This association remained stable with corrections for the age, disease duration, and physical disability for both the dentate nucleus (β = 0.43, P = .001) and globus pallidus (β = 0.58, P < .001). An increased Signal Intensity Index in the dentate nucleus among patients with MS was associated with lower verbal fluency scores, which remained significant after correction for several aspects of disease severity (β = -0.40 P = .013). Our data corroborate previous reports of lasting gadolinium retention in brain tissues. An increased Signal Intensity Index in the dentate nucleus and globus pallidus was associated with lower verbal fluency, which does not prove causality but encourages further studies on cognition

When top-down becomes bottom up: behaviour of hyperdense howler monkeys (Alouatta seniculus) trapped on a 0.6 ha island.

PubMed

Orihuela, Gabriela; Terborgh, John; Ceballos, Natalia; Glander, Kenneth

2014-01-01

Predators are a ubiquitous presence in most natural environments. Opportunities to contrast the behaviour of a species in the presence and absence of predators are thus rare. Here we report on the behaviour of howler monkey groups living under radically different conditions on two land-bridge islands in Lago Guri, Venezuela. One group of 6 adults inhabited a 190-ha island (Danto) where they were exposed to multiple potential predators. This group, the control, occupied a home range of 23 ha and contested access to food resources with neighbouring groups in typical fashion. The second group, containing 6 adults, was isolated on a remote, predator-free 0.6 ha islet (Iguana) offering limited food resources. Howlers living on the large island moved, fed and rested in a coherent group, frequently engaged in affiliative activities, rarely displayed agonistic behaviour and maintained intergroup spacing through howling. In contrast, the howlers on Iguana showed repulsion, as individuals spent most of their time spaced widely around the perimeter of the island. Iguana howlers rarely engaged in affiliative behaviour, often chased or fought with one another and were not observed to howl. These behaviors are interpreted as adjustments to the unrelenting deprivation associated with bottom-up limitation in a predator-free environment.

Salmonellosis

MedlinePlus

... for most infections in humans is carried by chickens, cows, pigs, and reptiles (such as turtles, lizards, and iguanas). What Is Salmonella Infection? Salmonella infection, or salmonellosis , is a foodborne ...

Molecular Identification of Food Sources in Triatomines in the Brazilian Northeast: Roles of Goats and Rodents in Chagas Disease Epidemiology

PubMed Central

Valença-Barbosa, Carolina; Fernandes, Fabiano Araújo; Santos, Helena Lucia Carneiro; Sarquis, Otília; Harry, Myriam; Almeida, Carlos Eduardo; Lima, Marli Maria

2015-01-01

We used the gut contents of triatomines collected from rural areas of Ceará State, northeastern Brazil, to identify their putative hosts via vertebrate cytb gene sequencing. Successful direct sequencing was obtained for 48% of insects, comprising 50 Triatoma brasiliensis, 7 Triatoma pseudomaculata, and 1 Rhodnius nasutus. Basic local alignment search tool (BLAST) procedure revealed that domestic animals, such as chickens (Gallus gallus) and goats (Capra hircus), are the main food source, including in sylvatic environment. Native hosts were also detected in peridomestic environment such as reptiles (Tropidurus sp. and Iguana iguana) and the Galea spixii (Rodentia: Caviidae). The role of goats and Galea spixii in Chagas disease epidemiology calls for further studies, because these mammals likely link the sylvatic and domestic Trypanosoma cruzi cycles. PMID:26350453

Regional cerebral metabolic patterns demonstrate the role of anterior forebrain mesocircuit dysfunction in the severely injured brain.

PubMed

Fridman, Esteban A; Beattie, Bradley J; Broft, Allegra; Laureys, Steven; Schiff, Nicholas D

2014-04-29

Although disorders of consciousness (DOCs) demonstrate widely varying clinical presentations and patterns of structural injury, global down-regulation and bilateral reductions in metabolism of the thalamus and frontoparietal network are consistent findings. We test the hypothesis that global reductions of background synaptic activity in DOCs will associate with changes in the pattern of metabolic activity in the central thalamus and globus pallidus. We compared 32 [(18)F]fluorodeoxyglucose PETs obtained from severely brain-injured patients (BIs) and 10 normal volunteers (NVs). We defined components of the anterior forebrain mesocircuit on high-resolution T1-MRI (ventral, associative, and sensorimotor striatum; globus pallidus; central thalamus and noncentral thalamus). Metabolic profiles for BI and NV demonstrated distinct changes in the pattern of uptake: ventral and association striatum (but not sensorimotor) were significantly reduced relative to global mean uptake after BI; a relative increase in globus pallidus metabolism was evident in BI subjects who also showed a relative reduction of metabolism in the central thalamus. The reversal of globus pallidus and central thalamus profiles across BIs and NVs supports the mesocircuit hypothesis that broad functional (or anatomic) deafferentation may combine to reduce central thalamus activity and release globus pallidus activity in DOCs. In addition, BI subjects showed broad frontoparietal metabolic down-regulation consistent with prior studies supporting the link between central thalamic/pallidal metabolism and down-regulation of the frontoparietal network. Recovery of left hemisphere frontoparietal metabolic activity was further associated with command following.

Comparative Genomics of Campylobacter iguaniorum to Unravel Genetic Regions Associated with Reptilian Hosts

PubMed Central

Gilbert, Maarten J.; Miller, William G.; Yee, Emma; Kik, Marja; Zomer, Aldert L.; Wagenaar, Jaap A.; Duim, Birgitta

2016-01-01

Abstract Campylobacter iguaniorum is most closely related to the species C. fetus, C. hyointestinalis, and C. lanienae. Reptiles, chelonians and lizards in particular, appear to be a primary reservoir of this Campylobacter species. Here we report the genome comparison of C. iguaniorum strain 1485E, isolated from a bearded dragon (Pogona vitticeps), and strain 2463D, isolated from a green iguana (Iguana iguana), with the genomes of closely related taxa, in particular with reptile-associated C. fetus subsp. testudinum. In contrast to C. fetus, C. iguaniorum is lacking an S-layer encoding region. Furthermore, a defined lipooligosaccharide biosynthesis locus, encoding multiple glycosyltransferases and bounded by waa genes, is absent from C. iguaniorum. Instead, multiple predicted glycosylation regions were identified in C. iguaniorum. One of these regions is > 50 kb with deviant G + C content, suggesting acquisition via lateral transfer. These similar, but non-homologous glycosylation regions were located at the same position on the genome in both strains. Multiple genes encoding respiratory enzymes not identified to date within the C. fetus clade were present. C. iguaniorum shared highest homology with C. hyointestinalis and C. fetus. As in reptile-associated C. fetus subsp. testudinum, a putative tricarballylate catabolism locus was identified. However, despite colonizing a shared host, no recent recombination between both taxa was detected. This genomic study provides a better understanding of host adaptation, virulence, phylogeny, and evolution of C. iguaniorum and related Campylobacter taxa. PMID:27604878

Salmonella Infections (For Parents)

MedlinePlus

... iguanas). Another, rarer form — called Salmonella typhi — causes typhoid fever . What Is Salmonella Infection? Salmonella infection, or salmonellosis , ... More on this topic for: Parents Kids Teens Typhoid Fever E. Coli Stool Test: Bacteria Culture Food Safety ...

Age-related iron deposition in the basal ganglia of controls and Alzheimer disease patients quantified using susceptibility weighted imaging.

PubMed

Wang, Dan; Li, Yan-Ying; Luo, Jian-Hua; Li, Yue-Hua

2014-01-01

This study aimed to investigate age-related iron deposition changes in healthy subjects and Alzheimer disease patients using susceptibility weighted imaging. The study recruited 182 people, including 143 healthy volunteers and 39 Alzheimer disease patients. All underwent conventional magnetic resonance imaging and susceptibility weighted imaging sequences. The groups were divided according to age. Phase images were used to investigate iron deposition in the bilateral head of the caudate nucleus, globus pallidus and putamen, and the angle radian value was calculated. We hypothesized that age-related iron deposition changes may be different between Alzheimer disease patients and controls of the same age, and that susceptibility weighted imaging would be a more sensitive method of iron deposition quantification. The results revealed that iron deposition in the globus pallidus increased with age, up to 40 years. In the head of the caudate nucleus, iron deposition peaked at 60 years. There was a general increasing trend with age in the putamen, up to 50-70 years old. There was significant difference between the control and Alzheimer disease groups in the bilateral globus pallidus in both the 60-70 and 70-80 year old group comparisons. In conclusion, iron deposition increased with age in the globus pallidus, the head of the caudate nucleus and putamen, reaching a plateau at different ages. Furthermore, comparisons between the control and Alzheimer disease group revealed that iron deposition changes were more easily detected in the globus pallidus. Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.

Simultaneous Activation of Multiple Memory Systems during Learning: Insights from Electrophysiology and Modeling

DTIC Science & Technology

2010-06-01

autonomic and pain functions, and facilitating/inhibiting voluntary movements. The external segment of the globus pallidus (globus pallidus externa, GPe...or less responsive to pain stimuli. 1.2.4. Other cortico-basal ganglia loops Alexander, Strick and colleagues have additionally defined a number of... orofacial loop and loops through inferotemporal and posterior parietal cortical areas have also been defined. 1.2.5. Interactions between loops Once

Ranavirus infections associated with skin lesions in lizards

PubMed Central

2013-01-01

Ranaviral disease in amphibians has been studied intensely during the last decade, as associated mass-mortality events are considered to be a global threat to wild animal populations. Several studies have also included other susceptible ectothermic vertebrates (fish and reptiles), but only very few cases of ranavirus infections in lizards have been previously detected. In this study, we focused on clinically suspicious lizards and tested these animals for the presence of ranaviruses. Virological screening of samples from lizards with increased mortality and skin lesions over a course of four years led to the detection of ranaviral infections in seven different groups. Affected species were: brown anoles (Anolis sagrei), Asian glass lizards (Dopasia gracilis), green anoles (Anolis carolinensis), green iguanas (Iguana iguana), and a central bearded dragon (Pogona vitticeps). Purulent to ulcerative-necrotizing dermatitis and hyperkeratosis were diagnosed in pathological examinations. All animals tested positive for the presence of ranavirus by PCR and a part of the major capsid protein (MCP) gene of each virus was sequenced. Three different ranaviruses were isolated in cell culture. The analyzed portions of the MCP gene from each of the five different viruses detected were distinct from one another and were 98.4-100% identical to the corresponding portion of the frog virus 3 (FV3) genome. This is the first description of ranavirus infections in these five lizard species. The similarity in the pathological lesions observed in these different cases indicates that ranaviral infection may be an important differential diagnosis for skin lesions in lizards. PMID:24073785

Comparative Genomics of Campylobacter iguaniorum to Unravel Genetic Regions Associated with Reptilian Hosts.

PubMed

Gilbert, Maarten J; Miller, William G; Yee, Emma; Kik, Marja; Zomer, Aldert L; Wagenaar, Jaap A; Duim, Birgitta

2016-10-05

Campylobacter iguaniorum is most closely related to the species C fetus, C hyointestinalis, and C lanienae Reptiles, chelonians and lizards in particular, appear to be a primary reservoir of this Campylobacter species. Here we report the genome comparison of C iguaniorum strain 1485E, isolated from a bearded dragon (Pogona vitticeps), and strain 2463D, isolated from a green iguana (Iguana iguana), with the genomes of closely related taxa, in particular with reptile-associated C fetus subsp. testudinum In contrast to C fetus, C iguaniorum is lacking an S-layer encoding region. Furthermore, a defined lipooligosaccharide biosynthesis locus, encoding multiple glycosyltransferases and bounded by waa genes, is absent from C iguaniorum Instead, multiple predicted glycosylation regions were identified in C iguaniorum One of these regions is > 50 kb with deviant G + C content, suggesting acquisition via lateral transfer. These similar, but non-homologous glycosylation regions were located at the same position on the genome in both strains. Multiple genes encoding respiratory enzymes not identified to date within the C. fetus clade were present. C iguaniorum shared highest homology with C hyointestinalis and C fetus. As in reptile-associated C fetus subsp. testudinum, a putative tricarballylate catabolism locus was identified. However, despite colonizing a shared host, no recent recombination between both taxa was detected. This genomic study provides a better understanding of host adaptation, virulence, phylogeny, and evolution of C iguaniorum and related Campylobacter taxa. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Ranavirus infections associated with skin lesions in lizards.

PubMed

Stöhr, Anke C; Blahak, Silvia; Heckers, Kim O; Wiechert, Jutta; Behncke, Helge; Mathes, Karina; Günther, Pascale; Zwart, Peer; Ball, Inna; Rüschoff, Birgit; Marschang, Rachel E

2013-09-27

Ranaviral disease in amphibians has been studied intensely during the last decade, as associated mass-mortality events are considered to be a global threat to wild animal populations. Several studies have also included other susceptible ectothermic vertebrates (fish and reptiles), but only very few cases of ranavirus infections in lizards have been previously detected. In this study, we focused on clinically suspicious lizards and tested these animals for the presence of ranaviruses. Virological screening of samples from lizards with increased mortality and skin lesions over a course of four years led to the detection of ranaviral infections in seven different groups. Affected species were: brown anoles (Anolis sagrei), Asian glass lizards (Dopasia gracilis), green anoles (Anolis carolinensis), green iguanas (Iguana iguana), and a central bearded dragon (Pogona vitticeps). Purulent to ulcerative-necrotizing dermatitis and hyperkeratosis were diagnosed in pathological examinations. All animals tested positive for the presence of ranavirus by PCR and a part of the major capsid protein (MCP) gene of each virus was sequenced. Three different ranaviruses were isolated in cell culture. The analyzed portions of the MCP gene from each of the five different viruses detected were distinct from one another and were 98.4-100% identical to the corresponding portion of the frog virus 3 (FV3) genome. This is the first description of ranavirus infections in these five lizard species. The similarity in the pathological lesions observed in these different cases indicates that ranaviral infection may be an important differential diagnosis for skin lesions in lizards.

Atorvastatin protects GABAergic and dopaminergic neurons in the nigrostriatal system in an experimental rat model of transient focal cerebral ischemia.

PubMed

Sabogal, Angélica María; Arango, César Augusto; Cardona, Gloria Patricia; Céspedes, Ángel Enrique

2014-01-01

Cerebral ischemia is the third leading cause of death and the primary cause of permanent disability worldwide. Atorvastatin is a promising drug with neuroprotective effects that may be useful for the treatment of stroke. However, the effects of atorvastatin on specific neuronal populations within the nigrostriatal system following cerebral ischemia are unknown. To evaluate the effects of atorvastatin on dopaminergic and GABAergic neuronal populations in exofocal brain regions in a model of transient occlusion of the middle cerebral artery. Twenty-eight male eight-week-old Wistar rats were used in this study. Both sham and ischemic rats were treated with atorvastatin (10 mg/kg) or carboxymethylcellulose (placebo) by gavage at 6, 24, 48 and 72 hours post-reperfusion. We analyzed the immunoreactivity of glutamic acid decarboxylase and tyrosine hydroxylase in the globus pallidus, caudate putamen and substantia nigra. We observed neurological damage and cell loss in the caudate putamen following ischemia. We also found an increase in tyrosine hydroxylase immunoreactivity in the medial globus pallidus and substantia nigra reticulata, as well as a decrease in glutamic acid decarboxylase immunoreactivity in the lateral globus pallidus in ischemic animals treated with a placebo. However, atorvastatin treatment was able to reverse these effects, significantly decreasing tyrosine hydroxylase levels in the medial globus pallidus and substantia nigra reticulata and significantly increasing glutamic acid decarboxylase levels in the lateral globus pallidus. Our data suggest that post-ischemia treatment with atorvastatin can have neuro-protective effects in exofocal regions far from the ischemic core by modulating the GABAergic and dopaminergic neuronal populations in the nigrostriatal system, which could be useful for preventing neurological disorders.

Liver transplantation in a patient with rapid onset parkinsonism-dementia complex induced by manganism secondary to liver failure.

PubMed

Fabiani, Giorgio; Rogacheski, Enio; Wiederkehr, Júlio César; Khouri, Jussara; Cianfarano, Andréa

2007-09-01

Bilateral and symmetric globus-pallidus hyperintensities are observed on T1-weighted MRI in most of the patients with chronic liver failure, due to manganese accumulation. We report a 53-year-old man, with rapid onset parkinsonism-dementia complex associated with accumulation of manganese in the brain, secondary to liver failure. A brain MRI was performed and a high signal on T1-weighted images was seen on globus-pallidus, as well as on T2-weighted images on the hemispheric white-matter. He was referred to a liver-transplantation. The patient passed away on the seventh postoperative day. Our findings support the concept of the toxic effects of manganese on the globus-pallidus. The treatment of this form of parkinsonism is controversial and liver-transplantation should not be considered as first line treatment but as an alternative one.

Eleutherodactylus frog introductions to Hawaii

USGS Publications Warehouse

Kraus, Fred; Campbell, Earl W.; Allison, Allen; Pratt, Thane K.

1999-01-01

As an oceanic archipelago isolated from continental source areas, Hawaii lacks native terrestrial reptiles and amphibians, Polynesians apparently introduced seven gecko and skink species after discovering the islands approximately 1500 years ago, and another 15 reptiles and five frogs have been introduced in the last century and a half (McKeown 1996). The Polynesian introductions are probably inadvertent because the species involved are known stowaway dispersers (Gibbons 1985; Dye and Steadman 1990), In contrast, most of the herpetological introductions since European contact with Hawaii have been intentional. Several frog species were released for biocontrol of insects (e.g., Dendrobates auratus, Bufo marinus, Rana rugosa, Bryan 1932; Oliver and Shaw 1953), and most of the remaining species are released or escaped pets (e.g., Phelsuma spp., Chamaeleo jacksonii, Iguana iguana, McKeown 1996), Government-approved releases have not occurred for many years, but the rate of establishment of new species has increased in the past few decades because of the importation and subsequent release of pets.

Self-Assessing of the Emotional Intelligence and Organizational Intelligence in Schools

ERIC Educational Resources Information Center

Dagiene, Valentina; Juškeviciene, Anita; Carneiro, Roberto; Child, Camilla; Cullen, Joe

2015-01-01

The paper presents the results of an evaluation of the Emotional Intelligence (EI) and Organisational Intelligence (OI) competences self-assessment tools developed and applied by the IGUANA project. In the paper Emotional Intelligence and Organisational Intelligence competences are discussed, their use in action research experiments to assess and…

Bilateral globus pallidus internus deep brain stimulation for dyskinetic cerebral palsy supports success of cochlear implantation in a 5-year old ex-24 week preterm twin with absent cerebellar hemispheres.

PubMed

Lin, Jean-Pierre; Kaminska, Margaret; Perides, Sarah; Gimeno, Hortensia; Baker, Lesley; Lumsden, Daniel E; Britz, Anzell; Driver, Sandra; Fitzgerald-O'Connor, Alec; Selway, Richard

2017-01-01

Early onset dystonia (dyskinesia) and deafness in childhood pose significant challenges for children and carers and are the cause of multiple disability. It is particularly tragic when the child cannot make use of early cochlear implantation (CI) technology to relieve deafness and improve language and communication, because severe cervical and truncal dystonia brushes off the magnetic amplifier behind the ears. Bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) neuromodulation can reduce dyskinesia, thus supporting CI neuromodulation success. We describe the importance of the order of dual neuromodulation surgery for dystonia and deafness. First with bilateral GPi DBS using a rechargeable ACTIVA-RC neurostimulator followed 5 months later by unilateral CI with a Harmony (BTE) Advanced Bionics Hi Res 90 K cochlear device. This double neuromodulation was performed in series in a 12.5 kg 5 year-old ex-24 week gestation-born twin without a cerebellum. Relief of dyskinesia enabled continuous use of the CI amplifier. Language understanding and communication improved. Dystonic storms abated. Tolerance of sitting increased with emergence of manual function. Status dystonicus ensued 10 days after ACTIVA-RC removal for infection-erosion at 3 years and 10 months. He required intensive care and DBS re-implantation 3 weeks later together with 8 months of hospital care. Today he is virtually back to the level of functioning before the DBS removal in 2012 and background medication continues to be slowly weaned. This case illustrates that early neuromodulation with DBS for dystonic cerebral palsy followed by CI for deafness is beneficial. Both should be considered early i.e. under the age of five years. The DBS should precede the CI to maximise dystonia reduction and thus benefits from CI. This requires close working between the paediatric DBS and CI services. Copyright © 2016. Published by Elsevier Ltd.

Systemic administration of dizocilpine maleate (MK-801) or L-dopa reverses the increases in GAD65 and GAD67 mRNA expression in the globus pallidus in a rat hemiparkinsonian model.

PubMed

Bacci, Jean-Jacques; Salin, Pascal; Kerkerian-Le Goff, Lydia

2002-12-15

This study examined the consequences of systemic treatment with either L-dopa or MK-801 on the levels of mRNAs encoding the 65 and 67 kDa isoforms of glutamate decarboxylase (GAD65 and GAD67) in the striatum and globus pallidus (GP) of rats rendered hemiparkinsonian by intranigral 6-hydroxydopamine injection. GADs mRNA levels were assessed by means of in situ hybridization histochemistry. In the striatum, dopamine denervation resulted in increased GAD67 mRNA levels at the rostral and caudal levels, whereas GAD65 showed selective increase at the caudal level. L-dopa and MK-801 treatments showed differential effects on the two GAD isoform levels in rats with 6-hydroxydopamine lesion. The lesion-induced increases in GAD67 transcripts were potentiated by L-dopa but unaffected by MK-801, whereas the increases in GAD65 were suppressed by MK-801 but unaffected by L-dopa. These data suggest a heterogeneity of glutamate-dopamine interaction in the anteroposterior extent of the striatum and show that NMDA-mediated mechanisms are involved in the 6-hydroxydopamine lesion-induced transcriptional changes in striatal GAD65 but not GAD67. In GP, the 6-OHDA lesion elicited increases in both GAD65 and GAD67 mRNA levels. L-dopa or MK-801 treatment suppressed the lesion-induced augmentations in the two GADs mRNA levels. These results indicate that dopamine denervation-induced changes in the functional activity of GP neurons involve both dopamine and glutamate NMDA receptor-mediated mechanisms. Comparison between the effects of L-dopa and MK-801 treatments on markers of the activity of striatal and pallidal GABA neurons further suggest that the impact of these treatments at the GP level do not depend solely on the striatopallidal input. Copyright 2002 Wiley-Liss, Inc.

All about Reptiles. Animal Life for Children. [Videotape].

ERIC Educational Resources Information Center

2000

Dinosaurs may be extinct, but reptiles are distant cousins to the beasts that once walked the earth. From snakes and lizards to iguanas and tuataras, children learn what factors make them different from other animals. In this videotape, students explore the mysterious, often misunderstood, world of reptiles and learn about their characteristics…

Towards Distributed Intelligence: A High Level Definition

DTIC Science & Technology

2004-12-01

Some of the first research in multi-robot systems came in the foraging /sorting area by Parker [77] and Beckers [9] and was likely fueled by the bio...chapter 24, pages 28–39. Artificial Intelligence at MIT. The MIT Press, 1989. 15. R.A. Brooks. Robotic Science, chapter 11, The Whole Iguana , pages 432

The Galapagos Islands: Darwin and Modern Conservation Stories

ERIC Educational Resources Information Center

Burr, Susan

2010-01-01

The author visited the Galapagos Islands in 2009 and here looks at their biodiversity through pictures taken then. The diverse habitats of the Islands are reflected in the great diversity of flora and fauna found on them, with many species endemic to the Islands. The stories of the land iguanas, control of introduced species and the giant…

Relationship between brain R(2) and liver and serum iron concentrations in elderly men.

PubMed

House, Michael J; St Pierre, Timothy G; Milward, Elizabeth A; Bruce, David G; Olynyk, John K

2010-02-01

Studies of iron overload in humans and animals suggest that brain iron concentrations may be related in a regionally specific way to body iron status. However, few quantitative studies have investigated the associations between peripheral and regional brain iron in a normal elderly cohort. To examine these relationships, we used MRI to measure the proton transverse relaxation rate (R(2)) in 13 gray and white matter brain regions in 18 elderly men (average age, 75.5 years) with normal cognition. Brain R(2) values were compared with liver iron concentrations measured using the FerriScan MRI technique and serum iron indices. R(2) values in high-iron gray matter regions were significantly correlated (positively) with liver iron concentrations (globus pallidus, ventral pallidum) and serum transferrin saturation (caudate nucleus, globus pallidus, putamen) measured concurrently with brain R(2), and with serum iron concentrations (caudate nucleus, globus pallidus) measured three years before the current study. Our results suggest that iron levels in specific gray matter brain regions are influenced by systemic iron status in elderly men.

Endorphin mediation of post-ictal effects of kindled seizures in rats.

PubMed

Kelsey, J E; Belluzzi, J D

1982-12-16

Brief electrical stimulation of the enkephalin-rich globus pallidus at 1-h intervals produced kindled, clonic seizures in rats as rapidly as similar stimulation of the amygdala. Massing the kindling trials at 10-min intervals inhibited the occurrence of subsequent seizures, especially following globus pallidus stimulation. Naloxone (20 mg/kg), an opiate receptor antagonist, reversed this post-ictal inhibition of seizures following massed trials, but had no effect on seizures kindled at 1-h intervals. Thus, endorphin-released during seizures do not appear to mediate the production of kindled seizures, but do appear to mediate the transient posts ictal inhibition of seizures.

New Lepidocyrtus Bourlet, 1839 from riverine woodland in Hungary (Collembola, Entomobryidae).

PubMed

Winkler, Daniel

2017-04-10

Systematic soil fauna survey of riverine and swamp woodland habitats in West Hungary provided the opportunity to describe the new species L. isabelleae sp. nov. belonging to the the Lepidocyrtus pallidus-serbicus group. The new species is characterized by the dorsal macrochaetae formula R0R1sR1R2STSo/00/0101+2, the absence of scales on the antennae and legs beyond coxae and an additional dorsolateral macrochaeta (a7) on Abd. III. On this occasion, the L. pallidus-serbicus group has been revised and reinterpreted, and a differentiation key for the derived L. serbicus group has been developed.

Changes in Signal Intensity of the Dentate Nucleus and Globus Pallidus in Pediatric Patients: Impact of Brain Irradiation and Presence of Primary Brain Tumors Independent of Linear Gadolinium-based Contrast Agent Administration.

PubMed

Tamrazi, Benita; Nguyen, Binh; Liu, Chia-Shang J; Azen, Colleen G; Nelson, Mary B; Dhall, Girish; Nelson, Marvin D

2018-05-01

Purpose To determine whether whole-brain irradiation, chemotherapy, and primary brain pathologic conditions affect magnetic resonance (MR) imaging signal changes in pediatric patients independent of the administration of gadolinium-based contrast agents (GBCAs). Materials and Methods This institutional review board-approved, HIPAA-compliant study included 144 pediatric patients who underwent intravenous GBCA-enhanced MR imaging examinations (55 patients with primary brain tumors and whole-brain irradiation, 19 with primary brain tumors and chemotherapy only, 52 with primary brain tumors without any treatment, and 18 with neuroblastoma without brain metastatic disease). The signal intensities (SIs) in the globus pallidus (GP), thalamus (T), dentate nucleus (DN), and pons (P) were measured on unenhanced T1-weighted images. GP:T and DN:P SI ratios were compared between groups by using the analysis of variance and were analyzed relative to group, total cumulative number of doses of GBCA, age, and sex by using multivariable linear models. Results DN:P ratio for the radiation therapy group was greater than that for the other groups except for the group of brain tumors treated with chemotherapy (P < .05). The number of GBCA doses was correlated with the DN:P ratio for the nontreated brain tumor group (P < .0001). The radiation therapy-treated brain tumor group demonstrated higher DN:P ratios than the nontreated brain tumor group for number of doses less than or equal to 10 (P < .0001), whereas ratios in the nontreated brain tumor group were higher than those in the radiation therapy-treated brain tumor group for doses greater than 20 (P = .05). The GP:T ratios for the brain tumor groups were greater than that for the neuroblastoma group (P = .01). Conclusion Changes in SI of the DN and GP that are independent of the administration of GBCA occur in patients with brain tumors undergoing brain irradiation, as well as in patients with untreated primary brain tumors. © RSNA

Pallidus beetle, Delphastus pallidus LeConte (Insecta: Coleoptera: Coccinellidae), a native predatory beetle of whitefly species in Florida

USDA-ARS?s Scientific Manuscript database

Beetles in the genus Delphastus Casey are small whitefly-specific predatory ladybird beetles belonging to the coccinellid tribe Serangiini. They feed on all immature stages of whitefly and are reared and sold commercially all over the world for this purpose. They are compatible with the application ...

A taxonomic revision of small neotropical saurian Malarias allied to Plasmodium minasense.

PubMed

Telford, S R

1979-01-01

Saurian malaria species which produce schizonts smaller than normal erythrocyte nuclei, with 4-8 merozoietes and gametocytes equal to or smaller than erythrocyte nuclei in size, parasitizing hosts of the lizard families Scincidae, Iguanidae and Teiidae in the Neotropics are considered to be Plasmodium minasense Carini and Rudolph, 1912. Subspecific designations are given to distinctive populations parasitizing different host species: P. minasense minasense is recognized from the type host, Mabuya mabouya of Brasil; P. minasense carinii Leger and Mouzels, 1917 from Iguana iguana of coastal South America; P. minasense anolisi subsp. nov. from Anolis limifrons of Panama; P. minasense capitoi subsp. nov. from Anolis capito of Panama; P. minasense plicae subsp. nov. from Plica umbra of Guyana; P. minasense tegui subsp. nov. from Tupinambis teguixin of Venezuela; and P. minasense diminutivum Telford, 1973, new combination, from Ameiva ameiva of Panama. Plasmodium rhadinurum Thompson and Huff, 1944 is recognized as a distinct species at present on the basis of possessing schizonts of different shape, asexual stages with filamentous projections in most portions of its range, and larger gametocytes, as well as apparent sympatry with P. minasense carinii in some areas.

Different mechanisms of secondary neuronal damage in thalamic nuclei after focal cerebral ischemia in rats.

PubMed

Dihné, Marcel; Grommes, Christian; Lutzenburg, Michael; Witte, Otto W; Block, Frank

2002-12-01

After focal cerebral ischemia, depending on its localization and extent, secondary neuronal damage may occur that is remote from the initial lesion. In this study differences in secondary damage of the ventroposterior thalamic nucleus (VPN) and the reticular thalamic nucleus (RTN) were investigated with the use of different ischemia models. Transient middle cerebral artery occlusion (MCAO) leads to cortical infarction, including parts of the basal ganglia such as the globus pallidus, and to widespread edema. Photothrombotic ischemia generates pure cortical infarcts sparing the basal ganglia and with only minor edema. Neuronal degeneration was quantified within the ipsilateral RTN and VPN 14 days after ischemia. Glial reactions were studied with the use of immunohistochemistry. MCAO resulted in delayed neuronal cell loss of the ipsilateral VPN and RTN. Glial activation occurred in both nuclei beginning after 24 hours. Photothrombotic ischemia resulted in delayed neuronal cell loss only within the VPN. Even 2 weeks after photothrombotic ischemia, glial activation could only be seen within the VPN. Pure cortical infarcts after photothrombotic ischemia, without major edema and without effects on the globus pallidus of the basal ganglia, only lead to secondary VPN damage that is possibly due to retrograde degeneration. MCAO, which results in infarction of cortex and globus pallidus and which causes widespread edema, leads to secondary damage in the VPN and RTN. Thus, additional RTN damage may be due to loss of protective GABAergic input from the globus pallidus to the RTN or due to the extensive edema. Retrograde degeneration is not possible because the RTN, in contrast to the VPN, has no efferents to the cortex.

Fos and serotonin immunoreactivity in the raphe nuclei of the cat during carbachol-induced active sleep: a double-labeling study.

PubMed

Yamuy, J; Sampogna, S; López-Rodríguez, F; Luppi, P H; Morales, F R; Chase, M H

1995-07-01

The microinjection of carbachol into the nucleus pontis oralis produces a state which is polygraphically and behaviorally similar to active sleep (rapid eye movement sleep). In the present study, using double-labeling techniques for serotonin and the protein product of c-fos (Fos), we sought to examine whether immunocytochemically identified serotonergic neurons of the raphe nuclei of the cat were activated, as indicated by their expression of c-fos, during this pharmacologically-induced behavioral state (active sleep-carbachol). Compared with control cats, which were injected with saline, active sleep-carbachol cats exhibited a significantly greater number of c-fos-expressing neurons in the raphe dorsalis, magnus and pallidus. Whereas most of the c-fos-expressing neurons in the raphe dorsalis were small, those in the raphe magnus were medium-sized and in the raphe pallidus they were small and medium-sized. The mean number of serotonergic neurons that expressed c-fos (i.e. double-labeled cells) was similar in control and active sleep-carbachol cats. These data indicate that there is an increased number of non-serotonergic, c-fos-expressing neurons in the raphe dorsalis, magnus and pallidus during the carbachol-induced state.(ABSTRACT TRUNCATED AT 250 WORDS)

Cognitive Implications of Deep Gray Matter Iron in Multiple Sclerosis.

PubMed

Fujiwara, E; Kmech, J A; Cobzas, D; Sun, H; Seres, P; Blevins, G; Wilman, A H

2017-05-01

Deep gray matter iron accumulation is increasingly recognized in association with multiple sclerosis and can be measured in vivo with MR imaging. The cognitive implications of this pathology are not well-understood, especially vis-à-vis deep gray matter atrophy. Our aim was to investigate the relationships between cognition and deep gray matter iron in MS by using 2 MR imaging-based iron-susceptibility measures. Forty patients with multiple sclerosis (relapsing-remitting, n = 16; progressive, n = 24) and 27 healthy controls were imaged at 4.7T by using the transverse relaxation rate and quantitative susceptibility mapping. The transverse relaxation rate and quantitative susceptibility mapping values and volumes (atrophy) of the caudate, putamen, globus pallidus, and thalamus were determined by multiatlas segmentation. Cognition was assessed with the Brief Repeatable Battery of Neuropsychological Tests. Relationships between cognition and deep gray matter iron were examined by hierarchic regressions. Compared with controls, patients showed reduced memory ( P < .001) and processing speed ( P = .02) and smaller putamen ( P < .001), globus pallidus ( P = .002), and thalamic volumes ( P < .001). Quantitative susceptibility mapping values were increased in patients compared with controls in the putamen ( P = .003) and globus pallidus ( P = .003). In patients only, thalamus ( P < .001) and putamen ( P = .04) volumes were related to cognitive performance. After we controlled for volume effects, quantitative susceptibility mapping values in the globus pallidus ( P = .03; trend for transverse relaxation rate, P = .10) were still related to cognition. Quantitative susceptibility mapping was more sensitive compared with the transverse relaxation rate in detecting deep gray matter iron accumulation in the current multiple sclerosis cohort. Atrophy and iron accumulation in deep gray matter both have negative but separable relationships to cognition in multiple sclerosis. �

Anomalous subcortical morphology in boys, but not girls, with ADHD compared to typically developing controls and correlates with emotion dysregulation

PubMed Central

Crocetti, Deana; Mostofsky, Stewart H.; Miller, Michael I.; Rosch, Keri S.

2017-01-01

There has been limited investigation of volume and shape difference in subcortical structures in children with ADHD and a paucity of examination of the influence of sex on these findings. The objective of this study was to examine morphology (volume and shape) of subcortical structures and their association with emotion dysregulation (ED) in girls and boys with ADHD as compared to their typically-developing (TD) counterparts. Participants included 218 children ages 8-12 years old with and without DSM-IV ADHD. Structural magnetic resonance images were obtained, and shape analyses were conducted using large deformation diffeomorphic metric mapping (LDDMM). Compared to TD boys, boys with ADHD showed reduced volumes in the bilateral globus pallidus and amygdala. There were no volumetric differences in any structure between ADHD and TD girls. Shape analysis revealed localized compressions within the globus pallidus, putamen and amygdala in ADHD boys relative to TD boys, as well as significant correlations between increased ED and unique subregion expansion in right globus pallidus, putamen, and right amygdala. Our findings suggest a sexually dimorphic pattern of differences in subcortical structures in children with ADHD compared to TD children, and a possible neurobiological mechanism by which boys with ADHD demonstrate increased difficulties with ED. PMID:28104573

Basal ganglia and thalamic morphology in schizophrenia and bipolar disorder.

PubMed

Womer, Fay Y; Wang, Lei; Alpert, Kathryn I; Smith, Matthew J; Csernansky, John G; Barch, Deanna M; Mamah, Daniel

2014-08-30

In this study, we examined the morphology of the basal ganglia and thalamus in bipolar disorder (BP), schizophrenia-spectrum disorders (SCZ-S), and healthy controls (HC) with particular interest in differences related to the absence or presence of psychosis. Volumetric and shape analyses of the basal ganglia and thalamus were performed in 33 BP individuals [12 without history of psychotic features (NPBP) and 21 with history of psychotic features (PBP)], 32 SCZ-S individuals [28 with SCZ and 4 with schizoaffective disorder], and 27 HC using FreeSurfer-initiated large deformation diffeomorphic metric mapping. Significant volume differences were found in the caudate and globus pallidus, with volumes smallest in the NPBP group. Shape abnormalities showing inward deformation of superior regions of the caudate were observed in BP (and especially in NPBP) compared with HC. Shape differences were also found in the globus pallidus and putamen when comparing BP and SCZ-S groups. No significant differences were seen in the nucleus accumbens and thalamus. In summary, structural abnormalities in the caudate and globus pallidus are present in BP and SCZ-S. Differences were more apparent in the NPBP subgroup. The findings herein highlight the potential importance of separately examining BP subgroups in neuroimaging studies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Neural targets for relieving parkinsonian rigidity and bradykinesia with pallidal deep brain stimulation

PubMed Central

Zhang, Jianyu; Ghosh, Debabrata; McIntyre, Cameron C.; Vitek, Jerrold L.

2012-01-01

Clinical evidence has suggested that subtle changes in deep brain stimulation (DBS) settings can have differential effects on bradykinesia and rigidity in patients with Parkinson's disease. In this study, we first investigated the degree of improvement in bradykinesia and rigidity during targeted globus pallidus DBS in three 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated rhesus macaques. Behavioral outcomes of DBS were then coupled with detailed, subject-specific computational models of neurons in the globus pallidus internus (GPi), globus pallidus externus (GPe), and internal capsule (IC) to determine which neuronal pathways when modulated with high-frequency electrical stimulation best correlate with improvement in motor symptoms. The modeling results support the hypothesis that multiple neuronal pathways can underlie the therapeutic effect of DBS on parkinsonian bradykinesia and rigidity. Across all three subjects, improvements in rigidity correlated most strongly with spread of neuronal activation into IC, driving a small percentage of fibers within this tract (<10% on average). The most robust effect on bradykinesia resulted from stimulating a combination of sensorimotor axonal projections within the GP, specifically at the site of the medial medullary lamina. Thus the beneficial effects of pallidal DBS for parkinsonian symptoms may occur from multiple targets within and near the target nucleus. PMID:22514292

Notes on the distribution of Oregon bats.

Treesearch

Chris Maser; Stephen P. Cross

1981-01-01

Distributional data are given for 15 species of bats known to occur in Oregon: Antrozous pallidus, Eptesicus fuscus, Euderma maculatum, Lasionycteris noctivagans, Lasiurus cinereus, Myotis californicus, M. evotis, ...

Snakes in the wrong places: Gordon Rodda’s career in invasive species research

USGS Publications Warehouse

Wilson, Jim

2012-01-01

When USGS research zoologist Gordon G. Rodda was a graduate student at Cornell University studying behavioral biology of alligators —or later, completing a post-doc at the Smithsonian Institute studying the social behavior of green iguanas in Venezuela or following that, as a statistics and sociobiology instructor at the University of Tennessee—he did not foresee that his professional future was in snakes. Lots of snakes, and in places they don’t belong.

A Short History of the NCO

DTIC Science & Technology

1991-01-01

marched with the Army of the West, leaving Fort Leavenworth on 26 June 1846. Marching in detachments to ensure that enough forage and water would be...anything in his last will and testament. His clothing records for 1898 are as follows: 2 Blouses #5 1 Forage Cap 2 Cap Devices 1 CL Chevrons 1 Coat...food. They ate horses, iguanas , monkeys, crows, and carabao (water buffalo). Men had dreams that centered on fresh bread, plum butter, blackberry

Suitability of Invertebrate and Vertebrate Cells in a Portable Impedance-Based Toxicity Sensor: Temperature Mediated Impacts on Long-Term Survival

DTIC Science & Technology

2013-07-25

ovary cells from Spodoptera frugiperda ATCCa CRL-1711 Grace VA) (Vaughn et al., 1977) HvAM1: pupal ovary cells from Heliothis virescens Dr. C Goodman...iguana. Ecology 78, 297–307. Vaughn, J.L., Goodwind, R.H., Tompkins, G.J., McCawley, P., 1977. Establishment of 2 cell lines from insect Spodoptera ... frugiperda . In Vitro 13, 213–217. Wilson, S.M., Nagler, J.J., 2006. Age, but not salinity, affects the upper lethal temperature limits for juvenile

Evaluation of Brain Iron Content Based on Magnetic Resonance Imaging (MRI): Comparison among Phase Value, R2* and Magnitude Signal Intensity

PubMed Central

Yan, Shen-Qiang; Sun, Jian-Zhong; Yan, Yu-Qing; Wang, He; Lou, Min

2012-01-01

Background and Purpose Several magnetic resonance imaging (MRI) techniques are being exploited to measure brain iron levels increasingly as iron deposition has been implicated in some neurodegenerative diseases. However, there remains no unified evaluation of these methods as postmortem measurement isn't commonly available as the reference standard. The purpose of this study was to make a comparison among these methods and try to find a new index of brain iron. Methods We measured both phase values and R2* in twenty-four adults, and performed correlation analysis among the two methods and the previously published iron concentrations. We also proposed a new method using magnitude signal intensity and compared it with R2* and brain iron. Results We found phase value correlated with R2* in substantia nigra (r = −0.723, p<0.001) and putamen (r = −0.514, p = 0.010), while no correlations in red nucleus (r = −0.236, p = 0.268) and globus pallidus (r = −0.111, p = 0.605). And the new magnitude method had significant correlations in red nucleus (r = −0.593, p = 0.002), substantia nigra (r = −0.521, p = 0.009), globus pallidus (r = −0.750, p<0.001) and putamen (r = −0.547, p = 0.006) with R2*. A strong inverse correlation was also found between the new magnitude method and previously published iron concentrations in seven brain regions (r = −0.982, P<0.001). Conclusions Our study indicates that phase value may not be used for assessing the iron content in some brain regions especially globus pallidus. The new magnitude method is highly consistent with R2* especially in globus pallidus, and we assume that this approach may be acceptable as an index of iron content in iron-rich brain regions. PMID:22363719

Iron as a risk factor in neurological diseases

NASA Astrophysics Data System (ADS)

Galazka-Friedman, Jolanta

2008-02-01

In this review the properties of iron in various human brain structures (e.g. Substantia nigra, globus pallidus, hippocampus) were analyzed to assess the possibility of initiation of oxidative stress leading to such diseases as Parkinson’s and Alzheimer’s disease, and progressive supranuclear palsy. Our own studies with the use of Mössbauer spectroscopy, electron microscopy and enzyme-linked immuno-absorbent assay (ELISA) were confronted with other methods used in other laboratories. Our results suggest that hippocampus is the most fragile for oxidative stress structure in human brain (the death of nervous cells in hippocampus leads to Alzheimer’s disease). Changes in iron metabolism were also found in substantia nigra (the death of nervous cells of this structure produces Parkinson’s disease) and in globus pallidus (neurodegeneration of this structure causes progressive supranuclear palsy).

Evolutionary stability of sex chromosomes in snakes.

PubMed

Rovatsos, Michail; Vukić, Jasna; Lymberakis, Petros; Kratochvíl, Lukáš

2015-12-22

Amniote vertebrates possess various mechanisms of sex determination, but their variability is not equally distributed. The large evolutionary stability of sex chromosomes in viviparous mammals and birds was believed to be connected with their endothermy. However, some ectotherm lineages seem to be comparably conserved in sex determination, but previously there was a lack of molecular evidence to confirm this. Here, we document a stability of sex chromosomes in advanced snakes based on the testing of Z-specificity of genes using quantitative PCR (qPCR) across 37 snake species (our qPCR technique is suitable for molecular sexing in potentially all advanced snakes). We discovered that at least part of sex chromosomes is homologous across all families of caenophidian snakes (Acrochordidae, Xenodermatidae, Pareatidae, Viperidae, Homalopsidae, Colubridae, Elapidae and Lamprophiidae). The emergence of differentiated sex chromosomes can be dated back to about 60 Ma and preceded the extensive diversification of advanced snakes, the group with more than 3000 species. The Z-specific genes of caenophidian snakes are (pseudo)autosomal in the members of the snake families Pythonidae, Xenopeltidae, Boidae, Erycidae and Sanziniidae, as well as in outgroups with differentiated sex chromosomes such as monitor lizards, iguanas and chameleons. Along with iguanas, advanced snakes are therefore another example of ectothermic amniotes with a long-term stability of sex chromosomes comparable with endotherms. © 2015 The Author(s).

Evolutionary stability of sex chromosomes in snakes

PubMed Central

Rovatsos, Michail; Vukić, Jasna; Lymberakis, Petros; Kratochvíl, Lukáš

2015-01-01

Amniote vertebrates possess various mechanisms of sex determination, but their variability is not equally distributed. The large evolutionary stability of sex chromosomes in viviparous mammals and birds was believed to be connected with their endothermy. However, some ectotherm lineages seem to be comparably conserved in sex determination, but previously there was a lack of molecular evidence to confirm this. Here, we document a stability of sex chromosomes in advanced snakes based on the testing of Z-specificity of genes using quantitative PCR (qPCR) across 37 snake species (our qPCR technique is suitable for molecular sexing in potentially all advanced snakes). We discovered that at least part of sex chromosomes is homologous across all families of caenophidian snakes (Acrochordidae, Xenodermatidae, Pareatidae, Viperidae, Homalopsidae, Colubridae, Elapidae and Lamprophiidae). The emergence of differentiated sex chromosomes can be dated back to about 60 Ma and preceded the extensive diversification of advanced snakes, the group with more than 3000 species. The Z-specific genes of caenophidian snakes are (pseudo)autosomal in the members of the snake families Pythonidae, Xenopeltidae, Boidae, Erycidae and Sanziniidae, as well as in outgroups with differentiated sex chromosomes such as monitor lizards, iguanas and chameleons. Along with iguanas, advanced snakes are therefore another example of ectothermic amniotes with a long-term stability of sex chromosomes comparable with endotherms. PMID:26702042

Importance of extended spatial coverage for quantitative susceptibility mapping of iron-rich deep gray matter.

PubMed

Elkady, Ahmed M; Sun, Hongfu; Wilman, Alan H

2016-05-01

Quantitative Susceptibility Mapping (QSM) is an emerging area of brain research with clear application to brain iron studies in deep gray matter. However, acquisition of standard whole brain QSM can be time-consuming. One means to reduce scan time is to use a focal acquisition restricted only to the regions of interest such as deep gray matter. However, the non-local dipole field necessary for QSM reconstruction extends far beyond the structure of interest. We demonstrate the practical implications of these non-local fields on the choice of brain volume for QSM. In an illustrative numerical simulation and then in human brain experiments, we examine the effect on QSM of volume reduction in each dimension. For the globus pallidus, as an example of iron-rich deep gray matter, we demonstrate that substantial errors can arise even when the field-of-view far exceeds the physical structural boundaries. Thus, QSM reconstruction requires a non-local field-of-view prescription to ensure minimal errors. An axial QSM acquisition, centered on the globus pallidus, should encompass at least 76mm in the superior-inferior direction to conserve susceptibility values from the globus pallidus. This dimension exceeds the physical coronal extent of this structure by at least five-fold. As QSM sees wider use in the neuroscience community, its unique requirement for an extended field-of-view needs to be considered. Copyright © 2016 Elsevier Inc. All rights reserved.

Treating post-traumatic tremor with deep brain stimulation: report of five cases.

PubMed

Issar, Neil M; Hedera, Peter; Phibbs, Fenna T; Konrad, Peter E; Neimat, Joseph S

2013-12-01

Post-traumatic tremor is one of the most common movement disorders resulting from severe head trauma. However, literature regarding successful deep brain stimulation (DBS) treatment is scarce, resulting in ambiguity regarding the optimal lead location. Most cases support the ventral intermediate nucleus, but there is evidence to defend DBS of the zona incerta, ventral oralis anterior/posterior, and/or a combination of these targets. We report five patients with disabling post-traumatic tremor treated with DBS of the ventral intermediate nucleus and of the globus pallidus internus. Patients were referred to the Vanderbilt Movement Disorders Division, and surgical intervention was determined by a DBS Multidisciplinary Committee. Standard DBS procedure was followed. Patients 1-4 sustained severe diffuse axonal injuries. Patients 1-3 underwent unilateral ventral intermediate nucleus DBS for contralateral tremor, while Patient 4 underwent bilateral ventral intermediate nucleus DBS. Patients 1-3 experienced good tremor reduction, while Patient 4 experienced moderate tremor reduction with some dystonic posturing of the hands. Patient 5 had dystonic posturing of the right upper extremity with tremor of the left upper extremity. He was treated with bilateral DBS of the globus pallidus internus and showed good tremor reduction at follow-up. Unilateral or bilateral DBS of the ventral intermediate nucleus and bilateral DBS of the globus pallidus internus may be effective and safe treatment modalities for intractable post-traumatic tremor. Further studies are needed to clarify the optimal target for surgical treatment of post-traumatic tremor. Published by Elsevier Ltd.

Basal Ganglia Shape Abnormalities in the Unaffected Siblings of Schizophrenia Patients

PubMed Central

Mamah, Daniel; Harms, Michael P.; Wang, Lei; Barch, Deanna; Thompson, Paul; Kim, Jaeyun; Miller, Michael I.; Csernansky, John G.

2008-01-01

Objective Abnormalities of basal ganglia structure in schizophrenia have been attributed to the effects of antipsychotic drugs. Our aim was to test the hypothesis that abnormalities of basal ganglia structure are intrinsic features of schizophrenia, by assessing basal ganglia volume and shape in the unaffected siblings of schizophrenia subjects. Method The study involved 25 pairs of schizophrenia subjects and their unaffected siblings and 40 pairs of healthy controls and their siblings. Large deformation, high-dimensional brain mapping was used to obtain surface representations of the caudate, putamen, and globus pallidus. Surfaces were derived from transformations of anatomical templates and shapes were analyzed using reduced-dimensional measures of surface variability (i.e. principal components and canonical analysis). Canonical functions were derived using schizophrenia and control groups, and were then used to compare shapes in the sibling groups. To visualize shape differences, maps of the estimated surface displacement between groups were created. Results In the caudate, putamen and globus pallidus, the degree of shape abnormality observed in the siblings of the schizophrenia subjects was intermediate between the schizophrenia subjects and the controls. In the schizophrenia subjects, significant correlations were observed between measures of caudate, putamen and globus pallidus structure and the selected measures of lifetime psychopathology. Conclusions Attenuated abnormalities of basal ganglia structure are present in the unaffected siblings of schizophrenia subjects. This finding implies that basal ganglia structural abnormalities observed in subjects with schizophrenia are at least in part an intrinsic feature of the illness. PMID:18295189

Effects of Age, Gender and Hemispheric Location on T2 Hypointensity in the Pulvinar at 3T.

PubMed

White, Matthew L; Zhang, Yan; Helvey, Jason T; Yu, Fang; Omojola, Matthew F

2014-12-01

Pulvinar signal intensity decrease on T2-weighted images has been reported in some neurological abnormalities. We aimed to define the normal T2 signal hypointensity pattern present in the pulvinar to avoid erroneous radiological interpretation. One hundred and forty-two subjects (54 men and 88 women; age range 9-91 years) with unremarkable brain 3T MR findings were enrolled. MR images were analyzed with regard to signal intensity of the pulvinar relative to the thalamus on fluid attenuated inversion recovery images. Effects of age, gender and hemispheric location on the degree of T2 hypointensity were statistically analyzed. The statistical association was measured between the pattern of signal changes in the pulvinar region and that in the putamen and the globus pallidus. We detected a linear signal decrease in the pulvinar region with age. The male subjects had a more rapid decrease of signal with age than female subjects. The right pulvinar region had a higher chance of hypointensity compared to the left. A positive linear association was found when signal change from the pulvinar region was compared with signal in the putamen and globus pallidus. We detected a linear signal decrease with age in the pulvinar. The physiological signal features of the pulvinar also depend on gender and hemispheric lateralization. The pattern of signal change in the pulvinar is similar to but not the same as that in the putamen and globus pallidus.

A study of bat populations at Los Alamos National Laboratory and Bandelier National Monument, Jemez Mountains, New Mexico: FY95--97 report to Los Alamos National Laboratory and Bandelier National Monument

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bogan, M.A.; O`Shea, T.J.; Cryan, P.M.

In 1995, a three-year study was initiated to assess the current status of bat species of concern, elucidate distribution and relative abundance, and obtain information on roosting sites of bats. The authors captured and released 1532 bats of 15 species (Myotis californicus, M. ciliolabrum, M. evotis, M. thysanodes, M. volans, M. yumanensis, Lasiurus cinereus, Lasionycteris noctivagans, Pipistrellus hesperus, Eptesicus fuscus, Euderma maculatum, Corynorhinus townsendii, Antrozous pallidus, Tadarida brasiliensis, and Nyctinomops macrotis) and followed 32 bats of eight species (M. evotis, M. thysanodes, M. volans, E. fuscus, E. maculatum, C. townsendii, A. pallidus, and N. macrotis) to 51 active diurnal roosts.more » The most abundant species were L. noctivagans, E. fuscus, L. cinereus, M. evotis, M. volans, and M. ciliolabrum. Most of these species are typical inhabitants of ponderosa pine-mixed coniferous forests.« less

Semiochemicals From Fungal Associates of Bark Beetles May Mediate Host Location Behavior of Parasitoids

Treesearch

Brian T. Sullivan; C. Wayne Berisford

2004-01-01

In laboratory olfactometer bioassays, females of two hymenopteran parasitoid species, Roptrocerus xylophagorum (Ratzeburg) (Hymenoptera: Pteromalidae) and Spathius pallidus (Ashmead) (Hymenoptera: Braconidae), were attracted to odors from bark or bolts of loblolly pine, Pinus taeda L., colonized by bluestain fungi (genus ...

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Subthalamic Nucleus and Globus Pallidus Internus Deep Brain Stimulation for the Treatment of Patients With Parkinson's Disease: Executive Summary.

PubMed

Rughani, Anand; Schwalb, Jason M; Sidiropoulos, Christos; Pilitsis, Julie; Ramirez-Zamora, Adolfo; Sweet, Jennifer A; Mittal, Sandeep; Espay, Alberto J; Martinez, Jorge Gonzalez; Abosch, Aviva; Eskandar, Emad; Gross, Robert; Alterman, Ron; Hamani, Clement

2018-06-01

Is bilateral subthalamic nucleus deep brain stimulation (STN DBS) more, less, or as effective as bilateral globus pallidus internus deep brain stimulation (GPi DBS) in treating motor symptoms of Parkinson's disease, as measured by improvements in Unified Parkinson's Disease Rating Scale, part III (UPDRS-III) scores? Given that bilateral STN DBS is at least as effective as bilateral GPi DBS in treating motor symptoms of Parkinson's disease (as measured by improvements in UPDRS-III scores), consideration can be given to the selection of either target in patients undergoing surgery to treat motor symptoms. (Level I). Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in allowing reduction of dopaminergic medication in Parkinson's disease? When the main goal of surgery is reduction of dopaminergic medications in a patient with Parkinson's disease, then bilateral STN DBS should be performed instead of GPi DBS. (Level I). Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in treating dyskinesias associated with Parkinson's disease? There is insufficient evidence to make a generalizable recommendation regarding the target selection for reduction of dyskinesias. However, when the reduction of medication is not anticipated and there is a goal to reduce the severity of "on" medication dyskinesias, the GPi should be targeted. (Level I). Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in improving quality of life measures in Parkinson's disease? When considering improvements in quality of life in a patient undergoing DBS for Parkinson's disease, there is no basis to recommend bilateral DBS in 1 target over the other. (Level I). Is bilateral STN DBS associated with greater, lesser, or a similar impact on neurocognitive function than bilateral GPi DBS in Parkinson disease? If there is significant concern about cognitive decline, particularly in regards to processing speed and working memory in a patient undergoing DBS

Populations at risk: conservation genetics of kangaroo mice (Microdipodops) of the Great Basin Desert.

PubMed

Andersen, John J; Portnoy, David S; Hafner, John C; Light, Jessica E

2013-08-01

The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Dark (Microdipodops megacephalus) and pallid (M. pallidus) kangaroo mice are ecological specialists found within the Great Basin Desert and are potentially ideal organisms for assessing ecosystem health and inferring the biogeographic history of this vulnerable region. Herein, newly acquired nuclear-encoded microsatellite loci were utilized to assess patterns of variation within and among spatially discrete groups of kangaroo mice and to evaluate gene flow, demographic trends, and genetic integrity. Results confirm that there are at least three genetically distinct units within M. megacephalus and two such units within M. pallidus. The three units of M. megacephalus appear to have different demographic histories, with effectively no gene flow among them since their divergence. Similarly, the two units of M. pallidus also appear to have experienced different demographic histories, with effectively no gene exchange. Contemporary effective population sizes of all groups within Microdipodops appear to be low (<500), suggesting that each genetic lineage may have difficulty coping with changing environmental pressures and hence may be at risk of extirpation. Results of this study indicate that each Microdipodops group should be recognized, and therefore managed, as a separate unit in an effort to conserve these highly specialized taxa that contribute to the diversity of the Great Basin Desert ecosystem. The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Herein, newly acquired nuclear-encoded microsatellite

Phylogeography of the dark kangaroo mouse, Microdipodops megacephalus: cryptic lineages and dispersal routes in North America's Great Basin.

PubMed

Hafner, John C; Upham, Nathan S

2011-06-01

AIM: The rodent genus Microdipodops (kangaroo mice) includes two sand-obligate endemics of the Great Basin Desert: M. megacephalus and M. pallidus. The dark kangaroo mouse, M. megacephalus, is distributed throughout the Great Basin and our principal aims were to formulate phylogenetic hypotheses for this taxon and make phylogeographical comparisons with its congener. LOCATION: The Great Basin Desert of western North America. METHODS: DNA sequence data from three mitochondrial genes were examined from 186 individuals of M. megacephalus, representing 47 general localities. Phylogenetic inference was used to analyse the sequence data. Directional analysis of phylogeographical patterns was used to examine haplotype sharing patterns and recover routes of gene exchange. Haplotype-area curves were constructed to evaluate the relationship between genetic variation and distributional island size for M. megacephalus and M. pallidus. RESULTS: Microdipodops megacephalus is a rare desert rodent (trapping success was 2.67%). Temporal comparison of trapping data shows that kangaroo mice are becoming less abundant in the study area. The distribution has changed slightly since the 1930s but many northern populations now appear to be small, fragmented, or locally extinct. Four principal phylogroups (the Idaho isolate and the western, central and eastern clades) are evident; mean sequence divergence between phylogroups for cytochrome b is c. 8%. Data from haplotype sharing show two trends: a north-south trend and a web-shaped trend. Analyses of haplotype-area curves reveal significant positive relationships. MAIN CONCLUSIONS: The four phylogroups of M. megacephalus appear to represent morphologically cryptic species; in comparison, a companion study revealed two cryptic lineages in M. pallidus. Estimated divergence times of the principal clades of M. megacephalus (c. 2-4 Ma) indicate that these kangaroo mice were Pleistocene invaders into the Great Basin coincident with the formation

Ticks on captive and free-living wild animals in northeastern Brazil.

PubMed

Dantas-Torres, Filipe; Ferreira, Débora R A; de Melo, Louise M; Lima, Polly-Ana C P; Siqueira, Daniel B; Rameh-de-Albuquerque, Luciana C; de Melo, Adriana V; Ramos, Janaina A C

2010-02-01

From 2005 to 2009, 147 ticks found on 32 wild animals from or referred to two zoobotanical parks (Parque Zoobotânico Arruda Câmara and Parque Estadual Dois Irmãos) located in northeastern Brazil were identified. Ticks found on two veterinarians working in one of the parks (i.e., Parque Estadual Dois Irmãos), after return from forested areas within the park's territory, were also identified. The following tick-host associations were recorded: Amblyomma fuscum Neumann on Boa constrictor L.; Amblyomma longirostre Koch on Ramphastos vitellinus ariel Vigors and Coendou prehensilis (L.); Amblyomma varium Koch on Bradypus variegates Schinz; Amblyomma rotundatum Koch on Chelonoidis carbonaria (Spix), Chelonoidis denticulata (L.), Micrurus ibiboboca (Merrem), Python molurus bivittatus Kuhl, Iguana iguana (L.) and B. variegatus; Amblyomma nodosum Neumann on Myrmecophaga tridactyla L. and Tamandua tetradactyla (L.); and Rhipicephalus sanguineus (Latreille) on Nasua nasua (L.). The ticks found on the veterinarians were identified as nine Amblyomma larvae. The presence of Am. nodosum in Pernambuco and Am. rotundatum and Am. varium in Paraíba is recorded for the first time and the occurrence of Am. longirostre in Pernambuco is confirmed. Ramphastos vitellinus ariel is a new host record for Am. longirostre whereas M. ibiboboca and B. variegatus are new host records for Am. rotundatum. Finally, the human parasitism by Amblyomma ticks is reported for the first time in Pernambuco, highlighting the potential of tick-borne pathogen transmission in this state.

A young woman with visual hallucinations, delusions of persecution and a history of performing arson with possible three-generation Fahr disease.

PubMed

Shirahama, M; Akiyoshi, J; Ishitobi, Y; Tanaka, Y; Tsuru, J; Matsushita, H; Hanada, H; Kodama, K

2010-01-01

Fahr disease (FD) is a rare neurological and psychiatric disorder. The disease is classified by intracranial calcification of the basal ganglia with the globus pallidus region being particularly affected. We examined a young woman with visual hallucinations, delusions of persecution and a history of performing arson with possible third-generation FD. Case report of third-generation FD. A 23-year-old woman was arrested for two arsons: i) The patient exhibited progressive psychotic symptoms, including visual hallucinations, delusion of injury, irritability, lability of mood, mental retardation and visual disorders and ii) Computed tomography (CT) imaging demonstrated bilateral calcifications of the basal ganglia (globus pallidus) in the patient, her mother and her grandmother. We found a family with a three-generation history of FD who exhibited calcification in the brain and mental retardation. Compared to her mother, the patient described here displayed anticipation of disease onset.

Sex differences in neurotensin and substance P following nicotine self-administration in rats.

PubMed

Pittenger, Steven T; Swalve, Natashia; Chou, Shinnyi; Smith, Misty D; Hoonakker, Amanda J; Pudiak, Cindy M; Fleckenstein, Annette E; Hanson, Glen R; Bevins, Rick A

2016-08-01

Investigator-administered nicotine alters neurotensin and substance P levels in Sprague-Dawley rats. This finding suggested a role of the dopamine-related endogenous neuropeptides in nicotine addiction. We sought to extend this observation by determining the responses of neurotensin and substance P systems (assessed using radioimmunoassay) in male and female rats following nicotine self-administration (SA). Male and female Sprague-Dawley were trained to self-administer nicotine, or receive saline infusions yoked to a nicotine-administering rat during daily sessions (1-h; 21 days). Brains were extracted 3 h after the last SA session. Nicotine SA increased tissue levels of neurotensin in the males in the anterior and posterior caudate, globus pallidus, frontal cortex, nucleus accumbens core and shell, and ventral tegmental area. Nicotine SA also increased tissue levels of neurotensin in the females in the anterior caudate, globus pallidus, nucleus accumbens core and shell, but not in the posterior caudate, frontal cortex, or ventral tegmental area. There were fewer sex differences observed in the substance P systems. Nicotine SA increased tissue levels of substance P in both the males and females in the posterior caudate, globus pallidus, frontal cortex, nucleus accumbens shell, and ventral tegmental area. A sex difference was observed in the nucleus accumbens core, where nicotine SA increased tissue levels of substance P in the males, yet decreased levels in the females. The regulation of neuropeptides following nicotine SA may play a role in the susceptibility to nicotine dependence in females and males. Synapse 70:336-346, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Ticks infesting amphibians and reptiles in Pernambuco, Northeastern Brazil.

PubMed

Dantas-Torres, Filipe; Oliveira-Filho, Edmilson F; Soares, Fábio Angelo M; Souza, Bruno O F; Valença, Raul Baltazar P; Sá, Fabrício B

2008-01-01

Ticks infesting amphibians and reptiles in the State of Pernambuco are reviewed, based on the current literature and new collections recently carried out by the authors. To date, three tick species have been found on amphibians and reptiles in Pernambuco. Amblyomma fuscum appears to be exclusively associated with Boa constrictor, its type host. Amblyomma rotundatum has a relatively low host-specificity, being found on toads, snakes, and iguana. Amblyomma dissimile has been found on a lizard and also small mammals (i.e., rodents and marsupials). New tick-host associations and locality records are given.

Subthalamic Nucleus Stimulation Modulates Motor Cortex Oscillatory Activity in Parkinson's Disease

ERIC Educational Resources Information Center

Devos, D.; Labyt, E.; Derambure, P.; Bourriez, J. L.; Cassim, F.; Reyns, N.; Blond, S.; Guieu, J. D.; Destee, A.; Defebvre, L.

2004-01-01

In Parkinson's disease, impaired motor preparation has been related to an increased latency in the appearance of movement-related desynchronization (MRD) throughout the contralateral primary sensorimotor (PSM) cortex. Internal globus pallidus (GPi) stimulation improved movement desynchronization over the PSM cortex during movement execution but…

Population dynamics of pond zooplankton, I. Diaptomus pallidus Herrick

USGS Publications Warehouse

Armitage, K.B.; Saxena, B.; Angino, E.E.

1973-01-01

The simultaneous and lag relationships between 27 environmental variables and seven population components of a perennial calanoid copepod were examined by simple and partial correlations and stepwise regression. The analyses consistently explained more than 70% of the variation of a population component. The multiple correlation coefficient (R) usually was highest in no lag or in 3-week or 4-week lag except for clutch size in which R was highest in 1-week lag. Population control, egg-bearing, and clutch size were affected primarily by environmental components categorized as weather; food apparently was relatively minor in affecting population control or reproduction. ?? 1973 Dr. W. Junk B.V. Publishers.

Improvement of both dystonia and tics with 60 Hz pallidal deep brain stimulation.

PubMed

Hwynn, Nelson; Tagliati, Michele; Alterman, Ron L; Limotai, Natlada; Zeilman, Pamela; Malaty, Irene A; Foote, Kelly D; Morishita, Takashi; Okun, Michael S

2012-09-01

Deep brain stimulation has been utilized in both dystonia and in medication refractory Tourette syndrome. We present an interesting case of a patient with a mixture of disabling dystonia and Tourette syndrome whose coexistent dystonia and tics were successfully treated with 60 Hz-stimulation of the globus pallidus region.

Bilateral subthalamic or pallidal stimulation for Parkinson's disease affects neither memory nor executive functions: a consecutive series of 62 patients.

PubMed

Ardouin, C; Pillon, B; Peiffer, E; Bejjani, P; Limousin, P; Damier, P; Arnulf, I; Benabid, A L; Agid, Y; Pollak, P

1999-08-01

There is a renewal of interest in surgical approaches including lesions and deep brain stimulation directed at motor subcorticofrontal loops. Bilateral lesioning presents a far greater risk of adverse effects, especially cognitive impairment. Furthermore, the main advantages of the stimulation procedure over lesioning are adaptability and reversibility of effects. The aim of this study was to assess the influence of bilateral stimulation of the subthalamic nucleus or internal globus pallidus on memory and executive functions in Parkinson's disease. Sixty-two patients were assessed before and after 3 to 6 months of chronic bilateral stimulation of the subthalamic nucleus (n = 49) or internal globus pallidus (n = 13). The neuropsychological tests used were the Mattis Dementia Rating Scale, the Grober and Buschke Verbal Learning Test, the Wisconsin Card Sorting Test, category and literal fluency, graphic and motor series, the Stroop Test, and the Trail Making Test. Mood was evaluated by the Beck Depression Inventory. Only 4 of 25 cognitive variables were affected by deep brain stimulation. Under stimulation, performance improved for Parts A and B of the Trail Making Test, but there was a deterioration in literal and total lexical fluency. There was also a mild but significant improvement in mood. It may therefore be concluded that stimulation of the subthalamic nucleus or internal globus pallidus does not change the overall cognitive performance in Parkinson's disease and does not greatly affect the functioning of subcorticofrontal loops involved in cognition in humans. This relative absence of cognitive impairment in bilateral deep brain stimulation is likely because of the accurate positioning of the electrodes, allowing the effects of stimulation to be confined to sensorimotor circuits.

Orexin-A projections to the caudal medulla and orexin-induced c-Fos expression, food intake, and autonomic function.

PubMed

Zheng, Huiyuan; Patterson, Laurel M; Berthoud, Hans-Rudolf

2005-05-02

Orexin-expressing neurons in the hypothalamus project throughout the neuraxis and are involved in regulation of the sleep/wake cycle, food intake, and autonomic functions. Here we specifically analyze the anatomical organization of orexin projections to the dorsal vagal complex (DVC) and raphe pallidus and effects on ingestive behavior and autonomic functions of local orexin-A administration in nonanesthetized rats. Retrograde tracing experiments revealed that as many as 20% of hypothalamic orexin neurons project to the DVC, where they form straight varicose axon profiles, some of which are in close anatomical apposition with tyrosine hydroxylase (TH)-, glucagon-like peptide-1-, gamma-aminobutyric acid-, and nitric oxide synthase-immunoreactive neurons in a nonselective manner. Similar contacts were frequently observed with neurons of the nucleus of the solitary tract whose activation by gastrointestinal food stimuli was demonstrated by the expression of nuclear c-Fos immunoreactivity. Orexin-A administration to the fourth ventricle induced significant Fos-expression throughout the DVC compared with saline control injections, with about 20-25% of TH-ir neurons among the stimulated ones. Fourth ventricular orexin injections also significantly stimulated chow and water intake in nonfood-deprived rats. Direct bilateral injections of orexin into the DVC increased intake of palatable high-fat pellets. Orexin-ir fibers also innervated raphe pallidus. Fourth ventricular orexin-A (1 nmol) activated Fos expression in the raphe pallidus and C1/A1 catecholaminergic neurons in the ventral medulla and increased body temperature, heart rate, and locomotor activity. The results confirm that hypothalamomedullary orexin projections are involved in a variety of physiological functions, including ingestive behavior and sympathetic outflow. Copyright 2005 Wiley-Liss, Inc.

Demyelination of subcortical nuclei in multiple sclerosis

NASA Astrophysics Data System (ADS)

Krutenkova, E.; Aitmagambetova, G.; Khodanovich, M.; Bowen, J.; Gangadharan, B.; Henson, L.; Mayadev, A.; Repovic, P.; Qian, P.; Yarnykh, V.

2016-02-01

Myelin containing in basal ganglia in multiple sclerosis patients was evaluated using new noninvasive quantitative MRI method fast whole brain macromolecular proton fraction mapping. Myelin level in globus pallidus and putamen significantly decreased in multiple sclerosis patients as compared with healthy control subjects but not in substantia nigra and caudate nucleus.

Gonadotrophin-Releasing Hormone Agonists and Other Contraceptive Medications in Exotic Companion Animals.

PubMed

Schoemaker, Nico J

2018-05-01

The use of a gonadotrophin-releasing hormone agonist slow-release implant (GnRH A-SRI) has become increasingly popular as an alternative for surgical contraception in many species. Although these implants have proven to be very effective in some species (eg, ferrets, rats, chicken, psittacines, and iguanas), they have been found less effective in other species (eg, male guinea pigs and rabbits, veiled chameleons, slider turtles, and leopard geckos). This review provides an overview of the available literature on the effects of GnRH A-SRIs in companion exotic animals. Copyright © 2018 Elsevier Inc. All rights reserved.

Thousand cankers disease: Geosmithia morbida spores isolated from a weevil

Treesearch

Michele Warmund; Jerry. Van Sambeek

2014-01-01

Recently, Geosmithia morbida, the canker-causing fungus associated with thousand cankers disease, was isolated from Stenomimus pallidus weevils found on two stressed black walnut trees in Yellowwood State Forest near Nashville, Indiana. This is the first report of Geosmithia fungus occurring on an insect other than the walnut twig beetle (Pityophthorus juglandis)....

Comparison of high MRI T1 signals with manganese concentration in brains of cynomolgus monkeys after 8 months of stainless steel welding-fume exposure.

PubMed

Park, Jung Duck; Chung, Yong Hyun; Kim, Choong Yong; Ha, Chang Soo; Yang, Seoung Oh; Khang, Hyun Soo; Yu, In Kyu; Cheong, Hae Kwan; Lee, Jong Seong; Song, Chang-Woo; Kwon, Il Hoon; Han, Jeong Hee; Sung, Jae Hyuck; Heo, Jeong Doo; Choi, Byung Sun; Im, Ruth; Jeong, Jayoung; Yu, Il Je

2007-09-01

Several pharmacokinetic studies on inhalation exposure to manganese (Mn) have already demonstrated that Mn readily accumulates in the olfactory and brain regions. However, a shortening of the magnetic resonance imaging (MRI) T1 relaxation time or high T1 signal intensity in specific sites of the brain, including the globus pallidus and subcortical frontal white matter, as indicative of tissue manganese accumulation has not yet been clearly established for certain durations of known doses of welding-fume exposure in experimental animals. Accordingly, to investigate the movement of manganese after welding-fume exposure, six cynomolgus monkeys were acclimated and assigned to three dose groups: unexposed, low dose (31 mg/m(3) total suspended particulate [TSP], 0.9 mg/m(3) of Mn), and high dose (62 mg/m(3) TSP, 1.95 mg/m(3) of Mn) of total suspended particulate. The primates were exposed to manual metal arc stainless steel (MMA-SS) welding fumes for 2 h per day in an inhalation chamber system equipped with an automatic fume generator. Magnetic resonance imaging (MRI) studies were conducted before the initiation of exposure and thereafter every month. The tissue Mn concentrations were then measured after a plateau was reached regarding the shortening of the MRI T1 relaxation time. A dose-dependent increase in the Mn concentration was found in the lungs, while noticeable increases in the Mn concentrations were found in certain tissues, such as the liver, kidneys, and testes. Slight increases in the Mn concentrations were found in the caudate, putamen, frontal lobe, and substantia nigra, while a dose-dependent noticeable increase was only found in the globus pallidus. Therefore, the present results indicated that a shortening of the MRI T1 relaxation time corresponded well with the Mn concentration in the globus pallidus after prolonged welding-fume exposure.

Evolution of deep gray matter volume across the human lifespan.

PubMed

Narvacan, Karl; Treit, Sarah; Camicioli, Richard; Martin, Wayne; Beaulieu, Christian

2017-08-01

Magnetic resonance imaging of subcortical gray matter structures, which mediate behavior, cognition and the pathophysiology of several diseases, is crucial for establishing typical maturation patterns across the human lifespan. This single site study examines T1-weighted MPRAGE images of 3 healthy cohorts: (i) a cross-sectional cohort of 406 subjects aged 5-83 years; (ii) a longitudinal neurodevelopment cohort of 84 subjects scanned twice approximately 4 years apart, aged 5-27 years at first scan; and (iii) a longitudinal aging cohort of 55 subjects scanned twice approximately 3 years apart, aged 46-83 years at first scan. First scans from longitudinal subjects were included in the cross-sectional analysis. Age-dependent changes in thalamus, caudate, putamen, globus pallidus, nucleus accumbens, hippocampus, and amygdala volumes were tested with Poisson, quadratic, and linear models in the cross-sectional cohort, and quadratic and linear models in the longitudinal cohorts. Most deep gray matter structures best fit to Poisson regressions in the cross-sectional cohort and quadratic curves in the young longitudinal cohort, whereas the volume of all structures except the caudate and globus pallidus decreased linearly in the longitudinal aging cohort. Males had larger volumes than females for all subcortical structures, but sex differences in trajectories of change with age were not significant. Within subject analysis showed that 65%-80% of 13-17 year olds underwent a longitudinal decrease in volume between scans (∼4 years apart) for the putamen, globus pallidus, and hippocampus, suggesting unique developmental processes during adolescence. This lifespan study of healthy participants will form a basis for comparison to neurological and psychiatric disorders. Hum Brain Mapp 38:3771-3790, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Geosmithia morbida found on weevil species Stenominus pallidus in Indiana

Treesearch

Jennifer Juzwik; Mark T. Banik; Sharon E. Reed; James T. English; Matthew D. Ginzel

2015-01-01

The canker pathogen Geosmithia morbida is known to be transmitted to Juglans species by the bark beetle Pityophthorus juglandis, and to lead to development of thousand cankers disease. In an Indiana-wide trap-tree survey of ambrosia and bark beetles and weevils colonizing stressed Juglans nigra...

Central neural pathways for thermoregulation

PubMed Central

Morrison, Shaun F.; Nakamura, Kazuhiro

2010-01-01

Central neural circuits orchestrate a homeostatic repertoire to maintain body temperature during environmental temperature challenges and to alter body temperature during the inflammatory response. This review summarizes the functional organization of the neural pathways through which cutaneous thermal receptors alter thermoregulatory effectors: the cutaneous circulation for heat loss, the brown adipose tissue, skeletal muscle and heart for thermogenesis and species-dependent mechanisms (sweating, panting and saliva spreading) for evaporative heat loss. These effectors are regulated by parallel but distinct, effector-specific neural pathways that share a common peripheral thermal sensory input. The thermal afferent circuits include cutaneous thermal receptors, spinal dorsal horn neurons and lateral parabrachial nucleus neurons projecting to the preoptic area to influence warm-sensitive, inhibitory output neurons which control thermogenesis-promoting neurons in the dorsomedial hypothalamus that project to premotor neurons in the rostral ventromedial medulla, including the raphe pallidus, that descend to provide the excitation necessary to drive thermogenic thermal effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus neurons controlling cutaneous vasoconstriction. PMID:21196160

Central neural pathways for thermoregulation.

PubMed

Morrison, Shaun F; Nakamura, Kazuhiro

2011-01-01

Central neural circuits orchestrate a homeostatic repertoire to maintain body temperature during environmental temperature challenges and to alter body temperature during the inflammatory response. This review summarizes the functional organization of the neural pathways through which cutaneous thermal receptors alter thermoregulatory effectors: the cutaneous circulation for heat loss, the brown adipose tissue, skeletal muscle and heart for thermogenesis and species-dependent mechanisms (sweating, panting and saliva spreading) for evaporative heat loss. These effectors are regulated by parallel but distinct, effector-specific neural pathways that share a common peripheral thermal sensory input. The thermal afferent circuits include cutaneous thermal receptors, spinal dorsal horn neurons and lateral parabrachial nucleus neurons projecting to the preoptic area to influence warm-sensitive, inhibitory output neurons which control thermogenesis-promoting neurons in the dorsomedial hypothalamus that project to premotor neurons in the rostral ventromedial medulla, including the raphe pallidus, that descend to provide the excitation necessary to drive thermogenic thermal effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus neurons controlling cutaneous vasoconstriction.

Diversity of Polyhydroxynaphthoquinone Pigments in North Pacific Sea Urchins.

PubMed

Vasileva, Elena A; Mishchenko, Natalia P; Fedoreyev, Sergey A

2017-09-01

Using high-performance liquid chromatography with diode-array detection and mass spectrometry (HPLC-DAD/MS) we investigated the composition of polyhydroxynaphthoquinone (PHNQ) pigments from sea urchins Strongylocentrotus pallidus, St. polyacanthus, St. droebachiensis, Brisaster latifrons and Echinarachnius parma, collected in the Sea of Okhotsk and the Bering Sea. Identification of PHNQ pigments from sea urchins St. polyacanthus, B. latifrons, and E. parma was performed for the first time. Among the usual PHNQ pigments, mono- and dimethoxy derivatives of spinochrome E, not previously found in other sea urchins, were discovered in St. polyacanthus and St. droebachiensis. In St. droebachiensis, two monomethoxy derivatives of echinochrome A were detected, isolated previously from only tropical sea urchins. It was found that the composition and total content of pigments of St. droebachiensis depends on the collection area of the sea urchins and its depth and varies from 88 to 331 μg/g of dry shells. Sea urchins St. pallidus, B. latifrons and E. parma had average values for PHNQ pigment content, approximately 30 μg/g, and St. polyacanthus had a low PHNQ content, 13 μg/g. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Correlation of computed tomography, magnetic resonance imaging and clinical outcome in acute carbon monoxide poisoning.

PubMed

Ozcan, Namik; Ozcam, Giray; Kosar, Pinar; Ozcan, Ayse; Basar, Hulya; Kaymak, Cetin

2016-01-01

Carbon monoxide is a toxic gas for humans and is still a silent killer in both developed and developing countries. The aim of this case series was to evaluate early radiological images as a predictor of subsequent neuropsychological sequelae, following carbon monoxide poisoning. After carbon monoxide exposure, early computed tomography scans and magnetic resonance imaging findings of a 52-year-old woman showed bilateral lesions in the globus pallidus. This patient was discharged and followed for 90 days. The patient recovered without any neurological sequela. In a 58-year-old woman exposed to carbon monoxide, computed tomography showed lesions in bilateral globus pallidus and periventricular white matter. Early magnetic resonance imaging revealed changes similar to that like in early tomography images. The patient recovered and was discharged from hospital. On the 27th day of exposure, the patient developed disorientation and memory impairment. Late magnetic resonance imaging showed diffuse hyperintensity in the cerebral white matter. White matter lesions which progress to demyelination and end up in neuropsychological sequelae cannot always be diagnosed by early computed tomography and magnetic resonance imaging in carbon monoxide poisoning. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Use of Tricaine Methanesulfonate (MS222) for Euthanasia of Reptiles

PubMed Central

Conroy, CJ; Papenfuss, T; Parker, J; Hahn, NE

2009-01-01

Tricaine methanesulfonate (MS222) injected into the intracoelomic cavity of reptiles was evaluated as a chemical euthanasia method. Three western fence lizards, 2 desert iguanas, 4 garter snakes, and 6 geckos were euthanized by intracoelomic injection of 250 to 500 mg/kg of 0.7% to 1% sodium-bicarbonate–buffered MS222 solution followed by intracoelomic injection of 0.1 to 1.0 ml unbuffered 50% (v/v) MS222 solution. A simple 2-stage protocol for euthanasia of reptiles by using MS222 is outlined. In addition, the conditions for safe use of MS222 are discussed. MS222 offers an alternative to sodium pentobarbital for euthanasia of reptiles. PMID:19245747

A receptor autoradiographic and in situ hybridization analysis of the distribution of the 5-ht7 receptor in rat brain.

PubMed Central

Gustafson, E. L.; Durkin, M. M.; Bard, J. A.; Zgombick, J.; Branchek, T. A.

1996-01-01

1. Receptor autoradiography and in situ hybridization histochemistry have been used to delineate the distribution of the 5-ht7 receptor and its mRNA in rat brain. Receptor autoradiographic studies were performed using [3H]-5-carboxamidotryptamine (5-CT) as the radioligand. The binding characteristics of the masking compounds were determined in Cos-7 cells transfected with a panel of 5-HT receptor subtype cDNAs, including the rat 5-ht7 cDNA. In situ hybridization studies were carried out with 35S-labelled oligonucleotide probes to the rat 5-ht7 mRNA. 2. Specific binding of [3H]-5-CT was observed in many areas of the rat brain. Following co-incubation with 1 microM ergotamine, this binding was completely eliminated. After addition of the masking ligands, [3H]-5-CT binding remained in layers 1-3 of cortex, septum, globus pallidus, thalamus, hypothalamus, centromedial amygdala, substantia nigra, periaquaductal gray, and superior colliculus. Addition of the antagonist, methiothepin, to the incubation regimen eliminated most of the remaining [3H]-5-CT binding in the brain, with the exception of the globus pallidus and substantia nigra. 3. The 5-ht7 mRNA was discretely localized in rat brain. The most intense hybridization signals were observed over the thalamus, the anterior hippocampal rudiment, and over the CA3 region of the hippocampus. Other regions containing hybridization signals included the septum, the hypothalamus, the centromedial amygdala and the periaquaductal gray. The regions exhibiting a modest receptor binding signal after methiothepin incubation, the globus pallidus and the substantia nigra, contained no 5-ht7 hybridization signals, suggesting a non-5-ht7 subtype in these two related structures. 4. The distribution of the 5-ht7 receptor and its mRNA is suggestive of multiple roles for this novel 5-HT receptor, within several brain systems. The limbic system (centromedial amygdala, anterior hippocampal rudiment, hypothalamus) is particularly well

Identification of Novel Compound Mutations in PLA2G6-Associated Neurodegeneration Patient with Characteristic MRI Imaging.

PubMed

Guo, Sen; Yang, Liu; Liu, Huijie; Chen, Wei; Li, Jinchen; Yu, Ping; Sun, Zhong Sheng; Chen, Xiang; Du, Jie; Cai, Tao

2017-08-01

Neurodegeneration with brain iron accumulation comprises a heterogeneous group of disorders characterized clinically by progressive motor dysfunction. Accurate identification of de novo and rare inherited mutations is important for determining causative genes of undiagnosed neurological diseases. In the present study, we report a unique case with cerebellar ataxia symptoms and social communication difficulties in an intermarriage family. MRI showed a marked cerebellar atrophy and the "eye-of-the-tiger"-like sign in the medial globus pallidus. Potential genetic defects were screened by whole-exome sequencing (WES) for the patient and four additional family members. A previously undescribed de novo missense mutation (c.1634A>G, p.K545R) in the exon 12 of the PLA2G6 gene was identified. A second rare variant c.1077G>A at the end of exon 7 was also identified, which was inherited from the mother, and resulted in a frame-shift mutation (c.1074_1077del.GTCG) due to an alternative splicing. In conclusion, the identification of the "eye-of-the-tiger"-like sign in the globus pallidus of the patient expands the phenotypic spectrum of PLA2G6-associated disorders and reveals its value in differential diagnosis of PLA2G6-associated disorders.

Brain iron chelation by deferiprone in a phase 2 randomised double-blinded placebo controlled clinical trial in Parkinson's disease.

PubMed

Martin-Bastida, Antonio; Ward, Roberta J; Newbould, Rexford; Piccini, Paola; Sharp, David; Kabba, Christina; Patel, Maneesh C; Spino, Michael; Connelly, John; Tricta, Fernando; Crichton, Robert R; Dexter, David T

2017-05-03

Parkinson's disease (PD) is associated with increased iron levels in the substantia nigra (SNc). This study evaluated whether the iron chelator, deferiprone, is well tolerated, able to chelate iron from various brain regions and improve PD symptomology. In a randomised double-blind, placebo controlled trial, 22 early onset PD patients, were administered deferiprone, 10 or 15 mg/kg BID or placebo, for 6 months. Patients were evaluated for PD severity, cognitive function, depression rating and quality of life. Iron concentrations were assessed in the substantia nigra (SNc), dentate and caudate nucleus, red nucleus, putamen and globus pallidus by T2* MRI at baseline and after 3 and 6 months of treatment. Deferiprone therapy was well tolerated and was associated with a reduced dentate and caudate nucleus iron content compared to placebo. Reductions in iron content of the SNc occurred in only 3 patients, with no changes being detected in the putamen or globus pallidus. Although 30 mg/kg deferiprone treated patients showed a trend for improvement in motor-UPDRS scores and quality of life, this did not reach significance. Cognitive function and mood were not adversely affected by deferiprone therapy. Such data supports more extensive clinical trials into the potential benefits of iron chelation in PD.

Anatomical brain difference of subthreshold depression in young and middle-aged individuals.

PubMed

Li, Jing; Wang, Zengjian; Hwang, JiWon; Zhao, Bingcong; Yang, Xinjing; Xin, Suicheng; Wang, Yu; Jiang, Huili; Shi, Peng; Zhang, Ye; Wang, Xu; Lang, Courtney; Park, Joel; Bao, Tuya; Kong, Jian

2017-01-01

Subthreshold depression (StD) is associated with substantial functional impairments due to depressive symptoms that do not fully meet the diagnosis of major depressive disorder (MDD). Its high incidence in the general population and debilitating symptoms has recently put it at the forefront of mood disorder research. In this study we investigated common volumetric brain changes in both young and middle-aged StD patients. Two cohorts of StD patients, young and middle-aged, ( n  = 57) and matched controls ( n  = 76) underwent voxel-based morphometry (VBM). VBM analysis found that: 1) compared with healthy controls, StD patients showed decreased gray matter volume (GMV) in the bilateral globus pallidus and precentral gyrus, as well as increased GMV in the left thalamus and right rostral anterior cingulate cortex/medial prefrontal cortex; 2) there is a significant association between Center for Epidemiological Studies Depression Scale scores and the bilateral globus pallidus (negative) and left thalamus (positive); 3) there is no interaction between age (young vs. middle-age) and group (StD vs. controls). Our findings indicate significant VBM brain changes in both young and middle-aged individuals with StD. Individuals with StD, regardless of age, may share common neural characteristics.

Central neural control of thermoregulation and brown adipose tissue

PubMed Central

Morrison, Shaun F.

2016-01-01

Central neural circuits orchestrate the homeostatic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response. This review summarizes the experimental underpinnings of our current model of the CNS pathways controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction controlling heat loss, and shivering and brown adipose tissue for thermogenesis. The activation of these effectors is regulated by parallel but distinct, effector-specific, core efferent pathways within the CNS that share a common peripheral thermal sensory input. Via the lateral parabrachial nucleus, skin thermal afferent input reaches the hypothalamic preoptic area to inhibit warm-sensitive, inhibitory output neurons which control heat production by inhibiting thermogenesis-promoting neurons in the dorsomedial hypothalamus that project to thermogenesis-controlling premotor neurons in the rostral ventromedial medulla, including the raphe pallidus, that descend to provide the excitation of spinal circuits necessary to drive thermogenic thermal effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus sympathetic premotor neurons controlling cutaneous vasoconstriction. The model proposed for central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation and elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation. PMID:26924538

Perspective on basal ganglia connections as described by Nauta and Mehler in 1966: Where we were and how this paper effected where we are now.

PubMed

Haber, Suzanne

2016-08-15

The fiber degenerations resulting from variously located lesions of the lentiform nucleus were studied in the rhesus monkey by the aid of the Nauta-Gygax and Albrecht-Fernstrom techniques. The following observations were made. (1) Putaminofugal connections. Thin fibers originating in the putamen and composing Wilson's 'pencil' bundles traverse the globus pallidus, converging toward the medial point of the lentiform nucleus. The mjority of these fibers terminate in both segments of the globus pallidus, but a considerable number continue caudalward, perforating the cerebral peduncle as ventral components of Edinger's comb system, and terminate in lateral parts of the substantia nigra, pars reticulata. (2) Pallidofugal connections. The ansa lenticularis as defined by von Monakow originates exclusively from the globus pallidus. Its middle division, composed of fibers of medium calibre, arises in the external pallidal segment and traverses the cerebral peduncle as the dorsal component of the comb system to end in the subthalamic nucleus. The thick-fibered dorsal and ventral ansal divisions arise in the internal pallidal segment and combine to form the fasciculus lenticularis which represents the only apparent direct connection of the globus pallidus with the thalamus and the mesencephalic tegmentum. (a) Pallidothalamic fibers follow successively the lenticular and thalamic fasciculi and are distributed to the nuclei ventralis lateralis (subnuclei medialis and oralis of Olszewski and Baxter; none to Zone X and subnucleus caudalis) and ventralis anterior (except subnucleus VAmc). A considerable number of thinner fibers, possibly collaterals of those to VL and VA, terminate in the 'centre médian'; this connection appears to close a potential transthalamic circuit: putamen-globus pallidus-'centre médian'-putamen. (b) There is suggestive evidence of pallidofugal fibers following the stratum zonale thalami to the habenula. (c) Pallidohypothalamic connections could not be

Characterization of multifocal T2*-weighted MRI hypointensities in the basal ganglia of elderly, community-dwelling subjects☆

PubMed Central

Glatz, Andreas; Valdés Hernández, Maria C.; Kiker, Alexander J.; Bastin, Mark E.; Deary, Ian J.; Wardlaw, Joanna M.

2013-01-01

Multifocal T2*-weighted (T2*w) hypointensities in the basal ganglia, which are believed to arise predominantly from mineralized small vessels and perivascular spaces, have been proposed as a biomarker for cerebral small vessel disease. This study provides baseline data on their appearance on conventional structural MRI for improving and automating current manual segmentation methods. Using a published thresholding method, multifocal T2*w hypointensities were manually segmented from whole brain T2*w volumes acquired from 98 community-dwelling subjects in their early 70s. Connected component analysis was used to derive the average T2*w hypointensity count and load per basal ganglia nucleus, as well as the morphology of their connected components, while nonlinear spatial probability mapping yielded their spatial distribution. T1-weighted (T1w), T2-weighted (T2w) and T2*w intensity distributions of basal ganglia T2*w hypointensities and their appearance on T1w and T2w MRI were investigated to gain further insights into the underlying tissue composition. In 75/98 subjects, on average, 3 T2*w hypointensities with a median total volume per intracranial volume of 50.3 ppm were located in and around the globus pallidus. Individual hypointensities appeared smooth and spherical with a median volume of 12 mm3 and median in-plane area of 4 mm2. Spatial probability maps suggested an association between T2*w hypointensities and the point of entry of lenticulostriate arterioles into the brain parenchyma. T1w and T2w and especially the T2*w intensity distributions of these hypointensities, which were negatively skewed, were generally not normally distributed indicating an underlying inhomogeneous tissue structure. Globus pallidus T2*w hypointensities tended to appear hypo- and isointense on T1w and T2w MRI, whereas those from other structures appeared iso- and hypointense. This pattern could be explained by an increased mineralization of the globus pallidus. In conclusion, the

Parkinsonism after glycine-derivate exposure.

PubMed

Barbosa, E R; Leiros da Costa, M D; Bacheschi, L A; Scaff, M; Leite, C C

2001-05-01

This 54-year-old man accidentally sprayed himself with the chemical agent glyphosate, a herbicide derived from the amino acid glycine. He developed disseminated skin lesions 6 hours after the accident. One month later, he developed a symmetrical parkinsonian syndrome. Two years after the initial exposure to glyphosate, magnetic resonance imaging revealed hyperintense signal in the globus pallidus and substantia nigra, bilaterally, on T2-weighted images. Levodopa/benserazide 500/125 mg daily provided satisfactory clinical outcome.

Magnetic Resonance Spectroscopy for Evaluating Portal-Systemic Encephalopathy in Patients with Chronic Hepatic Schistosomiasis Japonicum.

PubMed

Li, Ying; Mei, Lihong; Qiang, Jinwei; Ju, Shuai; Zhao, Shuhui

2016-12-01

Portal-systemic encephalopathy (PSE) is classified as type B hepatic encephalopathy. Portal-systemic shunting rather than liver dysfunction is the main cause of PSE in chronic hepatic schistosomiasis japonicum (HSJ) patients. Owing to lack of detectable evidence of intrinsic liver disease, chronic HSJ patients with PSE are frequently clinically undetected or misdiagnosed, especially chronic HSJ patients with covert PSE (subclinical encephalopathy). In this study, we investigated whether magnetic resonance spectroscopy (MRS) could be a useful tool for diagnosing PSE in chronic HSJ patients. Magnetic resonance (MR) T1-weighted imaging, diffusion-weighted imaging, and MRS were performed in 41 chronic HSJ patients with suspected PSE and in 21 age-matched controls. The T1 signal intensity index (T1SI) and apparent diffusion coefficient (ADC) value were obtained in the Globus pallidus. Liver function was also investigated via serum ammonia and liver function tests. Higher T1SI and ADC values, increased lactate and glutamine levels, and decreased myo-inositol were found in the bilateral Globus pallidus in chronic HSJ patients with PSE. No significantly abnormal serum ammonia or liver function tests were observed in chronic HSJ patients with PSE. On the basis of these findings, we propose a diagnostic procedure for PSE in chronic HSJ patients. This study reveals that MRS can be useful for diagnosing PSE in chronic HSJ patients.

Testing Proposed Neuronal Models of Effective Connectivity Within the Cortico-basal Ganglia-thalamo-cortical Loop During Loss of Consciousness.

PubMed

Crone, Julia Sophia; Lutkenhoff, Evan Scott; Bio, Branden Joseph; Laureys, Steven; Monti, Martin Max

2017-04-01

In recent years, a number of brain regions and connectivity patterns have been proposed to be crucial for loss and recovery of consciousness but have not been compared in detail. In a 3 T resting-state functional magnetic resonance imaging paradigm, we test the plausibility of these different neuronal models derived from theoretical and empirical knowledge. Specifically, we assess the fit of each model to the dynamic change in effective connectivity between specific cortical and subcortical regions at different consecutive levels of propofol-induced sedation by employing spectral dynamic causal modeling. Surprisingly, our findings indicate that proposed models of impaired consciousness do not fit the observed patterns of effective connectivity. Rather, the data show that loss of consciousness, at least in the context of propofol-induced sedation, is marked by a breakdown of corticopetal projections from the globus pallidus. Effective connectivity between the globus pallidus and the ventral posterior cingulate cortex, present during wakefulness, fades in the transition from lightly sedated to full loss of consciousness and returns gradually as consciousness recovers, thereby, demonstrating the dynamic shift in brain architecture of the posterior cingulate "hub" during changing states of consciousness. These findings highlight the functional role of a previously underappreciated direct pallido-cortical connectivity in supporting consciousness. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Image-guided preoperative prediction of pyramidal tract side effect in deep brain stimulation

NASA Astrophysics Data System (ADS)

Baumgarten, C.; Zhao, Y.; Sauleau, P.; Malrain, C.; Jannin, P.; Haegelen, C.

2016-03-01

Deep brain stimulation of the medial globus pallidus is a surgical procedure for treating patients suffering from Parkinson's disease. Its therapeutic effect may be limited by the presence of pyramidal tract side effect (PTSE). PTSE is a contraction time-locked to the stimulation when the current spreading reaches the motor fibers of the pyramidal tract within the internal capsule. The lack of side-effect predictive model leads the neurologist to secure an optimal electrode placement by iterating clinical testing on an awake patient during the surgical procedure. The objective of the study was to propose a preoperative predictive model of PTSE. A machine learning based method called PyMAN (for Pyramidal tract side effect Model based on Artificial Neural network) that accounted for the current of the stimulation, the 3D electrode coordinates and the angle of the trajectory, was designed to predict the occurrence of PTSE. Ten patients implanted in the medial globus pallidus have been tested by a clinician to create a labeled dataset of the stimulation parameters that trigger PTSE. The kappa index value between the data predicted by PyMAN and the labeled data was .78. Further evaluation studies are desirable to confirm whether PyMAN could be a reliable tool for assisting the surgeon to prevent PTSE during the preoperative planning.

Quantitative analysis of diffusion tensor imaging (DTI) using statistical parametric mapping (SPM) for brain disorders

NASA Astrophysics Data System (ADS)

Lee, Jae-Seung; Im, In-Chul; Kang, Su-Man; Goo, Eun-Hoe; Kwak, Byung-Joon

2013-07-01

This study aimed to quantitatively analyze data from diffusion tensor imaging (DTI) using statistical parametric mapping (SPM) in patients with brain disorders and to assess its potential utility for analyzing brain function. DTI was obtained by performing 3.0-T magnetic resonance imaging for patients with Alzheimer's disease (AD) and vascular dementia (VD), and the data were analyzed using Matlab-based SPM software. The two-sample t-test was used for error analysis of the location of the activated pixels. We compared regions of white matter where the fractional anisotropy (FA) values were low and the apparent diffusion coefficients (ADCs) were increased. In the AD group, the FA values were low in the right superior temporal gyrus, right inferior temporal gyrus, right sub-lobar insula, and right occipital lingual gyrus whereas the ADCs were significantly increased in the right inferior frontal gyrus and right middle frontal gyrus. In the VD group, the FA values were low in the right superior temporal gyrus, right inferior temporal gyrus, right limbic cingulate gyrus, and right sub-lobar caudate tail whereas the ADCs were significantly increased in the left lateral globus pallidus and left medial globus pallidus. In conclusion by using DTI and SPM analysis, we were able to not only determine the structural state of the regions affected by brain disorders but also quantitatively analyze and assess brain function.

Grey matter alterations in patients with Pantothenate Kinase-Associated Neurodegeneration (PKAN).

PubMed

Rodriguez-Raecke, Rea; Roa-Sanchez, Pedro; Speckter, Herwin; Fermin-Delgado, Rafael; Perez-Then, Eddy; Oviedo, Jairo; Stoeter, Peter

2014-09-01

Pantothenate Kinase-Associated Neurodegeneration (PKAN) is a rare heritable disease marked by dystonia and loss of movement control. In contrast to the well-known "Eye-of-the-Tiger" sign affecting the globus pallidus, little is known about other deviations of brain morphology, especially about grey matter changes. We investigated 29 patients with PKAN and 29 age-matched healthy controls using Magnet Resonance Imaging and Voxel-Based Morphometry. As compared to controls, children with PKAN showed increased grey matter density in the putamen and nucleus caudatus and adults with PKAN showed increased grey matter density in the ventral part of the anterior cingulate cortex. A multiple regression analysis with dystonia score as predictor showed grey matter reduction in the cerebellum, posterior cingulate cortex, superior parietal lobule, pars triangularis and small frontal and temporal areas and an analysis with age as predictor showed grey matter decreases in the putamen, nucleus caudatus, supplementary motor area and anterior cingulate cortex. The grey matter increases may be regarded as a secondary phenomenon compensating the increased activity of the motor system due to a reduced inhibitory output of the globus pallidus. With increasing age, the grey matter reduction of cortical midline structures however might contribute to the progression of dystonic symptoms due to loss of this compensatory control. Copyright © 2014 Elsevier Ltd. All rights reserved.

Health risk assessment of hazardous metals for population via consumption of seafood from Ogoniland, Rivers State, Nigeria; a case study of Kaa, B-Dere, and Bodo City.

PubMed

Nkpaa, K W; Patrick-Iwuanyanwu, K C; Wegwu, M O; Essien, E B

2016-01-01

This study was designed to investigate the human health risk through consumption of seafood from contaminated sites in Kaa, B-Dere, and Bodo City all in Ogoniland. The potential non-carcinogenic health risk for consumers were investigated by assessing the estimated daily intake and target hazard quotients for Cr, Cd, Zn, Pb, Mn, and Fe while carcinogenic health effect from Cr, Cd, and Pb was also estimated. The estimated daily intake from seafood consumption was below the threshold values for Cr, Mn, and Zn while they exceeded the threshold for Cd, Pb, and Fe. The target hazard quotients for Zn and Cr were below 1. Target hazard quotients values for Cd, Pb, Mn, and Fe were greater than 1 except for Fe level in Liza falcipinis from Kaa. Furthermore, estimation of carcinogenic risk for Cr in all samples under study exceeded the accepted risk level of 10E-4. Also, Cd carcinogenic risk level for L. falcipinis and Callinectes pallidus collected from B-Dere and C. pallidus collected from Bodo City was 1.1E-3 which also exceeded the accepted risk level of 10E-4 for Cd. Estimation of carcinogenic risk for Pb was within the acceptable range of 10E-4. Consumers of seafood from these sites in Ogoniland may be exposed to metal pollution.

Which factors are associated with global cognitive impairment in Wilson's disease?

PubMed Central

Frota, Norberto Anízio Ferreira; Barbosa, Egberto Reis; Porto, Claudia Sellitto; Lucato, Leandro Tavares; Ono, Carla Rachel; Buchpiguel, Carlos Alberto; Machado, Alexandre Aluizio Costa; Caramelli, Paulo

2016-01-01

Background Patients with Wilson's disease (WD) present cognitive impairment, especially in executive functions. Which other factors might be associated with global cognitive decline in these patients remains unclear. Objective To assess which factors are associated with worse performance on a global cognitive test in patients with WD. Methods Twenty patients with WD underwent cognitive assessment with the following tests: the Mini-Mental State Examination (MMSE), Dementia Rating Scale (DRS), verbal fluency test, brief cognitive battery, clock drawing test, Frontal Assessment Battery, Stroop test, Wisconsin card sorting test, Hopper test, cubes (WAIS) and the Pfeffer questionnaire. MRI changes were quantified. Patients with poor performance on the DRS were compared to patients with normal performance. Results Nine patients had a poor performance on the DRS. This group had lower educational level (9.11±3.58× 12.82±3.06) and a greater number of changes on MRI (9.44±2.74× 6.27±2.45). The presence of hyperintensity in the globus pallidus on MRI was more frequent in this group (66.6% vs 9.0%), with OR=5.38 (95% CI 0.85-33.86). Conclusion Global cognitive impairment was prevalent in this sample of patients with WD and was associated with low educational level, number of changes on MRI and MRI hyperintensity in the globus pallidus. PMID:29213476

Central neural control of thermoregulation and brown adipose tissue.

PubMed

Morrison, Shaun F

2016-04-01

Central neural circuits orchestrate the homeostatic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response. This review summarizes the experimental underpinnings of our current model of the CNS pathways controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction controlling heat loss, and shivering and brown adipose tissue for thermogenesis. The activation of these effectors is regulated by parallel but distinct, effector-specific, core efferent pathways within the CNS that share a common peripheral thermal sensory input. Via the lateral parabrachial nucleus, skin thermal afferent input reaches the hypothalamic preoptic area to inhibit warm-sensitive, inhibitory output neurons which control heat production by inhibiting thermogenesis-promoting neurons in the dorsomedial hypothalamus that project to thermogenesis-controlling premotor neurons in the rostral ventromedial medulla, including the raphe pallidus, that descend to provide the excitation of spinal circuits necessary to drive thermogenic thermal effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus sympathetic premotor neurons controlling cutaneous vasoconstriction. The model proposed for central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation and elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation. Copyright © 2016 Elsevier B.V. All rights reserved.

Structural differences in basal ganglia of elite running versus martial arts athletes: a diffusion tensor imaging study.

PubMed

Chang, Yu-Kai; Tsai, Jack Han-Chao; Wang, Chun-Chih; Chang, Erik Chihhung

2015-07-01

The aim of this study was to use diffusion tensor imaging (DTI) to characterize and compare microscopic differences in white matter integrity in the basal ganglia between elite professional athletes specializing in running and martial arts. Thirty-three young adults with sport-related skills as elite professional runners (n = 11) or elite professional martial artists (n = 11) were recruited and compared with non-athletic and healthy controls (n = 11). All participants underwent health- and skill-related physical fitness assessments. Fractional anisotropy (FA) and mean diffusivity (MD), the primary indices derived from DTI, were computed for five regions of interest in the bilateral basal ganglia, including the caudate nucleus, putamen, globus pallidus internal segment (GPi), globus pallidus external segment (GPe), and subthalamic nucleus. Results revealed that both athletic groups demonstrated better physical fitness indices compared with their control counterparts, with the running group exhibiting the highest cardiovascular fitness and the martial arts group exhibiting the highest muscular endurance and flexibility. With respect to the basal ganglia, both athletic groups showed significantly lower FA and marginally higher MD values in the GPi compared with the healthy control group. These findings suggest that professional sport or motor skill training is associated with changes in white matter integrity in specific regions of the basal ganglia, although these positive changes did not appear to depend on the type of sport-related motor skill being practiced.

Basal Ganglia Neuronal Activity during Scanning Eye Movements in Parkinson’s Disease

PubMed Central

Sieger, Tomáš; Bonnet, Cecilia; Serranová, Tereza; Wild, Jiří; Novák, Daniel; Růžička, Filip; Urgošík, Dušan; Růžička, Evžen; Gaymard, Bertrand; Jech, Robert

2013-01-01

The oculomotor role of the basal ganglia has been supported by extensive evidence, although their role in scanning eye movements is poorly understood. Nineteen Parkinsońs disease patients, which underwent implantation of deep brain stimulation electrodes, were investigated with simultaneous intraoperative microelectrode recordings and single channel electrooculography in a scanning eye movement task by viewing a series of colored pictures selected from the International Affective Picture System. Four patients additionally underwent a visually guided saccade task. Microelectrode recordings were analyzed selectively from the subthalamic nucleus, substantia nigra pars reticulata and from the globus pallidus by the WaveClus program which allowed for detection and sorting of individual neurons. The relationship between neuronal firing rate and eye movements was studied by crosscorrelation analysis. Out of 183 neurons that were detected, 130 were found in the subthalamic nucleus, 30 in the substantia nigra and 23 in the globus pallidus. Twenty percent of the neurons in each of these structures showed eye movement-related activity. Neurons related to scanning eye movements were mostly unrelated to the visually guided saccades. We conclude that a relatively large number of basal ganglia neurons are involved in eye motion control. Surprisingly, neurons related to scanning eye movements differed from neurons activated during saccades suggesting functional specialization and segregation of both systems for eye movement control. PMID:24223158

Patterns of age related changes for phosphodiesterase type-10A in comparison with dopamine D2/3 receptors and sub-cortical volumes in the human basal ganglia: A PET study with 18F-MNI-659 and 11C-raclopride with correction for partial volume effect.

PubMed

Fazio, Patrik; Schain, Martin; Mrzljak, Ladislav; Amini, Nahid; Nag, Sangram; Al-Tawil, Nabil; Fitzer-Attas, Cheryl J; Bronzova, Juliana; Landwehrmeyer, Bernhard; Sampaio, Cristina; Halldin, Christer; Varrone, Andrea

2017-05-15

Phosphodiesterase 10A enzyme (PDE10A) is an important striatal target that has been shown to be affected in patients with neurodegenerative disorders, particularly Huntington´s disease (HD). PDE10A is expressed on striatal neurones in basal ganglia where other known molecular targets are enriched such as dopamine D 2/3 receptors (D 2/3 R). The aim of this study was to examine the availability of PDE10A enzyme in relation with age and gender and to compare those changes with those related to D 2/3 R and volumes in different regions of the basal ganglia. As a secondary objective we examined the relative distribution of D 2/3 R and PDE10A enzyme in the striatum and globus pallidus. Forty control subjects (20F/20M; age: 44±11y, age range 27-69) from an ongoing positron emission tomography (PET) study in HD gene expansion carriers were included. Subjects were examined with PET using the high-resolution research tomograph (HRRT) and with 3T magnetic resonance imaging (MRI). The PDE10A radioligand 18 F-MNI-659 and D 2/3 R radioligand 11 C-raclopride were used. The outcome measure was the binding potential (BP ND ) estimated with the two-tissue compartment model ( 18 F-MNI-659) and the simplified reference tissue model ( 11 C-raclopride) using the cerebellum as reference region. The PET data were corrected for partial volume effects. In the striatum, PDE10A availability showed a significant age-related decline that was larger compared to the age-related decline of D 2/3 R availability and to the age-related decline of volumes measured with MRI. In the globus pallidus, a less pronounced decline of PDE10A availability was observed, whereas D 2/3 R availability and volumes seemed to be rather stable with aging. The distribution of the PDE10A enzyme was different from the distribution of D 2/3 R, with higher availability in the globus pallidus. These results indicate that aging is associated with a considerable physiological reduction of the availability of PDE10A enzyme in

Different mechanisms may generate sustained hypertonic and rhythmic bursting muscle activity in idiopathic dystonia.

PubMed

Liu, Xuguang; Yianni, John; Wang, Shouyan; Bain, Peter G; Stein, John F; Aziz, Tipu Z

2006-03-01

Despite that deep brain stimulation (DBS) of the globus pallidus internus (GPi) is emerging as the favored intervention for patients with medically intractable dystonia, the pathophysiological mechanisms of dystonia are largely unclear. In eight patients with primary dystonia who were treated with bilateral chronic pallidal stimulation, we correlated symptom-related electromyogram (EMG) activity of the most affected muscles with the local field potentials (LFPs) recorded from the globus pallidus electrodes. In 5 dystonic patients with mobile involuntary movements, rhythmic EMG bursts in the contralateral muscles were coherent with the oscillations in the pallidal LFPs at the burst frequency. In contrast, no significant coherence was seen between EMG and LFPs either for the sustained activity separated out from the compound EMGs in those 5 cases, or in the EMGs in 3 other cases without mobile involuntary movements and rhythmic EMG bursts. In comparison with the resting condition, in both active and passive movements, significant modulation in the GPi LFPs was seen in the range of 8-16 Hz. The finding of significant coherence between GPi oscillations and rhythmic EMG bursts but not sustained tonic EMG activity suggests that the synchronized pallidal activity may be directly related to the rhythmic involuntary movements. In contrast, the sustained hypertonic muscle activity may be represented by less synchronized activity in the pallidum. Thus, the pallidum may play different roles in generating different components of the dystonic symptom complex.

Exploring personality traits related to dopamine D2/3 receptor availability in striatal subregions of humans.

PubMed

Caravaggio, Fernando; Fervaha, Gagan; Chung, Jun Ku; Gerretsen, Philip; Nakajima, Shinichiro; Plitman, Eric; Iwata, Yusuke; Wilson, Alan; Graff-Guerrero, Ariel

2016-04-01

While several studies have examined how particular personality traits are related to dopamine D2/3 receptor (D2/3R) availability in the striatum of humans, few studies have reported how multiple traits measured in the same persons are differentially related to D2/3R availability in different striatal sub-regions. We examined how personality traits measured with the Karolinska Scales of Personality are related to striatal D2/3R availability measured with [(11)C]-raclopride in 30 healthy humans. Based on previous the literature, five personality traits were hypothesized to be most likely related to D2/3R availability: impulsiveness, monotony avoidance, detachment, social desirability, and socialization. We found self-reported impulsiveness was negatively correlated with D2/3R availability in the ventral striatum and globus pallidus. After controlling for age and gender, monotony avoidance was also negatively correlated with D2/3R availability in the ventral striatum and globus pallidus. Socialization was positively correlated with D2/3R availability in the ventral striatum and putamen. After controlling for age and gender, the relationship between socialization and D2/3R availability in these regions survived correction for multiple comparisons (p-threshold=.003). Thus, within the same persons, different personality traits are differentially related to in vivo D2/3R availability in different striatal sub-regions. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

Association between genetic risk scoring for schizophrenia and bipolar disorder with regional subcortical volumes.

PubMed

Caseras, X; Tansey, K E; Foley, S; Linden, D

2015-12-08

Previous research has shown coincident abnormal regional brain volume in patients with schizophrenia (SCZ) and bipolar disorder (BD) compared with controls. Whether these abnormalities are genetically driven or explained by secondary effects of the disorder or environmental factors is unknown. We aimed to investigate the association between genetic risk scoring (GRS) for SCZ and BD with volume of brain areas previously shown to be different between these clinical groups and healthy controls. We obtained subcortical brain volume measures and GRS for SCZ and BD from a sample of 274 healthy volunteers (71.4% females, mean age 24.7 (s.d. 6.9)). Volume of the globus pallidus was associated with the shared GRS between SCZ and BD, and also with the independent GRS for each of these disorders. Volume of the amygdala was associated with the non-shared GRS between SCZ and BD, and with the independent GRS for BD. Our results for volume of the globus pallidus support the idea of SCZ and BD sharing a common underlying neurobiological abnormality associated with a common genetic risk for both these disorders. Results for volume of the amygdala, though, would suggest the existence of a distinct mechanism only associated with genetic risk for BD. Finally, the lack of association between genetic risk and volume of most subcortical structures suggests that the volumetric differences reported in patient-control comparisons may not be genetically driven, but a consequence of the disorder or co-occurring environmental factors.

2010 Carl Ludwig Distinguished Lectureship of the APS Neural Control and Autonomic Regulation Section: Central neural pathways for thermoregulatory cold defense

PubMed Central

2011-01-01

Central neural circuits orchestrate the homeostatic repertoire to maintain body temperature during environmental temperature challenges and to alter body temperature during the inflammatory response. This review summarizes the research leading to a model representing our current understanding of the neural pathways through which cutaneous thermal receptors alter thermoregulatory effectors: the cutaneous circulation for control of heat loss, and brown adipose tissue, skeletal muscle, and the heart for thermogenesis. The activation of these effectors is regulated by parallel but distinct, effector-specific core efferent pathways within the central nervous system (CNS) that share a common peripheral thermal sensory input. The thermal afferent circuit from cutaneous thermal receptors includes neurons in the spinal dorsal horn projecting to lateral parabrachial nucleus neurons that project to the medial aspect of the preoptic area. Within the preoptic area, warm-sensitive, inhibitory output neurons control heat production by reducing the discharge of thermogenesis-promoting neurons in the dorsomedial hypothalamus. The rostral ventromedial medulla, including the raphe pallidus, receives projections form the dorsomedial hypothalamus and contains spinally projecting premotor neurons that provide the excitatory drive to spinal circuits controlling the activity of thermogenic effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus sympathetic premotor neurons controlling cutaneous vasoconstriction. The model proposed for central thermoregulatory control provides a platform for further understanding of the functional organization of central thermoregulation. PMID:21270352

Isolation of a thermophilic and halophilic tyrosol-degrading Geobacillus from a Tunisian high-temperature oil field.

PubMed

Chamkha, Mohamed; Mnif, Sami; Sayadi, Sami

2008-06-01

An aerobic, thermophilic, halotolerant and Gram-positive bacterium, designated strain C5, was isolated from a high-temperature oil field, located in Sfax, Tunisia, after enrichment on tyrosol. Strain C5 grew between 25 and 70 degrees C and optimally at 50 degrees C. It grew in the presence of 0-12% (w/v) NaCl, with optimum growth at 3% (w/v) NaCl. Strain C5 was able to degrade tyrosol aerobically, in the presence of 30 g L(-1) NaCl and under warm conditions (55 degrees C). The degradation of tyrosol proceeded via p-hydroxyphenylacetic and 3,4-dihydroxyphenylacetic acids. The products were confirmed by HPLC and GC-MS analyses. Strain C5 was also found to degrde a wide range of other aromatic compounds, including benzoic, p-hydroxybenzoic, protocatechuic, vanillic, p-hydroxyphenylacetic, 3,4-dihydroxyphenylacetic, cinnamic and ferulic acids, phenol and m-cresol. Moreover, strain C5 was grown on diesel and crude oil as sole carbon and energy sources. Strain C5 was also able to utilize several carbohydrates. Phenotypic characteristics and phylogenetic analysis of the 16S rRNA gene sequence of strain C5 revealed that it was related to members of the genus Geobacillus, being most closely related to the type strain of G. pallidus (99% sequence similarity). In addition, we report on growth of the type strain of G. pallidus on different aromatic compounds and hydrocarbons.

Damage in the dorsal striatum alleviates addictive behavior.

PubMed

Muskens, J B; Schellekens, A F A; de Leeuw, F E; Tendolkar, I; Hepark, S

2012-01-01

The ventral striatum has been assigned a major role in addictive behavior. In addition, clinical lesion studies have described involvement of the insula and globus pallidus. To the best of our knowledge, this is the first report of alleviation of alcohol and nicotine addiction after a cerebrovascular incident in the dorsal striatum. The patient was still abstinent from alcohol and nicotine at follow-up. This observation suggests that the dorsal striatum may play a critical role in addiction to alcohol and nicotine. Copyright © 2012 Elsevier Inc. All rights reserved.

Clinical and neuropathological findings of acute carbon monoxide toxicity in chihuahuas following smoke inhalation.

PubMed

Kent, Marc; Creevy, Kate E; Delahunta, Alexander

2010-01-01

Three adult Chihuahuas were presented for evaluation after smoke inhalation during a house fire. All three dogs received supportive care and supplemental oxygen. After initial improvement, the dogs developed seizures. Despite anticonvulsant therapy and supportive care, the dogs died. The brains of two dogs were examined. Lesions were identified that were compatible with acute carbon monoxide (CO) toxicity. Lesions were confined to the caudate nucleus, the globus pallidus, and the substantia nigra bilaterally, as well as the cerebellum, cerebral cortex, and dorsal thalamus. This case report describes the clinicopathological sequelae in acute CO toxicity.

Iron Concentration in Deep Gray Matter Structures is Associated with Worse Visual Memory Performance in Healthy Young Adults

PubMed Central

Darnai, Gergely; Nagy, Szilvia Anett; Horváth, Réka; Ács, Péter; Perlaki, Gábor; Orsi, Gergely; Kovács, Norbert; Altbäcker, Anna; Plózer, Enikő; Tényi, Dalma; Weintraut, Rita; Schwarcz, Attila; John, Flóra; Varga, Eszter; Bereczkei, Tamás; Clemens, Zsófia; Komoly, Sámuel; Janszky, József

2017-01-01

Abnormally high deposition of iron can contribute to neurodegenerative disorders with cognitive impairment. Since previous studies investigating cognition-brain iron accumulation relationships focused on elderly people, our aim was to explore the association between iron concentration in subcortical nuclei and two types of memory performances in a healthy young population. Gender difference was found only in the globus pallidus. Our results showed that iron load characterized by R2* value on the MRI in the caudate and putamen was related to visual memory, while verbal memory was unrelated to iron concentration. PMID:28671115

New data on Pleistocene and Holocene herpetofauna of Marie Galante (Blanchard Cave, Guadeloupe Islands, French West Indies): Insular faunal turnover and human impact

NASA Astrophysics Data System (ADS)

Bailon, S.; Bochaton, C.; Lenoble, A.

2015-11-01

This work presents the herpetofaunal remains collected from Blanchard Cave (Marie-Galante, Guadeloupe Archipelago). This site has yielded the oldest stratigraphic layers (around 40,000 BP) of the island, along with data concerning the herpetofaunal biodiversity of the island from the Late Pleistocene to pre-Columbian and modern times. The study of these fossil remains reveals the presence of at least 11 amphibian and squamata taxa (Eleutherodactylus cf. martinicensis, Iguana sp., Anolis ferreus, Leiocephalus cf. cuneus, Thecadactylus cf. rapicauda, cf. Capitellum mariagalantae, Ameiva sp., cf. Antillotyphlops, Boa sp., Alsophis sp. and Colubridae sp. 2) during the Late Pleistocene and Holocene on Marie-Galante Island and provides new evidence concerning extinction times and the introduced or native status of taxa. This study also reveals that this bone assemblage is the result of diverse accumulation processes and provides new morphological data on the past herpetofauna of Marie-Galante.

Reptiles and Amphibians as Potential Reservoir Hosts of Chikungunya Virus.

PubMed

Bosco-Lauth, Angela M; Hartwig, Airn E; Bowen, Richard A

2018-03-01

Chikungunya virus is an emerging arbovirus of significant human-health concern. Little is known about its sylvatic cycle, including whether ectothermic vertebrates are permissive to infection. In this study, individuals from ten species of reptiles and amphibians were inoculated with chikungunya virus and samples of blood were tested to characterize viremia and seroconversion. Viremia was not detected in cane toads, house geckos, or American alligators, but most of the green iguanas, red-eared sliders, ball and Burmese pythons, leopard frogs, Texas toads, and garter snakes developed viremia. Peak virus titers in serum of up to 4.5, 4.7, and 5.1 log 10 plaque-forming units per milliliter were observed for garter snakes, ball pythons, and Texas toads, respectively. These results add to those of other studies that have suggested a possible role for ectothermic vertebrates in the ecology of arbovirus maintenance and transmission in nature.

Cortical stimulation evokes abnormal responses in the dopamine-depleted rat basal ganglia.

PubMed

Kita, Hitoshi; Kita, Takako

2011-07-13

The motor cortex (MC) sends massive projections to the basal ganglia. Motor disabilities in patients and animal models of Parkinson's disease (PD) may be caused by dopamine (DA)-depleted basal ganglia that abnormally process the information originating from MC. To study how DA depletion alters signal transfer in the basal ganglia, MC stimulation-induced (MC-induced) unitary responses were recorded from the basal ganglia of control and 6-hydroxydopamine-treated hemi-parkinsonian rats anesthetized with isoflurane. This report describes new findings about how DA depletion alters MC-induced responses. MC stimulation evokes an excitation in normally quiescent striatal (Str) neurons projecting to the globus pallidus external segment (GPe). After DA-depletion, the spontaneous firing of Str-GPe neurons increases, and MC stimulation evokes a shorter latency excitation followed by a long-lasting inhibition that was invisible under normal conditions. The increased firing activity and the newly exposed long inhibition generate tonic inhibition and a disfacilitation in GPe. The disfacilitation in GPe is then amplified in basal ganglia circuitry and generates a powerful long inhibition in the basal ganglia output nucleus, the globus pallidus internal segment. Intra-Str injections of a behaviorally effective dose of DA precursor l-3,4-dihydroxyphenylalanine effectively reversed these changes. These newly observed mechanisms also support the generation of pauses and burst activity commonly observed in the basal ganglia of parkinsonian subjects. These results suggest that the generation of abnormal response sequences in the basal ganglia contributes to the development of motor disabilities in PD and that intra-Str DA supplements effectively suppress abnormal signal transfer.

Meta-analysis of functional brain imaging in specific phobia.

PubMed

Ipser, Jonathan C; Singh, Leesha; Stein, Dan J

2013-07-01

Although specific phobia is a prevalent anxiety disorder, evidence regarding its underlying functional neuroanatomy is inconsistent. A meta-analysis was undertaken to identify brain regions that were consistently responsive to phobic stimuli, and to characterize changes in brain activation following cognitive behavioral therapy (CBT). We searched the PubMed, SCOPUS and PsycINFO databases to identify positron emission tomography and functional magnetic resonance imaging studies comparing brain activation in specific phobia patients and healthy controls. Two raters independently extracted study data from all the eligible studies, and pooled coordinates from these studies using activation likelihood estimation, a quantitative meta-analytic technique. Resulting statistical parametric maps were compared between patients and healthy controls, in response to phobic versus fear-evoking stimuli, and before and after therapy. Thirteen studies were included, comprising 327 participants. Regions that were consistently activated in response to phobic stimuli included the left insula, amygdala, and globus pallidus. Compared to healthy controls, phobic subjects had increased activation in response to phobic stimuli in the left amygdala/globus pallidus, left insula, right thalamus (pulvinar), and cerebellum. Following exposure-based therapy widespread deactivation was observed in the right frontal cortex, limbic cortex, basal ganglia and cerebellum, with increased activation detected in the thalamus. Exposure to phobia-specific stimuli elicits brain activation that is consistent with current understandings of the neuroanatomy of fear conditioning and extinction. There is evidence that the effects of CBT in specific phobia may be mediated through the same underlying neurocircuitry. © 2013 The Authors. Psychiatry and Clinical Neurosciences © 2013 Japanese Society of Psychiatry and Neurology.

Cannabis-Related Working Memory Deficits and Associated Subcortical Morphological Differences in Healthy Individuals and Schizophrenia Subjects

PubMed Central

Smith, Matthew J.

2014-01-01

Cannabis use is associated with working memory (WM) impairments; however, the relationship between cannabis use and WM neural circuitry is unclear. We examined whether a cannabis use disorder (CUD) was associated with differences in brain morphology between control subjects with and without a CUD and between schizophrenia subjects with and without a CUD, and whether these differences related to WM and CUD history. Subjects group-matched on demographics included 44 healthy controls, 10 subjects with a CUD history, 28 schizophrenia subjects with no history of substance use disorders, and 15 schizophrenia subjects with a CUD history. Large-deformation high-dimensional brain mapping with magnetic resonance imaging was used to obtain surface-based representations of the striatum, globus pallidus, and thalamus, compared across groups, and correlated with WM and CUD history. Surface maps were generated to visualize morphological differences. There were significant cannabis-related parametric decreases in WM across groups. Similar cannabis-related shape differences were observed in the striatum, globus pallidus, and thalamus in controls and schizophrenia subjects. Cannabis-related striatal and thalamic shape differences correlated with poorer WM and younger age of CUD onset in both groups. Schizophrenia subjects demonstrated cannabis-related neuroanatomical differences that were consistent and exaggerated compared with cannabis-related differences found in controls. The cross-sectional results suggest that both CUD groups were characterized by WM deficits and subcortical neuroanatomical differences. Future longitudinal studies could help determine whether cannabis use contributes to these observed shape differences or whether they are biomarkers of a vulnerability to the effects of cannabis that predate its misuse. PMID:24342821

Multifaceted impairments in impulsivity and brain structural abnormalities in opioid dependence and abstinence.

PubMed

Tolomeo, S; Gray, S; Matthews, K; Steele, J D; Baldacchino, A

2016-10-01

Chronic opioid exposure, as a treatment for a variety of disorders or as drug of misuse, is common worldwide, but behavioural and brain abnormalities remain under-investigated. Only a small percentage of patients who receive methadone maintenance treatment (MMT) for previous heroin misuse eventually achieve abstinence and studies on such patients are rare. The Cambridge Neuropsychological Test Automated Battery and T1 weighted magnetic resonance imaging (MRI) were used to study a cohort of 122 male individuals: a clinically stable opioid-dependent patient group receiving MMT (n = 48), an abstinent previously MMT maintained group (ABS) (n = 24) and healthy controls (n = 50). Stable MMT participants deliberated longer and placed higher bets earlier in the Cambridge Gambling Task (CGT) and showed impaired strategic planning compared with healthy controls. In contrast, ABS participants showed impairment in choosing the least likely outcome, delay aversion and risk adjustment on the CGT, and exhibited non-planning impulsivity compared with controls. MMT patients had widespread grey matter reductions in the orbitomedial prefrontal cortex, caudate, putamen and globus pallidus. In contrast, ABS participants showed midbrain-thalamic grey matter reductions. A higher methadone dose at the time of scanning was associated with a smaller globus pallidus in the MMT group. Our findings support an interpretation of heightened impulsivity in patients receiving MMT. Widespread structural brain abnormalities in the MMT group and reduced brain structural abnormality with abstinence suggest benefit of cessation of methadone intake. We suggest that a longitudinal study is required to determine whether abstinence improves abnormalities, or patients who achieve abstinence have reduced abnormalities before methadone cessation.

Unilateral lenticular infarcts: radiological and clinical syndromes, aetiology, and prognosis

PubMed Central

Giroud, M; Lemesle, M; Madinier, G; Billiar, T.; Dumas, R

1997-01-01

OBJECTIVES—To analyse the clinical features induced by lenticular infarction found in 20 patients, and to analyse the radiological and clinical correlations.
METHODS—Eight women and 12 men, mean age 73 years, were included in this study, which was carried out from 1 January 1994 to 30 November 1996. They were characterised by the onset of a lenticular infarction, shown by CT and MRI. A complete neurological and neurocognitive examination, and photon emission computed tomography (SPECT), were performed in all the patients and there was a long clinical follow up.
RESULTS—Two distinct clinical syndromes were identified corresponding to the two anatomical areas of the lenticular nucleus: behavioural and cognitive disorders were associated with infarcts within the globus pallidus, whereas both motor disorders (dystonia) and cognitive disorders were associated with infarcts within the putamen. Outcome was excellent in all the patients for motor function, but slight cognitive disorders, problems with short term memory, and dysphasia persisted for several months. The size of the lesion did not explain these symptoms. By contrast, the slight reduction in cerebral blood flow found in the adjacent frontotemporal area may explain them by a deafferentation or a diaschisis phenomenon.
CONCLUSION—It is possible to identify the clinical symptoms of a single lesion in the pallidus nucleus and in the putaminal nucleus, in which behavioural, cognitive, and movements disorders are important. After an acute and spectacular onset, outcome is in general excellent. A disease of the small arteries must be involved.

 PMID:9408102

Acute infarction limited to the lenticular nucleus: clinical, etiologic, and topographic features.

PubMed

Russmann, Heike; Vingerhoets, François; Ghika, Joseph; Maeder, Philippe; Bogousslavsky, Julien

2003-03-01

Chronic diseases involving the putamen and globus pallidus induce parkinsonism and other movement disorders. Sensory and motor dysfunction from deep middle cerebral artery infarction is usually due to an involvement of the internal capsule. The clinical picture associated with isolated infarction of the lenticular nucleus is less well established. To analyze clinical features, topographic correlations, and cause of purely lenticular ischemic infarction. We reviewed 820 consecutive patients with deep hemispheral infarct included in the Lausanne Stroke Registry between 1986 and 1998 and selected those with isolated lenticular involvement on computed tomography or magnetic resonance imaging. Thirteen patients had pure lenticular infarction. All had faciobrachiocrural hemisyndrome, while none showed acute or delayed parkinsonism or abnormal movement. Nine patients had a lesion restricted to the putamen. Two of them had ataxic motor hemisyndrome and 7 had sensorimotor hemisyndrome (with ataxia in 4, left hemineglect in 1, and deep pain in the arm and leg in 1). Four patients had a lesion of putamen and globus pallidus externus. Three of them had motor hemisyndrome (with nonfluent aphasia in 2 and ataxia in 1) and 1 had ataxic sensorimotor hemisyndrome. All infarcts were in the territory of the medial perforating branches of the medial cerebral artery. Presumed cause of stroke was small-artery disease in 5, artery-to-artery embolism in 4, cardioembolism in 3 and undetermined in 1. Acute lenticular infarction induces mainly hemiparesis but no movement disorder. Associated sensory deficits, aphasia, and hemineglect underline clinically the function of the lenticular nucleus in connection with the prefrontal, temporal, and parietal cortices.

[18F]fallypride characterization of striatal and extrastriatal D2/3 receptors in Parkinson's disease.

PubMed

Stark, Adam J; Smith, Christopher T; Petersen, Kalen J; Trujillo, Paula; van Wouwe, Nelleke C; Donahue, Manus J; Kessler, Robert M; Deutch, Ariel Y; Zald, David H; Claassen, Daniel O

2018-01-01

Parkinson's disease (PD) is characterized by widespread degeneration of monoaminergic (especially dopaminergic) networks, manifesting with a number of both motor and non-motor symptoms. Regional alterations to dopamine D 2/3 receptors in PD patients are documented in striatal and some extrastriatal areas, and medications that target D 2/3 receptors can improve motor and non-motor symptoms. However, data regarding the combined pattern of D 2/3 receptor binding in both striatal and extrastriatal regions in PD are limited. We studied 35 PD patients off-medication and 31 age- and sex-matched healthy controls (HCs) using PET imaging with [ 18 F]fallypride, a high affinity D 2/3 receptor ligand, to measure striatal and extrastriatal D 2/3 nondisplaceable binding potential (BP ND ). PD patients completed PET imaging in the off medication state, and motor severity was concurrently assessed. Voxel-wise evaluation between groups revealed significant BP ND reductions in PD patients in striatal and several extrastriatal regions, including the locus coeruleus and mesotemporal cortex. A region-of-interest (ROI) based approach quantified differences in dopamine D 2/3 receptors, where reduced BP ND was noted in the globus pallidus, caudate, amygdala, hippocampus, ventral midbrain, and thalamus of PD patients relative to HC subjects. Motor severity positively correlated with D 2/3 receptor density in the putamen and globus pallidus. These findings support the hypothesis that abnormal D 2/3 expression occurs in regions related to both the motor and non-motor symptoms of PD, including areas richly invested with noradrenergic neurons.

Cannabis-related working memory deficits and associated subcortical morphological differences in healthy individuals and schizophrenia subjects.

PubMed

Smith, Matthew J; Cobia, Derin J; Wang, Lei; Alpert, Kathryn I; Cronenwett, Will J; Goldman, Morris B; Mamah, Daniel; Barch, Deanna M; Breiter, Hans C; Csernansky, John G

2014-03-01

Cannabis use is associated with working memory (WM) impairments; however, the relationship between cannabis use and WM neural circuitry is unclear. We examined whether a cannabis use disorder (CUD) was associated with differences in brain morphology between control subjects with and without a CUD and between schizophrenia subjects with and without a CUD, and whether these differences related to WM and CUD history. Subjects group-matched on demographics included 44 healthy controls, 10 subjects with a CUD history, 28 schizophrenia subjects with no history of substance use disorders, and 15 schizophrenia subjects with a CUD history. Large-deformation high-dimensional brain mapping with magnetic resonance imaging was used to obtain surface-based representations of the striatum, globus pallidus, and thalamus, compared across groups, and correlated with WM and CUD history. Surface maps were generated to visualize morphological differences. There were significant cannabis-related parametric decreases in WM across groups. Similar cannabis-related shape differences were observed in the striatum, globus pallidus, and thalamus in controls and schizophrenia subjects. Cannabis-related striatal and thalamic shape differences correlated with poorer WM and younger age of CUD onset in both groups. Schizophrenia subjects demonstrated cannabis-related neuroanatomical differences that were consistent and exaggerated compared with cannabis-related differences found in controls. The cross-sectional results suggest that both CUD groups were characterized by WM deficits and subcortical neuroanatomical differences. Future longitudinal studies could help determine whether cannabis use contributes to these observed shape differences or whether they are biomarkers of a vulnerability to the effects of cannabis that predate its misuse.

Iron deposits in post-mortem brains of patients with neurodegenerative and cerebrovascular diseases: a semi-quantitative 7.0 T magnetic resonance imaging study.

PubMed

De Reuck, J L; Deramecourt, V; Auger, F; Durieux, N; Cordonnier, C; Devos, D; Defebvre, L; Moreau, C; Caparros-Lefebvre, D; Leys, D; Maurage, C A; Pasquier, F; Bordet, R

2014-07-01

Accumulation of iron (Fe) is often detected in brains of people suffering from neurodegenerative diseases. However, no studies have compared the Fe load between these disease entities. The present study investigates by T2*-weighted gradient-echo 7.0 T magnetic resonance imaging (MRI) the Fe content in post-mortem brains with different neurodegenerative and cerebrovascular diseases. One hundred and fifty-two post-mortem brains, composed of 46 with Alzheimer's disease (AD), 37 with frontotemporal lobar degeneration (FTLD), 11 with amyotrophic lateral sclerosis, 13 with Lewy body disease, 14 with progressive supranuclear palsy, 16 with vascular dementia (VaD) and 15 controls without a brain disease, were examined. The Fe load was determined semi-quantitatively on T2*-weighted MRI serial brain sections in the claustrum, caudate nucleus, putamen, globus pallidus, thalamus, subthalamic nucleus, hippocampus, mamillary body, lateral geniculate body, red nucleus, substantia nigra and dentate nucleus. The disease diagnosis was made on subsequent neuropathological examination. The Fe load was significantly increased in the claustrum, caudate nucleus and putamen of FTLD brains and to a lesser degree in the globus pallidus, thalamus and subthalamic nucleus. In the other neurodegenerative diseases no Fe accumulation was observed, except for a mild increase in the caudate nucleus of AD brains. In VaD brains no Fe increase was detected. Only FTLD displays a significant Fe load, suggesting that impaired Fe homeostasis plays an important role in the pathogenesis of this heterogeneous disease entity. © 2014 The Author(s) European Journal of Neurology © 2014 EAN.

Efficient digital implementation of a conductance-based globus pallidus neuron and the dynamics analysis

NASA Astrophysics Data System (ADS)

Yang, Shuangming; Wei, Xile; Deng, Bin; Liu, Chen; Li, Huiyan; Wang, Jiang

2018-03-01

Balance between biological plausibility of dynamical activities and computational efficiency is one of challenging problems in computational neuroscience and neural system engineering. This paper proposes a set of efficient methods for the hardware realization of the conductance-based neuron model with relevant dynamics, targeting reproducing the biological behaviors with low-cost implementation on digital programmable platform, which can be applied in wide range of conductance-based neuron models. Modified GP neuron models for efficient hardware implementation are presented to reproduce reliable pallidal dynamics, which decode the information of basal ganglia and regulate the movement disorder related voluntary activities. Implementation results on a field-programmable gate array (FPGA) demonstrate that the proposed techniques and models can reduce the resource cost significantly and reproduce the biological dynamics accurately. Besides, the biological behaviors with weak network coupling are explored on the proposed platform, and theoretical analysis is also made for the investigation of biological characteristics of the structured pallidal oscillator and network. The implementation techniques provide an essential step towards the large-scale neural network to explore the dynamical mechanisms in real time. Furthermore, the proposed methodology enables the FPGA-based system a powerful platform for the investigation on neurodegenerative diseases and real-time control of bio-inspired neuro-robotics.

Magnetic resonance spectroscopic study of parkinsonism related to boxing.

PubMed

Davie, C A; Pirtosek, Z; Barker, G J; Kingsley, D P; Miller, P H; Lees, A J

1995-06-01

Proton magnetic resonance spectroscopy, localised to the lentiform nucleus, was carried out in three ex-professional boxers who developed a parkinsonian syndrome, six patients with idiopathic Parkinson's disease, and six age matched controls. The three ex-boxers all showed a pronounced reduction in the absolute concentration of N-acetylaspartate compared with the patients with idiopathic Parkinson's disease and the control group. This reduction is likely to reflect neuronal loss occurring in the putamen and globus pallidus and supports the hypothesis that the extrapyramidal syndrome that may occur in ex-boxers is a distinct entity from idiopathic Parkinson's disease.

Magnetic resonance spectroscopic study of parkinsonism related to boxing.

PubMed Central

Davie, C A; Pirtosek, Z; Barker, G J; Kingsley, D P; Miller, P H; Lees, A J

1995-01-01

Proton magnetic resonance spectroscopy, localised to the lentiform nucleus, was carried out in three ex-professional boxers who developed a parkinsonian syndrome, six patients with idiopathic Parkinson's disease, and six age matched controls. The three ex-boxers all showed a pronounced reduction in the absolute concentration of N-acetylaspartate compared with the patients with idiopathic Parkinson's disease and the control group. This reduction is likely to reflect neuronal loss occurring in the putamen and globus pallidus and supports the hypothesis that the extrapyramidal syndrome that may occur in ex-boxers is a distinct entity from idiopathic Parkinson's disease. Images PMID:7608666

A parvovirus isolated from royal python (Python regius) is a member of the genus Dependovirus.

PubMed

Farkas, Szilvia L; Zádori, Zoltán; Benko, Mária; Essbauer, Sandra; Harrach, Balázs; Tijssen, Peter

2004-03-01

Parvoviruses were isolated from Python regius and Boa constrictor snakes and propagated in viper heart (VH-2) and iguana heart (IgH-2) cells. The full-length genome of a snake parvovirus was cloned and both strands were sequenced. The organization of the 4432-nt-long genome was found to be typical of parvoviruses. This genome was flanked by inverted terminal repeats (ITRs) of 154 nt, containing 122 nt terminal hairpins and contained two large open reading frames, encoding the non-structural and structural proteins. Genes of this new parvovirus were most similar to those from waterfowl parvoviruses and from adeno-associated viruses (AAVs), albeit to a relatively low degree and with some organizational differences. The structure of its ITRs also closely resembled those of AAVs. Based on these data, we propose to classify this virus, the first serpentine parvovirus to be identified, as serpentine adeno-associated virus (SAAV) in the genus Dependovirus.

New Entamoeba group in howler monkeys (Alouatta spp.) associated with parasites of reptiles.

PubMed

Villanueva-García, Claudia; Gordillo-Chávez, Elías José; Baños-Ojeda, Carlos; Rendón-Franco, Emilio; Muñoz-García, Claudia Irais; Carrero, Julio César; Córdoba-Aguilar, Alex; Maravilla, Pablo; Galian, José; Martínez-Hernández, Fernando; Villalobos, Guiehdani

2017-08-01

Our knowledge of the parasite species present in wildlife hosts is incomplete. Protozoans such as amoebae of the genus Entamoeba infect a large variety of vertebrate species, including NHPs. However, traditionally, their identification has been accomplished through microscopic evaluation; therefore, amoeba species have not always been identified correctly. We searched for Entamoeba spp. using a fragment of the small subunit rDNA in free-ranging howler monkeys (Alouatta palliata and A. pigra) from southeast Mexico. One hundred fifty five samples were collected, with 46 from A. palliata and 109 from A. pigra and 8 of the total samples were positive. We detected a new clade of Entamoeba, which was separated from other described species but closer to E. insolita, as well as an unnamed sequence typically found in iguana species with low shared identity values (<90%). We designated this new clade as conditional lineage 8 (CL8) and we have shown that members of this group are not exclusive to reptiles.

Salmonella serotypes in reptiles and humans, French Guiana.

PubMed

Gay, Noellie; Le Hello, Simon; Weill, François-Xavier; de Thoisy, Benoit; Berger, Franck

2014-05-14

In French Guiana, a French overseas territory located in the South American northern coast, nearly 50% of Salmonella serotypes isolated from human infections belong to serotypes rarely encountered in metropolitan France. A reptilian source of contamination has been investigated. Between April and June 2011, in the area around Cayenne, 151 reptiles were collected: 38 lizards, 37 snakes, 32 turtles, 23 green iguanas and 21 caimans. Cloacal swab samples were collected and cultured. Isolated Salmonella strains were identified biochemically and serotyped. The overall carriage frequency of carriage was 23.2% (95% confidence interval: 16.7-30.4) with 23 serotyped strains. The frequency of Salmonella carriage was significantly higher for wild reptiles. Near two-thirds of the Salmonella serotypes isolated from reptiles were also isolated from patients in French Guiana. Our results highlight the risk associated with the handling and consumption of reptiles and their role in the spread of Salmonella in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Conservation of sex chromosomes in lacertid lizards.

PubMed

Rovatsos, Michail; Vukić, Jasna; Altmanová, Marie; Johnson Pokorná, Martina; Moravec, Jiří; Kratochvíl, Lukáš

2016-07-01

Sex chromosomes are believed to be stable in endotherms, but young and evolutionary unstable in most ectothermic vertebrates. Within lacertids, the widely radiated lizard group, sex chromosomes have been reported to vary in morphology and heterochromatinization, which may suggest turnovers during the evolution of the group. We compared the partial gene content of the Z-specific part of sex chromosomes across major lineages of lacertids and discovered a strong evolutionary stability of sex chromosomes. We can conclude that the common ancestor of lacertids, living around 70 million years ago (Mya), already had the same highly differentiated sex chromosomes. Molecular data demonstrating an evolutionary conservation of sex chromosomes have also been documented for iguanas and caenophidian snakes. It seems that differences in the evolutionary conservation of sex chromosomes in vertebrates do not reflect the distinction between endotherms and ectotherms, but rather between amniotes and anamniotes, or generally, the differences in the life history of particular lineages. © 2016 John Wiley & Sons Ltd.

Magnetic Susceptibility Changes in the Basal Ganglia and Brain Stem of Patients with Wilson's Disease: Evaluation with Quantitative Susceptibility Mapping.

PubMed

Doganay, Selim; Gumus, Kazim; Koc, Gonca; Bayram, Ayse Kacar; Dogan, Mehmet Sait; Arslan, Duran; Gumus, Hakan; Gorkem, Sureyya Burcu; Ciraci, Saliha; Serin, Halil Ibrahim; Coskun, Abdulhakim

2018-01-10

Wilson's disease (WD) is characterized with the accumulation of copper in the liver and brain. The objective of this study is to quantitatively measure the susceptibility changes of basal ganglia and brain stem of pediatric patients with neurological WD using quantitative susceptibility mapping (QSM) in comparison to healthy controls. Eleven patients with neurological WD (mean age 15 ± 3.3 years, range 10-22 years) and 14 agematched controls were prospectively recruited. Both groups were scanned on a 1.5 Tesla clinical scanner. In addition to T 1 - and T 2 -weighted MR images, a 3D multi-echo spoiled gradient echo (GRE) sequence was acquired and QSM images were derived offline. The quantitative measurement of susceptibility of corpus striatum, thalamus of each hemisphere, midbrain, and pons were assessed with the region of interest analysis on the QSM images. The susceptibility values for the patient and control groups were compared using twosample t-test. One patient with WD had T 1 shortening in the bilateral globus pallidus. Another one had hyperintensity in the bilateral putamen, caudate nuclei, and substantia nigra on T 2 -weighted images. The rest of the patients with WD and all subjects of the control group had no signal abnormalities on conventional MR images. The susceptibility measures of right side of globus pallidus, putamen, thalamus, midbrain, and entire pons were significantly different in patients compared to controls (P < 0.05). QSM method exhibits increased susceptibility differences of basal ganglia and brain stem in patients with WD that have neurologic impairment even if no signal alteration is detected on T 1 - and T 2 -weighted MR images.

External pallidal stimulation improves parkinsonian motor signs and modulates neuronal activity throughout the basal ganglia thalamic network.

PubMed

Vitek, Jerrold L; Zhang, Jianyu; Hashimoto, Takao; Russo, Gary S; Baker, Kenneth B

2012-01-01

Deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) and the subthalamic nucleus (STN) are effective for the treatment of advanced Parkinson's disease (PD). We have shown previously that DBS of the external segment of the globus pallidus (GPe) is associated with improvements in parkinsonian motor signs; however, the mechanism of this effect is not known. In this study, we extend our findings on the effect of STN and GPi DBS on neuronal activity in the basal ganglia thalamic network to include GPe DBS using the 1-methyl-4-phenyl-1.2.3.6-tetrahydropyridine (MPTP) monkey model. Stimulation parameters that improved bradykinesia were associated with changes in the pattern and mean discharge rate of neuronal activity in the GPi, STN, and the pallidal [ventralis lateralis pars oralis (VLo) and ventralis anterior (VA)] and cerebellar [ventralis lateralis posterior pars oralis (VPLo)] receiving areas of the motor thalamus. Population post-stimulation time histograms revealed a complex pattern of stimulation-related inhibition and excitation for the GPi and VA/VLo, with a more consistent pattern of inhibition in STN and excitation in VPLo. Mean discharge rate was reduced in the GPi and STN and increased in the VPLo. Effective GPe DBS also reduced bursting in the STN and GPi. These data support the hypothesis that therapeutic DBS activates output from the stimulated structure and changes the temporal pattern of neuronal activity throughout the basal ganglia thalamic network and provide further support for GPe as a potential therapeutic target for DBS in the treatment of PD. Copyright © 2011 Elsevier Inc. All rights reserved.

Multi-modal and targeted imaging improves automated mid-brain segmentation

NASA Astrophysics Data System (ADS)

Plassard, Andrew J.; D'Haese, Pierre F.; Pallavaram, Srivatsan; Newton, Allen T.; Claassen, Daniel O.; Dawant, Benoit M.; Landman, Bennett A.

2017-02-01

The basal ganglia and limbic system, particularly the thalamus, putamen, internal and external globus pallidus, substantia nigra, and sub-thalamic nucleus, comprise a clinically relevant signal network for Parkinson's disease. In order to manually trace these structures, a combination of high-resolution and specialized sequences at 7T are used, but it is not feasible to scan clinical patients in those scanners. Targeted imaging sequences at 3T such as F-GATIR, and other optimized inversion recovery sequences, have been presented which enhance contrast in a select group of these structures. In this work, we show that a series of atlases generated at 7T can be used to accurately segment these structures at 3T using a combination of standard and optimized imaging sequences, though no one approach provided the best result across all structures. In the thalamus and putamen, a median Dice coefficient over 0.88 and a mean surface distance less than 1.0mm was achieved using a combination of T1 and an optimized inversion recovery imaging sequences. In the internal and external globus pallidus a Dice over 0.75 and a mean surface distance less than 1.2mm was achieved using a combination of T1 and FGATIR imaging sequences. In the substantia nigra and sub-thalamic nucleus a Dice coefficient of over 0.6 and a mean surface distance of less than 1.0mm was achieved using the optimized inversion recovery imaging sequence. On average, using T1 and optimized inversion recovery together produced significantly improved segmentation results than any individual modality (p<0.05 wilcox sign-rank test).

Resting-State Pallidal-Cortical Oscillatory Couplings in Patients With Predominant Phasic and Tonic Dystonia.

PubMed

Yokochi, Fusako; Kato, Kenji; Iwamuro, Hirokazu; Kamiyama, Tsutomu; Kimura, Katsuo; Yugeta, Akihiro; Okiyama, Ryoichi; Taniguchi, Makoto; Kumada, Satoko; Ushiba, Junichi

2018-01-01

Pallidal deep brain stimulation (DBS) improves the symptoms of dystonia. The improvement processes of dystonic movements (phasic symptoms) and tonic symptoms differ. Phasic symptoms improve rapidly after starting DBS treatment, but tonic symptoms improve gradually. This difference implies distinct neuronal mechanisms for phasic and tonic symptoms in the underlying cortico-basal ganglia neuronal network. Phasic symptoms are related to the pallido-thalamo-cortical pathway. The pathway related to tonic symptoms has been assumed to be different from that for phasic symptoms. In the present study, local field potentials of the globus pallidus internus (GPi) and globus pallidus externus (GPe) and electroencephalograms from the motor cortex (MCx) were recorded in 19 dystonia patients to analyze the differences between the two types of symptoms. The 19 patients were divided into two groups, 10 with predominant phasic symptoms (phasic patients) and 9 with predominant tonic symptoms (tonic patients). To investigate the distinct features of oscillations and functional couplings across the GPi, GPe, and MCx by clinical phenotype, power and coherence were calculated over the delta (2-4 Hz), theta (5-7 Hz), alpha (8-13 Hz), and beta (14-35 Hz) frequencies. In phasic patients, the alpha spectral peaks emerged in the GPi oscillatory activities, and alpha GPi coherence with the GPe and MCx was higher than in tonic patients. On the other hand, delta GPi oscillatory activities were prominent, and delta GPi-GPe coherence was significantly higher in tonic than in phasic patients. However, there was no significant delta coherence between the GPi/GPe and MCx in tonic patients. These results suggest that different pathophysiological cortico-pallidal oscillations are related to tonic and phasic symptoms.

Fast, shape-directed, landmark-based deep gray matter segmentation for quantification of iron deposition

NASA Astrophysics Data System (ADS)

Ekin, Ahmet; Jasinschi, Radu; van der Grond, Jeroen; van Buchem, Mark A.; van Muiswinkel, Arianne

2006-03-01

This paper introduces image processing methods to automatically detect the 3D volume-of-interest (VOI) and 2D region-of-interest (ROI) for deep gray matter organs (thalamus, globus pallidus, putamen, and caudate nucleus) of patients with suspected iron deposition from MR dual echo images. Prior to the VOI and ROI detection, cerebrospinal fluid (CSF) region is segmented by a clustering algorithm. For the segmentation, we automatically determine the cluster centers with the mean shift algorithm that can quickly identify the modes of a distribution. After the identification of the modes, we employ the K-Harmonic means clustering algorithm to segment the volumetric MR data into CSF and non-CSF. Having the CSF mask and observing that the frontal lobe of the lateral ventricle has more consistent shape accross age and pathological abnormalities, we propose a shape-directed landmark detection algorithm to detect the VOI in a speedy manner. The proposed landmark detection algorithm utilizes a novel shape model of the front lobe of the lateral ventricle for the slices where thalamus, globus pallidus, putamen, and caudate nucleus are expected to appear. After this step, for each slice in the VOI, we use horizontal and vertical projections of the CSF map to detect the approximate locations of the relevant organs to define the ROI. We demonstrate the robustness of the proposed VOI and ROI localization algorithms to pathologies, including severe amounts of iron accumulation as well as white matter lesions, and anatomical variations. The proposed algorithms achieved very high detection accuracy, 100% in the VOI detection , over a large set of a challenging MR dataset.

Performing label-fusion-based segmentation using multiple automatically generated templates.

PubMed

Chakravarty, M Mallar; Steadman, Patrick; van Eede, Matthijs C; Calcott, Rebecca D; Gu, Victoria; Shaw, Philip; Raznahan, Armin; Collins, D Louis; Lerch, Jason P

2013-10-01

Classically, model-based segmentation procedures match magnetic resonance imaging (MRI) volumes to an expertly labeled atlas using nonlinear registration. The accuracy of these techniques are limited due to atlas biases, misregistration, and resampling error. Multi-atlas-based approaches are used as a remedy and involve matching each subject to a number of manually labeled templates. This approach yields numerous independent segmentations that are fused using a voxel-by-voxel label-voting procedure. In this article, we demonstrate how the multi-atlas approach can be extended to work with input atlases that are unique and extremely time consuming to construct by generating a library of multiple automatically generated templates of different brains (MAGeT Brain). We demonstrate the efficacy of our method for the mouse and human using two different nonlinear registration algorithms (ANIMAL and ANTs). The input atlases consist a high-resolution mouse brain atlas and an atlas of the human basal ganglia and thalamus derived from serial histological data. MAGeT Brain segmentation improves the identification of the mouse anterior commissure (mean Dice Kappa values (κ = 0.801), but may be encountering a ceiling effect for hippocampal segmentations. Applying MAGeT Brain to human subcortical structures improves segmentation accuracy for all structures compared to regular model-based techniques (κ = 0.845, 0.752, and 0.861 for the striatum, globus pallidus, and thalamus, respectively). Experiments performed with three manually derived input templates suggest that MAGeT Brain can approach or exceed the accuracy of multi-atlas label-fusion segmentation (κ = 0.894, 0.815, and 0.895 for the striatum, globus pallidus, and thalamus, respectively). Copyright © 2012 Wiley Periodicals, Inc.

Harsh Corporal Punishment Is Associated With Increased T2 Relaxation Time in Dopamine-Rich Regions

PubMed Central

Sheu, Yi-Shin; Polcari, Ann; Anderson, Carl M.; Teicher, Martin H.

2010-01-01

Harsh corporal punishment (HCP) was defined as frequent parental administration of corporal punishment (CP) for discipline, with occasional use of objects such as straps, or paddles. CP is linked to increased risk for depression and substance abuse. We examine whether long-term exposure to HCP acts as sub-traumatic stressor that contributes to brain alterations, particularly in dopaminergic pathways, which may mediate their increased vulnerability to drug and alcohol abuse. Nineteen young adults who experienced early HCP but no other forms of maltreatment and twenty-three comparable controls were studied. T2 relaxation time (T2-RT) measurements were performed with an echo planar imaging TE stepping technique and T2 maps were calculated and analyzed voxel-by-voxel to locate regional T2-RT differences between groups. Previous studies indicated that T2-RT provides an indirect index of resting cerebral blood volume. Region of interest (ROI) analyses were also conducted in caudate, putamen, nucleus accumbens, anterior cingulate cortex, dorsolateral prefrontal cortex, thalamus, globus pallidus and cerebellar hemispheres. Voxel-based relaxometry showed that HCP was associated with increased T2-RT in right caudate and putamen. ROI analyses also revealed increased T2-RT in dorsolateral prefrontal cortex, substantia nigra, thalamus and accumbens but not globus pallidus or cerebellum. There were significant associations between T2-RT measures in dopamine target regions and use of drugs and alcohol, and memory performance. Alteration in the paramagnetic or hemodynamic properties of dopaminergic cell body and projection regions were observed in subjects with HCP, and these findings may relate to their increased risk for drug and alcohol abuse. PMID:20600981

Harsh corporal punishment is associated with increased T2 relaxation time in dopamine-rich regions.

PubMed

Sheu, Yi-Shin; Polcari, Ann; Anderson, Carl M; Teicher, Martin H

2010-11-01

Harsh corporal punishment (HCP) was defined as frequent parental administration of corporal punishment (CP) for discipline, with occasional use of objects such as straps, or paddles. CP is linked to increased risk for depression and substance abuse. We examine whether long-term exposure to HCP acts as sub-traumatic stressor that contributes to brain alterations, particularly in dopaminergic pathways, which may mediate their increased vulnerability to drug and alcohol abuse. Nineteen young adults who experienced early HCP but no other forms of maltreatment and twenty-three comparable controls were studied. T2 relaxation time (T2-RT) measurements were performed with an echo planar imaging TE stepping technique and T2 maps were calculated and analyzed voxel-by-voxel to locate regional T2-RT differences between groups. Previous studies indicated that T2-RT provides an indirect index of resting cerebral blood volume. Region of interest (ROI) analyses were also conducted in caudate, putamen, nucleus accumbens, anterior cingulate cortex, dorsolateral prefrontal cortex, thalamus, globus pallidus and cerebellar hemispheres. Voxel-based relaxometry showed that HCP was associated with increased T2-RT in right caudate and putamen. ROI analyses also revealed increased T2-RT in dorsolateral prefrontal cortex, substantia nigra, thalamus and accumbens but not globus pallidus or cerebellum. There were significant associations between T2-RT measures in dopamine target regions and use of drugs and alcohol, and memory performance. Alteration in the paramagnetic or hemodynamic properties of dopaminergic cell body and projection regions were observed in subjects with HCP, and these findings may relate to their increased risk for drug and alcohol abuse. Copyright 2010 Elsevier Inc. All rights reserved.

Altered Sleep Spindles in Delayed Encephalopathy after Acute Carbon Monoxide Poisoning.

PubMed

Yoshiike, Takuya; Nishida, Masaki; Yagishita, Kazuyoshi; Nariai, Tadashi; Ishii, Kenji; Nishikawa, Toru

2016-06-15

Delayed encephalopathy (DE) affects not only the cerebral white matter and globus pallidus but also the cortex and thalamus. However, it remains unknown whether these brain lesions alter sleep along with clinical manifestations of DE. A 46-year-old man with DE underwent repetitive hyperbaric oxygen therapy. The patient was evaluated by not only neuropsychological and neuroimaging testing but polysomnography over the clinical course. Neurological symptoms improved markedly; however, profound frontal cognitive deficits continued. The polysomnography revealed prolonged absence and delayed recovery of sleep spindles across recordings. Alterations in spindle oscillations in DE could provide further insight into sleep regulatory networks. © 2016 American Academy of Sleep Medicine.

[Cerebral MRT in neurofibromatosis: gliosis versus neoplasia?].

PubMed

Mautner, V F; Pressler, M; Fünsterer, C; Schneider, E

1989-08-01

15 patients aged 1-39 years with documented neurofibromatosis had MR examinations of the cerebrum within the scope of a basic diagnosis and therapy programme. Clinical examination did not lead to pathologic findings for 7 of the patients; 3 patients suffered from general developmental disabilities. A neurologico-psychiatric examination showed pathological findings in 5 patients. Signal-intense foci in proton density and T2-weighted MR images were found in the globus pallidus, thalamus, hippocampus, cerebellum and midbrain. In 2 patients, these foci could be found as well in T1-weighted images. Differentiation between gliosis areas and low grade astrocytomas was not possible in MR.

[Right extremities pain caused by a malacia lesion in the left putamen:a resting functional magnetic resonance imaging of the marginal division of the human brain].

PubMed

Chen, Zhi-Ye; Ma, Lin

2014-04-01

To explore the role of marginal division of the human brain in the pain modulation. Resting functional magnetic resonance imaging was applied in a patient with right extremities pain caused by a malacia lesion in the left putamen and in 8 healthy volunteers. Marginal division was defined using manual drawing on structure images, and was applied to the computation of fuctional connectivity maps. The functional connectivities in the left marginal division showed an evident decrease in the patient when compared with healthy controls. These connectivities were mainly located in the bilateral head of caudate nucleus, putamen, and left globus pallidus. The marginal division may be involved in the pain modulation.

Right external globus pallidus changes are associated with altered causal awareness in youth with depression

PubMed Central

Griffiths, K R; Lagopoulos, J; Hermens, D F; Hickie, I B; Balleine, B W

2015-01-01

Cognitive impairment is a functionally disabling feature of depression contributing to maladaptive decision-making, a loss of behavioral control and an increased disease burden. The ability to calculate the causal efficacy of ones actions in achieving specific goals is critical to normal decision-making and, in this study, we combined voxel-based morphometry (VBM), shape analysis and diffusion tensor tractography to investigate the relationship between cortical–basal ganglia structural integrity and such causal awareness in 43 young subjects with depression and 21 demographically similar healthy controls. Volumetric analysis determined a relationship between right pallidal size and sensitivity to the causal status of specific actions. More specifically, shape analysis identified dorsolateral surface vertices where an inward location was correlated with reduced levels of causal awareness. Probabilistic tractography revealed that affected parts of the pallidum were primarily connected with the striatum, dorsal thalamus and hippocampus. VBM did not reveal any whole-brain gray matter regions that correlated with causal awareness. We conclude that volumetric reduction within the indirect pathway involving the right dorsolateral pallidum is associated with reduced awareness of the causal efficacy of goal-directed actions in young depressed individuals. This causal awareness task allows for the identification of a functionally and biologically relevant subgroup to which more targeted cognitive interventions could be applied, potentially enhancing the long-term outcomes for these individuals. PMID:26440541

Spectral reconstruction of phase response curves reveals the synchronization properties of mouse globus pallidus neurons

PubMed Central

Atherton, Jeremy F.; Surmeier, D. James

2013-01-01

The propensity of a neuron to synchronize is captured by its infinitesimal phase response curve (iPRC). Determining whether an iPRC is biphasic, meaning that small depolarizing perturbations can actually delay the next spike, if delivered at appropriate phases, is a daunting experimental task because negative lobes in the iPRC (unlike positive ones) tend to be small and may be occluded by the normal discharge variability of a neuron. To circumvent this problem, iPRCs are commonly derived from numerical models of neurons. Here, we propose a novel and natural method to estimate the iPRC by direct estimation of its spectral modes. First, we show analytically that the spectral modes of the iPRC of an arbitrary oscillator are readily measured by applying weak harmonic perturbations. Next, applying this methodology to biophysical neuronal models, we show that a low-dimensional spectral reconstruction is sufficient to capture the structure of the iPRC. This structure was preserved reasonably well even with added physiological scale jitter in the neuronal models. To validate the methodology empirically, we applied it first to a low-noise electronic oscillator with a known design and then to cortical pyramidal neurons, recorded in whole cell configuration, that are known to possess a monophasic iPRC. Finally, using the methodology in conjunction with perforated-patch recordings from pallidal neurons, we show, in contrast to recent modeling studies, that these neurons have biphasic somatic iPRCs. Biphasic iPRCs would cause lateral somatically targeted pallidal inhibition to desynchronize pallidal neurons, providing a plausible explanation for their lack of synchrony in vivo. PMID:23966679

18 F-flortaucipir tau positron emission tomography distinguishes established progressive supranuclear palsy from controls and Parkinson disease: A multicenter study.

PubMed

Schonhaut, Daniel R; McMillan, Corey T; Spina, Salvatore; Dickerson, Bradford C; Siderowf, Andrew; Devous, Michael D; Tsai, Richard; Winer, Joseph; Russell, David S; Litvan, Irene; Roberson, Erik D; Seeley, William W; Grinberg, Lea T; Kramer, Joel H; Miller, Bruce L; Pressman, Peter; Nasrallah, Ilya; Baker, Suzanne L; Gomperts, Stephen N; Johnson, Keith A; Grossman, Murray; Jagust, William J; Boxer, Adam L; Rabinovici, Gil D

2017-10-01

18 F-flortaucipir (formerly 18 F-AV1451 or 18 F-T807) binds to neurofibrillary tangles in Alzheimer disease, but tissue studies assessing binding to tau aggregates in progressive supranuclear palsy (PSP) have yielded mixed results. We compared in vivo 18 F-flortaucipir uptake in patients meeting clinical research criteria for PSP (n = 33) to normal controls (n = 46) and patients meeting criteria for Parkinson disease (PD; n = 26). Participants underwent magnetic resonance imaging and positron emission tomography for amyloid-β ( 11 C-PiB or 18 F-florbetapir) and tau ( 18 F-flortaucipir). 18 F-flortaucipir standardized uptake value ratios were calculated (t = 80-100 minutes, cerebellum gray matter reference). Voxelwise and region-of-interest group comparisons were performed in template space, with receiver operating characteristic curve analyses to assess single-subject discrimination. Qualitative comparisons with postmortem tau are reported in 1 patient who died 9 months after 18 F-flortaucipir. Clinical PSP patients showed bilaterally elevated 18 F-flortaucipir uptake in globus pallidus, putamen, subthalamic nucleus, midbrain, and dentate nucleus relative to controls and PD patients (voxelwise p < 0.05 family wise error corrected). Globus pallidus binding best distinguished PSP patients from controls and PD (area under the curve [AUC] = 0.872 vs controls, AUC = 0.893 vs PD). PSP clinical severity did not correlate with 18 F-flortaucipir in any region. A patient with clinical PSP and pathological diagnosis of corticobasal degeneration had severe tau pathology in PSP-related brain structures with good correspondence between in vivo 18 F-flortaucipir and postmortem tau neuropathology. 18 F-flortaucipir uptake was elevated in PSP versus controls and PD patients in a pattern consistent with the expected distribution of tau pathology. Ann Neurol 2017;82:622-634. © 2017 American Neurological Association.

Longitudinal T1 relaxation rate (R1) captures changes in short-term Mn exposure in welders

PubMed Central

Lewis, Mechelle M.; Flynn, Michael R.; Lee, Eun-Young; Van Buren, Scott; Van Buren, Eric; Du, Guangwei; Fry, Rebecca C.; Herring, Amy H.; Kong, Lan; Mailman, Richard B.; Huang, Xuemei

2016-01-01

Objectives We demonstrated recently that the T1 relaxation rate (R1) captured short-term Mn exposure in welders with chronic, relatively low exposure levels in a cross-sectional study. In the current study, we used a longitudinal design to examine whether R1 values reflect the short-term dynamics of Mn exposure. Methods Twenty-nine welders were evaluated at baseline and 12 months. Occupational questionnaires estimated short-term welding exposure using welding hours in the 90 days prior to each study visit (HrsW90). In addition, blood Mn levels, the pallidal index (PI; globus pallidus T1-weighted intensity (T1WI)/frontal white matter T1WI), and R1 values in brain regions of interest (ROIs) were determined as Mn biomarkers at each visit. Associations between changes in estimated welding exposure and changes in purported Mn biomarkers were assessed by Spearman’s correlations with adjustment for age and baseline R1, HrsW90, and blood Mn values. Results Changes in welding hours (HrsW90: the short-term welding exposure estimate), was associated significantly with changes in R1 values in the putamen (r=0.541, p=0.005), caudate (R=0.453, p=0.023), globus pallidus (R=0.430, p=0.032), amygdala (R=0.461, p=0.020), and hippocampus (R=0.447, p=0.025), but not with changes in blood Mn levels or the PI. Discussion Changes in R1 values correlated with changes in the short-term welding exposure estimate, but not with more traditional measures of Mn exposure (blood Mn levels or PI). These results suggest that R1 may serve as a useful marker to capture the short-term dynamics in Mn brain accumulation related to welding exposure. PMID:27567731

The relative phases of basal ganglia activities dynamically shape effective connectivity in Parkinson's disease.

PubMed

Cagnan, Hayriye; Duff, Eugene Paul; Brown, Peter

2015-06-01

Optimal phase alignment between oscillatory neural circuits is hypothesized to optimize information flow and enhance system performance. This theory is known as communication-through-coherence. The basal ganglia motor circuit exhibits exaggerated oscillatory and coherent activity patterns in Parkinson's disease. Such activity patterns are linked to compromised motor system performance as evinced by bradykinesia, rigidity and tremor, suggesting that network function might actually deteriorate once a certain level of net synchrony is exceeded in the motor circuit. Here, we characterize the processes underscoring excessive synchronization and its termination. To this end, we analysed local field potential recordings from the subthalamic nucleus and globus pallidus of five patients with Parkinson's disease (four male and one female, aged 37-64 years). We observed that certain phase alignments between subthalamic nucleus and globus pallidus amplified local neural synchrony in the beta frequency band while others either suppressed it or did not induce any significant change with respect to surrogates. The increase in local beta synchrony directly correlated with how long the two nuclei locked to beta-amplifying phase alignments. Crucially, administration of the dopamine prodrug, levodopa, reduced the frequency and duration of periods during which subthalamic and pallidal populations were phase-locked to beta-amplifying alignments. Conversely ON dopamine, the total duration over which subthalamic and pallidal populations were aligned to phases that left beta-amplitude unchanged with respect to surrogates increased. Thus dopaminergic input shifted circuit dynamics from persistent periods of locking to amplifying phase alignments, associated with compromised motoric function, to more dynamic phase alignment and improved motoric function. This effect of dopamine on local circuit resonance suggests means by which novel electrical interventions might prevent resonance

The Effects of Mechanical and Thermal Stimuli on Local Field Potentials and Single Unit Activity in Parkinson's Disease Patients.

PubMed

Belasen, Abigail; Youn, Youngwon; Gee, Lucy; Prusik, Julia; Lai, Brant; Ramirez-Zamora, Adolfo; Rizvi, Khizer; Yeung, Philip; Shin, Damian S; Argoff, Charles; Pilitsis, Julie G

2016-10-01

Chronic pain is a major, debilitating symptom of Parkinson's disease (PD). Although, deep brain stimulation (DBS) has been shown to improve pain outcomes, the mechanisms underlying this phenomenon are unclear. Microelectrode recording allows us to measure both local field potentials (LFPs) and single neuronal unit activity (SUA). In this study, we examined how single unit and LFP oscillatory activity in the basal ganglia are impacted by mechanical and thermal sensory stimuli and explored their role in pain modulation. We assessed changes in LFPs and SUAs in the subthalamic nucleus (STN), globus pallidus interna (Gpi), and globus pallidus externa (Gpe) following exposure with mechanical or thermal stimuli. Sensory thresholds were determined pre-operatively using quantitative sensory testing. Based on these data, patients were exposed to innocuous and noxious mechanical, pressure, and thermal stimuli at individualized thresholds. In the STN, LFP alpha oscillatory activity and SUA increased in response to innocuous mechanical stimuli; SUA further increased in response to noxious mechanical, noxious pressure, and noxious thermal stimuli (p < 0.05). In the Gpe, LFP low betaactivity and SUA increased with noxious thermal stimuli; SUA also increased in response to innocuous thermal stimuli (p < 0.05). In the Gpi, innocuous thermal stimuli increased LFP gammaactivity; noxious pressure stimuli decreased low betaactivity; SUA increased in response to noxious thermal stimuli (p < 0.05). Our study is the first to demonstrate that mechanical and thermal stimuli alter basal ganglia LFPs and SUAs in PD. While STN SUA increases nearly uniformly to all sensory stimuli, SUA in the pallidal nuclei respond solely to thermal stimuli. Similarly, thermal stimuli yield increases in pallidal LFP activity, but not STN activity. We speculate that DBS may provide analgesia through suppression of stimuli-specific changes in basal ganglia activity, supporting a role for these nuclei

Repetitive transcranial magnetic stimulation induced modulations of resting state motor connectivity in writer's cramp.

PubMed

Bharath, R D; Biswal, B B; Bhaskar, M V; Gohel, S; Jhunjhunwala, K; Panda, R; George, L; Gupta, A K; Pal, P K

2015-05-01

Writer's cramp (WC) is a focal task-specific dystonia of the hand which is increasingly being accepted as a network disorder. Non-invasive cortical stimulation using repetitive transcranial magnetic stimulation (rTMS) has produced therapeutic benefits in some of these patients. This study aimed to visualize the motor network abnormalities in WC and also its rTMS induced modulations using resting state functional magnetic resonance imaging (rsfMRI). Nineteen patients with right-sided WC and 20 matched healthy controls (HCs) were prospectively evaluated. All patients underwent a single session of rTMS and rsfMRI was acquired before (R1) and after (R2) rTMS. Seed-based functional connectivity analysis of several regions in the motor network was performed for HCs, R1 and R2 using SPM8 software. Thresholded (P < 0.05, false discovery rate corrected) group level mean correlation maps were used to derive significantly connected region of interest pairs. Writer's cramp showed a significant reduction in resting state functional connectivity in comparison with HCs involving the left cerebellum, thalamus, globus pallidus, putamen, bilateral supplementary motor area, right medial prefrontal lobe and right post central gyrus. After rTMS there was a significant increase in the contralateral resting state functional connectivity through the left thalamus-right globus pallidus-right thalamus-right prefrontal lobe network loop. It is concluded that WC is a network disorder with widespread dysfunction much larger than clinically evident and changes induced by rTMS probably act through subcortical and trans-hemispheric unaffected connections. Longitudinal studies with therapeutic rTMS will be required to ascertain whether such information could be used to select patients prior to rTMS therapy. © 2015 EAN.

The role of cortical oscillations in a spiking neural network model of the basal ganglia

PubMed Central

Fountas, Zafeirios; Shanahan, Murray

2017-01-01

Although brain oscillations involving the basal ganglia (BG) have been the target of extensive research, the main focus lies disproportionally on oscillations generated within the BG circuit rather than other sources, such as cortical areas. We remedy this here by investigating the influence of various cortical frequency bands on the intrinsic effective connectivity of the BG, as well as the role of the latter in regulating cortical behaviour. To do this, we construct a detailed neural model of the complete BG circuit based on fine-tuned spiking neurons, with both electrical and chemical synapses as well as short-term plasticity between structures. As a measure of effective connectivity, we estimate information transfer between nuclei by means of transfer entropy. Our model successfully reproduces firing and oscillatory behaviour found in both the healthy and Parkinsonian BG. We found that, indeed, effective connectivity changes dramatically for different cortical frequency bands and phase offsets, which are able to modulate (or even block) information flow in the three major BG pathways. In particular, alpha (8–12Hz) and beta (13–30Hz) oscillations activate the direct BG pathway, and favour the modulation of the indirect and hyper-direct pathways via the subthalamic nucleus—globus pallidus loop. In contrast, gamma (30–90Hz) frequencies block the information flow from the cortex completely through activation of the indirect pathway. Finally, below alpha, all pathways decay gradually and the system gives rise to spontaneous activity generated in the globus pallidus. Our results indicate the existence of a multimodal gating mechanism at the level of the BG that can be entirely controlled by cortical oscillations, and provide evidence for the hypothesis of cortically-entrained but locally-generated subthalamic beta activity. These two findings suggest new insights into the pathophysiology of specific BG disorders. PMID:29236724

Quantitative comparison between a multiecho sequence and a single-echo sequence for susceptibility-weighted phase imaging.

PubMed

Gilbert, Guillaume; Savard, Geneviève; Bard, Céline; Beaudoin, Gilles

2012-06-01

The aim of this study was to investigate the benefits arising from the use of a multiecho sequence for susceptibility-weighted phase imaging using a quantitative comparison with a standard single-echo acquisition. Four healthy adult volunteers were imaged on a clinical 3-T system using a protocol comprising two different three-dimensional susceptibility-weighted gradient-echo sequences: a standard single-echo sequence and a multiecho sequence. Both sequences were repeated twice in order to evaluate the local noise contribution by a subtraction of the two acquisitions. For the multiecho sequence, the phase information from each echo was independently unwrapped, and the background field contribution was removed using either homodyne filtering or the projection onto dipole fields method. The phase information from all echoes was then combined using a weighted linear regression. R2 maps were also calculated from the multiecho acquisitions. The noise standard deviation in the reconstructed phase images was evaluated for six manually segmented regions of interest (frontal white matter, posterior white matter, globus pallidus, putamen, caudate nucleus and lateral ventricle). The use of the multiecho sequence for susceptibility-weighted phase imaging led to a reduction of the noise standard deviation for all subjects and all regions of interest investigated in comparison to the reference single-echo acquisition. On average, the noise reduction ranged from 18.4% for the globus pallidus to 47.9% for the lateral ventricle. In addition, the amount of noise reduction was found to be strongly inversely correlated to the estimated R2 value (R=-0.92). In conclusion, the use of a multiecho sequence is an effective way to decrease the noise contribution in susceptibility-weighted phase images, while preserving both contrast and acquisition time. The proposed approach additionally permits the calculation of R2 maps. Copyright © 2012 Elsevier Inc. All rights reserved.

Sample size requirements for one-year treatment effects using deep gray matter volume from 3T MRI in progressive forms of multiple sclerosis.

PubMed

Kim, Gloria; Chu, Renxin; Yousuf, Fawad; Tauhid, Shahamat; Stazzone, Lynn; Houtchens, Maria K; Stankiewicz, James M; Severson, Christopher; Kimbrough, Dorlan; Quintana, Francisco J; Chitnis, Tanuja; Weiner, Howard L; Healy, Brian C; Bakshi, Rohit

2017-11-01

The subcortical deep gray matter (DGM) develops selective, progressive, and clinically relevant atrophy in progressive forms of multiple sclerosis (PMS). This patient population is the target of active neurotherapeutic development, requiring the availability of outcome measures. We tested a fully automated MRI analysis pipeline to assess DGM atrophy in PMS. Consistent 3D T1-weighted high-resolution 3T brain MRI was obtained over one year in 19 consecutive patients with PMS [15 secondary progressive, 4 primary progressive, 53% women, age (mean±SD) 50.8±8.0 years, Expanded Disability Status Scale (median, range) 5.0, 2.0-6.5)]. DGM segmentation applied the fully automated FSL-FIRST pipeline ( http://fsl.fmrib.ox.ac.uk ). Total DGM volume was the sum of the caudate, putamen, globus pallidus, and thalamus. On-study change was calculated using a random-effects linear regression model. We detected one-year decreases in raw [mean (95% confidence interval): -0.749 ml (-1.455, -0.043), p = 0.039] and annualized [-0.754 ml/year (-1.492, -0.016), p = 0.046] total DGM volumes. A treatment trial for an intervention that would show a 50% reduction in DGM brain atrophy would require a sample size of 123 patients for a single-arm study (one-year run-in followed by one-year on-treatment). For a two-arm placebo-controlled one-year study, 242 patients would be required per arm. The use of DGM fraction required more patients. The thalamus, putamen, and globus pallidus, showed smaller effect sizes in their on-study changes than the total DGM; however, for the caudate, the effect sizes were somewhat larger. DGM atrophy may prove efficient as a short-term outcome for proof-of-concept neurotherapeutic trials in PMS.

Dynamical analysis of Parkinsonian state emulated by hybrid Izhikevich neuron models

NASA Astrophysics Data System (ADS)

Liu, Chen; Wang, Jiang; Yu, Haitao; Deng, Bin; Wei, Xile; Li, Huiyan; Loparo, Kenneth A.; Fietkiewicz, Chris

2015-11-01

Computational models play a significant role in exploring novel theories to complement the findings of physiological experiments. Various computational models have been developed to reveal the mechanisms underlying brain functions. Particularly, in the development of therapies to modulate behavioral and pathological abnormalities, computational models provide the basic foundations to exhibit transitions between physiological and pathological conditions. Considering the significant roles of the intrinsic properties of the globus pallidus and the coupling connections between neurons in determining the firing patterns and the dynamical activities of the basal ganglia neuronal network, we propose a hypothesis that pathological behaviors under the Parkinsonian state may originate from combined effects of intrinsic properties of globus pallidus neurons and synaptic conductances in the whole neuronal network. In order to establish a computational efficient network model, hybrid Izhikevich neuron model is used due to its capacity of capturing the dynamical characteristics of the biological neuronal activities. Detailed analysis of the individual Izhikevich neuron model can assist in understanding the roles of model parameters, which then facilitates the establishment of the basal ganglia-thalamic network model, and contributes to a further exploration of the underlying mechanisms of the Parkinsonian state. Simulation results show that the hybrid Izhikevich neuron model is capable of capturing many of the dynamical properties of the basal ganglia-thalamic neuronal network, such as variations of the firing rates and emergence of synchronous oscillations under the Parkinsonian condition, despite the simplicity of the two-dimensional neuronal model. It may suggest that the computational efficient hybrid Izhikevich neuron model can be used to explore basal ganglia normal and abnormal functions. Especially it provides an efficient way of emulating the large-scale neuron network

Gait-Related Brain Activity in People with Parkinson Disease with Freezing of Gait

PubMed Central

Peterson, Daniel S.; Pickett, Kristen A.; Duncan, Ryan; Perlmutter, Joel; Earhart, Gammon M.

2014-01-01

Approximately 50% of people with Parkinson disease experience freezing of gait, described as a transient inability to produce effective stepping. Complex gait tasks such as turning typically elicit freezing more commonly than simple gait tasks, such as forward walking. Despite the frequency of this debilitating and dangerous symptom, the brain mechanisms underlying freezing remain unclear. Gait imagery during functional magnetic resonance imaging permits investigation of brain activity associated with locomotion. We used this approach to better understand neural function during gait-like tasks in people with Parkinson disease who experience freezing- “FoG+” and people who do not experience freezing- ”FoG−“. Nine FoG+ and nine FoG− imagined complex gait tasks (turning, backward walking), simple gait tasks (forward walking), and quiet standing during measurements of blood oxygen level dependent (BOLD) signal. Changes in BOLD signal (i.e. beta weights) during imagined walking and imagined standing were analyzed across FoG+ and FoG− groups in locomotor brain regions including supplementary motor area, globus pallidus, putamen, mesencephalic locomotor region, and cerebellar locomotor region. Beta weights in locomotor regions did not differ for complex tasks compared to simple tasks in either group. Across imagined gait tasks, FoG+ demonstrated significantly lower beta weights in the right globus pallidus with respect to FoG−. FoG+ also showed trends toward lower beta weights in other right-hemisphere locomotor regions (supplementary motor area, mesencephalic locomotor region). Finally, during imagined stand, FoG+ exhibited lower beta weights in the cerebellar locomotor region with respect to FoG−. These data support previous results suggesting FoG+ exhibit dysfunction in a number of cortical and subcortical regions, possibly with asymmetric dysfunction towards the right hemisphere. PMID:24595265

The p.Thr11Met mutation in c19orf12 is frequent among adult Turkish patients with MPAN.

PubMed

Olgiati, Simone; Doğu, Okan; Tufekcioglu, Zeynep; Diler, Yunus; Saka, Esen; Gultekin, Murat; Kaleagasi, Hakan; Kuipers, Demy; Graafland, Josja; Breedveld, Guido J; Quadri, Marialuisa; Sürmeli, Reyhan; Sünter, Gülin; Doğan, Tuğrul; Yalçın, Ayşe Destina; Bilgiç, Başar; Elibol, Bülent; Emre, Murat; Hanagasi, Hasmet A; Bonifati, Vincenzo

2017-06-01

Mutations in the C19orf12 gene cause mitochondrial membrane protein associated neurodegeneration (MPAN), an autosomal recessive form of neurodegeneration with brain iron accumulation (NBIA). A limited number of patients with C19orf12 mutations, particularly those with adult onset of symptoms, have been reported. We sequenced the entire coding region of C19orf12 in 15 Turkish adult probands with idiopathic NBIA. We also performed haplotype analysis in families with a recurrent C19orf12 mutation. Clinical features were collected using a standardized form. Nine of our 15 probands (60%) carried the homozygous c.32C > T mutation in C19orf12 (predicted protein effect: p.Thr11Met). This homozygous mutation co-segregated with the disease in all affected relatives available for testing (16 homozygous subjects). Haplotypes across the C19orf12 locus were identical for a very small region, closest to the mutation, suggesting an old founder, or, two independent founders. The clinical phenotype was characterized by adult onset in most cases (mean 24.5 years, range 10-36), and broad spectrum, including prominent parkinsonism, pyramidal signs, psychiatric disturbances, cognitive decline, and motor axonal neuropathy, in various combinations. On T2- or susceptibility weighted-MRI images, all patients displayed bilateral hypointensities in globus pallidus and substantia nigra, without an eye-of-the-tiger sign; however, hyperintense streaking of the medial medullary lamina between the external and internal parts of globus pallidus was observed frequently. The C19orf12 p.Thr11Met mutation is frequent among adult Turkish patients with MPAN. These findings contribute to the characterization of this important NBIA form, and have direct implications for genetic testing of patients of Turkish origin. Copyright © 2017 Elsevier Ltd. All rights reserved.

The role of cortical oscillations in a spiking neural network model of the basal ganglia.

PubMed

Fountas, Zafeirios; Shanahan, Murray

2017-01-01

Although brain oscillations involving the basal ganglia (BG) have been the target of extensive research, the main focus lies disproportionally on oscillations generated within the BG circuit rather than other sources, such as cortical areas. We remedy this here by investigating the influence of various cortical frequency bands on the intrinsic effective connectivity of the BG, as well as the role of the latter in regulating cortical behaviour. To do this, we construct a detailed neural model of the complete BG circuit based on fine-tuned spiking neurons, with both electrical and chemical synapses as well as short-term plasticity between structures. As a measure of effective connectivity, we estimate information transfer between nuclei by means of transfer entropy. Our model successfully reproduces firing and oscillatory behaviour found in both the healthy and Parkinsonian BG. We found that, indeed, effective connectivity changes dramatically for different cortical frequency bands and phase offsets, which are able to modulate (or even block) information flow in the three major BG pathways. In particular, alpha (8-12Hz) and beta (13-30Hz) oscillations activate the direct BG pathway, and favour the modulation of the indirect and hyper-direct pathways via the subthalamic nucleus-globus pallidus loop. In contrast, gamma (30-90Hz) frequencies block the information flow from the cortex completely through activation of the indirect pathway. Finally, below alpha, all pathways decay gradually and the system gives rise to spontaneous activity generated in the globus pallidus. Our results indicate the existence of a multimodal gating mechanism at the level of the BG that can be entirely controlled by cortical oscillations, and provide evidence for the hypothesis of cortically-entrained but locally-generated subthalamic beta activity. These two findings suggest new insights into the pathophysiology of specific BG disorders.

Global and Regional Brain Assessment with Quantitative MR Imaging in Patients with Prior Exposure to Linear Gadolinium-based Contrast Agents.

PubMed

Kuno, Hirofumi; Jara, Hernán; Buch, Karen; Qureshi, Muhammad Mustafa; Chapman, Margaret N; Sakai, Osamu

2017-04-01

Purpose To assess the association of global and regional brain relaxation times in patients with prior exposure to linear gadolinium-based contrast agents (GBCAs). Materials and Methods The institutional review board approved this cross-sectional study. Thirty-five patients (nine who had received GBCA gadopentetate dimeglumine injections previously [one to eight times] and 26 patients who did not) who underwent brain magnetic resonance (MR) imaging with a mixed fast spin-echo pulse sequence were assessed. The whole brain was segmented according to white and gray matter by using a dual-clustering algorithm. In addition, regions of interest were measured in the globus pallidus, dentate nucleus, thalamus, and pons. The Mann-Whitney U test was used to assess the difference between groups. Multiple regression analysis was performed to assess the association of T1 and T2 with prior GBCA exposure. Results T1 values of gray matter were significantly shorter for patients with than for patients without prior GBCA exposure (P = .022). T1 of the gray matter of the whole brain (P < .001), globus pallidus (P = .002), dentate nucleus (P = .046), and thalamus (P = .026) and T2 of the whole brain (P = .004), dentate nucleus (P = .023), and thalamus (P = .002) showed a significant correlation with the accumulated dose of previous GBCA administration. There was no significant correlation between T1 and the accumulated dose of previous GBCA injections in the white matter (P = .187). Conclusion Global and regional quantitative assessments of T1 and T2 demonstrated an association with prior GBCA exposure, especially for gray matter structures. The results of this study confirm previous research findings that there is gadolinium deposition in wider distribution throughout the brain. © RSNA, 2016 Online supplemental material is available for this article.

Hemisphere, gender and age-related effects on iron deposition in deep gray matter revealed by quantitative susceptibility mapping.

PubMed

Gong, Nan-Jie; Wong, Chun-Sing; Hui, Edward S; Chan, Chun-Chung; Leung, Lam-Ming

2015-10-01

The purpose of this work was to investigate the effects of hemispheric location, gender and age on susceptibility value, as well as the association between susceptibility value and diffusional metrics, in deep gray matter. Iron content was estimated in vivo using quantitative susceptibility mapping. Microstructure was probed using diffusional kurtosis imaging. Regional susceptibility and diffusional metrics were measured for the putamen, caudate nucleus, globus pallidus, thalamus, substantia nigra and red nucleus in 42 healthy adults (age range 25-78 years). Susceptibility value was significantly higher in the left than the right side of the caudate nucleus (P = 0.043) and substantia nigra (P < 0.001). Women exhibited lower susceptibility values than men in the thalamus (P < 0.001) and red nucleus (P = 0.032). Significant age-related increases of susceptibility were observed in the putamen (P < 0.001), red nucleus (P < 0.001), substantia nigra (P = 0.004), caudate nucleus (P < 0.001) and globus pallidus (P = 0.017). The putamen exhibited the highest rate of iron accumulation with aging (slope of linear regression = 0.73 × 10(-3) ppm/year), which was nearly twice those in substantia nigra (slope = 0.40 × 10(-3) ppm/year) and caudate nucleus (slope = 0.39 × 10(-3) ppm/year). Significant positive correlations between the susceptibility value and diffusion measurements were observed for fractional anisotropy (P = 0.045) and mean kurtosis (P = 0.048) in the putamen without controlling for age. Neither correlation was significant after controlling for age. Hemisphere, gender and age-related differences in iron measurements were observed in deep gray matter. Notably, the putamen exhibited the highest rate of increase in susceptibility with aging. Correlations between susceptibility value and microstructural measurements were inconclusive. These findings could provide new clues for unveiling mechanisms underlying iron-related neurodegenerative diseases. Copyright �

Increased anxiety 3 months after brief exposure to MDMA ("Ecstasy") in rats: association with altered 5-HT transporter and receptor density.

PubMed

McGregor, Iain S; Clemens, Kelly J; Van der Plasse, Geoffrey; Li, Kong M; Hunt, Glenn E; Chen, Feng; Lawrence, Andrew J

2003-08-01

Male Wistar rats were treated with 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") using either a high dose (4 x 5 mg/kg over 4 h) or low dose (1 x 5 mg/kg over 4 h) regimen on each of 2 consecutive days. After 10 weeks, rats were tested in the social interaction and emergence tests of anxiety. Rats previously given either of the MDMA dose regimens were significantly more anxious on both tests. After behavioral testing, and 3 months after the MDMA treatment, the rats were killed and their brains examined. Rats given the high-, but not the low-, dose MDMA treatment regimen exhibited significant loss of 5-hydroxytryptamine (5-HT) and 5-HIAA in the amygdala, hippocampus, striatum, and cortex. Quantitative autoradiography showed loss of SERT binding in cortical, hippocampal, thalamic, and hypothalamic sites with the high-dose MDMA regime, while low-dose MDMA only produced significant loss in the medial hypothalamus. Neither high- nor low-dose MDMA affected 5HT(1A) receptor density. High-dose MDMA increased 5HT(1B) receptor density in the nucleus accumbens and lateral septum but decreased binding in the globus pallidus, insular cortex and medial thalamus. Low-dose MDMA decreased 5HT(1B) receptor density in the hippocampus, globus pallidus, and medial thalamus. High-dose MDMA caused dramatic decreases in cortical, striatal, thalamic, and hypothalamic 5HT(2A)/(2C) receptor density, while low-dose MDMA tended to produce similar effects but only significantly in the piriform cortex. These data suggest that even brief, relatively low-dose MDMA exposure can produce significant, long-term changes in 5-HT receptor and transporter function and associated emotional behavior. Interestingly, long-term 5-HT depletion may not be necessary to produce lasting effects on anxiety-like behavior after low-dose MDMA.

X-Ray Fluorescence Imaging: A New Tool for Studying Manganese Neurotoxicity

PubMed Central

Robison, Gregory; Zakharova, Taisiya; Fu, Sherleen; Jiang, Wendy; Fulper, Rachael; Barrea, Raul; Marcus, Matthew A.; Zheng, Wei; Pushkar, Yulia

2012-01-01

The neurotoxic effect of manganese (Mn) establishes itself in a condition known as manganism or Mn induced parkinsonism. While this condition was first diagnosed about 170 years ago, the mechanism of the neurotoxic action of Mn remains unknown. Moreover, the possibility that Mn exposure combined with other genetic and environmental factors can contribute to the development of Parkinson's disease has been discussed in the literature and several epidemiological studies have demonstrated a correlation between Mn exposure and an elevated risk of Parkinson's disease. Here, we introduce X-ray fluorescence imaging as a new quantitative tool for analysis of the Mn distribution in the brain with high spatial resolution. The animal model employed mimics deficits observed in affected human subjects. The obtained maps of Mn distribution in the brain demonstrate the highest Mn content in the globus pallidus, the thalamus, and the substantia nigra pars compacta. To test the hypothesis that Mn transport into/distribution within brain cells mimics that of other biologically relevant metal ions, such as iron, copper, or zinc, their distributions were compared. It was demonstrated that the Mn distribution does not follow the distributions of any of these metals in the brain. The majority of Mn in the brain was shown to occur in the mobile state, confirming the relevance of the chelation therapy currently used to treat Mn intoxication. In cells with accumulated Mn, it can cause neurotoxic action by affecting the mitochondrial respiratory chain. This can result in increased susceptibility of the neurons of the globus pallidus, thalamus, and substantia nigra pars compacta to various environmental or genetic insults. The obtained data is the first demonstration of Mn accumulation in the substantia nigra pars compacta, and thus, can represent a link between Mn exposure and its potential effects for development of Parkinson's disease. PMID:23185282

[Long-term care of Parkinson patients with deep brain stimulation].

PubMed

Allert, N; Barbe, M T; Timmermann, L; Coenen, V A

2011-12-01

For more than 15 years deep brain stimulation of the subthalamic nucleus and globus pallidus internus have become therapeutic options in advanced Parkinson's disease. The number of patients with long-term treatment is increasing steadily. This review focuses on issues of the long-term care of these Parkinson's patients, including differences of the available deep brain stimulation systems, recommendations for follow-up examinations, implications for medical diagnostics and therapies and an algorithm for symptom deterioration. Today, there is no profound evidence that deep brain stimulation prevents disease progression. However, symptomatic relief from motor symptoms is maintained during long-term follow-up and interruption of the therapy remains an exception. © Georg Thieme Verlag KG Stuttgart · New York.

MRI and clinical manifestations of delayed encephalopathy after carbon monoxide poisoning.

PubMed

Wang, Xiahong; Li, Zhenyu; Berglass, Jacqueline; He, Wenlong; Zhao, Jianmin; Zhang, Min; Gao, Chongyang; Zhang, Caixia; Zhang, Huimin; Yi, Xuewei

2016-11-01

To explore the relationship between the clinical manifestations and functional magnetic resonance images of delayed encephalopathy after carbon monoxide intoxication. Six patients received the MRI were diagnosed with delayed encephalopathy after carbon monoxide (CO) poisoning. Clinical manifestations were observed in each patient. MRI revealed multiple lesions. The majority of the lesions were located in the globus pallidus, sub cortical white matter, and basal ganglia. The cognitive injury, akinetic mutism, fecal and uroclepsia, forced crying, forced laughing and extra pyramidal syndromes such as chorea and parkinsonism were manifested in clinic. Cognitive impairment improved greatly while involuntary movements only improved slightly after several months. Meanwhile brain MRI suggested remarkable improvement. Neuroimaging directly correlated with the clinical manifestations.

Zolpidem in progressive supranuclear palsy.

PubMed

Dash, Sandip K

2013-01-01

Progressive supranuclear palsy (PSP) is a progressive neurodegenerative disorder, characterized by motor symptoms, postural instability, personality changes, and cognitive impairment. There is no effective treatment for this disorder. Reduced neurotransmission of GABA in the striatum and globus pallidus may contribute to the symptoms of motor and cognitive symptoms seen in PSP. Zolpidem is a GABA agonist of the benzodiazepine subreceptor BZ1. Here a nondiabetic, normotensive case of PSP is (Progressive Supranuclear Palsy) described, which showed improvement in swallowing, speech, and gaze paresis after zolpidem therapy and possible mechanism of actions are discussed. However, more trials are needed with large number of patients to confirm the effectiveness of zolpidem in progressive supranuclear palsy.

Distribution of lead in the brain tissues from DNTC patients using synchrotron radiation microbeams

NASA Astrophysics Data System (ADS)

Ide-Ektessabi, Ari; Ota, Yukihide; Ishihara, Ryoko; Mizuno, Yutaka; Takeuchi, Tohru

2005-12-01

Diffuse neurofibrillary tangles with calcification (DNTC) is a form of dementia with certain characteristics. Its pathology is characterized by cerebrum atrophy, calcification on globus pallidus and dentate nucleus and diffuse neurofibrillary tangles without senile plaques. In the present study brain tissues were prepared from patients with patients DNTC, calcified and non-calcified Alzheimer's disease (AD) patients. The brain tissues were examined non-destructively by X-ray fluorescence (XRF) spectroscopy using synchrotron radiation (SR) microbeams for trace metallic elements Ca, Fe, Cu, Zn and Pb. The XRF analysis showed that there were Pb concentrations in the calcified areas in the brain tissues with both DNTC and AD but there was none in those with non-calcified AD.

Textural and Carbon Isotopic Analyses of Modern Carbonate Microbialites: Possible Ancient and Martian Analogs

NASA Technical Reports Server (NTRS)

Thompson, Joel B.

1998-01-01

Many modem and ancient carbonate deposits around the world have been recognized as microbial buildups or microbialites. Ancient microbialite structures have been divided into two basic categories based on their internal fabric or texture. They include stromatolites which have a predominantly laminated internal fabric and thrombolites which have an open-porous clotted fabric, that lacks laminae. The origin of these two basic microbial fabrics is still being debated in the literature. Understanding the origin and the various microorganisms involved in forming these modem fabrics is the key to the interpretation of similar fabrics in ancient and possibly Martian rocks. Therefore, detailed studies are needed on the microbiological makeup and origin of the fabrics in modem microbialites. Such studies may serve as analogs for ancient and Martian microbialites in the future. The purpose of this study is to examine the textures and carbon isotopic signatures of the following modem microbialites from the Bahamas: 1) a modem subtidal microbialite from Iguana Cay, Bahamas and 2) a modem microbial mat (stromatolite) from a hypersaline pond on Lee Stocking Island, Bahamas.

A new Late Cretaceous iguanomorph from North America and the origin of New World Pleurodonta (Squamata, Iguania)

PubMed Central

Conrad, Jack L.; Head, Jason J.; Varricchio, David J.; Wilson, Gregory P.

2017-01-01

Iguanomorpha (stem + crown Iguania) is a diverse squamate clade with members that predominate many modern American lizard ecosystems. However, the temporal and palaeobiogeographic origins of its constituent crown clades (e.g. Pleurodonta (basilisks, iguanas, and their relatives)) are poorly constrained, mainly due to a meagre Mesozoic-age fossil record. Here, we report on two nearly complete skeletons from the Late Cretaceous (Campanian) of North America that represent a new and relatively large-bodied and possibly herbivorous iguanomorph that inhabited a semi-arid environment. The new taxon exhibits a mosaic of anatomical features traditionally used in diagnosing Iguania and non-iguanian squamates (i.e. Scleroglossa; e.g. parietal foramen at the frontoparietal suture, astragalocalcaneal notch in the tibia, respectively). Our cladistic analysis of Squamata revealed a phylogenetic link between Campanian-age North American and East Asian stem iguanomorphs (i.e. the new taxon + Temujiniidae). These results and our evaluation of the squamate fossil record suggest that crown pleurodontans were restricted to the low-latitude Neotropics prior to their early Palaeogene first appearances in the mid-latitudes of North America. PMID:28123087

Matched Behavioral and Neural Adaptations for Low Sound Level Echolocation in a Gleaning Bat, Antrozous pallidus.

PubMed

Measor, Kevin R; Leavell, Brian C; Brewton, Dustin H; Rumschlag, Jeffrey; Barber, Jesse R; Razak, Khaleel A

2017-01-01

In active sensing, animals make motor adjustments to match sensory inputs to specialized neural circuitry. Here, we describe an active sensing system for sound level processing. The pallid bat uses downward frequency-modulated (FM) sweeps as echolocation calls for general orientation and obstacle avoidance. The bat's auditory cortex contains a region selective for these FM sweeps (FM sweep-selective region, FMSR). We show that the vast majority of FMSR neurons are sensitive and strongly selective for relatively low levels (30-60 dB SPL). Behavioral testing shows that when a flying bat approaches a target, it reduces output call levels to keep echo levels between ∼30 and 55 dB SPL. Thus, the pallid bat behaviorally matches echo levels to an optimized neural representation of sound levels. FMSR neurons are more selective for sound levels of FM sweeps than tones, suggesting that across-frequency integration enhances level tuning. Level-dependent timing of high-frequency sideband inhibition in the receptive field shapes increased level selectivity for FM sweeps. Together with previous studies, these data indicate that the same receptive field properties shape multiple filters (sweep direction, rate, and level) for FM sweeps, a sound common in multiple vocalizations, including human speech. The matched behavioral and neural adaptations for low-intensity echolocation in the pallid bat will facilitate foraging with reduced probability of acoustic detection by prey.

Matched Behavioral and Neural Adaptations for Low Sound Level Echolocation in a Gleaning Bat, Antrozous pallidus

PubMed Central

Measor, Kevin R.; Leavell, Brian C.; Brewton, Dustin H.; Rumschlag, Jeffrey; Barber, Jesse R.

2017-01-01

Abstract In active sensing, animals make motor adjustments to match sensory inputs to specialized neural circuitry. Here, we describe an active sensing system for sound level processing. The pallid bat uses downward frequency-modulated (FM) sweeps as echolocation calls for general orientation and obstacle avoidance. The bat’s auditory cortex contains a region selective for these FM sweeps (FM sweep-selective region, FMSR). We show that the vast majority of FMSR neurons are sensitive and strongly selective for relatively low levels (30-60 dB SPL). Behavioral testing shows that when a flying bat approaches a target, it reduces output call levels to keep echo levels between ∼30 and 55 dB SPL. Thus, the pallid bat behaviorally matches echo levels to an optimized neural representation of sound levels. FMSR neurons are more selective for sound levels of FM sweeps than tones, suggesting that across-frequency integration enhances level tuning. Level-dependent timing of high-frequency sideband inhibition in the receptive field shapes increased level selectivity for FM sweeps. Together with previous studies, these data indicate that the same receptive field properties shape multiple filters (sweep direction, rate, and level) for FM sweeps, a sound common in multiple vocalizations, including human speech. The matched behavioral and neural adaptations for low-intensity echolocation in the pallid bat will facilitate foraging with reduced probability of acoustic detection by prey. PMID:28275715

Phosphodiesterase-10A Inverse Changes in Striatopallidal and Striatoentopeduncular Pathways of a Transgenic Mouse Model of DYT1 Dystonia.

PubMed

D'Angelo, Vincenza; Castelli, Valentina; Giorgi, Mauro; Cardarelli, Silvia; Saverioni, Ilaria; Palumbo, Francesca; Bonsi, Paola; Pisani, Antonio; Giampà, Carmela; Sorge, Roberto; Biagioni, Stefano; Fusco, Francesca R; Sancesario, Giuseppe

2017-02-22

We report that changes of phosphodiesterase-10A (PDE10A) can map widespread functional imbalance of basal ganglia circuits in a mouse model of DYT1 dystonia overexpressing mutant torsinA. PDE10A is a key enzyme in the catabolism of second messenger cAMP and cGMP, whose synthesis is stimulated by D1 receptors and inhibited by D2 receptors preferentially expressed in striatoentopeducuncular/substantia nigra or striatopallidal pathways, respectively. PDE10A was studied in control mice (NT) and in mice carrying human wild-type torsinA (hWT) or mutant torsinA (hMT). Quantitative analysis of PDE10A expression was assessed in different brain areas by rabbit anti-PDE10A antibody immunohistochemistry and Western blotting. PDE10A-dependent cAMP hydrolyzing activity and PDE10A mRNA were also assessed. Striatopallidal neurons were identified by rabbit anti-enkephalin antibody.In NT mice, PDE10A is equally expressed in medium spiny striatal neurons and in their projections to entopeduncular nucleus/substantia nigra and to external globus pallidus. In hMT mice, PDE10A content selectively increases in enkephalin-positive striatal neuronal bodies; moreover, PDE10A expression and activity in hMT mice, compared with NT mice, significantly increase in globus pallidus but decrease in entopeduncular nucleus/substantia nigra. Similar changes of PDE10A occur in hWT mice, but such changes are not always significant. However, PDE10A mRNA expression appears comparable among NT, hWT, and hMT mice.In DYT1 transgenic mice, the inverse changes of PDE10A in striatoentopeduncular and striatopallidal projections might result over time in an imbalance between direct and indirect pathways for properly focusing movement. The decrease of PDE10A in the striatoentopeduncular/nigral projections might lead to increased intensity and duration of D1-stimulated cAMP/cGMP signaling; conversely, the increase of PDE10A in the striatopallidal projections might lead to increased intensity and duration of D2

Iron accumulation in multiple sclerosis: an early pathogenic event.

PubMed

LeVine, Steven M; Bilgen, Mehmet; Lynch, Sharon G

2013-03-01

Iron has been shown to accumulate in deep gray matter structures in many forms of multiple sclerosis (MS), but detecting its presence early in the disease course (e.g., clinically isolated syndrome [CIS]) has been less clear. Here, we review a recent study where MRI scanning at 7 T together with susceptibility mapping was performed to assess iron deposition in CIS and control subjects. Susceptibility indicative of iron deposition was found to be increased in the globus pallidus, caudate, putamen and pulvinar of CIS patients compared with controls. The findings suggest that iron deposition is a pathological change that occurs early in the development of MS. Identifying the mechanisms of iron accumulation and determining whether iron promotes pathogenesis in MS are important areas of future research.

Renal Failure in Dementia with Lewy Bodies Presenting as Catatonia

PubMed Central

Fekete, Robert

2013-01-01

Catatonia, originally described by Karl Kahlbaum in 1874, may be regarded as a set of clinical features found in a subtype of schizophrenia, but the syndrome may also stem from organic causes including vascular parkinsonism, brain masses, globus pallidus lesions, metabolic derangements, and pharmacologic agents, especially first generation antipsychotics. Catatonia may include paratonia, waxy flexibility (cerea flexibilitas), stupor, mutism, echolalia, and catalepsy (abnormal posturing). A case of catatonia as a result of acute renal failure in a patient with dementia with Lewy bodies is described. This patient recovered after intravenous fluid administration and reinstitution of the atypical dopamine receptor blocking agent quetiapine, but benzodiazepines and amantadine are additional possible treatments. Recognition of organic causes of catatonia leads to timely treatment and resolution of the syndrome. PMID:23466522

[Deep brain stimulation in the treatment of movement disorders].

PubMed

Goto, Satoshi

2007-11-01

The introduction of deep brain stimulation (DBS) was a historical step forward for the treatment of advanced and medically intractable movement disorders that include Parkinson's disease, dystonias, essential tremor, and Holmes' tremor. DBS is able to modulate the target region electrically in a reversible and adjustable fashion in contrast to an irreversible and destructive lesioning procedure. In the treatment of movement disorders, the potential targets are the thalamic ventral intermediate nucleus (Vim), globus pallidus internus (GPi), subthalamic nucleus (STN), pedunculopontine nucleus (PPN), and thalamic Vo-complex nucleus. With the development of DBS technology and stereotactic neurosurgical techniques, its therapeutic efficacy has been increased while reducing surgical complications. DBS has become an established therapy for disabling movement disorders and is currently being used to treat neuropsychiatric disorders.

Recovering More than Tree Cover: Herbivores and Herbivory in a Restored Tropical Dry Forest

PubMed Central

2015-01-01

Intense and chronic disturbance may arrest natural succession, reduce environmental quality and lead to ecological interaction losses. Where natural succession does not occur, ecological restoration aims to accelerate this process. While plant establishment and diversity is promoted by restoration, few studies have evaluated the effect of restoration activities on ecological processes and animal diversity. This study assessed herbivory and lepidopteran diversity associated with two pioneer tree species growing in 4-year-old experimental restoration plots in a tropical dry forest at Sierra de Huautla, in Morelos, Mexico. The study was carried out during the rainy season of 2010 (July-October) in eleven 50 x 50 m plots in three different habitats: cattle-excluded, cattle-excluded with restoration plantings, and cattle grazing plots. At the beginning of the rainy season, 10 juveniles of Heliocarpus pallidus (Malvaceae) and Ipomoea pauciflora (Convolvulaceae) were selected in each plot (N = 110 trees). Herbivory was measured in 10 leaves per plant at the end of the rainy season. To evaluate richness and abundance of lepidopteran larvae, all plants were surveyed monthly. Herbivory was similar among habitats and I. pauciflora showed a higher percentage of herbivory. A total of 868 lepidopteran larvae from 65 morphospecies were recorded. The family with the highest number of morphospecies (9 sp.) was Geometridae, while the most abundant family was Saturnidae, with 427 individuals. Lepidopteran richness and abundance were significantly higher in H. pallidus than in I. pauciflora. Lepidopteran richness was significantly higher in the cattle-excluded plots, while abundance was significantly higher in the non-excluded plots. After four years of cattle exclusion and the establishment of plantings, lepidopteran richness increased 20 –fold in the excluded plots compared to the disturbed areas, whereas herbivory levels were equally high in both restored and disturbed sites

Circuits regulating pleasure and happiness: the evolution of reward-seeking and misery-fleeing behavioral mechanisms in vertebrates.

PubMed

Loonen, Anton J M; Ivanova, Svetlana A

2015-01-01

The very first free-moving animals in the oceans over 540 million years ago must have been able to obtain food, territory, and shelter, as well as reproduce. Therefore, they would have needed regulatory mechanisms to induce movements enabling achievement of these prerequisites for survival. It can be useful to consider these mechanisms in primitive chordates, which represent our earliest ancestors, to develop hypotheses addressing how these essential parts of human behavior are regulated and relate to more sophisticated behavioral manifestations such as mood. An animal comparable to lampreys was the earliest known vertebrate with a modern forebrain consisting of old and new cortical parts. Lampreys have a separate dorsal pallium, the forerunner of the most recently developed part of the cerebral cortex. In addition, the lamprey extrapyramidal system (EPS), which regulates movement, is modern. However, in lampreys and their putative forerunners, the hagfishes, the striatum, which is the input part of this EPS, probably corresponds to the human centromedial amygdala, which in higher vertebrates is part of a system mediating fear and anxiety. Both animals have well-developed nuclear habenulae, which are involved in several critical behaviors; in lampreys this system regulates the reward system that reinforces appetitive-seeking behavior or the avoidance system that reinforces flight behavior resulting from negative inputs. Lampreys also have a distinct glutamatergic nucleus, the so-called habenula-projection globus pallidus, which receives input from glutamatergic and GABAergic signals and gives output to the lateral habenula. Via this route, this nucleus influences midbrain monoaminergic nuclei and regulates the food acquisition system. These various structures involved in motor regulation in the lampreys may be conserved in humans and include two complementary mechanisms for reward reinforcement and avoidance behaviors. The first system is associated with

Comparison of Dopamine D3 and D2 Receptor Occupancies by a Single Dose of Blonanserin in Healthy Subjects: A Positron Emission Tomography Study With [11C]-(+)-PHNO.

PubMed

Tateno, Amane; Sakayori, Takeshi; Kim, Woo-Chan; Honjo, Kazuyoshi; Nakayama, Haruo; Arakawa, Ryosuke; Okubo, Yoshiro

2018-06-01

Blockade of D3 receptor, a member of the dopamine D2-like receptor family, has been suggested as a possible medication for schizophrenia. Blonanserin has high affinity in vitro for D3 as well as D2 receptors. We investigated whether a single dose of 12 mg blonanserin, which was within the daily clinical dose range (i.e., 8-24 mg) for the treatment of schizophrenia, occupies D3 as well as D2 receptors in healthy subjects. Six healthy males (mean 35.7±7.6 years) received 2 positron emission tomography scans, the first prior to taking blonanserin, and the second 2 hours after the administration of a single dose of 12 mg blonanserin. Dopamine receptor occupancies by blonanserin were evaluated by [11C]-(+)-PHNO. Occupancy of each region by 12 mg blonanserin was: caudate (range 64.3%-81.5%; mean±SD, 74.3±5.6%), putamen (range 60.4%-84.3%; mean±SD, 73.3%±8.2%), ventral striatum (range 40.1%-88.2%; mean±SD, 60.8%±17.1%), globus pallidus (range 65.8%-87.6%; mean±SD, 75.7%±8.6%), and substantia nigra (range 56.0%-88.7%; mean±SD, 72.4%±11.0%). Correlation analysis between plasma concentration of blonanserin and receptor occupancy in D2-rich (caudate and putamen) and D3-rich (globus pallidus and substantia nigra) regions showed that EC50 for D2-rich region was 0.39 ng/mL (r=0.43) and EC50 for D3-rich region was 0.40 ng/mL (r=0.79). A single dose of 12 mg blonanserin occupied D3 receptor to the same degree as D2 receptor in vivo. Our results were consistent with previous studies that reported that some of the pharmacological effect of blonanserin is mediated via D3 receptor antagonism.

Imaging dopamine D3 receptors in the human brain with positron emission tomography, [11C]PHNO, and a selective D3 receptor antagonist.

PubMed

Searle, Graham; Beaver, John D; Comley, Robert A; Bani, Massimo; Tziortzi, Andri; Slifstein, Mark; Mugnaini, Manolo; Griffante, Cristiana; Wilson, Alan A; Merlo-Pich, Emilio; Houle, Sylvain; Gunn, Roger; Rabiner, Eugenii A; Laruelle, Marc

2010-08-15

Dopamine D(3) receptors are involved in the pathophysiology of several neuropsychiatric conditions. [(11)C]-(+)-PHNO is a radiolabeled D(2) and D(3) agonist, suitable for imaging the agonist binding sites (denoted D(2HIGH) and D(3)) of these receptors with positron emission tomography (PET). PET studies in nonhuman primates documented that, in vivo, [(11)C]-(+)-PHNO displays a relative selectivity for D(3) compared with D(2HIGH) receptor sites and that the [(11)C]-(+)-PHNO signal is enriched in D(3) contribution compared with conventional ligands such as [(11)C] raclopride. To define the D(3) contribution (f(PHNO)(D3)) to [(11)C]-(+)-PHNO binding potential (BP(ND)) in healthy humans, 52 PET scans were obtained in 19 healthy volunteers at baseline and following oral administration of various doses of the selective D(3) receptor antagonist, GSK598809. The impact of GSK598809 on [(11)C]-(+)-PHNO was regionally selective. In dorsal regions of the striatum, GSK598809 did not significantly affect [(11)C]-(+)-PHNO BP(ND) (f(PHNO)(D3) approximately 0%). Conversely, in the substantia nigra, GSK598809 dose-dependently reduced [(11)C]-(+)-PHNO binding to nonspecific level (f(PHNO)(D3) approximately 100%). In ventral striatum (VST), globus pallidus and thalamus (THA), [(11)C]-(+)-PHNO BP(ND) was attributable to a combination of D(2HIGH) and D(3) receptor sites, with f(PHNO)(D3) of 26%, 67% and 46%, respectively. D(3) receptor binding potential (BP(ND)(D3)) was highest in globus pallidus (1.90) and substantial nigra (1.39), with lower levels in VST (.77) and THA (.18) and negligible levels in dorsal striatum. This study elucidated the pharmacologic nature of the [(11)C]-(+)-PHNO signal in healthy subjects and provided the first quantification of D(3) receptor availability with PET in the living human brain. Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Substance P receptors: localization by light microscopic autoradiography in rat brain using [3H]SP as the radioligand.

PubMed

Mantyh, P W; Hunt, S P; Maggio, J E

1984-07-30

Substance P (SP) is a putative neurotransmitter in both the peripheral and central nervous systems. In the present report we have used a modification of the Young and Kuhar technique to investigate some of the SP receptors binding properties and the distribution of SP receptors in rat brain. Tritiated SP [( 3H]SP) absorbed extensively to glass but this adsorbtion was greatly reduced by preincubating the slide-mounted tissue sections in a solution containing the cationic polymer polyethylenimine. [3H]SP was found to bind to rat tissue in a saturable fashion with a Bmax of 14.7 fmol/mg tissue wet weight and a Kd of 1.1 nM. The rank order of potencies for displacing [3H]SP binding from rat tissue sections was SP greater than SP sulphoxide greater than DiMeC7 greater than Eledoisin greater than SP(5-11) greater than SP(COOH) greater than SP(1-9) amide. Using autoradiography coupled with LKB tritium-sensitive Ultrofilm or the dry emulsion-coated coverslip technique the distribution of [3H]SP binding sites was found to be very dense within olfactory bulb, amygdalo-hippocampal area and the nucleus of the solitary tract. Heavy concentrations of receptors were observed in the septum, diagonal band of Broca, striatum subiculum, hypothalamus, locus coeruleus, parabrachial nucleus and lobule 9 and 10 of the cerebellum. Moderate to low concentrations of receptors were observed in the cerebral cortex, globus pallidus, raphe nuclei and the trigeminal nucleus. Very low densities were observed in most aspects of the dorsal thalamus, substantia nigra and cerebellum (other than lobule 9 and 10). Comparisons of the present data with SP peptide levels indicate that in some areas of the brain there is a rough correlation between peptide and receptor levels. However, in other brain areas (olfactory bulb, globus pallidus and substantia nigra) there is little obvious correlation between the two.

Quantitative Susceptibility Mapping of Amyloid-β Aggregates in Alzheimer's Disease with 7T MR.

PubMed

Tiepolt, Solveig; Schäfer, Andreas; Rullmann, Michael; Roggenhofer, Elisabeth; Gertz, Hermann-Josef; Schroeter, Matthias L; Patt, Marianne; Bazin, Pierre-Louis; Jochimsen, Thies H; Turner, Robert; Sabri, Osama; Barthel, Henryk

2018-05-28

PET imaging is an established technique to detect cerebral amyloid-β (Aβ) plaques in vivo. Some preclinical and postmortem data report an accumulation of redox-active iron near Aβ plaques. Quantitative susceptibility mapping (QSM) at high-field MRI enables iron deposits to be depicted with high spatial resolution. Aim of this study was to examine whether iron and Aβ plaque accumulation is related and thus, whether 7T MRI might be an additive diagnostic tool to Aβ PET imaging. Postmortem human Alzheimer's disease (AD) and healthy control (HC) frontal gray matter (GM) was imaged with 7T MRI which resulted in T1 maps and QSM. Aβ plaque load was determined by histopathology. In vivo, 10 Aβ PET-positive AD patients (74.1±6.0a) and 10 Aβ PET-negative HCs (67.1±4.4a) underwent 7T MR examination and QSM maps were analyzed. Severity of cognitive deficits was determined by MMSE. Postmortem, the susceptibility of Aβ plaque-containing GM were higher than those of Aβ plaque-free GM (0.011±0.002 versus - 0.008±0.003 ppm, p <  0.001). In vivo, only the bilateral globus pallidus showed significantly higher susceptibility in AD patients compared to HCs (right: 0.277±0.018 versus - 0.009±0.009 ppm; left: 0.293±0.014 versus - 0.007±0.012 ppm, p <  0.0001). The pallidal QSM values were negatively correlated with those of the MMSE (r = - 0.69, p = 0.001). The postmortem study revealed significant susceptibility differences between the Aβ plaque-containing and Aβ plaque-free GM, whereas in vivo only the QSM values of the globus pallidus differed significantly between AD and HC group. The pallidal QSM values correlated with the severity of cognitive deficits. These findings encourage efforts to optimize the 7T-QSM methodology.

Neural hyperactivity related to working memory in drug-naive boys with attention deficit hyperactivity disorder.

PubMed

Li, Yuanyuan; Li, Fei; He, Ning; Guo, Lanting; Huang, Xiaoqi; Lui, Su; Gong, Qiyong

2014-08-04

Impaired working memory is thought to be a core feature of attention deficit hyperactivity disorder (ADHD). Previous imaging studies investigating working memory in ADHD have used tasks involving different cognitive resources and ignoring the categorical judgments about objects that are essential parts of performance in visual working memory tasks, thus complicating the interpretation of their findings. In the present study, we explored differential neural activation in children and adolescents with ADHD and in healthy controls using functional magnetic resonance imaging (fMRI) with the categorical n-back task (CN-BT), which maximized demands for executive reasoning while holding memory demands constant. A total of 33 drug-naive, right-handed male ADHD without comorbidity (mean age 9.9±2.4 years) and 27 right-handed, healthy male controls (mean age 10.9±2.7 years) were recruited in the present study. Event-related fMRI was used to study differences in brain activity during the CN-BT between the two groups. The two groups did not differ in their accuracy in the CN-BT, although the ADHD patients showed significantly shorter reaction times to correct responses than did the controls. During the CN-BT, both ADHD patients and controls showed significant positive and negative activations by the correct responses, mainly in the sensory-motor pathways and the striato-cerebellum circuit. Additionally, the ADHD patients showed significantly higher activation in the bilateral globus pallidus and the right hippocampus compared with the controls. There was also a positive correlation between hyperactivation of the left globus pallidus and the reaction time to correct responses in ADHD. In contrast to controls, ADHD patients showed neural hyperactivation in the striatum and mediotemporal areas during a working memory task involving categorization. Hyperfunction in these areas might be the pathophysiological foundation of ADHD, related to the deficits of working memory and the

Sustained effects of ecstasy on the human brain: a prospective neuroimaging study in novel users.

PubMed

de Win, Maartje M L; Jager, Gerry; Booij, Jan; Reneman, Liesbeth; Schilt, Thelma; Lavini, Cristina; Olabarriaga, Sílvia D; den Heeten, Gerard J; van den Brink, Wim

2008-11-01

Previous studies have suggested toxic effects of recreational ecstasy use on the serotonin system of the brain. However, it cannot be excluded that observed differences between users and non-users are the cause rather than the consequence of ecstasy use. As part of the Netherlands XTC Toxicity (NeXT) study, we prospectively assessed sustained effects of ecstasy use on the brain in novel ecstasy users using repeated measurements with a combination of different neuroimaging parameters of neurotoxicity. At baseline, 188 ecstasy-naive volunteers with high probability of first ecstasy use were examined. After a mean period of 17 months follow-up, neuroimaging was repeated in 59 incident ecstasy users and 56 matched persistent ecstasy-naives and their outcomes were compared. Neuroimaging included [(123)I]beta-carbomethoxy-3beta-(4-iodophenyl)tropane (CIT) SPECT to measure serotonin transporter densities as indicators of serotonergic function; (1)H-MR spectroscopy ((1)H-MRS) to measure brain metabolites as indicators of neuronal damage; diffusion tensor imaging (DTI) to measure the apparent diffusion coefficient and fractional anisotropy (FA) of the diffusional motion of water molecules in the brain as indicators of axonal integrity; and perfusion weighted imaging (PWI) to measure regional relative cerebral blood volume (rrCBV) which indicates brain perfusion. With this approach, both structural ((1)H-MRS and DTI) and functional ([(123)I]beta-CIT SPECT and PWI) aspects of neurotoxicity were combined. Compared to persistent ecstasy-naives, novel low-dose ecstasy users (mean 6.0, median 2.0 tablets) showed decreased rrCBV in the globus pallidus and putamen; decreased FA in thalamus and frontoparietal white matter; increased FA in globus pallidus; and increased apparent diffusion coefficient in the thalamus. No changes in serotonin transporter densities and brain metabolites were observed. These findings suggest sustained effects of ecstasy on brain microvasculature, white

Assessment of bioaccumulation and neurotoxicity in rats with portacaval anastomosis and exposed to manganese phosphate: a pilot study.

PubMed

Salehi, F; Carrier, G; Normandin, L; Kennedy, G; Butterworth, R F; Hazell, A; Therrien, G; Mergler, D; Philippe, S; Zayed, J

2001-12-01

The use of the additive methylcyclopentadienyl manganese tricarbonyl in unleaded gasoline has resulted in increased attention to the potential toxic effects of manganese (Mn). Hypothetically, people with chronic liver disease may be more sensitive to the adverse neurotoxic effects of Mn. In this work, bioaccumulation of Mn, as well as histopathology and neurobehavioral damage, in end-to-side portacaval anastomosis (PCA) rats exposed to Mn phosphate via inhalation was investigated. During the week before the PCA operation, 4 wk after the PCA operation, and at the end of exposure, the rats were subjected to a locomotor evaluation (day-night activities) using a computerized autotrack system. Then a group of 6 PCA rats (EXP) was exposed to 3050 microg m(-3) (Mn phosphate) for 8 h/day, 5 days/wk for 4 consecutive weeks and compared to a control group (CON), 7 PCA rats exposed to 0.03 microg m(-3). After exposure, the rats were euthanized and Mn content in tissues and organs was determined by neutron activation analysis. The manganese concentrations in blood (0.05 microg/g vs. 0.02 microg/g), lung (1.32 microg/g vs. 0.24 microg/g), cerebellum (0.85 microg/g vs. 0.64 microg/g), frontal cortex (0.87 microg/g vs. 0.61 microg/g), and globus pallidus (3.56 microg/g vs. 1.33 microg/g) were significantly higher in the exposed group compared to the control group (p <.05). No difference was observed in liver, kidney, testes, and caudate putamen between the two groups. Neuronal cell loss was assessed by neuronal cell counts. The loss of cells in globus pallidus and caudate putamen as well as in frontal cortex was significantly higher (p <.05) for the EXP group. Assessment of the locomotor activities did not reveal any significant difference. This study constitutes a first step toward our understanding of the potential adverse effects of Mn in sensitive populations.

Aging in deep gray matter and white matter revealed by diffusional kurtosis imaging.

PubMed

Gong, Nan-Jie; Wong, Chun-Sing; Chan, Chun-Chung; Leung, Lam-Ming; Chu, Yiu-Ching

2014-10-01

Diffusion tensor imaging has already been extensively used to probe microstructural alterations in white matter tracts, and scarcely, in deep gray matter. However, results in literature regarding age-related degenerative mechanisms in white matter tracts and parametric changes in the putamen are inconsistent. Diffusional kurtosis imaging is a mathematical extension of diffusion tensor imaging, which could more comprehensively mirror microstructure, particularly in isotropic tissues such as gray matter. In this study, we used the diffusional kurtosis imaging method and a white-matter model that provided metrics of explicit neurobiological interpretations in healthy participants (58 in total, aged from 25 to 84 years). Tract-based whole-brain analyses and regions-of-interest (anterior and posterior limbs of the internal capsule, cerebral peduncle, fornix, genu and splenium of corpus callosum, globus pallidus, substantia nigra, red nucleus, putamen, caudate nucleus, and thalamus) analyses were performed to examine parametric differences across regions and correlations with age. In white matter tracts, evidence was found supportive for anterior-posterior gradient and not completely supportive for retrogenesis theory. Age-related degenerations appeared to be broadly driven by axonal loss. Demyelination may also be a major driving mechanism, although confined to the anterior brain. In terms of deep gray matter, higher mean kurtosis and fractional anisotropy in the globus pallidus, substantia nigra, and red nucleus reflected higher microstructural complexity and directionality compared with the putamen, caudate nucleus, and thalamus. In particular, the unique age-related positive correlations for fractional anisotropy, mean kurtosis, and radial kurtosis in the putamen opposite to those in other regions call for further investigation of exact underlying mechanisms. In summary, the results suggested that diffusional kurtosis can provide measurements in a new dimension that

Gadolinium Deposition in Human Brain Tissues after Contrast-enhanced MR Imaging in Adult Patients without Intracranial Abnormalities.

PubMed

McDonald, Robert J; McDonald, Jennifer S; Kallmes, David F; Jentoft, Mark E; Paolini, Michael A; Murray, David L; Williamson, Eric E; Eckel, Laurence J

2017-11-01

Purpose To determine whether gadolinium deposits in neural tissues of patients with intracranial abnormalities following intravenous gadolinium-based contrast agent (GBCA) exposure might be related to blood-brain barrier integrity by studying adult patients with normal brain pathologic characteristics. Materials and Methods After obtaining antemortem consent and institutional review board approval, the authors compared postmortem neuronal tissue samples from five patients who had undergone four to 18 gadolinium-enhanced magnetic resonance (MR) examinations between 2005 and 2014 (contrast group) with samples from 10 gadolinium-naive patients who had undergone at least one MR examination during their lifetime (control group). All patients in the contrast group had received gadodiamide. Neuronal tissues from the dentate nuclei, pons, globus pallidus, and thalamus were harvested and analyzed with inductively coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy with energy-dispersive x-ray spectroscopy, and light microscopy to quantify, localize, and assess the effects of gadolinium deposition. Results Tissues from the four neuroanatomic regions of gadodiamide-exposed patients contained 0.1-19.4 μg of gadolinium per gram of tissue in a statistically significant dose-dependent relationship (globus pallidus: ρ = 0.90, P = .04). In contradistinction, patients in the control group had undetectable levels of gadolinium with ICP-MS. All patients had normal brain pathologic characteristics at autopsy. Three patients in the contrast group had borderline renal function (estimated glomerular filtration rate <45 mL/min/1.73 m 2 ) and hepatobiliary dysfunction at MR examination. Gadolinium deposition in the contrast group was localized to the capillary endothelium and neuronal interstitium and, in two cases, within the nucleus of the cell. Conclusion Gadolinium deposition in neural tissues after GBCA administration occurs in the absence of intracranial

[Deep brain recording and length of surgery in stereotactic and functional neurosurgery for movement disorders].

PubMed

Teijeiro, Juan; Macías, Raúl J; Maragoto, Carlos; García, Iván; Alvarez, Mario; Quintanal, Nelson E

2014-01-01

Our objectives were to study the length of multi-unit recordings (MURs) of brain activity in 20 years of movement disorder neurosurgeries and to determine the number of times in which it was necessary for the teams using single-unit recording (SUR) to explore all the electrode tracks in the simultaneously recorded sites (SRS). This was a retrospective descriptive statistical analysis of MUR length on 4,296 tracks in 952 surgeries. The exclusion criteria were: tracks with fewer than 5 recorded signals, tracks that had a signal length different from the habitual 2s, or there being unusual situations not related to the MUR, as well as the first 20 surgeries of each surgical target. This yielded a total of 3,448 tracks in 805 surgeries. We also determined the number of the total 952 surgeries in which all the tracks in the SURs of the SRS were explored. The mean and its confidence interval (P=.05) of time per MUR track were 5.49±0.16min in subthalamic nucleus surgery, 8.82±0.24min in the medial or internal globus pallidus) and 18.51±1.31min in the ventral intermediate nucleus of the thalamus. For the total sum of tracks per surgery, in 75% of cases the total time was less than 39min in subthalamic nucleus, almost 42min in the medial or internal globus pallidus and less than 1h and 17min in ventral intermediate nucleus of the thalamus. All the tracks in the SUR SRS were explored in only 4.2% of the surgeries. The impact of MUR on surgical time is acceptable for this guide in objective localization for surgical targets, without having to use several simultaneous electrodes (not all indispensable in most of the cases). Consequently, there is less risk for the patient. Copyright © 2013 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

Weak trophic links between a crab-spider and the effective pollinators of a rewardless orchid

NASA Astrophysics Data System (ADS)

Quintero, Carolina; Corley, Juan C.; Aizen, Marcelo A.

2015-01-01

Sit and wait predators hunting on flowers are considered to be exploiters of plant-pollinator mutualisms. Several studies have shown that plant-pollinator interactions can be highly susceptible to the impact of a third trophic level, via consumptive (direct) and non-consumptive (indirect) effects that alter pollinator behavior and, ultimately, plant fitness. However, most flowering plants attract a wide array of flower visitors, from which only a subset will be effective pollinators. Hence, a negative effect of an ambush predator on plant fitness should be expected only when: (i) the effective pollinators are part of the predators' diet and/or (ii) the non-consumptive effects of predator presence (e.g. dead prey) alter the behavior of effective pollinators and pollen movement among individual plants. We analyzed the direct and indirect effects of a crab-spider (Misumenops pallidus), on the pollination and reproductive success of Chloraea alpina, a Patagonian rewardless orchid. Our results indicate that most of the flower visitors do not behave as effective pollinators and most effective pollinators were not observed as prey for the crab-spider. In terms of non-consumptive effects, inflorescences with and without spiders and/or dead-prey did not vary the frequency of flower visitors, nor pollinia removal or deposition. Hence, it is not surprising that M. pallidus has a neutral effect on pollinia removal and deposition as well as on fruit and seed set. Similar to other rewardless orchids, the low reproductive success of C. alpina (∼6% fruit set) was associated with the limited number of visits by effective pollinators. Negative top-down effects of a flower-visitor predator on plant pollination may not be anticipated without studying the direct and indirect effects of this predator on the effective pollinators. In pollination systems where effective pollinators visited flowers erratically, such as in deceptive orchids, we expect weak or no effect of predators on

Relationship between Iron Accumulation and White Matter Injury in Multiple Sclerosis: A Case-Control Study

PubMed Central

Raz, Eytan; Branson, Brittany; Jensen, Jens H.; Bester, Maxim; Babb, James S.; Herbert, Joseph; Grossman, Robert I.; Inglese, Matilde

2015-01-01

PURPOSE Despite the increasing development and applications of iron imaging, the pathophysiology of iron accumulation in multiple sclerosis (MS), and its role in disease progression and development of clinical disability, is poorly understood. The aims of our study were to determine the presence and extent of iron in T2 visible lesions and gray and white matter using magnetic field correlation (MFC) MRI and correlate with microscopic white matter (WM) injury as measured by diffusion tensor imaging (DTI). MATERIALS AND METHODS This is a case-control study incuding a series of 31 patients with clinically definite MS. The mean age was 39 years [standard deviation (SD)=9.55], they were 11 males and 20 females, with a disease duration average of 3 years (range 0-13) and a median EDSS of 2 (0-4.5). Seventeen healthy volunteers (6 males and 11 females) with a mean age of 36 years (SD=11.4) were recruited. All subjects underwent MR imaging on a 3T scanner using T2-weighted sequence, 3D T1 MPRAGE, MFC, single-shot DTI and postcontrast T1. T2-lesion volumes, brain volumetry, DTI parameters and iron quantification were calculated and multiple correlations were exploited. RESULTS Increased MFC was found in the putamen (p=0.061), the thalamus (p=0.123), the centrum semiovale (p=0.053), globus pallidus (p=0.008) and gray matter (GM) (p=0.004) of MS patients compared to controls. The mean lesional MFC was 121 s−2 (SD=67), significantly lower compared to the GM MFC (<0.0001). The GM mean diffusivity (MD) was inversely correlated with the MFC in the centrum semiovale (p<0.001), and in the splenium of the corpus callosum (p<0.001). CONCLUSION Patients with MS have increased iron in the globus pallidus, putamen and centrum with a trend toward increased iron in all the brain structures. Quantitative iron evaluation of WM and GM may improve the understanding of MS pathophysiology, and might serve as a surrogate marker of disease progression. PMID:25416468

Recovering more than tree cover: herbivores and herbivory in a restored tropical dry forest.

PubMed

Juan-Baeza, Iris; Martínez-Garza, Cristina; Del-Val, Ek

2015-01-01

Intense and chronic disturbance may arrest natural succession, reduce environmental quality and lead to ecological interaction losses. Where natural succession does not occur, ecological restoration aims to accelerate this process. While plant establishment and diversity is promoted by restoration, few studies have evaluated the effect of restoration activities on ecological processes and animal diversity. This study assessed herbivory and lepidopteran diversity associated with two pioneer tree species growing in 4-year-old experimental restoration plots in a tropical dry forest at Sierra de Huautla, in Morelos, Mexico. The study was carried out during the rainy season of 2010 (July-October) in eleven 50 x 50 m plots in three different habitats: cattle-excluded, cattle-excluded with restoration plantings, and cattle grazing plots. At the beginning of the rainy season, 10 juveniles of Heliocarpus pallidus (Malvaceae) and Ipomoea pauciflora (Convolvulaceae) were selected in each plot (N = 110 trees). Herbivory was measured in 10 leaves per plant at the end of the rainy season. To evaluate richness and abundance of lepidopteran larvae, all plants were surveyed monthly. Herbivory was similar among habitats and I. pauciflora showed a higher percentage of herbivory. A total of 868 lepidopteran larvae from 65 morphospecies were recorded. The family with the highest number of morphospecies (9 sp.) was Geometridae, while the most abundant family was Saturnidae, with 427 individuals. Lepidopteran richness and abundance were significantly higher in H. pallidus than in I. pauciflora. Lepidopteran richness was significantly higher in the cattle-excluded plots, while abundance was significantly higher in the non-excluded plots. After four years of cattle exclusion and the establishment of plantings, lepidopteran richness increased 20 -fold in the excluded plots compared to the disturbed areas, whereas herbivory levels were equally high in both restored and disturbed sites

Osteomyelitis due to Salmonella enterica subsp. arizonae: the price of exotic pets.

PubMed

Kolker, S; Itsekzon, T; Yinnon, A M; Lachish, T

2012-02-01

We describe a 31-year-old immunocompromised patient who developed sepsis and osteomyelitis due to Salmonella enterica subsp. arizonae secondary to exposure to iguana and snakes kept as pets at her home, and review all 23 previously published cases of bone and joint infections due to this organism, for a total of nine children and 15 adults. Eleven of the adults were female (73%), compared with three (33%) of the children (p <0.01). Significant underlying illnesses were present in all 15 adults and in five children (55%, p <0.05); 10 (77%) of the adults were immunosuppressed, compared with one child only (17%) (p <0.05). In ten of the adults the knee was infected (67%), compared with one child only (11%, p <0.01). Antibiotic therapy was prolonged in both adults and children, and in most cases consisted of 4-6 weeks of parenteral treatment. Complete cure and survival was attained in 11 of 15 adults (73%) and all nine children (NS). Optimal antibiotic treatment probably consists of ceftriaxone or a fluoroquinolone, if the organism is susceptible. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

FDG-PET study of the bilateral subthalamic nucleus stimulation effects on the regional cerebral metabolism in advanced Parkinson disease.

PubMed

Li, D; Zuo, C; Guan, Y; Zhao, Y; Shen, J; Zan, S; Sun, B

2006-01-01

The aim of the study was to evaluate the changes in regional cerebral metabolic rate of glucose (rCMRGlu) induced by bilateral subthalamic nucleurs (STN) stimulation in advanced Parkinson's disease (PD). 18F-Fluorodeoxyglucose (FDG) PET data obtained before and one month after stimulation were analyzed with statistical parametric mapping (SPM). As a result of clinically effective bilateral STN stimulation, rCMRGlu increased in lateral globus pallidus (GP), upper brain stem, dorsolateral prefrontal cortex (DLPFC) and posterior parietal-occipital cortex, and decreased in the orbital frontal cortex and parahippocampus gyrus (p < 0.001). We conclude that the alleviation of clinical symptoms in advanced PD by bilateral STN stimulation may be the result of activation of both ascending and descending pathways from STN and of restoration of the impaired higher-order cortex functions.

Microsatellite DNA markers for assessing phylogeographic and population structure in Preble's meadow jumping mice (Zapus hudsonius preblei) and cross-amplification among neighbouring taxa

USGS Publications Warehouse

King, T.L.; Eackles, M.S.; Young, C.

2006-01-01

We document the isolation and characterization of 14 tetranucleotide microsatellite DNA markers in Preble's meadow jumping mouse (Zapus hudsonius preblei). The identified markers displayed moderate levels of allelic diversity (averaging 4.9 alleles per locus) and heterozygosity (averaging 55.1%). Genotypic and allelic frequencies in a collection of 30 individuals conformed to Hardy-Weinberg equilibrium expectations and indicated no linkage disequilibrium. High levels of cross-amplification (95% overall) among neighbouring subspecies and two congeners (Zapus princeps and Zapus trinotatus) were observed. Multilocus genotypes resulting from these markers appear to provide ample genetic diversity for studies assessing individual- and population-level ecological interactions within Z. h. preblei and evolutionary relationships among neighbouring subspecies (Z. h. campestris, Z. h. intermedius, Z. h. pallidus and Z. h. luteus). ?? 2006 The Authors.

A comparison of the effects of morphine, enkephalin, kyotorphin and D-phenylalanine on rat central neurones.

PubMed Central

Stone, T. W.

1983-01-01

1 Morphine, Met-enkephalin, kyotorphin and D-phenylalanine have been applied by microiontophoresis to neurones in the globus pallidus and cerebral cortex of rats anaesthetized with urethane. 2 In the pallidum, most cells were inhibited by all the agonists, with a high correspondence between cells inhibited by Met-enkephalin and D-phenylalanine and by Met-enkephalin and kyotorphin. Whereas responses to Met-enkephalin were readily antagonized by naloxone, responses to kyotorphin and D-phenylalanine were not. 3 In the cerebral cortex a high proportion of cells was excited by all four agonists and antagonism by naloxone was less consistent than in pallidum. 4 It is concluded that the naloxone-reversible analgesic effects of kyotorphin and D-phenylalanine may be mediated indirectly, rather through an activation of opiate receptors. PMID:6871550

A comparison of the effects of morphine, enkephalin, kyotorphin and D-phenylalanine on rat central neurones.

PubMed

Stone, T W

1983-05-01

1 Morphine, Met-enkephalin, kyotorphin and D-phenylalanine have been applied by microiontophoresis to neurones in the globus pallidus and cerebral cortex of rats anaesthetized with urethane. 2 In the pallidum, most cells were inhibited by all the agonists, with a high correspondence between cells inhibited by Met-enkephalin and D-phenylalanine and by Met-enkephalin and kyotorphin. Whereas responses to Met-enkephalin were readily antagonized by naloxone, responses to kyotorphin and D-phenylalanine were not. 3 In the cerebral cortex a high proportion of cells was excited by all four agonists and antagonism by naloxone was less consistent than in pallidum. 4 It is concluded that the naloxone-reversible analgesic effects of kyotorphin and D-phenylalanine may be mediated indirectly, rather through an activation of opiate receptors.

Electro-acupuncture stimulation acts on the basal ganglia output pathway to ameliorate motor impairment in Parkinsonian model rats.

PubMed

Jia, Jun; Li, Bo; Sun, Zuo-Li; Yu, Fen; Wang, Xuan; Wang, Xiao-Min

2010-04-01

The role of electro-acupuncture (EA) stimulation on motor symptoms in Parkinson's disease (PD) has not been well studied. In a rat hemiparkinsonian model induced by unilateral transection of the medial forebrain bundle (MFB), EA stimulation improved motor impairment in a frequency-dependent manner. Whereas EA stimulation at a low frequency (2 Hz) had no effect, EA stimulation at a high frequency (100 Hz) significantly improved motor coordination. However, neither low nor high EA stimulation could significantly enhance dopamine levels in the striatum. EA stimulation at 100 Hz normalized the MFB lesion-induced increase in midbrain GABA content, but it had no effect on GABA content in the globus pallidus. These results suggest that high-frequency EA stimulation improves motor impairment in MFB-lesioned rats by increasing GABAergic inhibition in the output structure of the basal ganglia.

Review of the Nearctic genus Lacconotus LeConte (Coleoptera, Mycteridae, Eurypinae)

PubMed Central

Pollock, Darren; Majka, Christopher G.

2012-01-01

Abstract Lacconotus LeConte, the sole Nearctic representative of the eurypine Mycteridae, is revised, based on morphological features of adults. The following syn. n. is proposed: Lacconotus pallidus Van Dyke, 1928 = Lacconotus pinicola Horn, 1879. The former is a light-colored form with a southern California distribution. A subgen. n., Alcconotus, is described for Lacconotus pinicola, producing the following comb. n.: Lacconotus (Alcconotus) pinicola (Horn). A lectotype is designated for Lacconotus pinicola. A key separating the two subgenera and species is provided, as are photographs and illustrations of salient structures of adults, and maps showing collection localities. Lacconotus punctatus is newly recorded in Alabama, Arkansas, Massachusetts, Oklahoma, Texas, and Wisconsin; Lacconotus pinicola is newly recorded in Arizona and Utah in the USA, and Baja California Norte in Mexico. Phenology information shows a north-to-south gradation in occurrence time. PMID:22303123

Degradation of Lignin by Cyathus Species

PubMed Central

Abbott, Thomas P.; Wicklow, Donald T.

1984-01-01

The ability of 12 Cyathus species to degrade 14C-labeled lignin in kenaf was studied. The sum of 14C released into solution plus 14C released into the gas phase over a 32-day fermentation period was used to determine average daily rates of lignin biodegradation. Cyathus pallidus. C. africanus, and C. berkeleyanus delignified kenaf most rapidly. C. canna showed the greatest preference for lignin degradation over other plant components, and its rate of lignin degradation was only slightly lower than the three most active species. The apparent ability of fungi to metabolize low-molecular-weight lignin breakdown products correlated well with their overall delignification rates. C. stercoreus metabolized degradation products of lignin from wheat straw better than those from kenaf lignin, based on the amount of low-molecular-weight products left in solution. PMID:16346497

A specific role for posterior dorsolateral striatum in human habit learning

PubMed Central

Tricomi, Elizabeth; Balleine, Bernard W.; O’Doherty, John P.

2009-01-01

Habits are characterized by an insensitivity to their consequences and, as such, can be distinguished from goal-directed actions. The neural basis of the development of demonstrably outcome insensitive habitual actions in humans has not been previously characterized. In this experiment, we show that extensive training on a free-operant task reduces the sensitivity of participants’ behavior to a reduction in outcome value. Analysis of functional magnetic resonance imagine (fMRI) data acquired during training revealed a significant increase in task-related cue sensitivity in a right posterior putamen/globus pallidus region as training progressed. These results provide evidence for a shift from goal-directed to habit-based control of instrumental actions in humans, and suggest that cue-driven activation in a specific region of dorsolateral posterior putamen may contribute to the habitual control of behavior in humans. PMID:19490086

The Mosasaur Tooth Attachment Apparatus as Paradigm for the Evolution of the Gnathostome Periodontium

PubMed Central

Luan, Xianghong; Walker, Cameron; Dangaria, Smit; Ito, Yoshihiro; Druzinsky, Robert; Jarosius, Kristina; Lesot, Herve; Rieppel, Olivier

2009-01-01

Vertebrate teeth are attached to jaws by a variety of mechanisms, including acrodont, pleurodont, and thecodont modes of attachment. Recent studies have suggested that various modes of attachment exist within each sub-category. Especially squamates feature a broad diversity of modes of attachment. Here we have investigated tooth attachment tissues in the late cretaceous mosasaur Clidastes and compared mosasaur tooth attachment with modes of attachment found in other extant reptiles. Using histologic analysis of ultrathin ground sections, four distinct mineralized tissues that anchor mosasaur teeth to the jaw were identified: (i) an acellular cementum layer at the interface between root and cellular cementum, (ii) a massive cone consisting of trabecular cellular cementum, (iii) the mineralized periodontal ligament containing mineralized Sharpey’s fibers, and (iv) the interdental ridges connecting adjacent teeth. The complex, multilayered attachment apparatus in mosasaurs was compared with attachment tissues in extant reptiles, including Iguana and Caiman. Based on our comparative analysis we postulate the presence of a quadruple-layer tissue architecture underlying reptilian tooth attachment, comprised of acellular cementum, cellular cementum, mineralized periodontal ligament, and interdental ridge (alveolar bone). We propose that the mineralization status of the periodontal ligament is a dynamic feature in vertebrate evolution subject to functional adaptation. PMID:19469852

Pairing Animal Cartoon Characters With Produce Stimulates Selection Among Child Zoo Visitors

PubMed Central

Karpyn, Allison; Allen, Michael; Marks, Samantha; Filion, Nicole; Humphrey, Debora; Ye, Ai; May, Henry; Gardner, Meryl P.

2017-01-01

In order to address the pervasive trend of underconsumption of fruits and vegetables among children, we examined the hypothesis that children would be more likely to select fruits (apple slices, bananas, and oranges) and vegetables (baby carrots) when paired with animal cartoon image than when available without the character image. Tested in a randomized experiment using counterbalancing, products were arranged on two tables at two separate family fun nights held at a local zoo. Animal character produce parings were manipulated by placing one of two animals (tamarin or iguana) next to two of the four fruit or vegetable selections at each table, and by changing when available without the image. In total, 755 produce selections were made. Significantly more products paired with a character were selected (62.38%) than the same products, not paired (37.62%), χ2 = 46.32, df = 1, p < .001. The odds ratio of the treatment versus control was 1.66 (i.e., 471/284), indicating that children were 66% more likely to select a snack when paired with an animal cartoon. Study findings highlight the positive impact of animal cartoons on children’s fruit and vegetable snack selections, and results suggest the potential for using animal cartoons to encourage fruit and vegetable selection for children. PMID:27866159

Pairing Animal Cartoon Characters With Produce Stimulates Selection Among Child Zoo Visitors.

PubMed

Karpyn, Allison; Allen, Michael; Marks, Samantha; Filion, Nicole; Humphrey, Debora; Ye, Ai; May, Henry; Gardner, Meryl P

2017-08-01

In order to address the pervasive trend of underconsumption of fruits and vegetables among children, we examined the hypothesis that children would be more likely to select fruits (apple slices, bananas, and oranges) and vegetables (baby carrots) when paired with animal cartoon image than when available without the character image. Tested in a randomized experiment using counterbalancing, products were arranged on two tables at two separate family fun nights held at a local zoo. Animal character produce parings were manipulated by placing one of two animals (tamarin or iguana) next to two of the four fruit or vegetable selections at each table, and by changing when available without the image. In total, 755 produce selections were made. Significantly more products paired with a character were selected (62.38%) than the same products, not paired (37.62%), χ 2 = 46.32, df = 1, p < .001. The odds ratio of the treatment versus control was 1.66 (i.e., 471/284), indicating that children were 66% more likely to select a snack when paired with an animal cartoon. Study findings highlight the positive impact of animal cartoons on children's fruit and vegetable snack selections, and results suggest the potential for using animal cartoons to encourage fruit and vegetable selection for children.

Real-Time Electronic Dashboard Technology and Its Use to Improve Pediatric Radiology Workflow.

PubMed

Shailam, Randheer; Botwin, Ariel; Stout, Markus; Gee, Michael S

The purpose of our study was to create a real-time electronic dashboard in the pediatric radiology reading room providing a visual display of updated information regarding scheduled and in-progress radiology examinations that could help radiologists to improve clinical workflow and efficiency. To accomplish this, a script was set up to automatically send real-time HL7 messages from the radiology information system (Epic Systems, Verona, WI) to an Iguana Interface engine, with relevant data regarding examinations stored in an SQL Server database for visual display on the dashboard. Implementation of an electronic dashboard in the reading room of a pediatric radiology academic practice has led to several improvements in clinical workflow, including decreasing the time interval for radiologist protocol entry for computed tomography or magnetic resonance imaging examinations as well as fewer telephone calls related to unprotocoled examinations. Other advantages include enhanced ability of radiologists to anticipate and attend to examinations requiring radiologist monitoring or scanning, as well as to work with technologists and operations managers to optimize scheduling in radiology resources. We foresee increased utilization of electronic dashboard technology in the future as a method to improve radiology workflow and quality of patient care. Copyright © 2017 Elsevier Inc. All rights reserved.

Design and experimental analysis of a new malleovestibulopexy prosthesis using a finite element model of the human middle ear.

PubMed

Vallejo Valdezate, Luis A; Hidalgo Otamendi, Antonio; Hernández, Alberto; Lobo, Fernando; Gil-Carcedo Sañudo, Elisa; Gil-Carcedo García, Luis M

2015-01-01

Many designs of prostheses are available for middle ear surgery. In this study we propose a design for a new prosthesis, which optimises mechanical performance in the human middle ear and improves some deficiencies in the prostheses currently available. Our objective was to design and assess the theoretical acoustic-mechanical behaviour of this new total ossicular replacement prosthesis. The design of this new prosthesis was based on an animal model (an iguana). For the modelling and mechanical analysis of the new prosthesis, we used a dynamic 3D computer model of the human middle ear, based on the finite elements method (FEM). The new malleovestibulopexy prosthesis design demonstrates an acoustical-mechanical performance similar to that of the healthy human middle ear. This new design also has additional advantages, such as ease of implantation and stability in the middle ear. This study shows that computer simulation can be used to design and optimise the vibroacoustic characteristics of middle ear implants and demonstrates the effectiveness of a new malleovestibulopexy prosthesis in reconstructing the ossicular chain. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Brain glucose metabolism in adults with ataxia-telangiectasia and their asymptomatic relatives.

PubMed

Volkow, Nora D; Tomasi, Dardo; Wang, Gene-Jack; Studentsova, Yana; Margus, Brad; Crawford, Thomas O

2014-06-01

Ataxia-telangiectasia is a recessive genetic disorder (ATM is the mutated gene) of childhood with severe motor impairments and whereas homozygotes manifest the disorder, heterozygotes are asymptomatic. Structural brain imaging and post-mortem studies in individuals with ataxia-telangiectasia have reported cerebellar atrophy; but abnormalities of motor control characteristic of extrapyramidal dysfunction suggest impairment of broader motor networks. Here, we investigated possible dysfunction in other brain areas in individuals with ataxia-telangiectasia and tested for brain changes in asymptomatic relatives to assess if heterozygocity affects brain function. We used positron emission tomography and (18)F-fluorodeoxyglucose to measure brain glucose metabolism (quantified as µmol/100 g/min), which serves as a marker of brain function, in 10 adults with ataxia-telangiectasia, 19 non-affected adult relatives (12 siblings, seven parents) and 29 age-matched healthy controls. Statistical parametric mapping and region of interest analyses were used to compare individuals with ataxia-telangiectasia, asymptomatic relatives, and unrelated controls. We found that participants with ataxia-telangiectasia had lower metabolism in cerebellar hemispheres (14%, P < 0.001), anterior vermis (40%, P < 0.001) and fusiform gyrus (20%, P < 0.001) compared with controls or siblings, and lower metabolism in hippocampus (12%, P = 0.05) compared with controls, and showed significant intersubject variability (decreases in vermis ranged from 18% to 60%). Participants with ataxia-telangiectasia also had higher metabolism in globus pallidus (16%, P = 0.05), which correlated negatively with motor performance. Asymptomatic relatives had lower metabolism in anterior vermis (12%; P = 0.01) and hippocampus (19%; P = 0.002) than controls. Our results indicate that, in addition to the expected decrease in cerebellar metabolism, participants with ataxia-telangiectasia had widespread changes in metabolic

Assessment of bioaccumulation, neuropathology, and neurobehavior following subchronic (90 days) inhalation in Sprague-Dawley rats exposed to manganese phosphate.

PubMed

Normandin, Louise; Carrier, Gaétan; Gardiner, Phillip F; Kennedy, Greg; Hazell, Alan S; Mergler, Donna; Butterworth, Roger F; Philippe, Suzanne; Zayed, Joseph

2002-09-01

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic manganese (Mn) compound added to unleaded gasoline. It has been suggested that the combustion products of MMT containing Mn, such as manganese phosphate, could cause neurological symptoms similar to Parkinson's disease in humans. The aim of this work was to investigate the exposure-response relationship of bioaccumulation, neuropathology, and neurobehavior following a subchronic inhalation exposure to manganese phosphate in Sprague-Dawley male rats. Rats were exposed 6 h/day, 5 days/week for 13 consecutive weeks at 30, 300, or 3000 microg/m(3) Mn phosphate and compared to controls. Some rats were implanted with chronic EMG electrodes in the gastrocnemius muscle of the hind limb to assess tremor at the end of Mn exposure. Spontaneous motor activity was measured for 36 h using a computerized autotrack system. Rats were then sacrificed by exsanguination and Mn level in different brain tissues and other organs was determined by instrumental neutron activation analysis. Neuronal cell counts were obtained by assessing the sum of five grid areas for the caudate/putamen and the sum of two adjacent areas for the globus pallidus. Increased manganese concentrations were observed in all tissues of the brain and was dose-dependent in olfactory bulb and caudate/putamen. In fact, beginning with the highest level of exposure (3000 microg/m(3)) and ending with the control group, Mn concentrations in the olfactory bulb were 2.47 vs 1.28 vs 0.77 vs 0.64 ppm (P < 0.05) while for the caudate/putamen, Mn concentrations were 1.06 vs 0.73 vs 0.62 vs 0.47 ppm (P < 0.05). The Mn concentrations in lung were also dose-dependent (10.30 vs 1.40 vs 0.42 vs 0.17 ppm; P < 0.05). No statistical difference was observed for loss of neurons in caudate/putamen and globus pallidus. Locomotor activity assessment and tremor assessment did not reveal in neurobehavioral changes between the groups. Our results reinforce the hypothesis that the

Clinical and Imaging Presentation of a Patient with Beta-Propeller Protein-Associated Neurodegeneration, a Rare and Sporadic form of Neurodegeneration with Brain Iron Accumulation (NBIA).

PubMed

Hattingen, Elke; Handke, Nikolaus; Cremer, Kirsten; Hoffjan, Sabine; Kukuk, Guido Matthias

2017-12-01

Neurodegeneration with brain iron accumulation (NBIA) is a heterogeneous group of inherited neurologic disorders with iron accumulation in the basal ganglia, which share magnetic resonance (MR) imaging characteristics, histopathologic and clinical features. According to the affected basal nuclei, clinical features include extrapyramidal movement disorders and varying degrees of intellectual disability status. The most common NBIA subtype is caused by pathogenic variants in PANK2. The hallmark of MR imaging in patients with PANK2 mutations is an eye-of-the-tiger sign in the globus pallidus. We report a 33-year-old female with a rare subtype of NBIA, called beta-propeller protein-associated neurodegeneration (BPAN) with a hitherto unknown missense variant in WDR45. She presented with BPAN's particular biphasic course of neurological symptoms and with a dominant iron accumulation in the midbrain that enclosed a spotty T2-hyperintensity.

Five new, microendemic Asian Leaf-litter Frogs (Leptolalax) from the southern Annamite mountains, Vietnam.

PubMed

Rowley, Jodi J L; Tran, Dao T A; Le, Duong T T; Dau, Vinh Q; Peloso, Pedro L V; Nguyen, Truong Q; Hoang, Huy D; Nguyen, Tao T; Ziegler, Thomas

2016-03-01

The Leptolalax applebyi group of Asian leaf-litter frogs currently comprises four species of particularly small-bodied (<40 mm SVL) species distributed in the Central Highlands of Vietnam and northeastern Cambodia. In addition to their small size, the group is characterized by their morphological and genetic similarities, as well as their breeding habitat at headwaters of small mountain streams and seeps. A recent study suggested that at least two-thirds of the diversity of the group remained hidden within morphologically cryptic lineages. We expand upon the molecular, morphometric, and acoustic data and formally delineate and describe five of these lineages as distinct species: Leptolalax ardens sp. nov., Leptolalax kalonensis sp. nov., Leptolalax pallidus sp. nov., Leptolalax maculosus sp. nov., and Leptolalax tadungensis sp. nov. Due to habitat loss, the current ranges of these species are likely to be a fraction of their historical extent and under continued threat from deforestation.

Unusual presentation of death due to carbon monoxide poisoning. A report of two cases.

PubMed

Ruszkiewicz, A; de Boer, B; Robertson, S

1997-06-01

Two cases are reported representing opposite ends of the spectrum of death as a result of carbon monoxide poisoning from car exhaust fumes. In one case, a women was reported to be found dead in bed early in the morning by her husband. The cause of her death, established by autopsy, was carbon monoxide poisoning. Toxicology examination indicated a car engine as the possible source of carbon monoxide. The mode of administration was never established. In the second case, a women was found in a car located in her garage with a hose leading from the exhaust pipe to the interior of the sealed vehicle. Autopsy revealed negligible carboxyhemoglobin saturation of the blood, bilateral infarction of the globus pallidus, and extensive bronchopneumonia. It was concluded that inhalation of carbon monoxide resulted in sublethal hypoxia with subsequent exhalation of carbon monoxide and a delayed death.

Sex differences in amphetamine-induced displacement of [(18)F]fallypride in striatal and extrastriatal regions: a PET study.

PubMed

Riccardi, Patrizia; Zald, David; Li, Rui; Park, Sohee; Ansari, M Sib; Dawant, Benoit; Anderson, Sharlet; Woodward, Neil; Schmidt, Dennis; Baldwin, Ronald; Kessler, Robert

2006-09-01

The authors examined gender differences in d-amphetamine-induced displacements of [(18)F]fallypride in the striatal and extrastriatal brain regions and the correlations of these displacements with cognition and sensation seeking. Six women and seven men underwent positron emission tomography (PET) with [(18)F]fallypride before and after an oral dose of d-amphetamine. Percent displacements were calculated using regions of interest and parametric images of dopamine 2 (D(2)) receptor binding potential. Parametric images of dopamine release suggest that the female subjects had greater dopamine release than the male subjects in the right globus pallidus and right inferior frontal gyrus. Gender differences were observed in correlations of changes in cognition and sensation seeking with regional dopamine release. Findings revealed a greater dopamine release in women as well as gender differences in the relationship between regional dopamine release and sensation seeking and cognition.

Early neuroimaging markers of FOXP2 intragenic deletion.

PubMed

Liégeois, Frédérique J; Hildebrand, Michael S; Bonthrone, Alexandra; Turner, Samantha J; Scheffer, Ingrid E; Bahlo, Melanie; Connelly, Alan; Morgan, Angela T

2016-10-13

FOXP2 is the major gene associated with severe, persistent, developmental speech and language disorders. While studies in the original family in which a FOXP2 mutation was found showed volume reduction and reduced activation in core language and speech networks, there have been no imaging studies of different FOXP2 mutations. We conducted a multimodal MRI study in an eight-year-old boy (A-II) with a de novo FOXP2 intragenic deletion. A-II showed marked bilateral volume reductions in the hippocampus, thalamus, globus pallidus, and caudate nucleus compared with 26 control males (effect sizes from -1 to -3). He showed no detectable functional MRI activity when repeating nonsense words. The hippocampus is implicated for the first time in FOXP2 diseases. We conclude that FOXP2 anomaly is either directly or indirectly associated with atypical development of widespread subcortical networks early in life.

Successful deep brain stimulation surgery with intraoperative magnetic resonance imaging on a difficult neuroacanthocytosis case: case report.

PubMed

Lim, Thien Thien; Fernandez, Hubert H; Cooper, Scott; Wilson, Kathryn Mary K; Machado, Andre G

2013-07-01

Chorea acanthocytosis is a progressive hereditary neurodegenerative disorder characterized by hyperkinetic movements, seizures, and acanthocytosis in the absence of any lipid abnormality. Medical treatment is typically limited and disappointing. We report on a 32-year-old patient with chorea acanthocytosis with a failed attempt at awake deep brain stimulation (DBS) surgery due to intraoperative seizures and postoperative intracranial hematoma. He then underwent a second DBS operation, but under general anesthesia and with intraoperative magnetic resonance imaging guidance. Marked improvement in his dystonia, chorea, and overall quality of life was noted 2 and 8 months postoperatively. DBS surgery of the bilateral globus pallidus pars interna may be useful in controlling the hyperkinetic movements in neuroacanthocytosis. Because of the high propensity for seizures in this disorder, DBS performed under general anesthesia, with intraoperative magnetic resonance imaging guidance, may allow successful implantation while maintaining accurate target localization.

A Stepwise Approach: Decreasing Infection in Deep Brain Stimulation for Childhood Dystonic Cerebral Palsy.

PubMed

Johans, Stephen J; Swong, Kevin N; Hofler, Ryan C; Anderson, Douglas E

2017-09-01

Dystonia is a movement disorder characterized by involuntary muscle contractions, which cause twisting movements or abnormal postures. Deep brain stimulation has been used to improve the quality of life for secondary dystonia caused by cerebral palsy. Despite being a viable treatment option for childhood dystonic cerebral palsy, deep brain stimulation is associated with a high rate of infection in children. The authors present a small series of patients with dystonic cerebral palsy who underwent a stepwise approach for bilateral globus pallidus interna deep brain stimulation placement in order to decrease the rate of infection. Four children with dystonic cerebral palsy who underwent a total of 13 surgical procedures (electrode and battery placement) were identified via a retrospective review. There were zero postoperative infections. Using a multistaged surgical plan for pediatric patients with dystonic cerebral palsy undergoing deep brain stimulation may help to reduce the risk of infection.

A Hypothalamic Switch for REM and Non-REM Sleep.

PubMed

Chen, Kai-Siang; Xu, Min; Zhang, Zhe; Chang, Wei-Cheng; Gaj, Thomas; Schaffer, David V; Dan, Yang

2018-03-07

Rapid eye movement (REM) and non-REM (NREM) sleep are controlled by specific neuronal circuits. Here we show that galanin-expressing GABAergic neurons in the dorsomedial hypothalamus (DMH) comprise separate subpopulations with opposing effects on REM versus NREM sleep. Microendoscopic calcium imaging revealed diverse sleep-wake activity of DMH GABAergic neurons, but the galanin-expressing subset falls into two distinct groups, either selectively activated (REM-on) or suppressed (REM-off) during REM sleep. Retrogradely labeled, preoptic area (POA)-projecting galaninergic neurons are REM-off, whereas the raphe pallidus (RPA)-projecting neurons are primarily REM-on. Bidirectional optogenetic manipulations showed that the POA-projecting neurons promote NREM sleep and suppress REM sleep, while the RPA-projecting neurons have the opposite effects. Thus, REM/NREM switch is regulated antagonistically by DMH galaninergic neurons with intermingled cell bodies but distinct axon projections. Copyright © 2018 Elsevier Inc. All rights reserved.

Advanced Parkinson's disease: clinical characteristics and treatment. Part II.

PubMed

Kulisevsky, J; Luquin, M R; Arbelo, J M; Burguera, J A; Carrillo, F; Castro, A; Chacón, J; García-Ruiz, P J; Lezcano, E; Mir, P; Martinez-Castrillo, J C; Martínez-Torres, I; Puente, V; Sesar, A; Valldeoriola-Serra, F; Yañez, R

2013-01-01

Many patients who have had Parkinson's disease (PD) for several years will present severe motor fluctuations and dyskinesias which require more aggressive therapies. The different approaches which are now available include deep brain stimulation of the subthalamic nucleus or medial globus pallidus, subcutaneous infusion of apomorphine, and intestinal infusion of levodopa-carbidopa. To define the indications and results for the 3 available therapies for advanced PD. Exhaustive review of the literature concerning the indications and results of deep brain stimulation, subcutaneous apomorphine infusion and duodenal infusion of levodopa/carbidopa gel to treat patients with advanced Parkinson disease. Although numerous studies have confirmed the efficacy of the 3 different therapies in advanced PD, there are no comparative studies that would allow us to define the best candidate for each technique. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Investigating the neural correlates of smoking: Feasibility and results of combining electronic cigarettes with fMRI.

PubMed

Wall, Matthew B; Mentink, Alexander; Lyons, Georgina; Kowalczyk, Oliwia S; Demetriou, Lysia; Newbould, Rexford D

2017-09-12

Cigarette addiction is driven partly by the physiological effects of nicotine, but also by the distinctive sensory and behavioural aspects of smoking, and understanding the neural effects of such processes is vital. There are many practical difficulties associated with subjects smoking in the modern neuroscientific laboratory environment, however electronic cigarettes obviate many of these issues, and provide a close simulation of smoking tobacco cigarettes. We have examined the neural effects of 'smoking' electronic cigarettes with concurrent functional Magnetic Resonance Imaging (fMRI). The results demonstrate the feasibility of using these devices in the MRI environment, and show brain activation in a network of cortical (motor cortex, insula, cingulate, amygdala) and sub-cortical (putamen, thalamus, globus pallidus, cerebellum) regions. Concomitant relative deactivations were seen in the ventral striatum and orbitofrontal cortex. These results reveal the brain processes involved in (simulated) smoking for the first time, and validate a novel approach to the study of smoking, and addiction more generally.

Revision of the Neotropical water scavenger beetle genus Tobochares Short & García, 2007 (Coleoptera, Hydrophilidae, Acidocerinae)

PubMed Central

Kohlenberg, Alex T.; Short, Andrew Edward Z.

2017-01-01

Abstract The genus Tobochares Short & García, 2007 is revised. A combination of morphological and molecular data provide support for ten distinct species. Five new species are described: T. canaliculatus sp. n. (Venezuela), T. canthus sp. n. (Venezuela), T. emarginatus sp. n. (Suriname), T. kusad sp. n. (Guyana), and T. pallidus sp. n. (Venezuela). All four preexisting species are redescribed. A tenth species, known from a single female from Venezuela, is left undescribed pending the collection of additional specimens. New collecting records are provided for T. sulcatus Short & García, 2007 and T. kasikasima Short, 2013. Tobochares sipaliwini Short & Kadosoe, 2011 is newly recorded from Guyana. All species are associated with seepage or wet rock habitats, although some species have also been found along the margins of streams that flow over rocky substrates. High-resolution images including scanning electron micrographs are provided, as well as a key to species and habitat photographs. PMID:28769656

Neuroanatomical pathways underlying the effects of hypothalamo-hypophysial-adrenal hormones on exploratory activity.

PubMed

Lalonde, Robert; Strazielle, Catherine

2017-07-26

When injected via the intracerebroventricular route, corticosterone-releasing hormone (CRH) reduced exploration in the elevated plus-maze, the center region of the open-field, and the large chamber in the defensive withdrawal test. The anxiogenic action of CRH in the elevated plus-maze also occurred when infused in the basolateral amygdala, ventral hippocampus, lateral septum, bed nucleus of the stria terminalis, nucleus accumbens, periaqueductal grey, and medial frontal cortex. The anxiogenic action of CRH in the defensive withdrawal test was reproduced when injected in the locus coeruleus, while the amygdala, hippocampus, lateral septum, nucleus accumbens, and lateral globus pallidus contribute to center zone exploration in the open-field. In addition to elevated plus-maze and open-field tests, the amygdala appears as a target region for CRH-mediated anxiety in the elevated T-maze. Thus, the amygdala is the principal brain region identified with these three tests, and further research must identify the neural circuits underlying this form of anxiety.

Neuroimaging and cognitive changes during déjà vu.

PubMed

Kovacs, Norbert; Auer, Tibor; Balas, Istvan; Karadi, Kazmer; Zambo, Katalin; Schwarcz, Attila; Klivenyi, Peter; Jokeit, Hennric; Horvath, Krisztina; Nagy, Ferenc; Janszky, Jozsef

2009-01-01

The cause or the physiological role of déjà vu (DV) in healthy people is unknown. The pathophysiology of DV-type epileptic aura is also unresolved. Here we describe a 22-year-old woman treated with deep brain stimulation (DBS) of the left internal globus pallidus for hemidystonia. At certain stimulation settings, DBS elicited reproducible episodes of DV. Neuropsychological tests and single-photon-emission computed tomography (SPECT) were performed during DBS-evoked DV and during normal DBS stimulation without DV. SPECT during DBS-evoked DV revealed hyperperfusion of the right (contralateral to the electrode) hippocampus and other limbic structures. Neuropsychological examinations performed during several evoked DV episodes revealed disturbances in nonverbal memory. Our results confirm the role of mesiotemporal structures in the pathogenesis of DV. We hypothesize that individual neuroanatomy and disturbances in gamma oscillations or in the dopaminergic system played a role in DBS-elicited DV in our patient.

Therapeutic deep brain stimulation in Parkinsonian rats directly influences motor cortex.

PubMed

Li, Qian; Ke, Ya; Chan, Danny C W; Qian, Zhong-Ming; Yung, Ken K L; Ko, Ho; Arbuthnott, Gordon W; Yung, Wing-Ho

2012-12-06

Much recent discussion about the origin of Parkinsonian symptoms has centered around the idea that they arise with the increase of beta frequency waves in the EEG. This activity may be closely related to an oscillation between subthalamic nucleus (STN) and globus pallidus. Since STN is the target of deep brain stimulation, it had been assumed that its action is on the nucleus itself. By means of simultaneous recordings of the firing activities from populations of neurons and the local field potentials in the motor cortex of freely moving Parkinsonian rats, this study casts doubt on this assumption. Instead, we found evidence that the corrective action is upon the cortex, where stochastic antidromic spikes originating from the STN directly modify the firing probability of the corticofugal projection neurons, destroy the dominance of beta rhythm, and thus restore motor control to the subjects, be they patients or rodents. Copyright © 2012 Elsevier Inc. All rights reserved.

Parkinsonism due to manganism in a welder: neurological and neuropsychological sequelae.

PubMed

Bowler, Rosemarie M; Koller, William; Schulz, Paul E

2006-05-01

A 33-year-old welder with 3 years of exposure to manganese (Mn) bearing welding fumes was seen by neurologists for cognitive and motor complaints. He exhibited signs and symptoms of Parkinson's disease, including tremor, bradykinesia, gait disturbance and cogwheel rigidity. However, he was young and had significant inattention and forgetfulness, had found levodopa unhelpful and moved with a cock-walk gait, all of which suggested manganism. His serum and urine levels of Mn were, in fact, elevated, and his brain MRI had increased T1-weighted signal intensities in the basal ganglia bilaterally (globus pallidus) consistent with Mn deposition. Two years later, he underwent comprehensive neuropsychological testing. Clinical history indicated a mild tremor and emotional dysfunction with irritability, anxiety, and depression with psychotic features. He showed deficits in cognitive flexibility, information processing and speed, and greatly reduced motor speed, which are consistent with a fronto-subcortical process. These findings support a diagnosis of early onset parkinsonism from welding.

Automated segmentation of neuroanatomical structures in multispectral MR microscopy of the mouse brain.

PubMed

Ali, Anjum A; Dale, Anders M; Badea, Alexandra; Johnson, G Allan

2005-08-15

We present the automated segmentation of magnetic resonance microscopy (MRM) images of the C57BL/6J mouse brain into 21 neuroanatomical structures, including the ventricular system, corpus callosum, hippocampus, caudate putamen, inferior colliculus, internal capsule, globus pallidus, and substantia nigra. The segmentation algorithm operates on multispectral, three-dimensional (3D) MR data acquired at 90-microm isotropic resolution. Probabilistic information used in the segmentation is extracted from training datasets of T2-weighted, proton density-weighted, and diffusion-weighted acquisitions. Spatial information is employed in the form of prior probabilities of occurrence of a structure at a location (location priors) and the pairwise probabilities between structures (contextual priors). Validation using standard morphometry indices shows good consistency between automatically segmented and manually traced data. Results achieved in the mouse brain are comparable with those achieved in human brain studies using similar techniques. The segmentation algorithm shows excellent potential for routine morphological phenotyping of mouse models.

The influence of puberty on subcortical brain development.

PubMed

Goddings, Anne-Lise; Mills, Kathryn L; Clasen, Liv S; Giedd, Jay N; Viner, Russell M; Blakemore, Sarah-Jayne

2014-03-01

Puberty is characterized by hormonal, physical and psychological transformation. The human brain undergoes significant changes between childhood and adulthood, but little is known about how puberty influences its structural development. Using a longitudinal sample of 711 magnetic resonance imaging scans from 275 individuals aged 7-20years, we examined how subcortical brain regions change in relation to puberty. Our regions of interest included the amygdala, hippocampus and corpus striatum including the nucleus accumbens (NA), caudate, putamen and globus pallidus (GP). Pubertal development was significantly related to structural volume in all six regions in both sexes. Pubertal development and age had both independent and interactive influences on volume for the amygdala, hippocampus and putamen in both sexes, and the caudate in females. There was an interactive puberty-by-age effect on volume for the NA and GP in both sexes, and the caudate in males. These findings suggest a significant role for puberty in structural brain development. © 2013. Published by Elsevier Inc. All rights reserved.

The influence of puberty on subcortical brain development

PubMed Central

Goddings, Anne-Lise; Mills, Kathryn L.; Clasen, Liv S.; Giedd, Jay N.; Viner, Russell M.; Blakemore, Sarah-Jayne

2014-01-01

Puberty is characterized by hormonal, physical and psychological transformation. The human brain undergoes significant changes between childhood and adulthood, but little is known about how puberty influences its structural development. Using a longitudinal sample of 711 magnetic resonance imaging scans from 275 individuals aged 7–20 years, we examined how subcortical brain regions change in relation to puberty. Our regions of interest included the amygdala, hippocampus and corpus striatum including the nucleus accumbens (NA), caudate, putamen and globus pallidus (GP). Pubertal development was significantly related to structural volume in all six regions in both sexes. Pubertal development and age had both independent and interactive influences on volume for the amygdala, hippocampus and putamen in both sexes, and the caudate in females. There was an interactive puberty-by-age effect on volume for the NA and GP in both sexes, and the caudate in males. These findings suggest a significant role for puberty in structural brain development. PMID:24121203

Surgical treatment of Parkinson’s disease: Past, present, and future

PubMed Central

Duker, Andrew P.; Espay, Alberto J.

2013-01-01

Advances in functional neurosurgery have expanded the treatment of Parkinson’s disease (PD), from early lesional procedures to targeted electrical stimulation of specific nodes in the basal ganglia circuitry. Deep brain stimulation (DBS), applied to selected patients with Parkinson’s disease (PD) and difficult-to-manage motor fluctuations, yields substantial reductions in off time and dyskinesia. Outcomes for DBS targeting the two major studied targets in PD, the subthalamic nucleus (STN) and the internal segment of the globus pallidus (GPi), appear to be broadly similar and the choice is best made based on individual patient factors and surgeon preference. Emerging concepts in DBS include examination of new targets, such as the potential efficacy of pedunculopontine nucleus (PPN) stimulation for treatment of freezing and falls, the utilization of pathologic oscillations in the beta band to construct an adaptive “closed-loop” DBS, and new technologies, including segmented electrodes to steer current toward specific neural populations. PMID:23896506

Symmetrical and bilateral basal ganglia calcification. Case series and literature review.

PubMed

Jiménez-Ruiz, Amado; Cárdenas-Sáenz, Omar; Ruiz-Sandoval, José Luis

2018-01-01

Symmetric, bilateral basal ganglia calcification is rare finding that sometimes occurs asymptomatically. Its prevalence increases with age, and the most affected site is the globus pallidus. A series of seven cases with clinical and imaging diagnosis of basal ganglia calcification, recorded during the 2012 to 2016 period at the Department of Internal Medicine of the Hospital Civil de Guadalajara "Fray Antonio Alcalde, is presented. Most common clinical presentation was with altered alertness, headache and seizures. There was one case with movement disorders; there were no cases identified with dementia or tetany. Ganglia calcification can be associated with age-related neurodegenerative changes, but it can be an initial manifestation of a variety of systemic pathologies, including disorders of the calcium metabolism, intoxication by different agents, and autoimmune and genetic diseases. Correlation of typical imaging findings with clinical manifestations and laboratory results should be established to reach a definitive judgment. Copyright: © 2018 SecretarÍa de Salud.

Human subcortical brain asymmetries in 15,847 people worldwide reveal effects of age and sex.

PubMed

Guadalupe, Tulio; Mathias, Samuel R; vanErp, Theo G M; Whelan, Christopher D; Zwiers, Marcel P; Abe, Yoshinari; Abramovic, Lucija; Agartz, Ingrid; Andreassen, Ole A; Arias-Vásquez, Alejandro; Aribisala, Benjamin S; Armstrong, Nicola J; Arolt, Volker; Artiges, Eric; Ayesa-Arriola, Rosa; Baboyan, Vatche G; Banaschewski, Tobias; Barker, Gareth; Bastin, Mark E; Baune, Bernhard T; Blangero, John; Bokde, Arun L W; Boedhoe, Premika S W; Bose, Anushree; Brem, Silvia; Brodaty, Henry; Bromberg, Uli; Brooks, Samantha; Büchel, Christian; Buitelaar, Jan; Calhoun, Vince D; Cannon, Dara M; Cattrell, Anna; Cheng, Yuqi; Conrod, Patricia J; Conzelmann, Annette; Corvin, Aiden; Crespo-Facorro, Benedicto; Crivello, Fabrice; Dannlowski, Udo; de Zubicaray, Greig I; de Zwarte, Sonja M C; Deary, Ian J; Desrivières, Sylvane; Doan, Nhat Trung; Donohoe, Gary; Dørum, Erlend S; Ehrlich, Stefan; Espeseth, Thomas; Fernández, Guillén; Flor, Herta; Fouche, Jean-Paul; Frouin, Vincent; Fukunaga, Masaki; Gallinat, Jürgen; Garavan, Hugh; Gill, Michael; Suarez, Andrea Gonzalez; Gowland, Penny; Grabe, Hans J; Grotegerd, Dominik; Gruber, Oliver; Hagenaars, Saskia; Hashimoto, Ryota; Hauser, Tobias U; Heinz, Andreas; Hibar, Derrek P; Hoekstra, Pieter J; Hoogman, Martine; Howells, Fleur M; Hu, Hao; Hulshoff Pol, Hilleke E; Huyser, Chaim; Ittermann, Bernd; Jahanshad, Neda; Jönsson, Erik G; Jurk, Sarah; Kahn, Rene S; Kelly, Sinead; Kraemer, Bernd; Kugel, Harald; Kwon, Jun Soo; Lemaitre, Herve; Lesch, Klaus-Peter; Lochner, Christine; Luciano, Michelle; Marquand, Andre F; Martin, Nicholas G; Martínez-Zalacaín, Ignacio; Martinot, Jean-Luc; Mataix-Cols, David; Mather, Karen; McDonald, Colm; McMahon, Katie L; Medland, Sarah E; Menchón, José M; Morris, Derek W; Mothersill, Omar; Maniega, Susana Munoz; Mwangi, Benson; Nakamae, Takashi; Nakao, Tomohiro; Narayanaswaamy, Janardhanan C; Nees, Frauke; Nordvik, Jan E; Onnink, A Marten H; Opel, Nils; Ophoff, Roel; Paillère Martinot, Marie-Laure; Papadopoulos Orfanos, Dimitri; Pauli, Paul; Paus, Tomáš; Poustka, Luise; Reddy, Janardhan Yc; Renteria, Miguel E; Roiz-Santiáñez, Roberto; Roos, Annerine; Royle, Natalie A; Sachdev, Perminder; Sánchez-Juan, Pascual; Schmaal, Lianne; Schumann, Gunter; Shumskaya, Elena; Smolka, Michael N; Soares, Jair C; Soriano-Mas, Carles; Stein, Dan J; Strike, Lachlan T; Toro, Roberto; Turner, Jessica A; Tzourio-Mazoyer, Nathalie; Uhlmann, Anne; Hernández, Maria Valdés; van den Heuvel, Odile A; van der Meer, Dennis; van Haren, Neeltje E M; Veltman, Dick J; Venkatasubramanian, Ganesan; Vetter, Nora C; Vuletic, Daniella; Walitza, Susanne; Walter, Henrik; Walton, Esther; Wang, Zhen; Wardlaw, Joanna; Wen, Wei; Westlye, Lars T; Whelan, Robert; Wittfeld, Katharina; Wolfers, Thomas; Wright, Margaret J; Xu, Jian; Xu, Xiufeng; Yun, Je-Yeon; Zhao, JingJing; Franke, Barbara; Thompson, Paul M; Glahn, David C; Mazoyer, Bernard; Fisher, Simon E; Francks, Clyde

2017-10-01

The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods. Volumetric asymmetry of seven subcortical structures was assessed in 15,847 MRI scans from 52 datasets worldwide. There were sex differences in the asymmetry of the globus pallidus and putamen. Heritability estimates, derived from 1170 subjects belonging to 71 extended pedigrees, revealed that additive genetic factors influenced the asymmetry of these two structures and that of the hippocampus and thalamus. Handedness had no detectable effect on subcortical asymmetries, even in this unprecedented sample size, but the asymmetry of the putamen varied with age. Genetic drivers of asymmetry in the hippocampus, thalamus and basal ganglia may affect variability in human cognition, including susceptibility to psychiatric disorders.

Preferential responses in amygdala and insula during presentation of facial contempt and disgust.

PubMed

Sambataro, Fabio; Dimalta, Savino; Di Giorgio, Annabella; Taurisano, Paolo; Blasi, Giuseppe; Scarabino, Tommaso; Giannatempo, Giuseppe; Nardini, Marcello; Bertolino, Alessandro

2006-10-01

Some authors consider contempt to be a basic emotion while others consider it a variant of disgust. The neural correlates of contempt have not so far been specifically contrasted with disgust. Using functional magnetic resonance imaging (fMRI), we investigated the neural networks involved in the processing of facial contempt and disgust in 24 healthy subjects. Facial recognition of contempt was lower than that of disgust and of neutral faces. The imaging data indicated significant activity in the amygdala and in globus pallidus and putamen during processing of contemptuous faces. Bilateral insula and caudate nuclei and left as well as right inferior frontal gyrus were engaged during processing of disgusted faces. Moreover, direct comparisons of contempt vs. disgust yielded significantly different activations in the amygdala. On the other hand, disgusted faces elicited greater activation than contemptuous faces in the right insula and caudate. Our findings suggest preferential involvement of different neural substrates in the processing of facial emotional expressions of contempt and disgust.

Inhibitory Control in the Cortico-Basal Ganglia-Thalamocortical Loop: Complex Regulation and Interplay with Memory and Decision Processes.

PubMed

Wei, Wei; Wang, Xiao-Jing

2016-12-07

We developed a circuit model of spiking neurons that includes multiple pathways in the basal ganglia (BG) and is endowed with feedback mechanisms at three levels: cortical microcircuit, corticothalamic loop, and cortico-BG-thalamocortical system. We focused on executive control in a stop signal task, which is known to depend on BG across species. The model reproduces a range of experimental observations and shows that the newly discovered feedback projection from external globus pallidus to striatum is crucial for inhibitory control. Moreover, stopping process is enhanced by the cortico-subcortical reverberatory dynamics underlying persistent activity, establishing interdependence between working memory and inhibitory control. Surprisingly, the stop signal reaction time (SSRT) can be adjusted by weights of certain connections but is insensitive to other connections in this complex circuit, suggesting novel circuit-based intervention for inhibitory control deficits associated with mental illness. Our model provides a unified framework for inhibitory control, decision making, and working memory. Copyright © 2016 Elsevier Inc. All rights reserved.

[Bilateral Pallidotomy for Tardive Dystonia:A Case Report].

PubMed

Kohara, Kotaro; Taira, Takaomi; Horisawa, Shiro; Hanada, Tomoko; Kawamata, Takakazu

2017-11-01

Tardive dystonia is a movement disorder related to the use of dopamine-receptor-blocking drugs. Several reports have shown that deep brain stimulation of the globus pallidus internus(GPi-DBS)is effective in treating tardive dystonia. However, a few reports demonstrated the efficacy of ablation of the GPi(pallidotomy). We herein report a case of tardive dystonia successfully treated with bilateral pallidotomy. A 32-year-old man developed severe tardive dystonia 10 years after the chronic use of antipsychotic drugs. Withdrawal of the drugs and botulinum toxin injections were ineffective. The patient underwent bilateral pallidotomy for tardive dystonia because of rejection of the implanted DBS devices. Significant improvement was observed, with a 95% decrease in the Burke-Fahn-Marsden Dystonia Rating Scale(BFMDRS)movement score, and no severe adverse events occurred. Symptomatic relief persisted for nine months. Pallidotomy is a feasible and efficacious procedure for tardive dystonia treatment without the use of hardware implantations.

Momentum-based morphometric analysis with application to Parkinson's disease

NASA Astrophysics Data System (ADS)

Chen, Jingyun; Khan, Ali R.; McKeown, Martin J.; Beg, Mirza F.

2011-03-01

We apply the initial momentum shape representation of diffeomorphic metric mapping from a template region of interest (ROI) to a given ROI as a morphometic marker in Parkinson's disease. We used a three-step segmentation-registrationmomentum process to derive feature vectors from ROIs in a group of 42 subjects consisting of 19 Parkinson's Disease (PD) subjects and 23 normal control (NC) subjects. Significant group differences between PD and NC subjects were detected in four basal ganglia structures including the caudate, putamen, thalamus and globus pallidus. The magnitude of regionally significant between-group differences detected ranged between 34-75%. Visualization of the different structural deformation pattern between-groups revealed that some parts of basal ganglia structure actually hypertrophy, presumably as a compensatory response to more widespread atrophy. Our results of both hypertrophy and atrophy in the same structures further demonstrate the importance of morphological measures as opposed to overall volume in the assessment of neurodegenerative disease.

Sensitivity analysis of discharge patterns of subthalamic nucleus in the model of basal ganglia in Parkinson disease.

PubMed

Singh, Jyotsna; Singh, Phool; Malik, Vikas

2017-01-01

Parkinson disease alters the information patterns in movement related pathways in brain. Experimental results performed on rats show that the activity patterns changes from single spike activity to mixed burst mode in Parkinson disease. However the cause of this change in activity pattern is not yet completely understood. Subthalamic nucleus is one of the main nuclei involved in the origin of motor dysfunction in Parkinson disease. In this paper, a single compartment conductance based model is considered which focuses on subthalamic nucleus and synaptic input from globus pallidus (external). This model shows highly nonlinear behavior with respect to various intrinsic parameters. Behavior of model has been presented with the help of activity patterns generated in healthy and Parkinson condition. These patterns have been compared by calculating their correlation coefficient for different values of intrinsic parameters. Results display that the activity patterns are very sensitive to various intrinsic parameters and calcium shows some promising results which provide insights into the motor dysfunction.

Differential inputs to striatal cholinergic and parvalbumin interneurons imply functional distinctions

PubMed Central

Klug, Jason R; Engelhardt, Max D; Cadman, Cara N; Li, Hao; Smith, Jared B; Ayala, Sarah; Williams, Elora W; Hoffman, Hilary

2018-01-01

Striatal cholinergic (ChAT) and parvalbumin (PV) interneurons exert powerful influences on striatal function in health and disease, yet little is known about the organization of their inputs. Here using rabies tracing, electrophysiology and genetic tools, we compare the whole-brain inputs to these two types of striatal interneurons and dissect their functional connectivity in mice. ChAT interneurons receive a substantial cortical input from associative regions of cortex, such as the orbitofrontal cortex. Amongst subcortical inputs, a previously unknown inhibitory thalamic reticular nucleus input to striatal PV interneurons is identified. Additionally, the external segment of the globus pallidus targets striatal ChAT interneurons, which is sufficient to inhibit tonic ChAT interneuron firing. Finally, we describe a novel excitatory pathway from the pedunculopontine nucleus that innervates ChAT interneurons. These results establish the brain-wide direct inputs of two major types of striatal interneurons and allude to distinct roles in regulating striatal activity and controlling behavior. PMID:29714166

Basal Ganglia Contributions to Motor Control: A Vigorous Tutor

PubMed Central

Turner, Robert S.; Desmurget, Michel

2010-01-01

SUMMARY OF RECENT ADVANCES The roles of the basal ganglia (BG) in motor control are much debated. Many influential hypotheses have grown from studies in which output signals of the BG were not blocked, but pathologically-disturbed. A weakness of that approach is that the resulting behavioral impairments reflect degraded function of the BG per se mixed together with secondary dysfunctions of BG-recipient brain areas. To overcome that limitation, several studies have focused on the main skeletomotor output region of the BG, the globus pallidus internus (GPi). Using single-cell recording and inactivation protocols these studies provide consistent support for two hypotheses: the BG modulates movement performance (“vigor”) according to motivational factors (i.e., context-specific cost/reward functions) and the BG contributes to motor learning. Results from these studies also add to the problems that confront theories positing that the BG selects movement, inhibits unwanted motor responses, corrects errors online, or stores and produces well-learned motor skills. PMID:20850966

[Wilson disease. A case report and review of the literature].

PubMed

Alva-Moncayo, Edith; Castro-Tarín, María; González-Serrano, Adolfo

2011-01-01

Wilson disease is a problem of cuprum metabolism, with recesive autosomic hereditary transmission and a prevalence of one in 30,000 habitants. The cuprum is deposit in a progressive and irreversible way in the liver and encephalus and it is not liberated with quelant treatment. Neurological manifestations are tremor, disartria, extrapiramidal manifestations or distonia. Ophthalmic exploration shows corneal limb with sign of Kayser-Fleischer. a 15-year-old masculine patient with previous hepatitis outbreak in two times. During the last year he presented distonia, bradicinecious, stiffness and indifference with ictericia. Ophthalmological examination reported Kayser-Fleisher rings. Magnetic resonance of brain showed high dense images in lenticular, pallidus globe and caudate nucleus suggestive of Wilson disease. Ceruloplasmin concentration, cuprum in the liver biopsy confirmed the diagnosis. the importance of the case was the hepatic initial manifestations and two years after presented with inexpressive face, and it was considered a psychiatric disease, but the neurological evaluation and the liver biopsy confirmed the diagnosis of Wilson disease.

Thermophilic bacteria in Moroccan hot springs, salt marshes and desert soils.

PubMed

Aanniz, Tarik; Ouadghiri, Mouna; Melloul, Marouane; Swings, Jean; Elfahime, Elmostafa; Ibijbijen, Jamal; Ismaili, Mohamed; Amar, Mohamed

2015-06-01

The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.

Thermophilic bacteria in Moroccan hot springs, salt marshes and desert soils

PubMed Central

Aanniz, Tarik; Ouadghiri, Mouna; Melloul, Marouane; Swings, Jean; Elfahime, Elmostafa; Ibijbijen, Jamal; Ismaili, Mohamed; Amar, Mohamed

2015-01-01

The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively. PMID:26273259

Neuropathologic findings in an aged albino gorilla.

PubMed

Márquez, M; Serafin, A; Fernández-Bellon, H; Serrat, S; Ferrer-Admetlla, A; Bertranpetit, J; Ferrer, I; Pumarola, M

2008-07-01

Pallido-nigral spheroids associated with iron deposition have been observed in some aged clinically normal nonhuman primates. In humans, similar findings are observed in neurodegeneration with brain iron accumulation diseases, which, in some cases, show associated mutations in pantothenate kinase 2 gene (PANK2). Here we present an aged gorilla, 40 years old, suffering during the last 2 years of life from progressive tetraparesis, nystagmus, and dyskinesia of the arms, hands, and neck, with accompanying abnormal behavior. The postmortem neuropathologic examination revealed, in addition to aging-associated changes in the brain, numerous corpora amylacea in some brain areas, especially the substantia nigra, and large numbers of axonal spheroids associated with iron accumulation in the internal globus pallidus. Sequencing of the gorilla PANK2 gene failed to detect any mutation. The clinical, neuropathologic, and genetic findings in this gorilla point to an age-related pallido-nigral degeneration that presented PKAN-like neurologic deficits.

Development of Wideband Feed

NASA Astrophysics Data System (ADS)

Ujihara, Hideki; Takefuji, Kazuhiro; Sekido, Mamoru; Kondo, Tetsuro

2015-08-01

Wideband feeds have developed for Kashima 34m antenna and new 2.4m portable VLBI antennas. Prototypes of the wideband feeds are multimode horns, first one was set on 34m in the end of 2013, and then replaced next one with 6.5-15.0GHz receiving frequency. Now, a new feed for 3.2GHz-14.4GHz will be installed in 2.4m and 34m antennas in this spring, which are named NINJA feed, because of its design flexibility in beam shpae. Next, IGUANA feed is now under design and fabrication, which is aimed for 2.2-22GHz and covers VGOS(VLBI2010) specification. This has coaxial structure, the smaller "daughter feed" for 6.4-22GHz is placed in the center of the larger "Mother feed" for 2.2-6.4GHz.They are used for our project of time and frequency transfer between remote atomic clocks by wideband VLBI, named Gala-V(Garapagos VLBI), and will also be used wideband VLBI observation for astronmy and geodesy.Prototype feeds were tested in measurement of aperture efficiency, SEFD and Tsys of 34m "Super Kashima Antenna" and both 6.7/12.2GHz methanol maser detection in one reciever system, and then better one is used for wideband VLBI observations.

The international trade in reptiles (Reptilia)--the cause of the transfer of exotic ticks (Acari: Ixodida) to Poland.

PubMed

Nowak, Magdalena

2010-05-11

The problem of the unnatural transfer of exotic ticks (Acari: Ixodida) on reptiles (Reptilia) imported to Poland is presented. In the period from 2003 to 2007, 382 specimens of reptiles belonging to the following genera were investigated: Testudo, Iguana, Varanus, Gongylophis, Python, Spalerosophis, Psammophis. The reptiles most infested with ticks are imported to Poland from Ghana in Africa, and are the commonly bred terrarium reptiles: Varanus exanthematicus and Python regius. As a result of the investigations, the transfer of exotic ticks on reptiles to Poland was confirmed. There were 2104 specimens of the genera Amblyomma and Hyalomma. The following species were found: Amblyomma exornatum Koch, 1844, Amblyomma flavomaculatum (Lucas, 1846), Amblyomma latum Koch, 1844, Amblyomma nuttalli Donitz, 1909, Amblyomma quadricavum (Schulze, 1941), Amblyomma transversale (Lucas, 1844), Amblyomma varanense (Supino, 1897), Amblyomma sp. Koch, 1844, Hyalomma aegyptium (Linnaeus, 1758). All the species of ticks of genus Amblyomma revealed have been discovered in Poland for the first time. During the research, 13 cases of anomalies of morphological structure were confirmed in the ticks A. flavomaculatum, A. latum and H. aegyptium. The expanding phenomenon of the import of exotic reptiles in Poland and Central Europe is important for parasitological and epidemiological considerations, and therefore requires monitoring and wide-ranging prophylactic activities to prevent the inflow of exotic parasites to Poland. (c) 2010 Elsevier B.V. All rights reserved.

Galapagos Islands

NASA Technical Reports Server (NTRS)

2002-01-01

This true-color image of the Galapagos Islands was acquired on March 12, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The Galapagos Islands, which are part of Ecuador, sit in the Pacific Ocean about 1000 km (620 miles) west of South America. As the three craters on the largest island (Isabela Island) suggest, the archipelago was created by volcanic eruptions, which took place millions of years ago. Unlike most remote islands in the Pacific, the Galapagos have gone relatively untouched by humans over the past few millennia. As a result, many unique species have continued to thrive on the islands. Over 95 percent of the islands' reptile species and nearly three quarters of its land bird species cannot be found anywhere else in the world. Two of the more well known are the Galapagos giant tortoise and marine iguanas. The unhindered evolutionary development of the islands' species inspired Charles Darwin to begin The Origin of Species eight years after his visit there. To preserve the unique wildlife on the islands, the Ecuadorian government made the entire archipelago a national park in 1959. Each year roughly 60,000 tourists visit these islands to experience what Darwin did over a century and a half ago. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

Striatal Direct and Indirect Pathway Output Structures are Differentially Altered in Mouse Models of Huntington's Disease.

PubMed

Barry, Joshua; Akopian, Garnik; Cepeda, Carlos; Levine, Michael S

2018-04-24

The present study examined synaptic communication between direct and indirect output pathway striatal medium-sized spiny neurons (MSNs) and their target structures, the substantia nigra pars reticulata (SNr) and the external globus pallidus (GPe) in two mouse models of Huntington's disease (HD). Cre-recombination, optogenetics, and whole-cell patch clamp recordings were used to determine alterations in intrinsic and synaptic properties of SNr and GPe neurons from both male and female symptomatic R6/2 (>60 days) and pre- (2 months) or symptomatic (10-12 months) YAC128 mice. Cell membrane capacitance was decreased whereas input resistance was increased in SNr neurons from R6/2, but not YAC128 mice. The amplitude of GABAergic responses evoked by optogenetic stimulation of direct pathway terminals was reduced in SNr neurons of symptomatic mice of both models. A decrease in spontaneous GABA synaptic activity, in particular large-amplitude events, in SNr neurons also was observed. Passive membrane properties of GPe neurons were not different between R6/2 or YAC128 mice and their control littermates. Similarly, the amplitude of GABA responses evoked by activation of indirect pathway MSN terminals and the frequency of spontaneous GABA synaptic activity were similar in HD and control animals. In contrast, the decay time of the evoked GABA response was significantly longer in cells from HD mice. Interestingly, activation of indirect pathway MSNs within the striatum evoked larger-amplitude responses in direct pathway MSNs. Together, these results demonstrate differential alterations in responses evoked by direct and indirect pathway terminals in SNr and GPe leading to striatal output imbalance and motor dysfunction. SIGNIFICANCE STATEMENT Previous work on Huntington's disease (HD) focused on striatal medium-sized spiny neurons (MSNs) almost exclusively. Little is known about the effects that alterations in the striatum have on output structures of the direct and indirect

Deep brain stimulation changes basal ganglia output nuclei firing pattern in the dystonic hamster.

PubMed

Leblois, Arthur; Reese, René; Labarre, David; Hamann, Melanie; Richter, Angelika; Boraud, Thomas; Meissner, Wassilios G

2010-05-01

Dystonia is a heterogeneous syndrome of movement disorders characterized by involuntary muscle contractions leading to abnormal movements and postures. While medical treatment is often ineffective, deep brain stimulation (DBS) of the internal pallidum improves dystonia. Here, we studied the impact of DBS in the entopeduncular nucleus (EP), the rodent equivalent of the human globus pallidus internus, on basal ganglia output in the dt(sz)-hamster, a well-characterized model of dystonia by extracellular recordings. Previous work has shown that EP-DBS improves dystonic symptoms in dt(sz)-hamsters. We report that EP-DBS changes firing pattern in the EP, most neurons switching to a less regular firing pattern during DBS. In contrast, EP-DBS did not change the average firing rate of EP neurons. EP neurons display multiphasic responses to each stimulation impulse, likely underlying the disruption of their firing rhythm. Finally, neurons in the substantia nigra pars reticulata display similar responses to EP-DBS, supporting the idea that EP-DBS affects basal ganglia output activity through the activation of common afferent fibers. Copyright 2010 Elsevier Inc. All rights reserved.

Records of Bat Flies (Diptera: Nycteribiidae and Streblidae) in the Semi-Arid Caatinga in the State of Paraíba, Northeastern Brazil.

PubMed

Barbier, E; Prado-Neto, J G; Bernard, E

2016-12-01

One of the largest gaps in the knowledge of ectoparasitic flies of the families Nycteribiidae and Streblidae in Brazil is the northeastern region, where most states do not have any record. Here, we present the first records of those two bat fly families for the state of Paraíba. We recorded a total of 10 species of five genera parasitizing eight bat species of four families. Trichobius diphyllae Wenzel (Streblidae) was the most abundant species, found parasitizing Diphylla ecaudata (Phyllostomidae), and T. dugesioides dugesioides Wenzel, the second, found on Trachops cirrhosus (Phyllostomidae). Three species were recorded for the first time in northeastern Brazil and seven species are new for the semi-arid Caatinga. We collected T. galei Wenzel and T. pallidus (Curran) on Natalus macrourus (Natalidae) and Furipterus horrens (Furipteridae), respectively, two endangered bat species, and the species-specific relationship with their hosts points out to some degree of vulnerability. In addition, we present information on host-parasite relationship, and data that extend the known geographic distribution of some species.

A neural mass model of basal ganglia nuclei simulates pathological beta rhythm in Parkinson's disease

NASA Astrophysics Data System (ADS)

Liu, Fei; Wang, Jiang; Liu, Chen; Li, Huiyan; Deng, Bin; Fietkiewicz, Chris; Loparo, Kenneth A.

2016-12-01

An increase in beta oscillations within the basal ganglia nuclei has been shown to be associated with movement disorder, such as Parkinson's disease. The motor cortex and an excitatory-inhibitory neuronal network composed of the subthalamic nucleus (STN) and the external globus pallidus (GPe) are thought to play an important role in the generation of these oscillations. In this paper, we propose a neuron mass model of the basal ganglia on the population level that reproduces the Parkinsonian oscillations in a reciprocal excitatory-inhibitory network. Moreover, it is shown that the generation and frequency of these pathological beta oscillations are varied by the coupling strength and the intrinsic characteristics of the basal ganglia. Simulation results reveal that increase of the coupling strength induces the generation of the beta oscillation, as well as enhances the oscillation frequency. However, for the intrinsic properties of each nucleus in the excitatory-inhibitory network, the STN primarily influences the generation of the beta oscillation while the GPe mainly determines its frequency. Interestingly, describing function analysis applied on this model theoretically explains the mechanism of pathological beta oscillations.

What basal ganglia changes underlie the parkinsonian state? The significance of neuronal oscillatory activity

PubMed Central

Quiroga-Varela, A.; Walters, J.R.; Brazhnik, E.; Marin, C.; Obeso, J.A.

2014-01-01

One well accepted functional feature of the parkinsonian state is the recording of enhanced beta oscillatory activity in the basal ganglia. This has been demonstrated in patients with Parkinson's disease (PD) and in animal models such as the rat with 6-hydroxydopamine (6-OHDA)-induced lesion and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys, all of which are associated with severe striatal dopamine depletion. Neuronal hyper-synchronization in the beta (or any other) band is not present despite the presence of bradykinetic features in the rat and monkey models, suggesting that increased beta band power may arise when nigro-striatal lesion is advanced and that it is not an essential feature of the early parkinsonian state. Similar observations and conclusions have been previously made for increased neuronal firing rate in the subthalamic and globus pallidus pars interna nuclei. Accordingly, it is suggested that early parkinsonism may be associated with dynamic changes in basal ganglia output activity leading to reduced movement facilitation that may be an earlier feature of the parkinsonian state. PMID:23727447

Age-related changes in HSP25 expression in basal ganglia and cortex of F344/BN rats

PubMed Central

Gupte, Anisha A.; Morris, Jill K.; Zhang, Hongyu; Bomhoff, Gregory L.; Geiger, Paige C.; Stanford, John A.

2010-01-01

Normal aging is associated with chronic oxidative stress. In the basal ganglia, oxidative stress may contribute to the increased risk of Parkinson's disease in the elderly. Neurons are thought to actively utilize compensatory defense mechanisms, such as heat shock proteins (HSPs), to protect from persisting stress. Despite their protective role, little is known about HSP expression in the aging basal ganglia. The purpose of this study was to examine HSP expression in striatum, substantia nigra, globus pallidus and cortex in 6-, 18- and 30-month-old Fischer 344/Brown Norway rats. We found robust age-related increases in phosphorylated and total HSP25 in each brain region studied. Conversely, HSP72 (the inducible form of HSP70) was reduced with age, but only in the striatum. p38 MAPK, a protein implicated in activating HSP25, did not change with age, nor did HSC70 (the constitutive form of HSP70), or HSP60. These results suggest that HSP25 is especially responsive to age-related stress in the basal ganglia. PMID:20144690

[Effect of acute hypoxia on the intensity of free radical processes in the basal nuclei of the brain, and the rat behaviour in the open field test under conditions of altered photoperiod].

PubMed

Sopova, I Iu; Zamorskiĭ, I I

2011-03-01

The effect of acute hypoxia on the intensity of free radical processes in the basal nuclei (the nucleus caudatus, globus pallidus. nucleus accumbens. amygdaloid complex) of the brain, and the rat behaviour in the open field test has been studied under conditions of altered photoperiod. It has been shown that constant darkness levels the effect of acute hypoxia on the intensity of lipid peroxidation, preserves the activity of superoxide dismutase and catalase at a higher level, lowers the activity of glutathione peroxidase. Under light, the sensitivity of basal nuclei neurons to acute hypoxia is enhanced, the latter being reflected in intensification of lipid peroxidation at the expense of increased formation of dien conjugates. The activity of catalase at that considerably exceeds the level of even intact rats in all the structures. It has been established that an altered photoperiod modulates the effect of acute hypoxia on the parameters of rat's activity in the open field, the character of their change depending on the nature of a photophase change.

Separate encoding of model-based and model-free valuations in the human brain.

PubMed

Beierholm, Ulrik R; Anen, Cedric; Quartz, Steven; Bossaerts, Peter

2011-10-01

Behavioral studies have long shown that humans solve problems in two ways, one intuitive and fast (System 1, model-free), and the other reflective and slow (System 2, model-based). The neurobiological basis of dual process problem solving remains unknown due to challenges of separating activation in concurrent systems. We present a novel neuroeconomic task that predicts distinct subjective valuation and updating signals corresponding to these two systems. We found two concurrent value signals in human prefrontal cortex: a System 1 model-free reinforcement signal and a System 2 model-based Bayesian signal. We also found a System 1 updating signal in striatal areas and a System 2 updating signal in lateral prefrontal cortex. Further, signals in prefrontal cortex preceded choices that are optimal according to either updating principle, while signals in anterior cingulate cortex and globus pallidus preceded deviations from optimal choice for reinforcement learning. These deviations tended to occur when uncertainty regarding optimal values was highest, suggesting that disagreement between dual systems is mediated by uncertainty rather than conflict, confirming recent theoretical proposals. Copyright © 2011 Elsevier Inc. All rights reserved.

Image-guided preoperative prediction of pyramidal tract side effect in deep brain stimulation: proof of concept and application to the pyramidal tract side effect induced by pallidal stimulation.

PubMed

Baumgarten, Clement; Zhao, Yulong; Sauleau, Paul; Malrain, Cecile; Jannin, Pierre; Haegelen, Claire

2016-04-01

Deep brain stimulation of the medial globus pallidus (GPm) is a surgical procedure for treating patients suffering from Parkinson's disease. Its therapeutic effect may be limited by the presence of pyramidal tract side effect (PTSE). PTSE is a contraction time-locked to the stimulation when the current spreading reaches the motor fibers of the pyramidal tract within the internal capsule. The objective of the study was to propose a preoperative predictive model of PTSE. A machine learning-based method called PyMAN (PTSE model based on artificial neural network) accounting for the current used in stimulation, the three-dimensional electrode coordinates and the angle of the trajectory, was designed to predict the occurrence of PTSE. Ten patients implanted in the GPm have been tested by a clinician to create a labeled dataset of the stimulation parameters that trigger PTSE. The kappa index value between the data predicted by PyMAN and the labeled data was 0.78. Further evaluation studies are desirable to confirm whether PyMAN could be a reliable tool for assisting the surgeon to prevent PTSE during the preoperative planning.

Effect of micro lesions of the basal ganglia on ballistic movements in patients with deep brain stimulation.

PubMed

Singh, Arun; Mehrkens, Jan H; Bötzel, Kai

2012-03-15

Bradykinesia and hypokinesia are the prominent symptoms of substantia nigra degeneration in Parkinson's disease (PD). In segmental dystonia, movements of not affected limbs are not impaired. Here we studied the impact of the mere implantation of stimulation electrodes on the performance of fast movements in these two groups. We investigated 9 PD patients with subthalamic electrodes and 9 patients with segmental dystonia with electrodes in the globus pallidus internum. Patients were studied on the first postoperative day without electrical stimulation of the electrodes. Subjects had to perform boxing movements with either touching the target or stopping the fist in front of the target. PD subjects performed significantly faster movements in the touch-task only as compared to dystonic patients. No difference was seen in the stopping task. In conclusion, our findings suggest that a small subthalamic lesion in individuals with PD specifically reverses bradykinesia during simple ballistic movements (touch) but not during complex ones requiring more pre-programming (no-touch paradigm). Copyright © 2011 Elsevier B.V. All rights reserved.

Angiotensin-converting enzyme in epithelial and neuroepithelial cells.

PubMed

Defendini, R; Zimmerman, E A; Weare, J A; Alhenc-Gelas, F; Erdös, E G

1983-07-01

Angiotensin-converting enzyme (CE) occurs in three types of cell: endothelial, epithelial, and neuroepithelial. In all three, it appears to be bound to plasma membrane. With antisera to the human enzyme, CE is demonstrated in paraffin sections on the apical surface of epithelial cells in the proximal tubule of the kidney, the mucosa of the small intestine, the syncytial trophoblast of the placenta, and the choroid plexus. Epithelial CE is characteristically found on microvillous surfaces in contact with an effluent, well placed to act on substrate in flux. In the brain, CE occurs in nerve fibers and terminals, mainly mesiobasally and in basal ganglia. Mesiobasal CE coincides with other components of the renin-angiotensin system (RAS) in the choroid/ventricular fluid, the subfornical organ, and the magnocellular neurosecretory system of the hypothalamus. Extrapyramidal CE, however, may not be related to the RAS. In the substantia nigra and the globus pallidus, the enzyme has the same cellular distribution as two putative neuromodulators, substance P and enkephalin, the latter a known substrate of CE.

Alteration of the coenzyme A biosynthetic pathway in neurodegeneration with brain iron accumulation syndromes.

PubMed

Venco, Paola; Dusi, Sabrina; Valletta, Lorella; Tiranti, Valeria

2014-08-01

NBIA (neurodegeneration with brain iron accumulation) comprises a heterogeneous group of neurodegenerative diseases having as a common denominator, iron overload in specific brain areas, mainly basal ganglia and globus pallidus. In the past decade a bunch of disease genes have been identified, but NBIA pathomechanisms are still not completely clear. PKAN (pantothenate kinase-associated neurodegeneration), an autosomal recessive disorder with progressive impairment of movement, vision and cognition, is the most common form of NBIA. It is caused by mutations in the PANK2 (pantothenate kinase 2) gene, coding for a mitochondrial enzyme that phosphorylates vitamin B5 in the first reaction of the CoA (coenzyme A) biosynthetic pathway. A distinct form of NBIA, denominated CoPAN (CoA synthase protein-associated neurodegeneration), is caused by mutations in the CoASY (CoA synthase) gene coding for a bifunctional mitochondrial enzyme, which catalyses the final steps of CoA biosynthesis. These two inborn errors of CoA metabolism further support the concept that dysfunctions in CoA synthesis may play a crucial role in the pathogenesis of NBIA.

Microbiology of animal bite wound infections.

PubMed

Abrahamian, Fredrick M; Goldstein, Ellie J C

2011-04-01

The microbiology of animal bite wound infections in humans is often polymicrobial, with a broad mixture of aerobic and anaerobic microorganisms. Bacteria recovered from infected bite wounds are most often reflective of the oral flora of the biting animal, which can also be influenced by the microbiome of their ingested prey and other foods. Bacteria may also originate from the victim's own skin or the physical environment at the time of injury. Our review has focused on bite wound infections in humans from dogs, cats, and a variety of other animals such as monkeys, bears, pigs, ferrets, horses, sheep, Tasmanian devils, snakes, Komodo dragons, monitor lizards, iguanas, alligators/crocodiles, rats, guinea pigs, hamsters, prairie dogs, swans, and sharks. The medical literature in this area has been made up mostly of small case series or case reports. Very few studies have been systematic and are often limited to dog or cat bite injuries. Limitations of studies include a lack of established or inconsistent criteria for an infected wound and a failure to utilize optimal techniques in pathogen isolation, especially for anaerobic organisms. There is also a lack of an understanding of the pathogenic significance of all cultured organisms. Gathering information and conducting research in a more systematic and methodical fashion through an organized research network, including zoos, veterinary practices, and rural clinics and hospitals, are needed to better define the microbiology of animal bite wound infections in humans.

Microbiology of Animal Bite Wound Infections

PubMed Central

Abrahamian, Fredrick M.; Goldstein, Ellie J. C.

2011-01-01

Summary: The microbiology of animal bite wound infections in humans is often polymicrobial, with a broad mixture of aerobic and anaerobic microorganisms. Bacteria recovered from infected bite wounds are most often reflective of the oral flora of the biting animal, which can also be influenced by the microbiome of their ingested prey and other foods. Bacteria may also originate from the victim's own skin or the physical environment at the time of injury. Our review has focused on bite wound infections in humans from dogs, cats, and a variety of other animals such as monkeys, bears, pigs, ferrets, horses, sheep, Tasmanian devils, snakes, Komodo dragons, monitor lizards, iguanas, alligators/crocodiles, rats, guinea pigs, hamsters, prairie dogs, swans, and sharks. The medical literature in this area has been made up mostly of small case series or case reports. Very few studies have been systematic and are often limited to dog or cat bite injuries. Limitations of studies include a lack of established or inconsistent criteria for an infected wound and a failure to utilize optimal techniques in pathogen isolation, especially for anaerobic organisms. There is also a lack of an understanding of the pathogenic significance of all cultured organisms. Gathering information and conducting research in a more systematic and methodical fashion through an organized research network, including zoos, veterinary practices, and rural clinics and hospitals, are needed to better define the microbiology of animal bite wound infections in humans. PMID:21482724

Evolution of Karyotypes in Chameleons

PubMed Central

Rovatsos, Michail; Altmanová, Marie; Johnson Pokorná, Martina; Velenský, Petr; Kratochvíl, Lukáš

2017-01-01

The reconstruction of the evolutionary dynamics of karyotypes and sex determining systems in squamate reptiles is precluded by the lack of data in many groups including most chameleons (Squamata: Acrodonta: Chamaeleonidae). We performed cytogenetic analysis in 16 species of chameleons from 8 genera covering the phylogenetic diversity of the family and also phylogenetic reconstruction of karyotype evolution in this group. In comparison to other squamates, chameleons demonstrate rather variable karyotypes, differing in chromosome number, morphology and presence of interstitial telomeric signal (ITS). On the other hand, the location of rDNA is quite conserved among chameleon species. Phylogenetic analysis combining our new results and previously published data tentatively suggests that the ancestral chromosome number for chameleons is 2n = 36, which is the same as assumed for other lineages of the clade Iguania, i.e., agamids and iguanas. In general, we observed a tendency for the reduction of chromosome number during the evolution of chameleons, however, in Rieppeleon brevicaudatus, we uncovered a chromosome number of 2n = 62, very unusual among squamates, originating from a number of chromosome splits. Despite the presence of the highly differentiated ZZ/ZW sex chromosomes in the genus Furcifer, we did not detect any unequivocal sexual differences in the karyotypes of any other studied species of chameleons tested using differential staining and comparative genomic hybridization, suggesting that sex chromosomes in most chameleons are only poorly differentiated. PMID:29231849

Does population size affect genetic diversity? A test with sympatric lizard species.

PubMed

Hague, M T J; Routman, E J

2016-01-01

Genetic diversity is a fundamental requirement for evolution and adaptation. Nonetheless, the forces that maintain patterns of genetic variation in wild populations are not completely understood. Neutral theory posits that genetic diversity will increase with a larger effective population size and the decreasing effects of drift. However, the lack of compelling evidence for a relationship between genetic diversity and population size in comparative studies has generated some skepticism over the degree that neutral sequence evolution drives overall patterns of diversity. The goal of this study was to measure genetic diversity among sympatric populations of related lizard species that differ in population size and other ecological factors. By sampling related species from a single geographic location, we aimed to reduce nuisance variance in genetic diversity owing to species differences, for example, in mutation rates or historical biogeography. We compared populations of zebra-tailed lizards and western banded geckos, which are abundant and short-lived, to chuckwallas and desert iguanas, which are less common and long-lived. We assessed population genetic diversity at three protein-coding loci for each species. Our results were consistent with the predictions of neutral theory, as the abundant species almost always had higher levels of haplotype diversity than the less common species. Higher population genetic diversity in the abundant species is likely due to a combination of demographic factors, including larger local population sizes (and presumably effective population sizes), faster generation times and high rates of gene flow with other populations.

Rediscovery of the 220-year-old holotype of the Banded Iguana, Brachylophus fasciatus (Brongniart, 1800) in the Paris Natural History Museum

USGS Publications Warehouse

Ineich, Ivan; Fisher, Robert N.

2016-01-01

The Paris Natural History Museum herpetological collection (MNHN-RA) has seven historical specimens of Brachylophus spp. collected late in the 18th and early in the 19th centuries. Brachylophus fasciatus was described in 1800 by Brongniart but its type was subsequently considered as lost and never present in MNHN-RA collections. We found that 220 year old holotype among existing collections, registered without any data, and we show that it was donated to MNHN-RA from Brongniart’s private collection after his death in 1847. It was registered in the catalogue of 1851 but without any data or reference to its type status. According to the coloration (uncommon midbody saddle-like dorsal banding pattern) and morphometric data given in its original description and in the subsequent examination of the type in 1802 by Daudin and in 1805 by Brongniart we found that lost holotype in the collections. Another MNHN-RA specimen has Horn Islands (Wallis and Futuna) as the collection location but we show that most of the collections given to MNHN-RA by its collector, Louis Arnoux, have mixed localities in the MNHN-RA catalogues. We thus conclude that the locality is wrong and that the species never inhabited those islands located west of Western Samoa and north-east of Fiji.

Rediscovery of the 220-year-old holotype of the Banded Iguana, Brachylophus fasciatus (Brongniart, 1800) in the Paris Natural History Museum.

PubMed

Ineich, Ivan; Fisher, Robert N

2016-07-15

The Paris Natural History Museum herpetological collection (MNHN-RA) has seven historical specimens of Brachylophus spp. collected late in the 18^th and early in the 19th centuries. Brachylophus fasciatus was described in 1800 by Brongniart but its type was subsequently considered as lost and never present in MNHN-RA collections. We found that 220 year old holotype among existing collections, registered without any data, and we show that it was donated to MNHN-RA from Brongniart's private collection after his death in 1847. It was registered in the catalogue of 1851 but without any data or reference to its type status. According to the coloration (uncommon midbody saddle-like dorsal banding pattern) and morphometric data given in its original description and in the subsequent examination of the type in 1802 by Daudin and in 1805 by Brongniart we found that lost holotype in the collections. Another MNHN-RA specimen has Horn Islands (Wallis and Futuna) as the collection location but we show that most of the collections given to MNHN-RA by its collector, Louis Arnoux, have mixed localities in the MNHN-RA catalogues. We thus conclude that the locality is wrong and that the species never inhabited those islands located west of Western Samoa and north-east of Fiji.

Frequency and function in the basal ganglia: the origins of beta and gamma band activity.

PubMed

Blenkinsop, Alexander; Anderson, Sean; Gurney, Kevin

2017-07-01

Neuronal oscillations in the basal ganglia have been observed to correlate with behaviours, although the causal mechanisms and functional significance of these oscillations remain unknown. We present a novel computational model of the healthy basal ganglia, constrained by single unit recordings from non-human primates. When the model is run using inputs that might be expected during performance of a motor task, the network shows emergent phenomena: it functions as a selection mechanism and shows spectral properties that match those seen in vivo. Beta frequency oscillations are shown to require pallido-striatal feedback, and occur with behaviourally relevant cortical input. Gamma oscillations arise in the subthalamic-globus pallidus feedback loop, and occur during movement. The model provides a coherent framework for the study of spectral, temporal and functional analyses of the basal ganglia and lays the foundation for an integrated approach to study basal ganglia pathologies such as Parkinson's disease in silico. Neural oscillations in the basal ganglia (BG) are well studied yet remain poorly understood. Behavioural correlates of spectral activity are well described, yet a quantitative hypothesis linking time domain dynamics and spectral properties to BG function has been lacking. We show, for the first time, that a unified description is possible by interpreting previously ignored structure in data describing globus pallidus interna responses to cortical stimulation. These data were used to expose a pair of distinctive neuronal responses to the stimulation. This observation formed the basis for a new mathematical model of the BG, quantitatively fitted to the data, which describes the dynamics in the data, and is validated against other stimulus protocol experiments. A key new result is that when the model is run using inputs hypothesised to occur during the performance of a motor task, beta and gamma frequency oscillations emerge naturally during static-force and

Diving through the thermal window: implications for a warming world

PubMed Central

Campbell, Hamish A.; Dwyer, Ross G.; Gordos, Matthew; Franklin, Craig E.

2010-01-01

Population decline and a shift in the geographical distribution of some ectothermic animals have been attributed to climatic warming. Here, we show that rises in water temperature of a few degrees, while within the thermal window for locomotor performance, may be detrimental to diving behaviour in air-breathing ectotherms (turtles, crocodilians, marine iguanas, amphibians, snakes and lizards). Submergence times and internal and external body temperature were remotely recorded from freshwater crocodiles (Crocodylus johnstoni) while they free-ranged throughout their natural habitat in summer and winter. During summer, the crocodiles' mean body temperature was 5.2 ± 0.1°C higher than in winter and the largest proportion of total dive time was composed of dive durations approximately 15 min less than in winter. Diving beyond 40 min during summer required the crocodiles to exponentially increase the time they spent on the surface after the dive, presumably to clear anaerobic debt. The relationship was not as significant in winter, even though a greater proportion of dives were of a longer duration, suggesting that diving lactate threshold (DLT) was reduced in summer compared with winter. Additional evidence for a reduced DLT in summer was derived from the stronger influence body mass exerted upon dive duration, compared to winter. The results demonstrate that the higher summer body temperature increased oxygen demand during the dive, implying that thermal acclimatization of the diving metabolic rate was inadequate. If the study findings are common among air-breathing diving ectotherms, then long-term warming of the aquatic environment may be detrimental to behavioural function and survivorship. PMID:20610433

Molecular Characterization of Reptile Pathogens Currently Known as Members of the Chrysosporium Anamorph of Nannizziopsis vriesii Complex and Relationship with Some Human-Associated Isolates

PubMed Central

Hambleton, Sarah; Paré, Jean A.

2013-01-01

In recent years, the Chrysosporium anamorph of Nannizziopsis vriesii (CANV), Chrysosporium guarroi, Chrysosporium ophiodiicola, and Chrysosporium species have been reported as the causes of dermal or deep lesions in reptiles. These infections are contagious and often fatal and affect both captive and wild animals. Forty-nine CANV isolates from reptiles and six isolates from human sources were compared with N. vriesii based on their cultural characteristics and DNA sequence data. Analyses of the sequences of the internal transcribed spacer and small subunit of the nuclear ribosomal gene revealed that the reptile pathogens and human isolates belong in well-supported clades corresponding to three lineages that are distinct from all other taxa within the family Onygenaceae of the order Onygenales. One lineage represents the genus Nannizziopsis and comprises N. vriesii, N. guarroi, and six additional species encompassing isolates from chameleons and geckos, crocodiles, agamid and iguanid lizards, and humans. Two other lineages comprise the genus Ophidiomyces, with the species Ophidiomyces ophiodiicola occurring only in snakes, and Paranannizziopsis gen. nov., with three new species infecting squamates and tuataras. The newly described species are Nannizziopsis dermatitidis, Nannizziopsis crocodili, Nannizziopsis barbata, Nannizziopsis infrequens, Nannizziopsis hominis, Nannizziopsis obscura, Paranannizziopsis australasiensis, Paranannizziopsis californiensis, and Paranannizziopsis crustacea. Chrysosporium longisporum has been reclassified as Paranannizziopsis longispora. N. guarroi causes yellow fungus disease, a common infection in bearded dragons and green iguanas, and O. ophiodiicola is an emerging pathogen of captive and wild snakes. Human-associated species were not recovered from reptiles, and reptile-associated species were recovered only from reptiles, thereby mitigating concerns related to zoonosis. PMID:23926168

Risk factors for invasive reptile-associated salmonellosis in children.

PubMed

Meyer Sauteur, Patrick M; Relly, Christa; Hug, Martina; Wittenbrink, Max M; Berger, Christoph

2013-06-01

Reptile-associated salmonellosis (RAS) in children has been reported primarily due to direct contact with turtles, but recently also due to indirect contact with more exotic reptiles, causing disease in infants. To evaluate risk factors for RAS, we reviewed the RAS cases published in the literature since 1965. A case was defined as a child ≤18 years of age with an epidemiological link by identification of Salmonella enterica in cultures from both the affected child and the exposed reptile. We identified a total of 177 otherwise healthy children (median age 1.0 years, range 2 days to 17.0 years). RAS manifested mainly with gastrointestinal disease, but 15% presented with invasive RAS, including septicemia, meningitis, and bone and joint infection. The children with invasive RAS were significantly younger than children with noninvasive disease (median age 0.17 and 2.0 years, p<0.0001). RAS is most frequently seen after exposure to turtles (42%). However, children with invasive RAS had been exposed more often (p≤0.001) to reptiles other than turtles, including iguanas, bearded dragons, snakes, chameleons, and geckos. Children exposed to those latter reptiles usually kept indoors were younger than children exposed to turtles mostly kept outdoors (p<0.0001). RAS in children is significantly associated with invasive disease at young age, in particular infants <6 months of age. Exposure to reptiles, other than turtles, kept indoors is associated with RAS at younger age and more invasive disease. This finding is helpful for recognizing or even preventing invasive RAS in young infants that are at highest risk.

Molecular characterization of reptile pathogens currently known as members of the chrysosporium anamorph of Nannizziopsis vriesii complex and relationship with some human-associated isolates.

PubMed

Sigler, Lynne; Hambleton, Sarah; Paré, Jean A

2013-10-01

In recent years, the Chrysosporium anamorph of Nannizziopsis vriesii (CANV), Chrysosporium guarroi, Chrysosporium ophiodiicola, and Chrysosporium species have been reported as the causes of dermal or deep lesions in reptiles. These infections are contagious and often fatal and affect both captive and wild animals. Forty-nine CANV isolates from reptiles and six isolates from human sources were compared with N. vriesii based on their cultural characteristics and DNA sequence data. Analyses of the sequences of the internal transcribed spacer and small subunit of the nuclear ribosomal gene revealed that the reptile pathogens and human isolates belong in well-supported clades corresponding to three lineages that are distinct from all other taxa within the family Onygenaceae of the order Onygenales. One lineage represents the genus Nannizziopsis and comprises N. vriesii, N. guarroi, and six additional species encompassing isolates from chameleons and geckos, crocodiles, agamid and iguanid lizards, and humans. Two other lineages comprise the genus Ophidiomyces, with the species Ophidiomyces ophiodiicola occurring only in snakes, and Paranannizziopsis gen. nov., with three new species infecting squamates and tuataras. The newly described species are Nannizziopsis dermatitidis, Nannizziopsis crocodili, Nannizziopsis barbata, Nannizziopsis infrequens, Nannizziopsis hominis, Nannizziopsis obscura, Paranannizziopsis australasiensis, Paranannizziopsis californiensis, and Paranannizziopsis crustacea. Chrysosporium longisporum has been reclassified as Paranannizziopsis longispora. N. guarroi causes yellow fungus disease, a common infection in bearded dragons and green iguanas, and O. ophiodiicola is an emerging pathogen of captive and wild snakes. Human-associated species were not recovered from reptiles, and reptile-associated species were recovered only from reptiles, thereby mitigating concerns related to zoonosis.

Efficacy and Safety of Pedunculopontine Nuclei (PPN) Deep Brain Stimulation in the Treatment of Gait Disorders: A Meta-Analysis of Clinical Studies.

PubMed

Golestanirad, Laleh; Elahi, Behzad; Graham, Simon J; Das, Sunit; Wald, Lawrence L

2016-01-01

Pedunculopontine nucleus (PPN) has complex reciprocal connections with basal ganglia, especially with internal globus pallidus and substantia nigra, and it has been postulated that PPN stimulation may improve gait instability and freezing of gait. In this meta-analysis, we will assess the evidence for PPN deep brain stimulation in treatment of gait and motor abnormalities especially focusing on Parkinson disease patients. PubMed and Scopus electronic databases were searched for related studies published before February 2014. Medline (1966-2014), Embase (1974-2010), CINAHL, Web of Science, Scopus bibliographic, and Google Scholar databases (1960-2014) were also searched for studies investigating effect of PPN deep brain stimulation in treatment of postural and postural instability and total of ten studies met the inclusion criteria for this analysis. Our findings showed a significant improvement in postural instability (p<0.001) and motor symptoms of Parkinson disease on and off medications (p<0.05), but failed to show improvement in freezing of gait. Despite significant improvement in postural instability observed in included studies, evidence from current literature is not sufficient to generalize these findings to the majority of patients.

The Development of the Basal Ganglia in Capuchin Monkeys (Cebus apella)

PubMed Central

Phillips, Kimberley A.; Sobieski, Courtney A.; Gilbert, Valerie R.; Chiappini-Williamson, Christine; Sherwood, Chet C.; Strick, Peter L.

2010-01-01

The basal ganglia are subcortical structures involved in the planning, initiation and regulation of movement as well as a variety of non-motor, cognitive and affective functions. Capuchin monkeys share several important characteristics of development with humans, including a prolonged infancy and juvenile period, a long lifespan, and complex manipulative abilities. This makes capuchins important comparative models for understanding age-related neuroanatomical changes in these structures. Here we report developmental volumetric data on the three subdivisions of the basal ganglia, the caudate, putamen and globus pallidus in brown capuchin monkeys (Cebus apella). Based on a cross-sectional sample, we describe brain development in 28 brown capuchin monkeys (male n = 17, female n = 11; age range = 2 months – 20 years) using high-resolution structural MRI. We found that the raw volumes of the putamen and caudate varied significantly with age, decreasing in volume from birth through early adulthood. Notably, developmental changes did not differ between sexes. Because these observed developmental patterns are similar to humans, our results suggest that capuchin monkeys may be useful animal models for investigating neurodevelopmental disorders of the basal ganglia. PMID:20227397

Quantitative analysis of brain magnetic resonance imaging for hepatic encephalopathy

NASA Astrophysics Data System (ADS)

Syh, Hon-Wei; Chu, Wei-Kom; Ong, Chin-Sing

1992-06-01

High intensity lesions around ventricles have recently been observed in T1-weighted brain magnetic resonance images for patients suffering hepatic encephalopathy. The exact etiology that causes magnetic resonance imaging (MRI) gray scale changes has not been totally understood. The objective of our study was to investigate, through quantitative means, (1) the amount of changes to brain white matter due to the disease process, and (2) the extent and distribution of these high intensity lesions, since it is believed that the abnormality may not be entirely limited to the white matter only. Eleven patients with proven haptic encephalopathy and three normal persons without any evidence of liver abnormality constituted our current data base. Trans-axial, sagittal, and coronal brain MRI were obtained on a 1.5 Tesla scanner. All processing was carried out on a microcomputer-based image analysis system in an off-line manner. Histograms were decomposed into regular brain tissues and lesions. Gray scale ranges coded as lesion were then brought back to original images to identify distribution of abnormality. Our results indicated the disease process involved pallidus, mesencephalon, and subthalamic regions.

Subcortical Correlates of Individual Differences in Aptitude

PubMed Central

Jung, Rex E.; Ryman, Sephira G.; Vakhtin, Andrei A.; Carrasco, Jessica; Wertz, Chris; Flores, Ranee A.

2014-01-01

The study of individual differences encompasses broad constructs including intelligence, creativity, and personality. However, substantially less research is devoted to the study of specific aptitudes in spite of their importance to educational, occupational, and avocational success. We sought to determine subcortical brain structural correlates of several broad aptitudes including Math, Vocabulary, Foresight, Paper Folding, and Inductive Reasoning in a large (N = 107), healthy, young (age range  = 16–29) cohort. Subcortical volumes were measured using an automated technique (FreeSurfer) across structures including bilateral caudate, putamen, globus pallidus, thalamus, nucleus accumbens, hippocampus, amygdala, and five equal regions of the corpus callosum. We found that performance on measures of each aptitude was predicted by different subcortical structures: Math – higher right nucleus accumbens volume; Vocabulary – higher left hippocampus volume; Paper Folding – higher right thalamus volume; Foresight – lower right thalamus and higher mid anterior corpus callosum volume; Inductive Reasoning – higher mid anterior corpus callosum volume. Our results support general findings, within the cognitive neurosciences, showing lateralization of structure-function relationships, as well as more specific relationships between individual structures (e.g., left hippocampus) and functions relevant to particular aptitudes (e.g., Vocabulary). PMID:24586770

Taxonomy of Paraplatyarthrus Javidkar and King (Isopoda: Oniscidea: Paraplatyarthridae) with description of five new species from Western Australia, and comments on Australian Trichorhina Budde-Lunde, 1908 (Platyarthridae).

PubMed

Javidkar, Mohammad; King, Rachael A; Cooper, Steven J B; Humphreys, William F; Austin, Andrew D

2017-03-16

The oniscidean fauna of Australia is generally poorly known but recent sampling has revealed a new family, Paraplatyarthridae, found in both terrestrial and groundwater calcretes of central Western Australia. The family was initially described based on a new genus and species, Paraplatyarthrus subterraneus Javidkar and King, 2015. Here we describe an additional five Paraplatyarthrus species from the Yilgarn region of Western Australia, based on both morphological and molecular evidence (COI divergences). Four species are subterranean: P. crebesconiscus Javidkar and King sp. nov., P. cunyuensis Javidkar and King sp. nov., P. occidentoniscus Javidkar and King sp. nov., and P. pallidus Javidkar and King sp. nov., and one is a surface species, P. nahidae Javidkar and King sp. nov. A key to their identification is provided along with information on their distribution. In addition, type material of the two described Australian species of Platyarthridae, Trichorhina australiensis Wahrberg, 1922 from Western Australia and T. tropicalis Lewis, 1998 from Queensland, are examined. Morphological reassessment of type material shows T. australiensis belongs to Paraplatyarthrus (comb. nov.) and that T. tropicalis is correctly placed in Trichorhina, confirming that the genus and family Platyarthridae occur in Australia.

[Motivation and Emotional States: Structural Systemic, Neurochemical, Molecular and Cellular Mechanisms].

PubMed

Bazyan, A S

2016-01-01

The structural, systemic, neurochemical, molecular and cellular mechanisms of organization and coding motivation and emotional states are describe. The GABA and glutamatergic synaptic systems of basal ganglia form a neural network and participate in the implementation of voluntary behavior. Neuropeptides, neurohormones and paracrine neuromodulators involved in the organization of motivation and emotional states, integrated with synaptic systems, controlled by neural networks and organizing goal-directed behavior. Structural centers for united and integrated of information in voluntary and goal-directed behavior are globus pallidus. Substantia nigra pars reticulata switches the information from corticobasal networks to thalamocortical networks, induces global dopaminergic (DA) signal and organize interaction of mesolimbic and nigostriatnoy DA systems controlled by prefrontal and motor cortex. Together with the motor cortex, substantia nigra displays information in the brainstem and spinal cord to implementation of behavior. Motivation states are formed in the interaction of neurohormonal and neuropeptide systems by monoaminergic systems of brain. Emotional states are formed by monoaminergic systems of the mid-brain, where the leading role belongs to the mesolimbic DA system. The emotional and motivation state of the encoded specific epigenetic molecular and chemical pattern of neuron.

Glutaric aciduria type 1: neuroimaging features with clinical correlation.

PubMed

Mohammad, Shaimaa Abdelsattar; Abdelkhalek, Heba Salah; Ahmed, Khaled A; Zaki, Osama K

2015-10-01

Glutaric aciduria type 1 is a rare neurometabolic disease with high morbidity. To describe the MR imaging abnormalities in glutaric aciduria type 1 and to identify any association between the clinical and imaging features. MRI scans of 29 children (mean age: 16.9 months) with confirmed diagnosis of glutaric aciduria type 1 were retrospectively reviewed. Gray matter and white matter scores were calculated based on a previously published pattern-recognition approach of assessing leukoencephalopathies. Hippocampal formation and opercular topography were assessed in relation to the known embryological basis. MRI scores were correlated with morbidity score. The most consistent MRI abnormality was widened operculum with dilatation of the subarachnoid spaces surrounding underdeveloped frontotemporal lobes. Incomplete hippocampal inversion was also seen. The globus pallidus was the most frequently involved gray matter structure (86%). In addition to the central tegmental tract, white matter abnormalities preferentially involved the central and periventricular regions. The morbidity score correlated with the gray matter abnormality score (P = 0.004). Patients with dystonia had higher gray matter and morbidity scores. Morbidity is significantly correlated with abnormality of gray matter, rather than white matter, whether secondary to acute encephalopathic crisis or insidious onset disease.

A single-neuron tracing study of arkypallidal and prototypic neurons in healthy rats.

PubMed

Fujiyama, Fumino; Nakano, Takashi; Matsuda, Wakoto; Furuta, Takahiro; Udagawa, Jun; Kaneko, Takeshi

2016-12-01

The external globus pallidus (GP) is known as a relay nucleus of the indirect pathway of the basal ganglia. Recent studies in dopamine-depleted and healthy rats indicate that the GP comprises two main types of pallidofugal neurons: the so-called "prototypic" and "arkypallidal" neurons. However, the reconstruction of complete arkypallidal neurons in healthy rats has not been reported. Here we visualized the entire axonal arborization of four single arkypallidal neurons and six single prototypic neurons in rat brain using labeling with a viral vector expressing membrane-targeted green fluorescent protein and examined the distribution of axon boutons in the target nuclei. Results revealed that not only the arkypallidal neurons but nearly all of the prototypic neurons projected to the striatum with numerous axon varicosities. Thus, the striatum is a major target nucleus for pallidal neurons. Arkypallidal and prototypic GP neurons located in the calbindin-positive and calbindin-negative regions mainly projected to the corresponding positive and negative regions in the striatum. Because the GP and striatum calbindin staining patterns reflect the topographic organization of the striatopallidal projection, the striatal neurons in the sensorimotor and associative regions constitute the reciprocal connection with the GP neurons in the corresponding regions.

Computation of an MRI brain atlas from a population of Parkinson’s disease patients

NASA Astrophysics Data System (ADS)

Angelidakis, L.; Papageorgiou, I. E.; Damianou, C.; Psychogios, M. N.; Lingor, P.; von Eckardstein, K.; Hadjidemetriou, S.

2017-11-01

Parkinson’s Disease (PD) is a degenerative disorder of the brain. This study presents an MRI-based brain atlas of PD to characterize associated alterations for diagnostic and interventional purposes. The atlas standardizes primarily the implicated subcortical regions such as the globus pallidus (GP), substantia nigra (SN), subthalamic nucleus (STN), caudate nucleus (CN), thalamus (TH), putamen (PUT), and red nucleus (RN). The data were 3.0 T MRI brain images from 16 PD patients and 10 matched controls. The images used were T1-weighted (T 1 w), T2-weighted (T 2 w) images, and Susceptibility Weighted Images (SWI). The T1w images were the reference for the inter-subject non-rigid registration available from 3DSlicer. Anatomic labeling was achieved with BrainSuite and regions were refined with the level sets segmentation of ITK-Snap. The subcortical centers were analyzed for their volume and signal intensity. Comparison with an age-matched control group unravels a significant PD-related T1w signal loss in the striatum (CN and PUT) centers, but approximately a constant volume. The results in this study improve MRI based PD localization and can lead to the development of novel biomarkers.

[Met5]Enkephalin content in brain regions of rats treated with lithium.

PubMed Central

Gillin, J C; Hong, J S; Yang, H Y; Costa, E

1978-01-01

In rats, chronic treatment with lithium elicits a dose-dependent increase in the [Met5]enkephalin content of nucleus caudatus and globus pallidus. A single injection of lithium fails to change the striatal [Met5]enkephalin content. The increase in [Met5]enkephalin caused by chronic lithium is proportional to the serum lithium level. The extent of the increase in striatal [Met5]enkephalin content levels off at a value of about 250% that of untreated rats. This increase has a time latency of 2--3 days and reaches a plateau at 5 days. The increase that was present at 5 days was no longer evident if the treatment was continued for 2 weeks. Lithium also increases striatal [Leu5]enkephalin content by an extent equal to the increase of [Met 5]enkephalin. Based on the characteristics of the lithium-induced increase in [Met6]enkephalin content, it is proposed that lithium may reduce the rate of release of [Met5]enkephalin from the small enkephalinergic neurons that are intrinsic to the striatum; this action may be related to a change in the regulation of striatal neurons. PMID:275866

R2* mapping for brain iron: associations with cognition in normal aging.

PubMed

Ghadery, Christine; Pirpamer, Lukas; Hofer, Edith; Langkammer, Christian; Petrovic, Katja; Loitfelder, Marisa; Schwingenschuh, Petra; Seiler, Stephan; Duering, Marco; Jouvent, Eric; Schmidt, Helena; Fazekas, Franz; Mangin, Jean-Francois; Chabriat, Hugues; Dichgans, Martin; Ropele, Stefan; Schmidt, Reinhold

2015-02-01

Brain iron accumulates during aging and has been associated with neurodegenerative disorders including Alzheimer's disease. Magnetic resonance (MR)-based R2* mapping enables the in vivo detection of iron content in brain tissue. We investigated if during normal brain aging iron load relates to cognitive impairment in region-specific patterns in a community-dwelling cohort of 336 healthy, middle aged, and older adults from the Austrian Stroke Prevention Family Study. MR imaging and R2* mapping in the basal ganglia and neocortex were done at 3T. Comprehensive neuropsychological testing assessed memory, executive function, and psychomotor speed. We found the highest iron concentration in the globus pallidus, and pallidal and putaminal iron was significantly and inversely associated with cognitive performance in all cognitive domains, except memory. These associations were iron load dependent. Vascular brain lesions and brain volume did not mediate the relationship between iron and cognitive performance. We conclude that higher R2*-determined iron in the basal ganglia correlates with cognitive impairment during brain aging independent of concomitant brain abnormalities. The prognostic significance of this finding needs to be determined. Copyright © 2015 Elsevier Inc. All rights reserved.

Neurotensin receptor binding levels in basal ganglia are not altered in Huntington's chorea or schizophrenia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palacios, J.M.; Chinaglia, G.; Rigo, M.

1991-02-01

Autoradiographic techniques were used to examine the distribution and levels of neurotensin receptor binding sites in the basal ganglia and related regions of the human brain. Monoiodo ({sup 125}I-Tyr3)neurotensin was used as a ligand. High amounts of neurotensin receptor binding sites were found in the substantia nigra pars compacta. Lower but significant quantities of neurotensin receptor binding sites characterized the caudate, putamen, and nucleus accumbens, while very low quantities were seen in both medial and lateral segments of the globus pallidus. In Huntington's chorea, the levels of neurotensin receptor binding sites were found to be comparable to those of controlmore » cases. Only slight but not statistically significant decreases in amounts of receptor binding sites were detected in the dorsal part of the head and in the body of caudate nucleus. No alterations in the levels of neurotensin receptor binding sites were observed in the substantia nigra pars compacta and reticulata. These results suggest that a large proportion of neurotensin receptor binding sites in the basal ganglia are located on intrinsic neurons and on extrinsic afferent fibers that do not degenerate in Huntington's disease.« less

Improvement of Isolated Myoclonus Phenotype in Myoclonus Dystonia after Pallidal Deep Brain Stimulation

PubMed Central

Ramdhani, Ritesh A.; Frucht, Steven J.; Behnegar, Anousheh; Kopell, Brian H.

2016-01-01

Background Myoclonus–dystonia is a condition that manifests predominantly as myoclonic jerks with focal dystonia. It is genetically heterogeneous with most mutations in the epsilon sarcoglycan gene (SGCE). In medically refractory cases, deep brain stimulation (DBS) has been shown to provide marked sustainable clinical improvement, especially in SGCE-positive patients. We present two patients with myoclonus–dystonia (one SGCE positive and the other SGCE negative) who have the isolated myoclonus phenotype and had DBS leads implanted in the bilateral globus pallidus internus (GPi). Methods We review their longitudinal Unified Myoclonus Rating Scale scores along with their DBS programming parameters and compare them with published cases in the literature. Results Both patients demonstrated complete amelioration of all aspects of myoclonus within 6–12 months after surgery. The patient with the SGCE-negative mutation responded just as well as the patient who was SGCE positive. High-frequency stimulation (130 Hz) with amplitudes greater than 2.5 V provided therapeutic benefit. Discussion This case series demonstrates that high frequency GPi-DBS is effective in treating isolated myoclonus in myoclonus–dystonia, regardless of the presence of SGCE mutation. PMID:26989574

The neural basis of audiomotor entrainment: an ALE meta-analysis

PubMed Central

Chauvigné, Léa A. S.; Gitau, Kevin M.; Brown, Steven

2014-01-01

Synchronization of body movement to an acoustic rhythm is a major form of entrainment, such as occurs in dance. This is exemplified in experimental studies of finger tapping. Entrainment to a beat is contrasted with movement that is internally driven and is therefore self-paced. In order to examine brain areas important for entrainment to an acoustic beat, we meta-analyzed the functional neuroimaging literature on finger tapping (43 studies) using activation likelihood estimation (ALE) meta-analysis with a focus on the contrast between externally-paced and self-paced tapping. The results demonstrated a dissociation between two subcortical systems involved in timing, namely the cerebellum and the basal ganglia. Externally-paced tapping highlighted the importance of the spinocerebellum, most especially the vermis, which was not activated at all by self-paced tapping. In contrast, the basal ganglia, including the putamen and globus pallidus, were active during both types of tapping, but preferentially during self-paced tapping. These results suggest a central role for the spinocerebellum in audiomotor entrainment. We conclude with a theoretical discussion about the various forms of entrainment in humans and other animals. PMID:25324765

Application of a data-mining method based on Bayesian networks to lesion-deficit analysis

NASA Technical Reports Server (NTRS)

Herskovits, Edward H.; Gerring, Joan P.

2003-01-01

Although lesion-deficit analysis (LDA) has provided extensive information about structure-function associations in the human brain, LDA has suffered from the difficulties inherent to the analysis of spatial data, i.e., there are many more variables than subjects, and data may be difficult to model using standard distributions, such as the normal distribution. We herein describe a Bayesian method for LDA; this method is based on data-mining techniques that employ Bayesian networks to represent structure-function associations. These methods are computationally tractable, and can represent complex, nonlinear structure-function associations. When applied to the evaluation of data obtained from a study of the psychiatric sequelae of traumatic brain injury in children, this method generates a Bayesian network that demonstrates complex, nonlinear associations among lesions in the left caudate, right globus pallidus, right side of the corpus callosum, right caudate, and left thalamus, and subsequent development of attention-deficit hyperactivity disorder, confirming and extending our previous statistical analysis of these data. Furthermore, analysis of simulated data indicates that methods based on Bayesian networks may be more sensitive and specific for detecting associations among categorical variables than methods based on chi-square and Fisher exact statistics.

Panic and fear induced by deep brain stimulation.

PubMed

Shapira, N A; Okun, M S; Wint, D; Foote, K D; Byars, J A; Bowers, D; Springer, U S; Lang, P J; Greenberg, B D; Haber, S N; Goodman, W K

2006-03-01

Mood, cognitive, and behavioural changes have been reported with deep brain stimulation (DBS) in the thalamus, globus pallidus interna, and anterior limb of the internal capsule/nucleus accumbens region. To investigate panic and fear resulting from DBS. Intraoperative DBS in the region of the right and then left anterior limb of the internal capsule and nucleus accumbens region was undertaken to treat a 52 year old man with treatment refractory obsessive-compulsive disorder (OCD). Mood, anxiety, OCD, alertness, heart rate, and subjective feelings were recorded during intraoperative test stimulation and at follow up programming sessions. DBS at the distal (0) contact (cathode 0-, anode 2+, pulse width 210 ms, rate 135 Hz, at 6 volts) elicited a panic attack (only seen at the (0) contact). The patient felt flushed, hot, fearful, and described himself as having a "panic attack." His heart rate increased from 53 to 111. The effect (present with either device) was witnessed immediately after turning the device on, and abruptly ceased in the off condition DBS of the anterior limb of the internal capsule and nucleus accumbens region caused severe "panic." This response may result from activation of limbic and autonomic networks.

Screening and characterization of thermo-active enzymes of biotechnological interest produced by thermophilic Bacillus isolated from hot springs in Tunisia.

PubMed

Thebti, Wajdi; Riahi, Yosra; Gharsalli, Rawand; Belhadj, Omrane

2016-01-01

As part of the contribution to the global efforts in research of thermostable enzymes being of industrial interest, we focus on the isolation of thermophilic bacteria from Tunisian hot springs. Among the collection of 161 strains of thermophilic Bacillus isolated from different samples of thermal water in Tunisia, 20% are capable of growing at 100°C and the rest grow at 70°C or above. Preliminary activity tests on media supplemented with enzyme-substrates confirmed that 35 strains produced amylases, 37 - proteases, 43 - cellulases, 31 - xylanases and 37 - mannanases. The study of the effect of temperature on enzyme activity led to determination of the optimal temperatures of activities that vary between 60 and 100°C. Several enzymes were active at high temperatures (80, 90 and 100°C) and kept their activity even at 110°C. Several isolated strains producing enzymes with high optimal temperatures of activity were described for the first time in this study. Both strains B62 and B120 are producers of amylase, protease, cellulase, xylanase, and mannanase. The sequencing of 16S DNA identified isolated strains as Geobacillus kaustophillus, Aeribacillus pallidus, Geobacillus galactosidasus and Geobacillus toebii.

Movement disorders and chronic psychosis

PubMed Central

Morgante, Francesca

2017-01-01

Abstract Purpose of review: To discuss selected peer-reviewed research articles published between 2014 and 2016 and highlight 5 clinically relevant messages related to hyperkinetic and hypokinetic movement disorders in patients with chronic psychosis. Recent findings: A recent population-based study complemented data from clinical trials in showing increased risk of developing extrapyramidal symptoms with antipsychotic use. A community service–based longitudinal study showed that dopamine transporter imaging could help identify subgroups of patients with parkinsonism associated with antipsychotics with a progressive course, potentially manageable with l-dopa. Data from recent noteworthy clinical trials showed that a new VMAT-2 inhibitor and, for pharmacologically refractory tardive dyskinesia, deep brain stimulation of the globus pallidus internus are promising interventions. Finally, a population-based study has confirmed that hyperkinesias (encompassing chorea, dystonia, and stereotypies) may be early predictors of psychosis even in childhood and adolescence. Summary: Movement disorders associated with new-generation antipsychotics, including widely used agents (e.g., aripiprazole), are not rare occurrences. Better monitoring is needed to assess their true effect on patients' quality of life and functioning and to prevent underascertainment. PMID:29185545

Deep brain stimulation for the treatment of uncommon tremor syndromes.

PubMed

Ramirez-Zamora, Adolfo; Okun, Michael S

2016-08-01

Deep brain stimulation (DBS) has become a standard therapy for the treatment of select cases of medication refractory essential tremor and Parkinson's disease however the effectiveness and long-term outcomes of DBS in other uncommon and complex tremor syndromes has not been well established. Traditionally, the ventralis intermedius nucleus (VIM) of the thalamus has been considered the main target for medically intractable tremors; however alternative brain regions and improvements in stereotactic techniques and hardware may soon change the horizon for treatment of complex tremors. In this article, we conducted a PubMed search using different combinations between the terms 'Uncommon tremors', 'Dystonic tremor', 'Holmes tremor' 'Midbrain tremor', 'Rubral tremor', 'Cerebellar tremor', 'outflow tremor', 'Multiple Sclerosis tremor', 'Post-traumatic tremor', 'Neuropathic tremor', and 'Deep Brain Stimulation/DBS'. Additionally, we examined and summarized the current state of evolving interventions for treatment of complex tremor syndromes. Expert commentary: Recently reported interventions for rare tremors include stimulation of the posterior subthalamic area, globus pallidus internus, ventralis oralis anterior/posterior thalamic subnuclei, and the use of dual lead stimulation in one or more of these targets. Treatment should be individualized and dictated by tremor phenomenology and associated clinical features.

Warping an atlas derived from serial histology to 5 high-resolution MRIs.

PubMed

Tullo, Stephanie; Devenyi, Gabriel A; Patel, Raihaan; Park, Min Tae M; Collins, D Louis; Chakravarty, M Mallar

2018-06-19

Previous work from our group demonstrated the use of multiple input atlases to a modified multi-atlas framework (MAGeT-Brain) to improve subject-based segmentation accuracy. Currently, segmentation of the striatum, globus pallidus and thalamus are generated from a single high-resolution and -contrast MRI atlas derived from annotated serial histological sections. Here, we warp this atlas to five high-resolution MRI templates to create five de novo atlases. The overall goal of this work is to use these newly warped atlases as input to MAGeT-Brain in an effort to consolidate and improve the workflow presented in previous manuscripts from our group, allowing for simultaneous multi-structure segmentation. The work presented details the methodology used for the creation of the atlases using a technique previously proposed, where atlas labels are modified to mimic the intensity and contrast profile of MRI to facilitate atlas-to-template nonlinear transformation estimation. Dice's Kappa metric was used to demonstrate high quality registration and segmentation accuracy of the atlases. The final atlases are available at https://github.com/CobraLab/atlases/tree/master/5-atlas-subcortical.

Activation of hypothalamic RIP-Cre neurons promotes beiging of WAT via sympathetic nervous system.

PubMed

Wang, Baile; Li, Ang; Li, Xiaomu; Ho, Philip Wl; Wu, Donghai; Wang, Xiaoqi; Liu, Zhuohao; Wu, Kelvin Kl; Yau, Sonata Sy; Xu, Aimin; Cheng, Kenneth Ky

2018-04-01

Activation of brown adipose tissue (BAT) and beige fat by cold increases energy expenditure. Although their activation is known to be differentially regulated in part by hypothalamus, the underlying neural pathways and populations remain poorly characterized. Here, we show that activation of rat-insulin-promoter-Cre (RIP-Cre) neurons in ventromedial hypothalamus (VMH) preferentially promotes recruitment of beige fat via a selective control of sympathetic nervous system (SNS) outflow to subcutaneous white adipose tissue (sWAT), but has no effect on BAT Genetic ablation of APPL2 in RIP-Cre neurons diminishes beiging in sWAT without affecting BAT, leading to cold intolerance and obesity in mice. Such defects are reversed by activation of RIP-Cre neurons, inactivation of VMH AMPK, or treatment with a β3-adrenergic receptor agonist. Hypothalamic APPL2 enhances neuronal activation in VMH RIP-Cre neurons and raphe pallidus, thereby eliciting SNS outflow to sWAT and subsequent beiging. These data suggest that beige fat can be selectively activated by VMH RIP-Cre neurons, in which the APPL2-AMPK signaling axis is crucial for this defending mechanism to cold and obesity. © 2018 The Authors.

Deepwater Chondrichthyan Bycatch of the Eastern King Prawn Fishery in the Southern Great Barrier Reef, Australia

PubMed Central

Rigby, Cassandra L.; White, William T.; Simpfendorfer, Colin A.

2016-01-01

The deepwater chondrichthyan fauna of the Great Barrier Reef is poorly known and life history information is required to enable their effective management as they are inherently vulnerable to exploitation. The chondrichthyan bycatch from the deepwater eastern king prawn fishery at the Swain Reefs in the southern Great Barrier Reef was examined to determine the species present and provide information on their life histories. In all, 1533 individuals were collected from 11 deepwater chondrichthyan species, with the Argus skate Dipturus polyommata, piked spurdog Squalus megalops and pale spotted catshark Asymbolus pallidus the most commonly caught. All but one species is endemic to Australia with five species restricted to waters offshore from Queensland. The extent of life history information available for each species varied but the life history traits across all species were characteristic of deep water chondrichthyans with relatively large length at maturity, small litters and low ovarian fecundity; all indicative of low biological productivity. However, variability among these traits and spatial and bathymetric distributions of the species suggests differing degrees of resilience to fishing pressure. To ensure the sustainability of these bycatch species, monitoring of their catches in the deepwater eastern king prawn fishery is recommended. PMID:27218654

Additional records of bats from the middle Rio Grande Valley, New Mexico

USGS Publications Warehouse

Valdez, Ernest W.; Stuart, James N.; Bogan, Michael A.

1999-01-01

The resident and migratory bat fauna of the middle Rio Grande Valley in central New Mexico is inadequately known. Many of the specimen records from this valley are from Bosque del Apache National Wildlife Refuge, ca. 20 km S of Socorro, Socorro Co. Findley et al. (1975) reported Myotis lucifugus, M. yumanensis, Lasiurus cinereus, and Tadarida brasiliensis from the refuge to which Reith (1982) added Antrozous pallidus. During June and July 1994, we netted nine nights and conducted visual searches of known roosts to capture 67 bats of seven species as part of a baseline survey of bats on the refuge. We surveyed artificial wetlands in the transitional zone between riparian forest and adjacent desert-grassland, within ca. 2 km of the Rio Grande. Nearby agricultural fields and ponds managed primarily for use by waterfowl provided numerous sites suitable for foraging and drinking by bats. We report four new species records for the refuge, one of  which is also a new county record. Voucher material is deposited in the Biological Survey Collection, Fort Collins (BS/FC), now housed in the Museum of Southwestern Biology (MSB), University of New Mexico.

Exploring risk factors for stuttering development in Parkinson disease after deep brain stimulation.

PubMed

Picillo, Marina; Vincos, Gustavo B; Sammartino, Francesco; Lozano, Andres M; Fasano, Alfonso

2017-05-01

Stuttering is a speech disorder with disruption of verbal fluency, occasionally present in Parkinson's disease (PD). PD co-incident stuttering may either worsen or improve after Deep Brain Stimulation (DBS). Sixteen out of 453 PD patients (3.5%) exhibited stuttering after DBS (PD-S) and were compared with a group of patients without stuttering (PD-NS) using non-parametric statistics. After DBS, stuttering worsened in 3 out of 4 patients with co-incidental stuttering. Most PD-S underwent subthalamic (STN) DBS, but 4 were implanted in the globus pallidus (GPi). Nine out of 16 PD-S (56.3%) reported a positive familial history for stuttering compared to none of the PD-NS. PD-S were mainly male (81.3%) with slight worse motor features compared to PD-NS. Herein, we describe a group of PD patients developing stuttering after DBS and report the presence of a positive familial history for stuttering as the most relevant risk factor, suggesting a possible underlying genetic cause. The fact that stuttering occurred after either STN or GPi DBS is an argument against the impact of medication reduction on stuttering. Copyright © 2017 Elsevier Ltd. All rights reserved.

Shifted dynamic interactions between subcortical nuclei and inferior frontal gyri during response preparation in persistent developmental stuttering.

PubMed

Metzger, F Luise; Auer, Tibor; Helms, Gunther; Paulus, Walter; Frahm, Jens; Sommer, Martin; Neef, Nicole E

2018-01-01

Persistent developmental stuttering is associated with basal ganglia dysfunction or dopamine dysregulation. Here, we studied whole-brain functional connectivity to test how basal ganglia structures coordinate and reorganize sensorimotor brain networks in stuttering. To this end, adults who stutter and fluent speakers (control participants) performed a response anticipation paradigm in the MRI scanner. The preparation of a manual Go/No-Go response reliably produced activity in the basal ganglia and thalamus and particularly in the substantia nigra. Strikingly, in adults who stutter, substantia nigra activity correlated positively with stuttering severity. Furthermore, functional connectivity analyses yielded altered task-related network formations in adults who stutter compared to fluent speakers. Specifically, in adults who stutter, the globus pallidus and the thalamus showed increased network synchronization with the inferior frontal gyrus. This implies dynamic shifts in the response preparation-related network organization through the basal ganglia in the context of a non-speech motor task in stuttering. Here we discuss current findings in the traditional framework of how D1 and D2 receptor activity shapes focused movement selection, thereby suggesting a disproportional involvement of the direct and the indirect pathway in stuttering.

Nannofossil and sequence chronostratigraphy of a marine flooding surface in the Turonian of Trinidad

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, T.C.

1996-08-01

A multi-well regional study in the Southern basin, Trinidad, reveals a very pronounced marine flooding surface in Turonian- age sediments. This surface is correlatable with global Turonian marine transgressions and genetically ties with the best hydrocarbon source rocks known in Trinidad. The Turonian marine flooding surface yields abundant nannoplankton. Most notable is Lithastrinus moratus Stover, a short-ranging marker of the Lithastrinus evolutionary series. Two morphotypes of Lithastrinus moratus have been found. The more delicate eight-rayed form evolves from Lithastrinus floralls in early Turonian time. Based on observations in Ste. Croix-1, Rocky Palace-1, Rochard-1, Marac-1, Moniga East-15, Iguana River-1, Lizard Spring-Imore » and Antilles Brighton-102, it occurs more frequently in the lower Turonian, but is rare in Trinidad. It has a more robust seven-rayed descendant that appears to be restricted to a narrow interval associated with peak Turonian marine transgression and usually dominates the nannofossil assemblage in the condensed section. The highest stratigraphic occurrence of this form coincides with the lowest occurrence of Marthastentes furcatus based on core sample studies. The age of the marine flooding surface is therefore well constrained to be in zone CC12 and is considered to be correlative with the 89 million year marine flooding surface. The marine flooding surface appears intercontinentally correlatable as it has also been identified in the Arcadia Shale of the Eagle Ford Group in Texas. Because of its wide areal distribution and ease of paleontological recognition, this surface is ideal for regional hydrocarbon source rock mapping, stratal correlation and structural control.« less

The serotonergic anatomy of the developing human medulla oblongata: implications for pediatric disorders of homeostasis.

PubMed

Kinney, Hannah C; Broadbelt, Kevin G; Haynes, Robin L; Rognum, Ingvar J; Paterson, David S

2011-07-01

The caudal serotonergic (5-HT) system is a critical component of a medullary "homeostatic network" that regulates protective responses to metabolic stressors such as hypoxia, hypercapnia, and hyperthermia. We define anatomically the caudal 5-HT system in the human medulla as 5-HT neuronal cell bodies located in the raphé (raphé obscurus, raphé magnus, and raphé pallidus), extra-raphé (gigantocellularis, paragigantocellularis lateralis, intermediate reticular zone, lateral reticular nucleus, and nucleus subtrigeminalis), and ventral surface (arcuate nucleus). These 5-HT neurons are adjacent to all of the respiratory- and autonomic-related nuclei in the medulla where they are positioned to modulate directly the responses of these effector nuclei. In the following review, we highlight the topography and development of the caudal 5-HT system in the human fetus and infant, and its inter-relationships with nicotinic, GABAergic, and cytokine receptors. We also summarize pediatric disorders in early life which we term "developmental serotonopathies" of the caudal (as well as rostral) 5-HT domain and which are associated with homeostatic imbalances. The delineation of the development and organization of the human caudal 5-HT system provides the critical foundation for the neuropathologic elucidation of its disorders directly in the human brain. Copyright © 2011 Elsevier B.V. All rights reserved.

Total and regional brain volumes in a population-based normative sample from 4 to 18 years: the NIH MRI Study of Normal Brain Development.

PubMed

2012-01-01

Using a population-based sampling strategy, the National Institutes of Health (NIH) Magnetic Resonance Imaging Study of Normal Brain Development compiled a longitudinal normative reference database of neuroimaging and correlated clinical/behavioral data from a demographically representative sample of healthy children and adolescents aged newborn through early adulthood. The present paper reports brain volume data for 325 children, ages 4.5-18 years, from the first cross-sectional time point. Measures included volumes of whole-brain gray matter (GM) and white matter (WM), left and right lateral ventricles, frontal, temporal, parietal and occipital lobe GM and WM, subcortical GM (thalamus, caudate, putamen, and globus pallidus), cerebellum, and brainstem. Associations with cross-sectional age, sex, family income, parental education, and body mass index (BMI) were evaluated. Key observations are: 1) age-related decreases in lobar GM most prominent in parietal and occipital cortex; 2) age-related increases in lobar WM, greatest in occipital, followed by the temporal lobe; 3) age-related trajectories predominantly curvilinear in females, but linear in males; and 4) small systematic associations of brain tissue volumes with BMI but not with IQ, family income, or parental education. These findings constitute a normative reference on regional brain volumes in children and adolescents.

The impact of multichannel microelectrode recording (MER) in deep brain stimulation of the basal ganglia.

PubMed

Kinfe, Thomas M; Vesper, Jan

2013-01-01

Deep brain stimulation (DBS) of the basal ganglia (Ncl. subthalamicus, Ncl. ventralis intermedius thalami, globus pallidus internus) has become an evidence-based and well-established treatment option in otherwise refractory movement disorders. The Ncl. subthalamicus (STN) is the target of choice in Parkinson's disease.However, a considerable discussion is currently ongoing with regard to the necessity for micro-electrode recording (MER) in DBS surgery.The present review provides an overview on deep brain stimulation and (MER) of the STN in patients with Parkinson's disease. Detailed description is given concerning the multichannel MER systems nowadays available for DBS of the basal ganglia, especially of the STN, as a useful tool for target refinement. Furthermore, an overview is given of the historical aspects, spatial mapping of the STN by MER, and its impact for accuracy and precision in current functional stereotactic neurosurgery.The pros concerning target refinement by MER means on the one hand, and cons including increased bleeding risk, increased operation time, local or general anesthesia, and single versus multichannel microelectrode recording are discussed in detail. Finally, the authors favor the use of MER with intraoperative testing combined with imaging to achieve a more precise electrode placement, aiming to ameliorate clinical outcome in therapy-resistant movement disorders.

Optogenetic Activation of the Sensorimotor Cortex Reveals "Local Inhibitory and Global Excitatory" Inputs to the Basal Ganglia.

PubMed

Ozaki, Mitsunori; Sano, Hiromi; Sato, Shigeki; Ogura, Mitsuhiro; Mushiake, Hajime; Chiken, Satomi; Nakao, Naoyuki; Nambu, Atsushi

2017-12-01

To understand how information from different cortical areas is integrated and processed through the cortico-basal ganglia pathways, we used optogenetics to systematically stimulate the sensorimotor cortex and examined basal ganglia activity. We utilized Thy1-ChR2-YFP transgenic mice, in which channelrhodopsin 2 is robustly expressed in layer V pyramidal neurons. We applied light spots to the sensorimotor cortex in a grid pattern and examined neuronal responses in the globus pallidus (GP) and entopeduncular nucleus (EPN), which are the relay and output nuclei of the basal ganglia, respectively. Light stimulation typically induced a triphasic response composed of early excitation, inhibition, and late excitation in GP/EPN neurons. Other response patterns lacking 1 or 2 of the components were also observed. The distribution of the cortical sites whose stimulation induced a triphasic response was confined, whereas stimulation of the large surrounding areas induced early and late excitation without inhibition. Our results suggest that cortical inputs to the GP/EPN are organized in a "local inhibitory and global excitatory" manner. Such organization seems to be the neuronal basis for information processing through the cortico-basal ganglia pathways, that is, releasing and terminating necessary information at an appropriate timing, while simultaneously suppressing other unnecessary information. © The Author 2017. Published by Oxford University Press.

Glutamate System Genes and Brain Volume Alterations in Pediatric Obsessive-Compulsive Disorder: A Preliminary Study

PubMed Central

Wu, Ke; Hanna, Gregory L.; Easter, Philip; Kennedy, James L.; Rosenberg, David R.; Arnold, Paul D

2012-01-01

Obsessive-compulsive disorder (OCD) has been associated with regional volumetric brain abnormalities, which provide promising intermediate phenotypes of the disorder. In this study, volumes of brain regions selected for a priori evidence of association with OCD (orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), thalamus, caudate, putamen, globus pallidus and pituitary) were measured using structural magnetic resonance imaging (MRI) in 20 psychotropic-naïve pediatric OCD patients. We examined the association between these regional brain volumes and a total of 519 single nucleotide polymorphisms (SNPs) from nine glutamatergic candidate genes (DLGAP1, DLGAP2, DLGAP3, GRIN2B, SLC1A1, GRIK2, GRIK3, SLITRK1 and SLITRK5). These genes were selected based on either previous reported association with OCD in humans or evidence from animal models of OCD. After correcting for multiple comparisons by permutation testing, no SNP remained significantly associated with volumetric changes. The strongest trend toward association was identified between two SNPs in DLGAP2 (rs6558484 and rs7014992) and OFC white matter volume (P = 0.000565, Padjusted= 0.3071). Our other top ranked association findings were with ACC, OFC and thalamus. These preliminary results suggest that sequence variants in glutamate candidate genes may be associated with structural neuroimaging phenotypes of OCD. PMID:23154099

Role of deep brain stimulation in modulating memory formation and recall

PubMed Central

Hu, Rollin; Eskandar, Emad; Williams, Ziv

2010-01-01

Deep brain stimulation (DBS) has become an increasingly popular tool for treating a variety of medically refractory neurological and psychiatric disorders such as Parkinson disease, essential tremor, depression, and obsessive-compulsive disorder. Several targets have been identified for ablation or stimulation based on their anatomical location and presumed function. Areas such as the subthalamic nucleus, globus pallidus, and thalamus, for example, are believed to play a key role in motor control and execution, and they are commonly used in the treatment of motor disorders. Limbic structures such as the cingulate cortex and ventral striatum, believed to be important in motivation, emotion, and higher cognition, have also been targeted for treatment of a number of psychiatric disorders. In all of these settings, DBS is largely aimed at addressing the deleterious aspects of these diseases. In Parkinson disease, for example, DBS has been used to reduce rigidity and tremor, whereas in obsessive-compulsive disorder it has been used to limit compulsive behavior. More recently, however, attention has also turned to the potential use of DBS for enhancing or improving otherwise nonpathological aspects of cognitive function. This review explores the potential role of DBS in augmenting memory formation and recall, and the authors discuss recent studies and future trends in this emerging field. PMID:19569891

Fully Bayesian inference for structural MRI: application to segmentation and statistical analysis of T2-hypointensities.

PubMed

Schmidt, Paul; Schmid, Volker J; Gaser, Christian; Buck, Dorothea; Bührlen, Susanne; Förschler, Annette; Mühlau, Mark

2013-01-01

Aiming at iron-related T2-hypointensity, which is related to normal aging and neurodegenerative processes, we here present two practicable approaches, based on Bayesian inference, for preprocessing and statistical analysis of a complex set of structural MRI data. In particular, Markov Chain Monte Carlo methods were used to simulate posterior distributions. First, we rendered a segmentation algorithm that uses outlier detection based on model checking techniques within a Bayesian mixture model. Second, we rendered an analytical tool comprising a Bayesian regression model with smoothness priors (in the form of Gaussian Markov random fields) mitigating the necessity to smooth data prior to statistical analysis. For validation, we used simulated data and MRI data of 27 healthy controls (age: [Formula: see text]; range, [Formula: see text]). We first observed robust segmentation of both simulated T2-hypointensities and gray-matter regions known to be T2-hypointense. Second, simulated data and images of segmented T2-hypointensity were analyzed. We found not only robust identification of simulated effects but also a biologically plausible age-related increase of T2-hypointensity primarily within the dentate nucleus but also within the globus pallidus, substantia nigra, and red nucleus. Our results indicate that fully Bayesian inference can successfully be applied for preprocessing and statistical analysis of structural MRI data.

The Serotonergic Anatomy of the Developing Human Medulla Oblongata: Implications for Pediatric Disorders of Homeostasis

PubMed Central

Kinney, Hannah C.; Broadbelt, Kevin G.; Haynes, Robin L.; Rognum, Ingvar J.; Paterson, David S.

2011-01-01

The caudal serotonergic (5-HT) system is a critical component of a medullary “homeostatic network” that regulates protective responses to metabolic stressors such as hypoxia, hypercapnia, and hyperthermia. We define anatomically the caudal 5-HT system in the human medulla as 5-HT neuronal cell bodies located in the raphé (raphé obscurus, raphé magnus, and raphé pallidus), extra-raphé (gigantocellularis, paragigantocellularis lateralis, intermediate reticular zone, lateral reticular nucleus, and nucleus subtrigeminalis), and ventral surface (arcuate nucleus). These 5-HT neurons are adjacent to all of the respiratory- and autonomic-related nuclei in the medulla where they are positioned to modulate directly the responses of these effector nuclei. In the following review, we highlight the topography and development of the caudal 5-HT system in the human fetus and infant, and its inter-relationships with nicotinic, GABAergic, and cytokine receptors. We also summarize pediatric disorders in early life which we term “developmental serotonopathies” of the caudal (as well as rostral) 5-HT domain and which are associated with homeostatic imbalances. The delineation of the development and organization of the human caudal 5-HT system provides the critical foundation for the neuropathologic elucidation of its disorders directly in the human brain. PMID:21640183

Increased serotonin axons (immunoreactive to 5-HT transporter) in postmortem brains from young autism donors.

PubMed

Azmitia, Efrain C; Singh, Jorawer S; Whitaker-Azmitia, Patricia M

2011-06-01

Imaging studies of serotonin transporter binding or tryptophan retention in autistic patients suggest that the brain serotonin system is decreased. However, treatment with drugs which increase serotonin (5-HT) levels, specific serotonin reuptake inhibitors (SSRIs), commonly produce a worsening of the symptoms. In this study we examined 5-HT axons that were immunoreactive to a serotonin transporter (5-HTT) antibody in a number of postmortem brains from autistic patients and controls with no known diagnosis who ranged in age from 2 to 29 years. Fine, highly branched, and thick straight fibers were found in forebrain pathways (e.g. medial forebrain bundle, stria terminalis and ansa lenticularis). Many immunoreactive varicose fine fibers were seen in target areas (e.g. globus pallidus, amygdala and temporal cortex). Morphometric analysis of the stained axons at all ages studied indicated that the number of serotonin axons was increased in both pathways and terminal regions in cortex from autism donors. Our findings provide morphological evidence to warrant caution when using serotonin enhancing drugs (e.g. SSRIs and receptor agonist) to treat autistic children. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'. Copyright © 2011 Elsevier Ltd. All rights reserved.

Long-term increase in coherence between the basal ganglia and motor cortex after asphyxial cardiac arrest and resuscitation in developing rats.

PubMed

Aravamuthan, Bhooma R; Shoykhet, Michael

2015-10-01

The basal ganglia are vulnerable to injury during cardiac arrest. Movement disorders are a common morbidity in survivors. Yet, neuronal motor network changes post-arrest remain poorly understood. We compared function of the motor network in adult rats that, during postnatal week 3, underwent 9.5 min of asphyxial cardiac arrest (n = 9) or sham intervention (n = 8). Six months after injury, we simultaneously recorded local field potentials (LFP) from the primary motor cortex (MCx) and single neuron firing and LFP from the rat entopeduncular nucleus (EPN), which corresponds to the primate globus pallidus pars interna. Data were analyzed for firing rates, power, and coherence between MCx and EPN spike and LFP activity. Cardiac arrest survivors display chronic motor deficits. EPN firing rate is lower in cardiac arrest survivors (19.5 ± 2.4 Hz) compared with controls (27.4 ± 2.7 Hz; P < 0.05). Cardiac arrest survivors also demonstrate greater coherence between EPN single neurons and MCx LFP (3-100 Hz; P < 0.001). This increased coherence indicates abnormal synchrony in the neuronal motor network after cardiac arrest. Increased motor network synchrony is thought to be antikinetic in primary movement disorders. Characterization of motor network synchrony after cardiac arrest may help guide management of post-hypoxic movement disorders.

Caudate Nucleus Volume Mediates the Link between Cardiorespiratory Fitness and Cognitive Flexibility in Older Adults

PubMed Central

Verstynen, Timothy D.; Lynch, Brighid; Miller, Destiny L.; Voss, Michelle W.; Prakash, Ruchika Shaurya; Chaddock, Laura; Basak, Chandramallika; Szabo, Amanda; Olson, Erin A.; Wojcicki, Thomas R.; Fanning, Jason; Gothe, Neha P.; McAuley, Edward; Kramer, Arthur F.; Erickson, Kirk I.

2012-01-01

The basal ganglia play a central role in regulating the response selection abilities that are critical for mental flexibility. In neocortical areas, higher cardiorespiratory fitness levels are associated with increased gray matter volume, and these volumetric differences mediate enhanced cognitive performance in a variety of tasks. Here we examine whether cardiorespiratory fitness correlates with the volume of the subcortical nuclei that make up the basal ganglia and whether this relationship predicts cognitive flexibility in older adults. Structural MRI was used to determine the volume of the basal ganglia nuclei in a group of older, neurologically healthy individuals (mean age 66 years, N = 179). Measures of cardiorespiratory fitness (VO2max), cognitive flexibility (task switching), and attentional control (flanker task) were also collected. Higher fitness levels were correlated with higher accuracy rates in the Task Switching paradigm. In addition, the volume of the caudate nucleus, putamen, and globus pallidus positively correlated with Task Switching accuracy. Nested regression modeling revealed that caudate nucleus volume was a significant mediator of the relationship between cardiorespiratory fitness, and task switching performance. These findings indicate that higher cardiorespiratory fitness predicts better cognitive flexibility in older adults through greater grey matter volume in the dorsal striatum. PMID:22900181

Deep brain stimulation for the treatment of uncommon tremor syndromes

PubMed Central

Ramirez-Zamora, Adolfo; Okun, Michael S.

2016-01-01

ABSTRACT Introduction: Deep brain stimulation (DBS) has become a standard therapy for the treatment of select cases of medication refractory essential tremor and Parkinson’s disease however the effectiveness and long-term outcomes of DBS in other uncommon and complex tremor syndromes has not been well established. Traditionally, the ventralis intermedius nucleus (VIM) of the thalamus has been considered the main target for medically intractable tremors; however alternative brain regions and improvements in stereotactic techniques and hardware may soon change the horizon for treatment of complex tremors. Areas covered: In this article, we conducted a PubMed search using different combinations between the terms ‘Uncommon tremors’, ‘Dystonic tremor’, ‘Holmes tremor’ ‘Midbrain tremor’, ‘Rubral tremor’, ‘Cerebellar tremor’, ‘outflow tremor’, ‘Multiple Sclerosis tremor’, ‘Post-traumatic tremor’, ‘Neuropathic tremor’, and ‘Deep Brain Stimulation/DBS’. Additionally, we examined and summarized the current state of evolving interventions for treatment of complex tremor syndromes. Expert c ommentary: Recently reported interventions for rare tremors include stimulation of the posterior subthalamic area, globus pallidus internus, ventralis oralis anterior/posterior thalamic subnuclei, and the use of dual lead stimulation in one or more of these targets. Treatment should be individualized and dictated by tremor phenomenology and associated clinical features. PMID:27228280

Can a Positive Allosteric Modulation of GABAergic Receptors Improve Motor Symptoms in Patients with Parkinson's Disease? The Potential Role of Zolpidem in the Treatment of Parkinson's Disease

PubMed Central

Daniele, Antonio; Panza, Francesco; Greco, Antonio; Logroscino, Giancarlo; Seripa, Davide

2016-01-01

At present, patients with advanced Parkinson's disease (PD) are unsatisfactorily controlled by currently used anti-Parkinsonian dopaminergic drugs. Various studies suggest that therapeutic strategies based on nondopaminergic drugs might be helpful in PD. Zolpidem, an imidazopyridine widely used as sleep inducer, shows high affinity only for GABAA receptors containing the α-1 subunit and facilitates GABAergic neurotransmission through a positive allosteric modulation of GABAA receptors. Various observations, although preliminary, consistently suggest that in PD patients zolpidem may induce beneficial (and sometimes remarkable) effects on motor symptoms even after single doses and may also improve dyskinesias. Since a high density of zolpidem binding sites is in the two main output structures of the basal ganglia which are abnormally overactive in PD (internal globus pallidus, GPi, and substantia nigra pars reticulata, SNr), it was hypothesized that in PD patients zolpidem may induce through GABAA receptors an inhibition of GPi and SNr (and, possibly, of the subthalamic nucleus also), resulting in an increased activity of motor cortical areas (such as supplementary motor area), which may give rise to improvement of motor symptoms of PD. Randomized clinical trials are needed in order to assess the efficacy, safety, and tolerability of zolpidem in treating motor symptoms of PD. PMID:27293955

Iron in typical and atypical parkinsonism - Mössbauer spectroscopy and MRI studies

NASA Astrophysics Data System (ADS)

Kuliński, R.; Bauminger, E. R.; Friedman, A.; Duda, P.; Gałązka-Friedman, J.

2016-12-01

Iron may play important role in neurodegeneration. The results of comparative studies of human brain areas (control and pathological) performed by Mössbauer spectroscopy (MS) and magnetic resonance imaging (MRI) techniques are presented. Mössbauer spectroscopy demonstrated a higher concentration of iron in atypical parkinsonism (progressive supranuclear palsy PSP) in the brain areas Substantia Nigra (SN) and Globus Pallidus (GP) involved in this pathological process, compared to control, while the concentration of iron in pathological tissues in typical parkinsonism (Parkinson's disease - PD) did not differ from that in control. These results were compared with the changes in 1/T1 and 1/T2 (T1 and T2 being the relaxation times determined by MRI). A good linear correlation curve was found between the concentration of iron as determined by MS in different areas of control human brains and between 1/T1 and 1/T2. Whereas the finding in PSP-GP (the brain area involved in PSP) also fitted to such a correlation, this was not so for the correlation between pathological SN - the brain area involved in both diseases - and 1/T2, indicating a dependence of T2 on other factors than just the concentration of iron.

Symptoms of posttraumatic stress disorder and exposure to traumatic stressors are related to brain structural volumes and behavioral measures of affective stimulus processing in police officers.

PubMed

Shucard, Janet Louise; Cox, Jennifer; Shucard, David William; Fetter, Holly; Chung, Charles; Ramasamy, Deepa; Violanti, John

2012-10-30

Traumatic experiences and subsequent symptoms of posttraumatic stress disorder (PTSD) have been shown to affect brain structure and function. Although police officers are routinely exposed to traumatic events, the neurobehavioral effects of trauma in this population have rarely been studied. In this study, police officers with exposure to trauma-related stressors underwent structural magnetic resonance imaging (MRI). They also provided valence and arousal ratings of neutral and negative (trauma-related) picture stimuli. Relationships were examined among PTSD symptom scores (avoidance, reexperiencing, and hyperarousal), picture ratings, structural MRI measures, and number of trauma exposures. We hypothesized that greater PTSD symptomatology would be related to higher valence and arousal ratings of trauma-related stimuli and to decreased volume of limbic and Basal ganglia structures. Results revealed that officers with higher reexperiencing scores tended to have higher arousal ratings of negative pictures and reduced amygdala, thalamus, and globus pallidus volumes. There was a trend toward higher reexperiencing and reduced hippocampal volume. The frequency of traumatic exposures was also related to MRI measures of atrophy and to increased PTSD symptomatology. These findings suggest that chronic reexperiencing of traumatic events may result in volumetric reductions in brain structures associated with autonomic arousal and the acquisition of conditioned fear. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

The Neural Bases of Disgust for Cheese: An fMRI Study

PubMed Central

Royet, Jean-Pierre; Meunier, David; Torquet, Nicolas; Mouly, Anne-Marie; Jiang, Tao

2016-01-01

The study of food aversion in humans by the induction of illness is ethically unthinkable, and it is difficult to propose a type of food that is disgusting for everybody. However, although cheese is considered edible by most people, it can also be perceived as particularly disgusting to some individuals. As such, the perception of cheese constitutes a good model to study the cerebral processes of food disgust and aversion. In this study, we show that a higher percentage of people are disgusted by cheese than by other types of food. Functional magnetic resonance imaging then reveals that the internal and external globus pallidus and the substantia nigra belonging to the basal ganglia are more activated in participants who dislike or diswant to eat cheese (Anti) than in other participants who like to eat cheese, as revealed following stimulation with cheese odors and pictures. We suggest that the aforementioned basal ganglia structures commonly involved in reward are also involved in the aversive motivated behaviors. Our results further show that the ventral pallidum, a core structure of the reward circuit, is deactivated in Anti subjects stimulated by cheese in the wanting task, highlighting the suppression of motivation-related activation in subjects disgusted by cheese. PMID:27799903

Revision of the Plant Bug Genus Tytthus (Hemiptera, Heteroptera, Miridae, Phylinae)

PubMed Central

Henry, Thomas J.

2012-01-01

Abstract The phyline plant bug genus Tytthus Fieber, previously containing 19 species, is revised. Isoproba Osborn and Drake, 1915, incorrectly placed in the subfamily Bryocorinae, tribe Dicyphini, is synonymized as a junior synonym of Tytthus Fieber, syn. n.; the only included species, Isoproba picea Osborn and Drake is transferred to Tytthus, comb. n., as the senior synonym of Tytthus hondurensis Carvalho, syn. n.; and Tytthus koreanus Josifov and Kerzhner, 1972 is synonymized with Tytthus chinensis (Stål 1860), syn. n.; and a lectotype for Tytthus parviceps is designated. The six new species Tytthus femoralis from Cuba, Ecuador, Guatemala, Jamaica, Mexico, and Peru,Tytthus fuscicornis from New Mexico (USA), Tytthus mexicanus from Mexico, Tytthus pallidus from Brazil and Panama, Tytthus uniformis from Arizona and New Mexico (USA), and Tytthus wheeleri from the eastern United States are described, bringing the total number of species for the genus to 24. A color adult habitus illustration of Tytthus wheeleri, color photographs for each species (except Tytthus juturnaiba Carvalho and Wallerstein), illustrations of male genitalia, scanning electron photomicrographs of selected structures of certain species, and an identification key are provided to facilitate species recognition. A phylogenetic analysis is offered to help infer relationships. PMID:23077429

[An fMRI Study of the Brain Activation Related to Intensive Positive Emotions During Viweing Erotic Pictures in 49-74 Old Men].

PubMed

Martynova, O; Portnova, G; Orlov, I

2016-01-01

According to psychological research erotic images are evaluated in the context of positive emotions as the most intense, most associated with emotional arousal, among the variety of pleasant and unpleasant stimuli. However it is difficult to separate areas of the brain that are related to the general emotional process from the activity of the brain areas involved in neuronal representations of reward system. The purpose of this study was to determine differences in the brain activity using functional magnetic resonance imaging (fMRI) in male subjects in evaluating an intensity of pleasant images, including erotic, or unpleasant and neutral pictures. When comparing the condition with evaluation of the pleasant erotic images with conditions containing neutral or unpleasant stimuli, a significant activation was observed in the posterior cingulate cortex; the prefrontal cortex and the right globus pallidus. An increased activity of the right anterior central gyrus was observed in the conditions related to evaluation of pleasant and neutral stimuli. Thus, in the process of evaluating the intensity of emotional images of an erotic nature the active brain areas were related not only to neuronal representations of emotions, but also to motivations and control system of emotional arousal, which should be taken into account while using erotic pictures as intensive positive emotional stimuli.

Regional atrophy of the basal ganglia and thalamus in idiopathic generalized epilepsy.

PubMed

Du, Hanjian; Zhang, Yuanchao; Xie, Bing; Wu, Nan; Wu, Guocai; Wang, Jian; Jiang, Tianzi; Feng, Hua

2011-04-01

To determine the regional changes in the shapes of subcortical structures in idiopathic generalized epilepsy using a vertex-based analysis method. Earlier studies found that gray matter volume in the frontal, parietal, and temporal lobes is significantly altered in idiopathic generalized epilepsy (IGE). Research has indicated that a relationship exists between the brain's subcortical structures and epilepsy. However, little is known about possible changes in the subcortical structures in IGE. This study aims to determine the changes in the shape of subcortical structures in IGE using vertex analysis. Fourteen male patients with IGE and 28 age- and sex-matched healthy controls were included in this study, which used high-resolution magnetic resonance imaging. We performed a vertex-based shape analysis, in which we compared patients with IGE with the controls, on the subcortical structures that we had obtained from the MRI data. Statistical analysis showed significant regional atrophy in the left thalamus, left putamen and bilateral globus pallidus in patients with IGE. These results indicate that regional atrophy of the basal ganglia and the thalamus may be related to seizure disorder. In the future, these findings may prove useful for choosing new therapeutic regimens. Copyright © 2011 Wiley-Liss, Inc.

Seasonal reliance on nectar by an insectivorous bat revealed by stable isotopes.

PubMed

Frick, Winifred F; Shipley, J Ryan; Kelly, Jeffrey F; Heady, Paul A; Kay, Kathleen M

2014-01-01

Many animals have seasonally plastic diets to take advantage of seasonally abundant plant resources, such as fruit or nectar. Switches from insectivorous diets that are protein rich to fruits or nectar that are carbohydrate rich present physiological challenges, but are routinely done by insectivorous songbirds during migration. In contrast, insectivorous bat species are not known to switch diets to consume fruit or nectar. Here, we use carbon stable isotope ratios to establish the first known case of a temperate bat species consuming substantial quantities of nectar during spring. We show that pallid bats (Antrozous pallidus) switch from a diet indistinguishable from that of sympatric insectivorous bat species in winter (when no cactus nectar is present) to a diet intermediate between those of insectivorous bats and nectarivorous bats during the spring bloom of a bat-adapted cactus species. Combined with previous results that established that pallid bats are effective pollinators of the cardon cactus (Pachycereus pringlei), our results suggest that the interaction between pallid bats and cardon cacti represents the first-known plant-pollinator mutualism between a plant and a temperate bat. Diet plasticity in pallid bats raises questions about the degree of physiological adaptations of insectivorous bats for incorporation of carbohydrate-rich foods, such as nectar or fruit, into the diet.

Surgical treatment of dystonia.

PubMed

Cury, Rubens Gisbert; Kalia, Suneil Kumar; Shah, Binit Bipin; Jimenez-Shahed, Joohi; Prashanth, Lingappa Kumar; Moro, Elena

2018-05-28

Treatment of dystonia should be individualized and tailored to the specific needs of patients. Surgical treatment is an important option in medically refractory cases. Several issues regarding type of the surgical intervention, targets, and predict factors of benefit are still under debate. Areas covered: To date, several clinical trials have proven the benefit and safety of deep brain stimulation (DBS) for inherited and idiopathic isolated dystonia, whereas there is still insufficient evidence in combined and acquired dystonia. The globus pallidus internus (GPi) is the target with the best evidence, but data on the subthalamic nucleus seems also to be promising. Evidence suggests that younger patients with shorter disease duration experience greater benefit following DBS. Pallidotomy and thalamotomy are currently used in subset of carefully selected patients. The development of MRI-guided focused ultrasound might bring new options to ablation approach in dystonia. Expert commentary: GPi-DBS is effective and safe in isolated dystonia and should not be delayed when symptoms compromise quality of life and functionality. Identifying the best candidates to surgery on acquired and combined dystonias is still necessary. New insights about pathophysiology of dystonia and new technological advances will undoubtedly help to tailor surgery and optimize clinical effects.

Is there evidence for neurodegenerative change following traumatic brain injury in children and youth? A scoping review.

PubMed

Keightley, Michelle L; Sinopoli, Katia J; Davis, Karen D; Mikulis, David J; Wennberg, Richard; Tartaglia, Maria C; Chen, Jen-Kai; Tator, Charles H

2014-01-01

While generalized cerebral atrophy and neurodegenerative change following traumatic brain injury (TBI) is well recognized in adults, it remains comparatively understudied in the pediatric population, suggesting that research should address the potential for neurodegenerative change in children and youth following TBI. This focused review examines original research findings documenting evidence for neurodegenerative change following TBI of all severities in children and youth. Our relevant inclusion and exclusion criteria identified a total of 16 articles for review. Taken together, the studies reviewed suggest there is evidence for long-term neurodegenerative change following TBI in children and youth. In particular both cross-sectional and longitudinal studies revealed volume loss in selected brain regions including the hippocampus, amygdala, globus pallidus, thalamus, periventricular white matter, cerebellum, and brain stem as well as overall decreased whole brain volume and increased CSF and ventricular space. Diffusion Tensor Imaging (DTI) studies also report evidence for decreased cellular integrity, particularly in the corpus callosum. Sensitivity of the hippocampus and deep limbic structures in pediatric populations are similar to findings in the adult literature and we consider the data supporting these changes as well as the need to investigate the possibility of neurodegenerative onset in childhood associated with mild traumatic brain injury (mTBI).

Changing pattern in the basal ganglia: motor switching under reduced dopaminergic drive

PubMed Central

Fiore, Vincenzo G.; Rigoli, Francesco; Stenner, Max-Philipp; Zaehle, Tino; Hirth, Frank; Heinze, Hans-Jochen; Dolan, Raymond J.

2016-01-01

Action selection in the basal ganglia is often described within the framework of a standard model, associating low dopaminergic drive with motor suppression. Whilst powerful, this model does not explain several clinical and experimental data, including varying therapeutic efficacy across movement disorders. We tested the predictions of this model in patients with Parkinson’s disease, on and off subthalamic deep brain stimulation (DBS), focussing on adaptive sensory-motor responses to a changing environment and maintenance of an action until it is no longer suitable. Surprisingly, we observed prolonged perseverance under on-stimulation, and high inter-individual variability in terms of the motor selections performed when comparing the two conditions. To account for these data, we revised the standard model exploring its space of parameters and associated motor functions and found that, depending on effective connectivity between external and internal parts of the globus pallidus and saliency of the sensory input, a low dopaminergic drive can result in increased, dysfunctional, motor switching, besides motor suppression. This new framework provides insight into the biophysical mechanisms underlying DBS, allowing a description in terms of alteration of the signal-to-baseline ratio in the indirect pathway, which better account of known electrophysiological data in comparison with the standard model. PMID:27004463

Substance P in the dorsal vagal complex inhibits medullary TRH-induced gastric acid secretion in rats.

PubMed

Yang, H; Taché, Y

1997-05-01

Neurons that contain substance P (SP) and thyrotropin-releasing hormone (TRH) in medullary midline raphe nuclei project to the dorsal vagal complex (DVC). The modulatory role of SP on basal gastric acid secretion (GAS) and TRH on DVC-induced stimulation of GAS was studied in urethan-anesthetized rats. The stable SP agonist, DiMe-C7 ([pGlu5, MePhe8, MeGly9]SP5-11, 50 and 100 pmol), injected unilaterally into the DVC reduced the GAS response (47 +/- 12 mumol/60 min) to coinjected TRH analog, RX 77368 (25 pmol), by 53% and 85%, respectively, whereas DiMe-C7 (100 pmol) alone had no effect on basal and pentagastrin-stimulated GAS. DiMe-C7 (100 pmol/site) inhibited the GAS response to kainic acid injected into the raphe pallidus (Rpa) when it was injected bilaterally into the DVC but not the hypoglossal nuclei. The SP nourokinin-1-receptor antagonist, CP-96,345, injected bilaterally into the DVC (1 nmol/ site) increased basal GAS (33 +/- 8 mumol/90 min) and potentiated the GAS response to kainic acid injected into the Rpa by 40%. These results suggest that SP acts on neurokinin-1 receptors in the DVC to reduce medullary TRH-induced stimulation of GAS in rats.

Afferent Connectivity of the Zebrafish Habenulae

PubMed Central

Turner, Katherine J.; Hawkins, Thomas A.; Yáñez, Julián; Anadón, Ramón; Wilson, Stephen W.; Folgueira, Mónica

2016-01-01

The habenulae are bilateral nuclei located in the dorsal diencephalon that are conserved across vertebrates. Here we describe the main afferents to the habenulae in larval and adult zebrafish. We observe afferents from the subpallium, nucleus rostrolateralis, posterior tuberculum, posterior hypothalamic lobe, median raphe; we also see asymmetric afferents from olfactory bulb to the right habenula, and from the parapineal to the left habenula. In addition, we find afferents from a ventrolateral telencephalic nucleus that neurochemical and hodological data identify as the ventral entopeduncular nucleus (vENT), confirming and extending observations of Amo et al. (2014). Fate map and marker studies suggest that vENT originates from the diencephalic prethalamic eminence and extends into the lateral telencephalon from 48 to 120 hour post-fertilization (hpf). No afferents to the habenula were observed from the dorsal entopeduncular nucleus (dENT). Consequently, we confirm that the vENT (and not the dENT) should be considered as the entopeduncular nucleus “proper” in zebrafish. Furthermore, comparison with data in other vertebrates suggests that the vENT is a conserved basal ganglia nucleus, being homologous to the entopeduncular nucleus of mammals (internal segment of the globus pallidus of primates) by both embryonic origin and projections, as previously suggested by Amo et al. (2014). PMID:27199671

Specific induction of PAG608 in cranial and spinal motor neurons of L-DOPA-treated parkinsonian rats.

PubMed

Shimizu, Masako; Miyazaki, Ikuko; Higashi, Youichirou; Eslava-Alva, Maria J; Diaz-Corrales, Francisco J; Asanuma, Masato; Ogawa, Norio

2008-04-01

We identified p53-activated gene 608 (PAG608) as a specifically induced gene in striatal tissue of L-DOPA (100mg/kg)-injected hemi-parkinsonian rats using differential display assay. In the present study, we further examined morphological distribution of PAG608 in the central nervous system of L-DOPA-treated hemi-parkinsonian rats. PAG608 expression was markedly induced in fibers and neuronal cells of the lateral globus pallidus and reticular thalamic nucleus adjacent to internal capsule, specifically in the parkinsonian side of L-DOPA-treated models. The protein was also constitutively expressed in motor neurons specifically in either side of the pontine nucleus and motor nuclei of trigeminal and facial nerves. Furthermore, L-DOPA-induced PAG608 expression on motor neurons in the contralateral side of the ventral horn of the spinal cord and the lateral corticospinal tract without cell loss. The specific induction of PAG608 6-48h after L-DOPA injection in the extrapyramidal tracts, pyramidal tracts and corresponding lower motor neurons of the spinal cords suggests its involvement in molecular events in stimulated motor neurons. Taken together with the constitutive expression of PAG608 in the motor nuclei of cranial nerves, PAG608 may be a useful marker of stressed or activated lower motor neurons.

Visualizing Iron Deposition in Multiple Sclerosis Cadaver Brains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habib, Charbel A.; Zheng Weili; Mark Haacke, E.

Aim: To visualize and validate iron deposition in two cases of multiple sclerosis using rapid scanning X-Ray Fluorescence (RS-XRF) and Susceptibility Weighted Imaging (SWI). Material and Methods: Two (2) coronal cadaver brain slices from patients clinically diagnosed with multiple sclerosis underwent magnetic resonance imaging (MRI), specifically SWI to image iron content. To confirm the presence of iron deposits and the absence of zinc-rich myelin in lesions, iron and zinc were mapped using RS-XRF. Results: MS lesions were visualized using FLAIR and correlated with the absence of zinc by XRF. XRF and SWI showed that in the first MS case, theremore » were large iron deposits proximal to the draining vein of the caudate nucleus as well as iron deposits associated with blood vessels throughout the globus pallidus. Less iron was seen in association with lesions than in the basal ganglia. The presence of larger amounts of iron correlated reasonably well between RS-XRF and SWI. In the second case, the basal ganglia appeared normal and acute perivascular iron deposition was absent. Conclusion: Perivascular iron deposition is seen in some but not all MS cases, giving credence to the use of SWI to assess iron involvement in MS pathology in vivo.« less

Visualizing Iron Deposition in Multiple Sclerosis Cadaver Brains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habib, A.C.; Zheng, W.; Haacke, E.M.

To visualize and validate iron deposition in two cases of multiple sclerosis using rapid scanning X-Ray Fluorescence (RS-XRF) and Susceptibility Weighted Imaging (SWI). Two (2) coronal cadaver brain slices from patients clinically diagnosed with multiple sclerosis underwent magnetic resonance imaging (MRI), specifically SWI to image iron content. To confirm the presence of iron deposits and the absence of zinc-rich myelin in lesions, iron and zinc were mapped using RS-XRF. MS lesions were visualized using FLAIR and correlated with the absence of zinc by XRF. XRF and SWI showed that in the first MS case, there were large iron deposits proximalmore » to the draining vein of the caudate nucleus as well as iron deposits associated with blood vessels throughout the globus pallidus. Less iron was seen in association with lesions than in the basal ganglia. The presence of larger amounts of iron correlated reasonably well between RS-XRF and SWI. In the second case, the basal ganglia appeared normal and acute perivascular iron deposition was absent. Perivascular iron deposition is seen in some but not all MS cases, giving credence to the use of SWI to assess iron involvement in MS pathology in vivo.« less

Arterial spin labelling reveals an abnormal cerebral perfusion pattern in Parkinson's disease.

PubMed

Melzer, Tracy R; Watts, Richard; MacAskill, Michael R; Pearson, John F; Rüeger, Sina; Pitcher, Toni L; Livingston, Leslie; Graham, Charlotte; Keenan, Ross; Shankaranarayanan, Ajit; Alsop, David C; Dalrymple-Alford, John C; Anderson, Tim J

2011-03-01

There is a need for objective imaging markers of Parkinson's disease status and progression. Positron emission tomography and single photon emission computed tomography studies have suggested patterns of abnormal cerebral perfusion in Parkinson's disease as potential functional biomarkers. This study aimed to identify an arterial spin labelling magnetic resonance-derived perfusion network as an accessible, non-invasive alternative. We used pseudo-continuous arterial spin labelling to measure cerebral grey matter perfusion in 61 subjects with Parkinson's disease with a range of motor and cognitive impairment, including patients with dementia and 29 age- and sex-matched controls. Principal component analysis was used to derive a Parkinson's disease-related perfusion network via logistic regression. Region of interest analysis of absolute perfusion values revealed that the Parkinson's disease pattern was characterized by decreased perfusion in posterior parieto-occipital cortex, precuneus and cuneus, and middle frontal gyri compared with healthy controls. Perfusion was preserved in globus pallidus, putamen, anterior cingulate and post- and pre-central gyri. Both motor and cognitive statuses were significant factors related to network score. A network approach, supported by arterial spin labelling-derived absolute perfusion values may provide a readily accessible neuroimaging method to characterize and track progression of both motor and cognitive status in Parkinson's disease.

Cognitive performance is associated with gray matter decline in first-episode psychosis.

PubMed

Dempster, Kara; Norman, Ross; Théberge, Jean; Densmore, Maria; Schaefer, Betsy; Williamson, Peter

2017-06-30

Progressive loss of gray matter has been demonstrated over the early course of schizophrenia. Identification of an association between cognition and gray matter may lead to development of early interventions directed at preserving gray matter volume and cognitive ability. The present study evaluated the association between gray matter using voxel-based morphometry (VBM) and cognitive testing in a sample of 16 patients with first-episode psychosis. A simple regression was applied to investigate the association between gray matter at baseline and 80 months and cognitive tests at baseline. Performance on the Wisconsin Card Sorting Task (WCST) at baseline was positively associated with gray matter volume in several brain regions. There was an association between decreased gray matter at baseline in the nucleus accumbens and Trails B errors. Performing worse on Trails B and making more WCST perseverative errors at baseline was associated with gray matter decline over 80 months in the right globus pallidus, left inferior parietal lobe, Brodmann's area (BA) 40, and left superior parietal lobule and BA 7 respectively. All significant findings were cluster corrected. The results support a relationship between aspects of cognitive impairment and gray matter abnormalities in first-episode psychosis. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Subthalamic hGAD65 Gene Therapy and Striatum TH Gene Transfer in a Parkinson’s Disease Rat Model

PubMed Central

Zheng, Deyu; Jiang, Xiaohua; Zhao, Junpeng; Duan, Deyi; Zhao, Huanying; Xu, Qunyuan

2013-01-01

The aim of the present study is to detect a combination method to utilize gene therapy for the treatment of Parkinson’s disease (PD). Here, a PD rat model is used for the in vivo gene therapy of a recombinant adeno-associated virus (AAV2) containing a human glutamic acid decarboxylase 65 (rAAV2-hGAD65) gene delivered to the subthalamic nucleus (STN). This is combined with the ex vivo gene delivery of tyrosine hydroxylase (TH) by fibroblasts injected into the striatum. After the treatment, the rotation behavior was improved with the greatest efficacy in the combination group. The results of immunohistochemistry showed that hGAD65 gene delivery by AAV2 successfully led to phenotypic changes of neurons in STN. And the levels of glutamic acid and GABA in the internal segment of the globus pallidus (GPi) and substantia nigra pars reticulata (SNr) were obviously lower than the control groups. However, hGAD65 gene transfer did not effectively protect surviving dopaminergic neurons in the SNc and VTA. This study suggests that subthalamic hGAD65 gene therapy and combined with TH gene therapy can alleviate symptoms of the PD model rats, independent of the protection the DA neurons from death. PMID:23738148

Differential loss of striatal projection neurons in Huntington disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reiner, A.; Albin, R.L.; Anderson, K.D.

1988-08-01

Huntington disease (HD) is characterized by the loss of striatal projection neurons, which constitute the vast majority of striatal neurons. To determine whether there is differential loss among different populations of striatal projection neurons, the integrity of the axon terminal plexuses arising from the different populations of substance P-containing and enkephalin-containing striatal projection neurons was studied in striatal target areas by immunohistochemistry. Analysis of 17 HD specimens indicated that in early and middle stages of HD, enkephalin-containing neurons projecting to the external segment of the globus pallidus were much more affected than substance P-containing neurons projecting to the internal pallidalmore » segment. Furthermore, substance P-containing neurons projecting to the substantia nigra pars reticulata were more affected than those projecting to the substantia nigra pars compacta. At the most advanced stages of the disease, projections to all striatal target areas were depleted, with the exception of some apparent sparing of the striatal projection to the substantia nigra pars compacta. These finding may explain some of the clinical manifestations and pharmacology of HD. They also may aid in identifying the neural defect underlying HD and provide additional data with which to evaluate current models of HD pathogenesis.« less

Anatomical correlates of reward-seeking behaviours in behavioural variant frontotemporal dementia

PubMed Central

Sturm, Virginia E.; Seeley, William W.; Miller, Bruce L.; Kramer, Joel H.; Rosen, Howard J.

2014-01-01

Behavioural variant frontotemporal dementia is characterized by abnormal responses to primary reward stimuli such as food, sex and intoxicants, suggesting abnormal functioning of brain circuitry mediating reward processing. The goal of this analysis was to determine whether abnormalities in reward-seeking behaviour in behavioural variant frontotemporal dementia are correlated with atrophy in regions known to mediate reward processing. Review of case histories in 103 patients with behavioural variant frontotemporal dementia identified overeating or increased sweet food preference in 80 (78%), new or increased alcohol or drug use in 27 (26%), and hypersexuality in 17 (17%). For each patient, a primary reward-seeking score of 0–3 was created with 1 point given for each target behaviour (increased seeking of food, drugs, or sex). Voxel-based morphometry performed in 91 patients with available imaging revealed that right ventral putamen and pallidum atrophy correlated with higher reward-seeking scores. Each of the reward-related behaviours involved partially overlapping right hemisphere reward circuit regions including putamen, globus pallidus, insula and thalamus. These findings indicate that in some patients with behavioural variant frontotemporal dementia, low volume of subcortical reward-related structures is associated with increased pursuit of primary rewards, which may be a product of increased thalamocortical feedback. PMID:24740987

Age, gender, and hemispheric differences in iron deposition in the human brain: an in vivo MRI study.

PubMed

Xu, Xiaojun; Wang, Qidong; Zhang, Minming

2008-03-01

It is well known that iron accumulates in the brains of patients with various neurodegenerative diseases. To better understand disease-related iron changes, it is necessary to know the physiological distribution and accumulation of iron in the human brain. Studies have shown that brain iron levels increase with aging. However, the effects of gender and hemispheric laterality on iron accumulation and distribution are not well established. In this study, we estimated the brain iron levels in vivo in 78 healthy adults ranging in age 22 to 78 years using magnetic susceptibility-weighted phase imaging. The effects of age, gender, and hemispheric location on brain iron levels were evaluated within the framework of a general linear model. We found that the left hemisphere had higher iron levels than the right in the putamen, globus pallidus, substantia nigra, thalamus, and frontal white matter. We argue that the hemispheric asymmetry of iron content may underlie that of the dopaminergic system and may be related to motor lateralization in humans. In addition, significant age-related iron accumulation occurred in the putamen, red nucleus, and frontal white matter, but no gender-related differences in iron levels were detected. The results of this study extend our knowledge of the physiological distribution and accumulation of iron in the human brain.

Subcortical regional morphology correlates with fluid and spatial intelligence.

PubMed

Burgaleta, Miguel; MacDonald, Penny A; Martínez, Kenia; Román, Francisco J; Álvarez-Linera, Juan; Ramos González, Ana; Karama, Sherif; Colom, Roberto

2014-05-01

Neuroimaging studies have revealed associations between intelligence and brain morphology. However, researchers have focused primarily on the anatomical features of the cerebral cortex, whereas subcortical structures, such as the basal ganglia (BG), have often been neglected despite extensive functional evidence on their relation with higher-order cognition. Here we performed shape analyses to understand how individual differences in BG local morphology account for variability in cognitive performance. Structural MRI was acquired in 104 young adults (45 men, 59 women, mean age = 19.83, SD = 1.64), and the outer surface of striatal structures (caudate, nucleus accumbens, and putamen), globus pallidus, and thalamus was estimated for each subject and hemisphere. Further, nine cognitive tests were used to measure fluid (Gf), crystallized (Gc), and spatial intelligence (Gv). Latent scores for these factors were computed by means of confirmatory factor analysis and regressed vertex-wise against subcortical shape (local displacements of vertex position), controlling for age, sex, and adjusted for brain size. Significant results (FDR < 5%) were found for Gf and Gv, but not Gc, for the right striatal structures and thalamus. The main results show a relative enlargement of the rostral putamen, which is functionally connected to the right dorsolateral prefrontal cortex and other intelligence-related prefrontal areas. Copyright © 2013 Wiley Periodicals, Inc.

A Perfusion MRI Study of Emotional Valence and Arousal in Parkinson's Disease

PubMed Central

Limsoontarakul, Sunsern; Campbell, Meghan C.; Black, Kevin J.

2011-01-01

Background. Brain regions subserving emotion have mostly been studied using functional magnetic resonance imaging (fMRI) during emotion provocation procedures in healthy participants. Objective. To identify neuroanatomical regions associated with spontaneous changes in emotional state over time. Methods. Self-rated emotional valence and arousal scores, and regional cerebral blood flow (rCBF) measured by perfusion MRI, were measured 4 or 8 times spanning at least 2 weeks in each of 21 subjects with Parkinson's disease (PD). A random-effects SPM analysis, corrected for multiple comparisons, identified significant clusters of contiguous voxels in which rCBF varied with valence or arousal. Results. Emotional valence correlated positively with rCBF in several brain regions, including medial globus pallidus, orbital prefrontal cortex (PFC), and white matter near putamen, thalamus, insula, and medial PFC. Valence correlated negatively with rCBF in striatum, subgenual cingulate cortex, ventrolateral PFC, and precuneus—posterior cingulate cortex (PCC). Arousal correlated positively with rCBF in clusters including claustrum-thalamus-ventral striatum and inferior parietal lobule and correlated negatively in clusters including posterior insula—mediodorsal thalamus and midbrain. Conclusion. This study demonstrates that the temporal stability of perfusion MRI allows within-subject investigations of spontaneous fluctuations in mental state, such as mood, over relatively long-time intervals. PMID:21969917

Reward, motivation, and emotion systems associated with early-stage intense romantic love.

PubMed

Aron, Arthur; Fisher, Helen; Mashek, Debra J; Strong, Greg; Li, Haifang; Brown, Lucy L

2005-07-01

Early-stage romantic love can induce euphoria, is a cross-cultural phenomenon, and is possibly a developed form of a mammalian drive to pursue preferred mates. It has an important influence on social behaviors that have reproductive and genetic consequences. To determine which reward and motivation systems may be involved, we used functional magnetic resonance imaging and studied 10 women and 7 men who were intensely "in love" from 1 to 17 mo. Participants alternately viewed a photograph of their beloved and a photograph of a familiar individual, interspersed with a distraction-attention task. Group activation specific to the beloved under the two control conditions occurred in dopamine-rich areas associated with mammalian reward and motivation, namely the right ventral tegmental area and the right postero-dorsal body and medial caudate nucleus. Activation in the left ventral tegmental area was correlated with facial attractiveness scores. Activation in the right anteromedial caudate was correlated with questionnaire scores that quantified intensity of romantic passion. In the left insula-putamen-globus pallidus, activation correlated with trait affect intensity. The results suggest that romantic love uses subcortical reward and motivation systems to focus on a specific individual, that limbic cortical regions process individual emotion factors, and that there is localization heterogeneity for reward functions in the human brain.

Visualizing Iron Deposition in Multiple Sclerosis Cadaver Brains

NASA Astrophysics Data System (ADS)

Habib, Charbel A.; Zheng, Weili; Mark Haacke, E.; Webb, Sam; Nichol, Helen

2010-07-01

Aim: To visualize and validate iron deposition in two cases of multiple sclerosis using rapid scanning X-Ray Fluorescence (RS-XRF) and Susceptibility Weighted Imaging (SWI). Material and Methods: Two (2) coronal cadaver brain slices from patients clinically diagnosed with multiple sclerosis underwent magnetic resonance imaging (MRI), specifically SWI to image iron content. To confirm the presence of iron deposits and the absence of zinc-rich myelin in lesions, iron and zinc were mapped using RS-XRF. Results: MS lesions were visualized using FLAIR and correlated with the absence of zinc by XRF. XRF and SWI showed that in the first MS case, there were large iron deposits proximal to the draining vein of the caudate nucleus as well as iron deposits associated with blood vessels throughout the globus pallidus. Less iron was seen in association with lesions than in the basal ganglia. The presence of larger amounts of iron correlated reasonably well between RS-XRF and SWI. In the second case, the basal ganglia appeared normal and acute perivascular iron deposition was absent. Conclusion: Perivascular iron deposition is seen in some but not all MS cases, giving credence to the use of SWI to assess iron involvement in MS pathology in vivo.

Surgery for Dystonia and Tremor.

PubMed

Crowell, Jason L; Shah, Binit B

2016-03-01

Surgical procedures for dystonia and tremor have evolved over the past few decades, and our understanding of risk, benefit, and predictive factors has increased substantially in that time. Deep brain stimulation (DBS) is the most utilized surgical treatment for dystonia and tremor, though lesioning remains an effective option in appropriate patients. Dystonic syndromes that have shown a substantial reduction in severity secondary to DBS are isolated dystonia, including generalized, cervical, and segmental, as well as acquired dystonia such as tardive dystonia. Essential tremor is quite amenable to DBS, though the response of other forms of postural and kinetic tremor is not nearly as robust or consistent based on available evidence. Regarding targeting, DBS lead placement in the globus pallidus internus has shown marked efficacy in dystonia reduction. The subthalamic nucleus is an emerging target, and increasing evidence suggests that this may be a viable target in dystonia as well. The ventralis intermedius nucleus of the thalamus is the preferred target for essential tremor, though targeting the subthalamic zone/caudal zona incerta has shown promise and may emerge as another option in essential tremor and possibly other tremor disorders. In the carefully selected patient, DBS and lesioning procedures are relatively safe and effective for the management of dystonia and tremor.

Iron accumulation in deep brain nuclei in migraine: A population-based Magnetic Resonance Imaging study

PubMed Central

Kruit, Mark C.; Launer, Lenore J.; Overbosch, Jelle; van Buchem, Mark A.; Ferrari, Michel D.

2011-01-01

Background A small MRI study showed increased iron depositions in the periaqueductal grey matter in migraineurs, suggestive of a disturbed central antinociceptive neuronal network. Procedures With 1.5T MRI, we assessed iron concentrations in seven deep brain nuclei in a large population-based cohort. We compared T2 values between migraineurs (n=138) and controls (n=75), with multivariate regression analysis. Analyses were conducted in age strata (<50, n=112; ≥50) because iron measures are increasingly influenced by non-iron related factors in the older group. Findings Overall, migraineurs and controls did not differ, nor did migraineurs with vs. without aura. In the younger migraineurs compared to controls, T2-values were lower in the putamen (p=0.02), globus pallidus (p=0.03) and red nucleus (p=0.03). Similarly, in these younger migraineurs, controlling for age, those with longer migraine-history had lower T2 values in the putamen (p=0.01), caudate (p=0.04) and red nucleus (p=0.001). Conclusions Repeated migraine attacks are associated with increased iron concentration / accumulation in multiple deep nuclei that are involved in central pain processing and migraine pathophysiology. It remains unclear whether iron accumulation in the antinociceptive network has a causative role in the development of (chronic) migraine headache. PMID:19025553

Critical Roles of the Direct GABAergic Pallido-cortical Pathway in Controlling Absence Seizures

PubMed Central

Li, Min; Ma, Tao; Wu, Shengdun; Ma, Jingling; Cui, Yan; Xia, Yang; Xu, Peng; Yao, Dezhong

2015-01-01

The basal ganglia (BG), serving as an intermediate bridge between the cerebral cortex and thalamus, are believed to play crucial roles in controlling absence seizure activities generated by the pathological corticothalamic system. Inspired by recent experiments, here we systematically investigate the contribution of a novel identified GABAergic pallido-cortical pathway, projecting from the globus pallidus externa (GPe) in the BG to the cerebral cortex, to the control of absence seizures. By computational modelling, we find that both increasing the activation of GPe neurons and enhancing the coupling strength of the inhibitory pallido-cortical pathway can suppress the bilaterally synchronous 2–4 Hz spike and wave discharges (SWDs) during absence seizures. Appropriate tuning of several GPe-related pathways may also trigger the SWD suppression, through modulating the activation level of GPe neurons. Furthermore, we show that the previously discovered bidirectional control of absence seizures due to the competition between other two BG output pathways also exists in our established model. Importantly, such bidirectional control is shaped by the coupling strength of this direct GABAergic pallido-cortical pathway. Our work suggests that the novel identified pallido-cortical pathway has a functional role in controlling absence seizures and the presented results might provide testable hypotheses for future experimental studies. PMID:26496656

A neuroanatomical analysis of the effects of a memory impairing dose of scopolamine in the rat brain using cytochrome c oxidase as principle marker.

PubMed

Hescham, Sarah; Temel, Yasin; Casaca-Carreira, João; Arslantas, Kemal; Yakkioui, Youssef; Blokland, Arjan; Jahanshahi, Ali

2014-09-01

Acetylcholine plays a role in mnemonic and attentional processes, but also in locomotor and anxiety-related behavior. Receptor blockage by scopolamine can therefore induce cognitive as well as motor deficits and increase anxiety levels. Here we show that scopolamine, at a dose that has previously been found to affect learning and memory performance (0.1 mg/kg i.p.), has a widespread effect on cytochrome c oxidase histochemistry in various regions of the rat brain. We found a down-regulation of cytochrome c oxidase in the nucleus basalis, in movement-related structures such as the primary motor cortex and the globus pallidus, memory-related structures such as the CA1 subfield of the hippocampus and perirhinal cortex and in anxiety-related structures like the amygdala, which also plays a role in memory. However choline acetyltransferase levels were only affected in the CA1 subfield of the hippocampus and both, choline acetyltransferase and c-Fos expression levels were decreased in the amygdala. These findings corroborate strong cognitive behavioral effects of this drug, but also suggest possible anxiety- and locomotor-related changes in subjects. Moreover, they present histochemical evidence that the effects of scopolamine are not ultimately restricted to cognitive parameters. Copyright © 2014 Elsevier B.V. All rights reserved.

Gray matter atrophy in narcolepsy: An activation likelihood estimation meta-analysis.

PubMed

Weng, Hsu-Huei; Chen, Chih-Feng; Tsai, Yuan-Hsiung; Wu, Chih-Ying; Lee, Meng; Lin, Yu-Ching; Yang, Cheng-Ta; Tsai, Ying-Huang; Yang, Chun-Yuh

2015-12-01

The authors reviewed the literature on the use of voxel-based morphometry (VBM) in narcolepsy magnetic resonance imaging (MRI) studies via the use of a meta-analysis of neuroimaging to identify concordant and specific structural deficits in patients with narcolepsy as compared with healthy subjects. We used PubMed to retrieve articles published between January 2000 and March 2014. The authors included all VBM research on narcolepsy and compared the findings of the studies by using gray matter volume (GMV) or gray matter concentration (GMC) to index differences in gray matter. Stereotactic data were extracted from 8 VBM studies of 149 narcoleptic patients and 162 control subjects. We applied activation likelihood estimation (ALE) technique and found significant regional gray matter reduction in the bilateral hypothalamus, thalamus, globus pallidus, extending to nucleus accumbens (NAcc) and anterior cingulate cortex (ACC), left mid orbital and rectal gyri (BAs 10 and 11), right inferior frontal gyrus (BA 47), and the right superior temporal gyrus (BA 41) in patients with narcolepsy. The significant gray matter deficits in narcoleptic patients occurred in the bilateral hypothalamus and frontotemporal regions, which may be related to the emotional processing abnormalities and orexin/hypocretin pathway common among populations of patients with narcolepsy. Copyright © 2015. Published by Elsevier Ltd.

Taxonomic changes in African Stratiomyidae (Diptera).

PubMed

Hauser, Martin; Woodley, Norman E; Fachin, Diego A

2017-05-08

Thirteen new generic synonyms, nineteen species synonyms and forty-eight new combinations of African Stratiomyidae are proposed (senior synonym in parentheses):Arthronemina Lindner in James, 1980 syn. nov. (=Argyrobrithes Grünberg, 1915), Arthronema Lindner, 1966b syn. nov. (=Argyrobrithes Grünberg, 1915), Brachyphleps Lindner, 1965 syn. nov. (=Psapharomys Grünberg, 1915), Dinosargus Lindner, 1968 syn. nov. (=Gongrosargus Lindner, 1959), Dolichodema Kertész, 1916 syn. nov. (=Thorasena Macquart, 1838), Gobertina Bigot, 1879a syn. nov. (=Sternobrithes Loew, 1857), Himantochaeta Lindner, 1939 syn. nov. (=Nyplatys Séguy, 1938), Hypoxycera Lindner 1966a syn. nov. (=Hypoceromys Lindner, 1935), Leucacron Lindner, 1966b syn. nov. (=Ptilinoxus Lindner, 1966b), Lonchobrithes Lindner, 1968 syn. nov. (=Argyrobrithes Grünberg, 1915), Meristomeringella Lindner 1965 syn. nov. (=Hypoceromys Lindner, 1935), Physometopon Lindner, 1966b syn. nov. (=Cardopomyia Kertész, 1916), Psapharomydops Lindner, 1966a syn. nov. (=Steleoceromys Grünberg, 1915), Adoxomyia grisea (Séguy, 1931) syn. nov. (=Adoxomyia argenteofasciata (Bezzi, 1906)), Argyrobrithes argenteus Grünberg, 1915 syn. nov. (=Argyrobrithes fuscicornis (Bezzi, 1914)), Argyrobrithes crinitus Lindner, 1972 syn. nov. (=Argyrobrithes zernyi Lindner, 1943), Brachyphleps tristis Lindner, 1965 syn. nov. (=Psapharomys salebrosa Grünberg, 1915), Chrysochroma laetum Lindner, 1966b syn. nov. (=Ptectisargus abditus (Lindner, 1936), Dolichodema africana Kertész, 1916 syn. nov. (=Thorasena pectoralis (Wiedemann, 1838)), Gongrosargus distinguendus Lindner, 1966c syn. nov. (=Gongrosargus glaucus (Bigot, 1859)), Gongrosargus exclamationis Lindner, 1968 syn. nov. (=Gongrosargus pallidus (Macquart, 1838)), Gongrosargus univittatus Lindner, 1966b syn. nov. (=Gongrosargus pallidus (Macquart, 1838)), Hypoxycera simplex Lindner, 1966a syn. nov. (=Hypoceromys jamesi (Lindner, 1965)), Lonchobrithes modestus Lindner, 1968 syn. nov

Rice by Weight, Other Produce by Bulk, and Snared Iguanas at So Much Per One. A Talk on Measurement Standards and on Metric Conversion.

ERIC Educational Resources Information Center

Allen, Harold Don

This script for a short radio broadcast on measurement standards and metric conversion begins by tracing the rise of the metric system in the international marketplace. Metric units are identified and briefly explained. Arguments for conversion to metric measures are presented. The history of the development and acceptance of the metric system is…

MRI Estimates of Brain Iron Concentration in Normal Aging Using Quantitative Susceptibility Mapping

PubMed Central

Bilgic, Berkin; Pfefferbaum, Adolf; Rohlfing, Torsten; Sullivan, Edith V.; Adalsteinsson, Elfar

2011-01-01

Quantifying tissue iron concentration in vivo is instrumental for understanding the role of iron in physiology and in neurological diseases associated with abnormal iron distribution. Herein, we use recently-developed Quantitative Susceptibility Mapping (QSM) methodology to estimate the tissue magnetic susceptibility based on MRI signal phase. To investigate the effect of different regularization choices, we implement and compare ℓ1 and ℓ2 norm regularized QSM algorithms. These regularized approaches solve for the underlying magnetic susceptibility distribution, a sensitive measure of the tissue iron concentration, that gives rise to the observed signal phase. Regularized QSM methodology also involves a pre-processing step that removes, by dipole fitting, unwanted background phase effects due to bulk susceptibility variations between air and tissue and requires data acquisition only at a single field strength. For validation, performances of the two QSM methods were measured against published estimates of regional brain iron from postmortem and in vivo data. The in vivo comparison was based on data previously acquired using Field-Dependent Relaxation Rate Increase (FDRI), an estimate of MRI relaxivity enhancement due to increased main magnetic field strength, requiring data acquired at two different field strengths. The QSM analysis was based on susceptibility-weighted images acquired at 1.5T, whereas FDRI analysis used Multi-Shot Echo-Planar Spin Echo images collected at 1.5T and 3.0T. Both datasets were collected in the same healthy young and elderly adults. The in vivo estimates of regional iron concentration comported well with published postmortem measurements; both QSM approaches yielded the same rank ordering of iron concentration by brain structure, with the lowest in white matter and the highest in globus pallidus. Further validation was provided by comparison of the in vivo measurements, ℓ1-regularized QSM versus FDRI and ℓ2-regularized QSM versus

Locomotor loading mechanics in the hindlimbs of tegu lizards (Tupinambis merianae): comparative and evolutionary implications.

PubMed

Sheffield, K Megan; Butcher, Michael T; Shugart, S Katherine; Gander, Jennifer C; Blob, Richard W

2011-08-01

Skeletal elements are usually able to withstand several times their usual load before they yield, and this ratio is known as the bone's safety factor. Limited studies on amphibians and non-avian reptiles have shown that they have much higher limb bone safety factors than birds and mammals. It has been hypothesized that this difference is related to the difference in posture between upright birds and mammals and sprawling ectotherms; however, limb bone loading data from a wider range of sprawling species are needed in order to determine whether the higher safety factors seen in amphibians and non-avian reptiles are ancestral or derived conditions. Tegus (family Teiidae) are an ideal lineage with which to expand sampling of limb bone loading mechanics for sprawling taxa, particularly for lizards, because they are from a different clade than previously sampled iguanas and exhibit different foraging and locomotor habits (actively foraging carnivore versus burst-activity herbivore). We evaluated the mechanics of locomotor loading for the femur of the Argentine black and white tegu (Tupinambus merianae) using three-dimensional measurements of the ground reaction force and hindlimb kinematics, in vivo bone strains and femoral mechanical properties. Peak bending stresses experienced by the femur were low (tensile: 10.4 ± 1.1 MPa; compressive: -17.4 ± 0.9 MPa) and comparable to those in other reptiles, with moderate shear stresses and strains also present. Analyses of peak femoral stresses and strains led to estimated safety factor ranges of 8.8-18.6 in bending and 7.8-17.5 in torsion, both substantially higher than typical for birds and mammals but similar to other sprawling tetrapods. These results broaden the range of reptilian and amphibian taxa in which high femoral safety factors have been evaluated and further indicate a trend for the independent evolution of lower limb bone safety factors in endothermic taxa.

Resource availability and diet in Harpy Eagle breeding territories on the Xingu River, Brazilian Amazon.

PubMed

Aguiar-Silva, F H; Junqueira, T G; Sanaiotti, T M; Guimarães, V Y; Mathias, P V C; Mendonça, C V

2015-08-01

In the Tapajos-Xingu interfluve, one of the largest birds of prey, the Harpy Eagle, is under intense anthropogenic pressure due to historical and recent reductions in forest cover. We studied prey availability and use by Harpy Eagle on six breeding territories on the low- and mid-Xingu River, between 2013 and 2015. We evaluated food resource availability using the environmental-surveys database from two methods: terrestrial surveys (RAPELD method) and fauna rescue/flushing before vegetation suppression for the Belo Monte Hydroelectric Complex construction. Harpy Eagle diet was identified by prey remains sampled around six nest trees. Eighteen species of mammals, birds and reptiles comprised the prey items. Most prey species were sloths, primates and porcupines, which have arboreal habits and are found in forested areas, but two species, hoatzin and iguana, are usually associated with riverine habitats. The proportion of prey from each species predated on the nest best studied was different from estimated availability (χ2 = 54.23; df = 16; p < 0.001), however there was a positive correlation (rs = 0.7; p < 0.01) between prey species consumed and abundance available, where the predation was more on species more abundant. Continuous monitoring of the Harpy Eagle diet at these nests could evidence changes in the assemblage of prey species available for Harpy Eagles, due to changes in the seasonal flood pulse of the Xingu River to be caused by the operation of the hydroelectric dam, and changes in habitat features by forest reduction around breeding territories. We believe that it is important to consider the protection of remnants of forested areas in the landscape matrix surrounding the breeding territories to maintain the food resource availability and allow all pairs to successfully reproduce.

Age progressive volcanism opposite Nazca plate motion: Insights from seamounts on the northeastern margin of the Galapagos Platform

NASA Astrophysics Data System (ADS)

Sinton, Christopher W.; Hauff, Folkmar; Hoernle, Kaj; Werner, Reinhard

2018-06-01

We present new geochemical and 40Ar/39Ar analyses from seven seamounts located off the northeastern margin of the shallow Galápagos Platform. Initial volcanism at 5.2 Ma created a small island (Pico) over the current location of the hotspot with geochemically enriched lavas. There is no further record of magmatism in the study area until 3.8 to 2.5 Ma, during which four roughly conical volcanoes (Sunray, Grande, Fitzroy, and Beagle) formed through eruption of lavas derived from a depleted mantle source. Sunray, Fitzroy, and Grande were islands that existed for 3 m.y. ending with the submergence of Fitzroy at 0.5 Ma. The youngest seamounts, Largo and Iguana, do not appear to have been subaerial and were active at 1.3 Ma and 0.5 Ma, respectively, with the style of edifice changing from the previous large cones to E-W elongate, composite structures. The progression of magmatism suggests that Pico erupted near 91.5°W near the location of the Galápagos plume while the others formed well east of the plume center. If the locations of initial volcanism are calculated using the eastward velocity of the Nazca plate, there appears to be a progression of younger volcanism toward the east, opposite what would be expected from a fixed mantle plume source. The rate that initial volcanism moves eastward is close to the plate velocity. A combination of higher temperature and geochemical enrichment of the thickened lithosphere of the Galápagos platform could have provided a viscosity gradient at the boundary between the thick lithosphere and the thinner oceanic lithosphere to the northeast. As this boundary moved eastward with the Nazca plate, it progressively triggered shear-driven mantle upwelling and volcanism.

Ldb1 is essential for development of Nkx2.1 lineage derived GABAergic and cholinergic neurons in the telencephalon.

PubMed

Zhao, Yangu; Flandin, Pierre; Vogt, Daniel; Blood, Alexander; Hermesz, Edit; Westphal, Heiner; Rubenstein, John L R

2014-01-01

The progenitor zones of the embryonic mouse ventral telencephalon give rise to GABAergic and cholinergic neurons. We have shown previously that two LIM-homeodomain (LIM-HD) transcription factors, Lhx6 and Lhx8, that are downstream of Nkx2.1, are critical for the development of telencephalic GABAergic and cholinergic neurons. Here we investigate the role of Ldb1, a nuclear protein that binds directly to all LIM-HD factors, in the development of these ventral telencephalon derived neurons. We show that Ldb1 is expressed in the Nkx2.1 cell lineage during embryonic development and in mature neurons. Conditional deletion of Ldb1 causes defects in the expression of a series of genes in the ventral telencephalon and severe impairment in the tangential migration of cortical interneurons from the ventral telencephalon. Similar to the phenotypes observed in Lhx6 or Lhx8 mutant mice, the Ldb1 conditional mutants show a reduction in the number of both GABAergic and cholinergic neurons in the telencephalon. Furthermore, our analysis reveals defects in the development of the parvalbumin-positive neurons in the globus pallidus and striatum of the Ldb1 mutants. These results provide evidence that Ldb1 plays an essential role as a transcription co-regulator of Lhx6 and Lhx8 in the control of mammalian telencephalon development. © 2013 Published by Elsevier Inc.

Ldb1 is essential for development of Nkx2.1 lineage derived GABAergic and cholinergic neurons in the telencephalon

PubMed Central

Zhao, Yangu; Flandin, Pierre; Vogt, Daniel; Blood, Alexander; Hermesz, Edit; Westphal, Heiner; Rubenstein, John

2013-01-01

The progenitor zones of the embryonic mouse ventral telencephalon give rise to GABAergic and cholinergic neurons. We have shown previously that two LIM-homeodomain (LIM-HD) transcription factors, Lhx6 and Lhx8, that are downstream of Nkx2.1, are critical for the development of telencephalic GABAergic and cholinergic neurons. Here we investigate the role of Ldb1, a nuclear protein that binds directly to all LIM-HD factors, in the development of these ventral telencephalon derived neurons. We show that Ldb1 is expressed in the Nkx2.1 cell lineage during embryonic development and in mature neurons. Conditional deletion of Ldb1 causes defects in the expression of a series of genes in the ventral telencephalon and severe impairment in the tangential migration of cortical interneurons from the ventral telencephalon. Similar to the phenotypes observed in Lhx6 or Lhx8 mutant mice, the Ldb1 conditional mutants show a reduction in the number of both GABAergic and cholinergic neurons in the telencephalon. Furthermore, our analysis reveals defects in the development of the parvalbumin-positive neurons in the globus pallidus and striatum of the Ldb1 mutants. These results provide evidence that Ldb1 plays an essential role as a transcription co-regulator of Lhx6 and Lhx8 in the control of mammalian telencephalon development. PMID:24157949

Developmental frontal lobe imaging in moral judgment: Arthur Benton's enduring influence 60 years later.

PubMed

Eslinger, Paul J; Robinson-Long, Melissa; Realmuto, Jennifer; Moll, Jorge; deOliveira-Souza, Ricardo; Tovar-Moll, Fernanda; Wang, Jianli; Yang, Qing X

2009-02-01

Early prefrontal cortex damage has been associated with developmental deficits in social adaptation, moral behavior, and empathy that alter the maturation of social cognition and social emotions. The seminal case of Ackerly and Benton (1948) continues to provide the most striking clinical example of prefrontal-related neurodevelopmental impairments, with more recent case reports confirming and elaborating these influential observations. This study investigated the prefrontal hypothesis of moral decision making in healthy, typically developing children and adolescents (10-17 years of age) using functional magnetic resonance imaging (fMRI). Participants judged the actions in age-appropriate moral vignettes as right or wrong, and results were contrasted to a nonsocial/nonmoral baseline condition requiring similar right versus wrong judgments. Results confirmed a predominant cluster of activity in the most rostral-medial (frontal polar) prefrontal region across moral judgment conditions, along with left lateroposterior orbitofrontal/ventrolateral prefrontal, left temporoparietal junction, midline thalamus and globus pallidus, and bilateral inferior occipital clusters. Trials entailing ambiguous moral situations activated considerably more prefrontal and parietal regions than did routine moral situations, suggesting the need for more neurocognitive resources. While age regression analysis identified a few regions of greater or lesser activity with age, the frontal polar activations did not change with age. Findings confirm a significant role for anterior-medial prefrontal cortex in the typical development and maturation of moral decision making, consistent with clinical lesion case descriptions.

Manganese-Enhanced Magnetic Resonance Imaging Reflects Brain Pathology During Progressive HIV-1 Infection of Humanized Mice.

PubMed

Bade, Aditya N; Gorantla, Santhi; Dash, Prasanta K; Makarov, Edward; Sajja, Balasrinivasa R; Poluektova, Larisa Y; Luo, Jiangtao; Gendelman, Howard E; Boska, Michael D; Liu, Yutong

2016-07-01

Progressive human immunodeficiency viral (HIV) infection commonly leads to a constellation of cognitive, motor, and behavioral impairments. These are collectively termed HIV-associated neurocognitive disorders (HAND). While antiretroviral therapy (ART) reduces HAND severity, it does not affect disease prevalence. Despite decades of research, there remain no biomarkers for HAND and all potential comorbid conditions must first be excluded for a diagnosis to be made. To this end, we now report that manganese (Mn(2+))-enhanced magnetic resonance imaging (MEMRI) can reflect brain region-specific HIV-1-induced neuropathology in chronically virus-infected NOD/scid-IL-2Rγc(null) humanized mice. MEMRI diagnostics mirrors the abilities of Mn(2+) to enter and accumulate in affected neurons during disease. T1 relaxivity and its weighted signal intensity are proportional to Mn(2+) activities in neurons. In 16-week virus-infected humanized mice, altered MEMRI signal enhancement was easily observed in affected brain regions. These included, but were not limited to, the hippocampus, amygdala, thalamus, globus pallidus, caudoputamen, substantia nigra, and cerebellum. MEMRI signal was coordinated with levels of HIV-1 infection, neuroinflammation (astro- and micro-gliosis), and neuronal injury. MEMRI accurately demonstrates the complexities of HIV-1-associated neuropathology in rodents that reflects, in measure, the clinical manifestations of neuroAIDS as it is seen in a human host.

Subthalamic deep brain stimulation in Parkinson׳s disease has no significant effect on perceptual timing in the hundreds of milliseconds range

PubMed Central

Cope, Thomas E.; Grube, Manon; Mandal, Arnab; Cooper, Freya E.; Brechany, Una; Burn, David J.; Griffiths, Timothy D.

2014-01-01

Bilateral, high-frequency stimulation of the basal ganglia (STN-DBS) is in widespread use for the treatment of the motor symptoms of Parkinson׳s disease (PD). We present here the first psychophysical investigation of the effect of STN-DBS upon perceptual timing in the hundreds of milliseconds range, with both duration-based (absolute) and beat-based (relative) tasks; 13 patients with PD were assessed with their STN-DBS ‘on’, ‘off’, and then ‘on’ again. Paired parametric analyses revealed no statistically significant differences for any task according to DBS status. We demonstrate, from the examination of confidence intervals, that any functionally relevant effect of STN-DBS on relative perceptual timing is statistically unlikely. For absolute, duration-based timing, we demonstrate that the activation of STN-DBS may either worsen performance or have no effect, but that it is unlikely to lead to significant improvement. Although these results are negative they have important implications for our understanding of perceptual timing and its relationship to motor functions within the timing network of the brain. They imply that the mechanisms involved in the perceptual processing of temporal information are likely to be functionally independent from those that underpin movement. Further, they suggest that the connections between STN and the subtantia nigra and globus pallidus are unlikely to be critical to beat-based perceptual timing. PMID:24613477

The Lateral Habenula Circuitry: Reward Processing and Cognitive Control

PubMed Central

Baker, Phillip M.; Jhou, Thomas; Matsumoto, Masayuki; Mizumori, Sheri J.Y.; Stephenson-Jones, Marcus

2016-01-01

There has been a growing interest in understanding the role of the lateral habenula (LHb) in reward processing, affect regulation, and goal-directed behaviors. The LHb gets major inputs from the habenula-projecting globus pallidus and the mPFC, sending its efferents to the dopaminergic VTA and SNc, serotonergic dorsal raphe nuclei, and the GABAergic rostromedial tegmental nucleus. Recent studies have made advances in our understanding of the LHb circuit organization, yet the precise mechanisms of its involvement in complex behaviors are largely unknown. To begin to address this unresolved question, we present here emerging cross-species perspectives with a goal to provide a more refined understanding of the role of the LHb circuits in reward and cognition. We begin by highlighting recent findings from rodent experiments using optogenetics, electrophysiology, molecular, pharmacology, and tracing techniques that reveal diverse neural phenotypes in the LHb circuits that may underlie previously undescribed behavioral functions. We then discuss results from electrophysiological studies in macaques that suggest that the LHb cooperates with the anterior cingulate cortex to monitor action outcomes and signal behavioral adjustment. Finally, we provide an integrated summary of cross-species findings and discuss how further research on the connectivity, neural signaling, and physiology of the LHb circuits can deepen our understanding of the role of the LHb in normal and maladaptive behaviors associated with mental illnesses and drug abuse. PMID:27911751

Population changes in bats from central Arizona: 1972 and 1997

USGS Publications Warehouse

O'Shea, T.J.; Vaughan, T.A.

1999-01-01

Prompted by concern about declining bat populations in the southwestern United States, we surveyed for changes in populations between 1972 and 1997 at a study area in central Arizona. We duplicated earlier searches of ancient Indian dwellings and crevices in surrounding cliffs for diurnally roosting bats during the time of year when maternity colonies should have been present, and repeated mist-netting to capture bats in flight along the cliffs at night. Antrozous pallidus was gone. A maternity colony of Myotis velifer no longer existed. Tadarida brasiliensis was rare in 1997 compared to 1972; aggregations of Myotis yumanensis seen in 1972 were missing in 1997. Breeding Corynorhinus townsendii were found in 1997, but were unknown at this location in 1972. Small numbers of Eptesicus fuscus, Myotis californicus, and Pipistrellus hesperus occupied the site in both 1972 and 1997. Additionally, museum records show that most of the bats we documented at this site also were present in 1931. Surrounding habitat did not appear substantially different between 1972 and 1997, and a reconstruction of possible impacts from bat biologists did not suggest that researchers caused the local extinctions we document. The most obvious change over 25 years was a dramatic increase in recreational use of the area. We believe that disturbances associated with recreationists resulted in the observed population changes, primarily through roost abandonment.

Effects of mindfulness and psychoeducation on working memory in adult ADHD: A randomised, controlled fMRI study.

PubMed

Bachmann, Katharina; Lam, Alexandra P; Sörös, Peter; Kanat, Manuela; Hoxhaj, Eliza; Matthies, Swantje; Feige, Bernd; Müller, Helge; Özyurt, Jale; Thiel, Christiane M; Philipsen, Alexandra

2018-07-01

Adult attention-deficit/hyperactivity disorder (ADHD) is a serious mental disorder associated with impaired neurocognitive performance related to working memory function. Recent clinical trials have suggested that mindfulness is a promising intervention in adults with ADHD. We performed a randomised controlled clinical trial to investigate working memory (WM) with an n-back task in adults with ADHD during fMRI before and after an 8-week mindfulness intervention (MAP) compared with psychoeducation (PE). ADHD symptoms were assessed using the self- and observer-rated Conners Adult ADHD Rating Scales (CAARS). The complete pre-post data of 21 MAP and 19 PE participants were analysed. We found no group difference in ADHD symptoms or task performance at the pre-measurement, but there was a significant decrease in ADHD symptoms and significant improvement in task performance in both groups at the post-measurement. Furthermore, we found a significant increase in task-related activation in the right parietal lobe, with no difference between groups. Exploratory two-sample paired t-tests revealed significant increased brain activation after MAP in the bilateral inferior parietal lobule, right posterior insula and right precuneus. A decrease in self-rated 'Inattention/Memory Problems' after MAP compared to baseline was associated with stronger activation in parts of the left putamen, globus pallidus and thalamus. Copyright © 2018 Elsevier Ltd. All rights reserved.

Home cage locomotor changes in non-human primates after prolonged welding-fume exposure.

PubMed

Kim, Choong Yong; Sung, Jae Hyuck; Chung, Yong Hyun; Park, Jung Duck; Han, Jeong Hee; Lee, Jong Seong; Heo, Jeong Doo; Yu, Il Je

2013-12-01

To define the relationship between the brain concentration of manganese and neurological signs, such as locomotion, after prolonged welding-fume exposure, cynomolgus monkeys were acclimated for 1 month and then divided into three concentration groups: unexposed, low concentration (31 mg/m(3) total suspended particulate (TSP), 0.9 mg/m(3) of Mn), and high concentration (62 mg/m(3) TSP, 1.95 mg/m(3) of Mn) of TSP. The monkeys were exposed to manual metal-arc stainless steel (MMA-SS) welding fumes for 2 h per day over 8 months in an inhalation chamber system equipped with an automatic fume generator. The home cage locomotor activity and patterns were determined using a camera system over 2-4 consecutive days. After 25 and 32 weeks of exposure, the home cage locomotor activity of the high-concentration primates was found to be 5-6 times higher than that of the unexposed primates, and this increased locomotor activity was maintained for 7 weeks after ceasing the welding-fume exposure, eventually subsiding to three times higher after 13 weeks of recovery. Therefore, the present results, along with our previous observations of a high magnetic resonance imaging (MRI) T1 signal in the globus pallidus and increased blood Mn concentration, indicate that prolonged welding-fume exposure can cause neurobehavioral changes in cynomolgus monkeys.

Time-course analysis of the neuroanatomical correlates of sexual arousal evoked by erotic video stimuli in healthy males.

PubMed

Sundaram, Thirunavukkarasu; Jeong, Gwang-Woo; Kim, Tae-Hoon; Kim, Gwang-Won; Baek, Han-Su; Kang, Heoung-Keun

2010-01-01

To assess the dynamic activations of the key brain areas associated with the time-course of the sexual arousal evoked by visual sexual stimuli in healthy male subjects. Fourteen right-handed heterosexual male volunteers participated in this study. Alternatively combined rest period and erotic video visual stimulation were used according to the standard block design. In order to illustrate and quantify the spatiotemporal activation patterns of the key brain regions, the activation period was divided into three different stages as the EARLY, MID and LATE stages. For the group result (p < 0.05), when comparing the MID stage with the EARLY stage, a significant increase of the brain activation was observed in the areas that included the inferior frontal gyrus, the supplementary motor area, the hippocampus, the head of the caudate nucleus, the midbrain, the superior occipital gyrus and the fusiform gyrus. At the same time, when comparing the EARLY stage with the MID stage, the putamen, the globus pallidus, the pons, the thalamus, the hypothalamus, the lingual gyrus and the cuneus yielded significantly increased activations. When comparing the LATE stage with the MID stage, all the above mentioned brain regions showed elevated activations except the hippocampus. Our results illustrate the spatiotemporal activation patterns of the key brain regions across the three stages of visual sexual arousal.

Time-Course Analysis of the Neuroanatomical Correlates of Sexual Arousal Evoked by Erotic Video Stimuli in Healthy Males

PubMed Central

Sundaram, Thirunavukkarasu; Kim, Tae-Hoon; Kim, Gwang-Won; Baek, Han-Su; Kang, Heoung-Keun

2010-01-01

Objective To assess the dynamic activations of the key brain areas associated with the time-course of the sexual arousal evoked by visual sexual stimuli in healthy male subjects. Materials and Methods Fourteen right-handed heterosexual male volunteers participated in this study. Alternatively combined rest period and erotic video visual stimulation were used according to the standard block design. In order to illustrate and quantify the spatiotemporal activation patterns of the key brain regions, the activation period was divided into three different stages as the EARLY, MID and LATE stages. Results For the group result (p < 0.05), when comparing the MID stage with the EARLY stage, a significant increase of the brain activation was observed in the areas that included the inferior frontal gyrus, the supplementary motor area, the hippocampus, the head of the caudate nucleus, the midbrain, the superior occipital gyrus and the fusiform gyrus. At the same time, when comparing the EARLY stage with the MID stage, the putamen, the globus pallidus, the pons, the thalamus, the hypothalamus, the lingual gyrus and the cuneus yielded significantly increased activations. When comparing the LATE stage with the MID stage, all the above mentioned brain regions showed elevated activations except the hippocampus. Conclusion Our results illustrate the spatiotemporal activation patterns of the key brain regions across the three stages of visual sexual arousal. PMID:20461181

Neural correlates of long-term intense romantic love.

PubMed

Acevedo, Bianca P; Aron, Arthur; Fisher, Helen E; Brown, Lucy L

2012-02-01

The present study examined the neural correlates of long-term intense romantic love using functional magnetic resonance imaging (fMRI). Ten women and 7 men married an average of 21.4 years underwent fMRI while viewing facial images of their partner. Control images included a highly familiar acquaintance; a close, long-term friend; and a low-familiar person. Effects specific to the intensely loved, long-term partner were found in: (i) areas of the dopamine-rich reward and basal ganglia system, such as the ventral tegmental area (VTA) and dorsal striatum, consistent with results from early-stage romantic love studies; and (ii) several regions implicated in maternal attachment, such as the globus pallidus (GP), substantia nigra, Raphe nucleus, thalamus, insular cortex, anterior cingulate and posterior cingulate. Correlations of neural activity in regions of interest with widely used questionnaires showed: (i) VTA and caudate responses correlated with romantic love scores and inclusion of other in the self; (ii) GP responses correlated with friendship-based love scores; (iii) hypothalamus and posterior hippocampus responses correlated with sexual frequency; and (iv) caudate, septum/fornix, posterior cingulate and posterior hippocampus responses correlated with obsession. Overall, results suggest that for some individuals the reward-value associated with a long-term partner may be sustained, similar to new love, but also involves brain systems implicated in attachment and pair-bonding.

Neural correlates of long-term intense romantic love

PubMed Central

Aron, Arthur; Fisher, Helen E.; Brown, Lucy L.

2012-01-01

The present study examined the neural correlates of long-term intense romantic love using functional magnetic resonance imaging (fMRI). Ten women and 7 men married an average of 21.4 years underwent fMRI while viewing facial images of their partner. Control images included a highly familiar acquaintance; a close, long-term friend; and a low-familiar person. Effects specific to the intensely loved, long-term partner were found in: (i) areas of the dopamine-rich reward and basal ganglia system, such as the ventral tegmental area (VTA) and dorsal striatum, consistent with results from early-stage romantic love studies; and (ii) several regions implicated in maternal attachment, such as the globus pallidus (GP), substantia nigra, Raphe nucleus, thalamus, insular cortex, anterior cingulate and posterior cingulate. Correlations of neural activity in regions of interest with widely used questionnaires showed: (i) VTA and caudate responses correlated with romantic love scores and inclusion of other in the self; (ii) GP responses correlated with friendship-based love scores; (iii) hypothalamus and posterior hippocampus responses correlated with sexual frequency; and (iv) caudate, septum/fornix, posterior cingulate and posterior hippocampus responses correlated with obsession. Overall, results suggest that for some individuals the reward-value associated with a long-term partner may be sustained, similar to new love, but also involves brain systems implicated in attachment and pair-bonding. PMID:21208991

Toward an agreement on terminology of nuclear and subnuclear divisions of the motor thalamus

NASA Technical Reports Server (NTRS)

Macchi, G.; Jones, E. G.; Bloom, F. E. (Principal Investigator)

1997-01-01

The nomenclature most commonly applied to the motor-related nuclei of the human thalamus differs substantially from that applied to the thalamus of other primates, from which most knowledge of input-output connections is derived. Knowledge of these connections in the human is a prerequisite for stereotactic neurosurgical approaches designed to alleviate movement disorders by the placement of lesions in specific nuclei. Transfer to humans of connectional information derived from experimental studies in nonhuman primates requires agreement about the equivalence of nuclei in the different species, and dialogue between experimentalists and neurosurgeons would be facilitated by the use of a common nomenclature. In this review, the authors compare the different nomenclatures and review the cyto- and chemoarchitecture of the nuclei in the anterolateral aspect of the ventral nuclear mass in humans and monkeys, suggest which nuclei are equivalent, and propose a common terminology. On this basis, it is possible to identify the nuclei of the human motor thalamus that transfer information from the substantia nigra, globus pallidus, cerebellum, and proprioceptive components of the medial lemniscus to prefrontal, premotor, motor, and somatosensory areas of the cerebral cortex. It also becomes possible to suggest the principal functional systems involved in stereotactically guided thalamotomies and the functional basis of the symptoms observed following ischemic lesions in different parts of the human thalamus.

Aeribacillus composti sp. nov., a thermophilic bacillus isolated from olive mill pomace compost.

PubMed

Finore, Ilaria; Gioiello, Alessia; Leone, Luigi; Orlando, Pierangelo; Romano, Ida; Nicolaus, Barbara; Poli, Annarita

2017-11-01

A Gram-stain-positive, aerobic, endospore-forming, thermophilic bacterium, strain N.8 T , was isolated from the curing step of an olive mill pomace compost sample, collected at the Composting Experimental Centre (CESCO, Salerno, Italy). Strain N.8 T , based on 16S rRNA gene sequence similarities, was most closely related to Aeribacillus pallidus strain H12 T (=DSM 3670 T ) (99.8 % similarity value) with a 25 % DNA-DNA relatedness value. Cells were rod-shaped, non-motile and grew optimally at 60 °C and pH 9.0, forming cream colonies. Strain N.8 was able to grow on medium containing up to 9.0 % (w/v) NaCl with an optimum at 6.0 % (w/v) NaCl. The cellular membrane contained MK-7, and C16 : 0 (48.4 %), iso-C17 : 0 (19.4 %) and anteiso-C17 : 0 (14.6 %) were the major cellular fatty acids. The DNA G+C content was 40.5 mol%. Based on phenotypic characteristics, 16S rRNA gene sequences, DNA-DNA hybridization values and chemotaxonomic characteristics, strain N.8 T represents a novel species of the genus Aeribacillus, for which the name Aeribacillus composti sp. nov. is proposed. The type strain is N.8 T (=KCTC 33824 T =JCM 31580 T ).

Functional magnetic resonance imaging during emotion recognition in social anxiety disorder: an activation likelihood meta-analysis

PubMed Central

Hattingh, Coenraad J.; Ipser, J.; Tromp, S. A.; Syal, S.; Lochner, C.; Brooks, S. J.; Stein, D. J.

2012-01-01

Background: Social anxiety disorder (SAD) is characterized by abnormal fear and anxiety in social situations. Functional magnetic resonance imaging (fMRI) is a brain imaging technique that can be used to demonstrate neural activation to emotionally salient stimuli. However, no attempt has yet been made to statistically collate fMRI studies of brain activation, using the activation likelihood-estimate (ALE) technique, in response to emotion recognition tasks in individuals with SAD. Methods: A systematic search of fMRI studies of neural responses to socially emotive cues in SAD was undertaken. ALE meta-analysis, a voxel-based meta-analytic technique, was used to estimate the most significant activations during emotional recognition. Results: Seven studies were eligible for inclusion in the meta-analysis, constituting a total of 91 subjects with SAD, and 93 healthy controls. The most significant areas of activation during emotional vs. neutral stimuli in individuals with SAD compared to controls were: bilateral amygdala, left medial temporal lobe encompassing the entorhinal cortex, left medial aspect of the inferior temporal lobe encompassing perirhinal cortex and parahippocampus, right anterior cingulate, right globus pallidus, and distal tip of right postcentral gyrus. Conclusion: The results are consistent with neuroanatomic models of the role of the amygdala in fear conditioning, and the importance of the limbic circuitry in mediating anxiety symptoms. PMID:23335892

Is the spatial distribution of brain lesions associated with closed-head injury predictive of subsequent development of attention-deficit/hyperactivity disorder? Analysis with brain-image database

NASA Technical Reports Server (NTRS)

Herskovits, E. H.; Megalooikonomou, V.; Davatzikos, C.; Chen, A.; Bryan, R. N.; Gerring, J. P.

1999-01-01

PURPOSE: To determine whether there is an association between the spatial distribution of lesions detected at magnetic resonance (MR) imaging of the brain in children after closed-head injury and the development of secondary attention-deficit/hyperactivity disorder (ADHD). MATERIALS AND METHODS: Data obtained from 76 children without prior history of ADHD were analyzed. MR images were obtained 3 months after closed-head injury. After manual delineation of lesions, images were registered to the Talairach coordinate system. For each subject, registered images and secondary ADHD status were integrated into a brain-image database, which contains depiction (visualization) and statistical analysis software. Using this database, we assessed visually the spatial distributions of lesions and performed statistical analysis of image and clinical variables. RESULTS: Of the 76 children, 15 developed secondary ADHD. Depiction of the data suggested that children who developed secondary ADHD had more lesions in the right putamen than children who did not develop secondary ADHD; this impression was confirmed statistically. After Bonferroni correction, we could not demonstrate significant differences between secondary ADHD status and lesion burdens for the right caudate nucleus or the right globus pallidus. CONCLUSION: Closed-head injury-induced lesions in the right putamen in children are associated with subsequent development of secondary ADHD. Depiction software is useful in guiding statistical analysis of image data.

Neuropeptide Y mRNA and peptide in the night-migratory redheaded bunting brain.

PubMed

Devraj, Singh; Kumari, Yatinesh; Rastogi, Ashutosh; Rani, Sangeeta; Kumar, Vinod

2013-11-01

This study investigated the distribution of neuropeptide Y (NPY) in the brain of the night-migratory redheaded bunting (Emberiza bruniceps). We first cloned the 275-bp NPY gene in buntings, with ≥95% homology with known sequences from other birds. The deduced peptide sequence contained all conserved 36 amino acids chain of the mature NPY peptide, but lacked 6 amino acids that form the NPY signal peptide. Using digosigenin-labeled riboprobe prepared from the cloned sequence, the brain cells that synthesize NPY were identified by in-situ hybridization. The NPY peptide containing cell bodies and terminals (fibers) were localized by immunocytochemistry. NPY mRNA and peptide were widespread throughout the bunting brain. This included predominant pallial and sub-pallial areas (cortex piriformis, cortex prepiriformis, hyperpallium apicale, hippocampus, globus pallidus) and thalamic and hypothalamic nuclei (organum vasculosum laminae terminalis, nucleus (n.) dorsolateralis anterior thalami, n. rotundus, n. infundibularis) including the median eminence and hind brain (n. pretectalis, n. opticus basalis, n. reticularis pontis caudalis pars gigantocellularis). The important structures with only NPY-immunoreactive fibers included the olfactory bulb, medial and lateral septal areas, medial preoptic nucleus, medial suprachiasmatic nucleus, paraventricular nucleus, ventromedial hypothalamic nucleus, optic tectum, and ventro-lateral geniculate nucleus. These results demonstrate that NPY is possibly involved in the regulation of several physiological functions (e.g. daily timing feeding, and reproduction) in the migratory bunting.

Brain activity related to phonation in young patients with adductor spasmodic dysphonia.

PubMed

Kiyuna, Asanori; Maeda, Hiroyuki; Higa, Asano; Shingaki, Kouta; Uehara, Takayuki; Suzuki, Mikio

2014-06-01

This study investigated the brain activities during phonation of young patients with adductor spasmodic dysphonia (ADSD) of relatively short disease duration (<10 years). Six subjects with ADSD of short duration (mean age: 24. 3 years; mean disease duration: 41 months) and six healthy controls (mean age: 30.8 years) underwent functional magnetic resonance imaging (fMRI) using a sparse sampling method to identify brain activity during vowel phonation (/i:/). Intragroup and intergroup analyses were performed using statistical parametric mapping software. Areas of activation in the ADSD and control groups were similar to those reported previously for vowel phonation. All of the activated areas were observed bilaterally and symmetrically. Intergroup analysis revealed higher brain activities in the SD group in the auditory-related areas (Brodmann's areas [BA] 40, 41), motor speech areas (BA44, 45), bilateral insula (BA13), bilateral cerebellum, and middle frontal gyrus (BA46). Areas with lower activation were in the left primary sensory area (BA1-3) and bilateral subcortical nucleus (putamen and globus pallidus). The auditory cortical responses observed may reflect that young ADSD patients control their voice by use of the motor speech area, insula, inferior parietal cortex, and cerebellum. Neural activity in the primary sensory area and basal ganglia may affect the voice symptoms of young ADSD patients with short disease duration. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

How does environmental enrichment reduce repetitive motor behaviors? Neuronal activation and dendritic morphology in the indirect basal ganglia pathway of a mouse model

PubMed Central

Bechard, Allison R.; Cacodcar, Nadia; King, Michael A.; Lewis, Mark H.

2015-01-01

Repetitive motor behaviors are observed in many neurodevelopmental and neurological disorders (e.g. autism spectrum disorders, Tourette syndrome, fronto-temporal dementia). Despite their clinical importance, the neurobiology underlying these highly stereotyped, apparently functionless behaviors is poorly understood. Identification of mechanisms that mediate the development of repetitive behaviors will aid in the discovery of new therapeutic targets and treatment development. Using a deer mouse model, we have shown that decreased indirect basal ganglia pathway activity is associated with high levels of repetitive behavior. Environmental enrichment (EE) markedly attenuates the development of such aberrant behaviors in mice, although mechanisms driving this effect are unknown. We hypothesized that EE would reduce repetitive motor behaviors by increasing indirect basal ganglia pathway function. We assessed neuronal activation and dendritic spine density in basal ganglia of adult deer mice reared in EE and standard housing. Significant increases in neuronal activation and dendritic spine densities were observed only in the subthalamic nucleus (STN) and globus pallidus (GP), and only for those mice that exhibited an EE-induced decrease in repetitive motor behavior. As the STN and GP lie within the indirect pathway, these data suggest that EE-induced attenuation of repetitive motor behaviors is associated with increased functional activation of the indirect basal ganglia pathway. These results are consistent with our other findings highlighting the importance of the indirect pathway in mediating repetitive motor behaviors. PMID:26620495

Exposure to the cytokine EGF leads to abnormal hyperactivity of pallidal GABA neurons: implications for schizophrenia and its modeling.

PubMed

Sotoyama, Hidekazu; Namba, Hisaaki; Chiken, Satomi; Nambu, Atsushi; Nawa, Hiroyuki

2013-08-01

Previous studies on a cytokine model for schizophrenia reveal that the hyperdopaminergic innervation and neurotransmission in the globus pallidus (GP) is involved in its behavioral impairments. Here, we further explored the physiological consequences of the GP abnormality in the indirect pathway, using the same schizophrenia model established by perinatal exposure to epidermal growth factor (EGF). Single-unit recordings revealed that the neural activity from the lateral GP was elevated in EGF-treated rats in vivo and in vitro (i.e., slice preparations), whereas the central area of the GP exhibited no significant differences. The increase in the pallidal activity was normalized by subchronic treatment with risperidone, which is known to ameliorate their behavioral deficits. We also monitored extracellular GABA concentrations in the substantia nigra, one of the targets of pallidal efferents. There was a significant increase in basal GABA levels in EGF-treated rats, whereas high potassium-evoked GABA effluxes and glutamate levels were not affected. A neurotoxic lesion in the GP of EGF-treated rats normalized GABA concentrations to control levels. Corroborating our in vivo results, GABA release from GP slices was elevated in EGF-treated animals. These findings suggest that the hyperactivity and enhanced GABA release of GP neurons represent the key pathophysiological features of this cytokine-exposure model for schizophrenia. © 2013 International Society for Neurochemistry.

Psychopathic traits modulate brain responses to drug cues in incarcerated offenders

PubMed Central

Cope, Lora M.; Vincent, Gina M.; Jobelius, Justin L.; Nyalakanti, Prashanth K.; Calhoun, Vince D.; Kiehl, Kent A.

2014-01-01

Recent neuroscientific evidence indicates that psychopathy is associated with abnormal function and structure in limbic and paralimbic areas. Psychopathy and substance use disorders are highly comorbid, but clinical experience suggests that psychopaths abuse drugs for different reasons than non-psychopaths, and that psychopaths do not typically experience withdrawal and craving upon becoming incarcerated. These neurobiological abnormalities may be related to psychopaths' different motivations for—and symptoms of—drug use. This study examined the modulatory effect of psychopathic traits on the neurobiological craving response to pictorial drug stimuli. Drug-related pictures and neutral pictures were presented and rated by participants while hemodynamic activity was monitored using functional magnetic resonance imaging. These data were collected at two correctional facilities in New Mexico using the Mind Research Network mobile magnetic resonance imaging system. The sample comprised 137 incarcerated adult males and females (93 females) with histories of substance dependence. The outcome of interest was the relation between psychopathy scores (using the Hare Psychopathy Checklist-Revised) and hemodynamic activity associated with viewing drug-related pictures vs. neutral pictures. There was a negative association between psychopathy scores and hemodynamic activity for viewing drug-related cues in the anterior cingulate, posterior cingulate, hippocampus, amygdala, caudate, globus pallidus, and parts of the prefrontal cortex. Psychopathic traits modulate the neurobiological craving response and suggest that individual differences are important for understanding and treating substance abuse. PMID:24605095

Effects of neurostimulation for advanced Parkinson’s disease patients on motor symptoms: A multiple-treatments meta-analysas of randomized controlled trials

PubMed Central

Xie, Cheng-Long; Shao, Bei; Chen, Jie; Zhou, Yi; Lin, Shi-Yi; Wang, Wen-Wen

2016-01-01

Deep brain stimulation (DBS) is the surgical procedure of choice for patients with advanced Parkinson disease (PD). We aim to evaluate the efficacy of GPi (globus pallidus internus), STN (subthalamic nucleus)-DBS and medical therapy for PD. We conducted a systematic review and multiple-treatments meta-analysis to investigate the efficacy of neurostimulation and medical therapy for PD patients. Sixteen eligible studies were included in this analysis. We pooled the whole data and found obvious difference between GPi-DBS versus medical therapy and STN-DBS versus medical therapy in terms of UPDRS scores (Unified Parkinson’s Disease Rating Scale). Meanwhile, we found GPi-DBS had the similar efficacy on the UPDRS scores when compared with STN-DBS. What is more, quality of life, measured by PDQ-39 (Parkinson’s disease Questionnaire) showed greater improvement after GPi-DBS than STN-DBS. Five studies showed STN-DBS was more effective for reduction in medication than GPi-DBS. Overall, either GPi-DBS or STN-DBS was an effective technique to control PD patients’ symptoms and improved their functionality and quality of life. Meanwhile, the UPDRS scores measuring parkinsonian symptoms revealed no significant difference between GPi-DBS and STN-DBS. STN-DBS was more effective for reduction in medication than GPi-DBS. Alternatively, GPi-DBS was more effective for improving the PDQ-39 score than STN-DBS. PMID:27142183

Clinical outcome and intraoperative neurophysiology for focal limb dystonic tremor without generalized dystonia treated with deep brain stimulation.

PubMed

Ramirez-Zamora, Adolfo; Kaszuba, Brian; Gee, Lucy; Prusik, Julia; Molho, Eric; Wilock, Meghan; Shin, Damian; Pilitsis, Julie G

2016-11-01

Dystonic tremor (DT) is defined as a postural/kinetic tremor occurring in the body region affected by dystonia. DT is typically characterized by focal tremors with irregular amplitudes and variable frequencies typically below 7Hz. Pharmacological treatment is generally unsuccessful and guidelines for deep brain stimulation (DBS) targeting and indications are scarce. In this article, we present the outcome and neurophysiologic data of two patients with refractory, focal limb DT treated with Globus Pallidus interna (Gpi) DBS and critically review the current literature regarding surgical treatment of DT discussing stereotactic targets and treatment considerations. A search of literature concerning treatment of DT was conducted. Additionally, Gpi DBS was performed in two patients with DT and microelectrode recordings for multi unit analysis (MUAs) and local field potentials (LFPs) were obtained. The mean percentage improvement in tremor severity was 80.5% at 3 years follow up. MUAs and LFPs did not show significant differences in DT patients compared with other forms of dystonia or PD except for higher interspikes bursting indices. LFP recordings in DT demonstrated high power at low frequencies with action (<3.5Hz). Gpi DBS is an effective treatment in patients with focal limb DT without associated generalized dystonia. Intraoperative neurophysiologic findings suggest that DT is part of phenotypic motor manifestations in dystonia. Copyright © 2016 Elsevier B.V. All rights reserved.

Dynamic brain glucose metabolism identifies anti-correlated cortical-cerebellar networks at rest.

PubMed

Tomasi, Dardo G; Shokri-Kojori, Ehsan; Wiers, Corinde E; Kim, Sunny W; Demiral, Şukru B; Cabrera, Elizabeth A; Lindgren, Elsa; Miller, Gregg; Wang, Gene-Jack; Volkow, Nora D

2017-12-01

It remains unclear whether resting state functional magnetic resonance imaging (rfMRI) networks are associated with underlying synchrony in energy demand, as measured by dynamic 2-deoxy-2-[ 18 F]fluoroglucose (FDG) positron emission tomography (PET). We measured absolute glucose metabolism, temporal metabolic connectivity (t-MC) and rfMRI patterns in 53 healthy participants at rest. Twenty-two rfMRI networks emerged from group independent component analysis (gICA). In contrast, only two anti-correlated t-MC emerged from FDG-PET time series using gICA or seed-voxel correlations; one included frontal, parietal and temporal cortices, the other included the cerebellum and medial temporal regions. Whereas cerebellum, thalamus, globus pallidus and calcarine cortex arose as the strongest t-MC hubs, the precuneus and visual cortex arose as the strongest rfMRI hubs. The strength of the t-MC linearly increased with the metabolic rate of glucose suggesting that t-MC measures are strongly associated with the energy demand of the brain tissue, and could reflect regional differences in glucose metabolism, counterbalanced metabolic network demand, and/or differential time-varying delivery of FDG. The mismatch between metabolic and functional connectivity patterns computed as a function of time could reflect differences in the temporal characteristics of glucose metabolism as measured with PET-FDG and brain activation as measured with rfMRI.

Cerebral venous infarction: a potentially avoidable complication of deep brain stimulation surgery.

PubMed

Morishita, Takashi; Okun, Michael S; Burdick, Adam; Jacobson, Charles E; Foote, Kelly D

2013-01-01

Despite numerous reports on the morbidity and mortality of deep brain stimulation (DBS), cerebral venous infarction has rarely been reported. We present four cases of venous infarct secondary to DBS surgery. The diagnosis of venous infarction was based on 1) delayed onset of new neurologic deficits on postoperative day 1 or 2; 2) significant edema surrounding the superficial aspect of the implanted lead, with or without subcortical hemorrhage on CT scan. Four cases (0.8% per lead, 1.3% per patient) of symptomatic cerebral venous infarction were identified out of 500 DBS lead implantation procedures between July 2002 and August 2009. All four patients had Parkinson's disease. Their DBS leads were implanted in the subthalamic nucleus (n = 2), and the globus pallidus internus (n = 2). Retrospective review of the targeting confirmed that the planned trajectory passed within 3 mm of a cortical vein in two cases for which contrast-enhanced preoperative magnetic resonance (MR) imaging was available. In the other two cases, contrasted targeting images were not obtained preoperatively. Cerebral venous infarction is a potentially avoidable, but serious complication. To minimize its incidence, we propose the use of high-resolution, contrast-enhanced, T1-weighted MR images to delineate cerebral venous anatomy, along with careful stereotactic planning of the lead trajectory to avoid injury to venous structures. © 2013 International Neuromodulation Society.

Associations between IQ, total and regional brain volumes, and demography in a large normative sample of healthy children and adolescents.

PubMed

Lange, Nicholas; Froimowitz, Michael P; Bigler, Erin D; Lainhart, Janet E

2010-01-01

In the course of efforts to establish quantitative norms for healthy brain development by magnetic resonance imaging (MRI) (Brain Development Cooperative Group, 2006), previously unreported associations of parental education and temporal and frontal lobe volumes with full scale IQ and its verbal and performance subscales were discovered. Our findings were derived from the largest, most representative MRI sample to date of healthy children and adolescents, ages 4 years 10 months to 18 years 4 months. We first find that parental education has a strong association with IQ in children that is not mediated by total or regional brain volumes. Second, we find that our observed correlations between temporal gray matter, temporal white matter and frontal white matter volumes with full scale IQ, between 0.14 to 0.27 in children and adolescents, are due in large part to their correlations with performance IQ and not verbal IQ. The volumes of other lobar gray and white matter, subcortical gray matter (thalamus, caudate nucleus, putamen, and globus pallidus), cerebellum, and brainstem do not contribute significantly to IQ variation. Third, we find that head circumference is an insufficient index of cerebral volume in typically developing older children and adolescents. The relations between total and regional brain volumes and IQ can best be discerned when additional variables known to be associated with IQ, especially parental education and other demographic measures, are considered concurrently.

Common limbic and frontal-striatal disturbances in patients with obsessive compulsive disorder, panic disorder and hypochondriasis.

PubMed

van den Heuvel, O A; Mataix-Cols, D; Zwitser, G; Cath, D C; van der Werf, Y D; Groenewegen, H J; van Balkom, A J L M; Veltman, D J

2011-11-01

Direct comparisons of brain function between obsessive compulsive disorder (OCD) and other anxiety or OCD spectrum disorders are rare. This study aimed to investigate the specificity of altered frontal-striatal and limbic activations during planning in OCD, a prototypical anxiety disorder (panic disorder) and a putative OCD spectrum disorder (hypochondriasis). The Tower of London task, a 'frontal-striatal' task, was used during functional magnetic resonance imaging measurements in 50 unmedicated patients, diagnosed with OCD (n=22), panic disorder (n=14) or hypochondriasis (n=14), and in 22 healthy subjects. Blood oxygen level-dependent (BOLD) signal changes were calculated for contrasts of interest (planning versus baseline and task load effects). Moreover, correlations between BOLD responses and both task performance and state anxiety were analysed. Overall, patients showed a decreased recruitment of the precuneus, caudate nucleus, globus pallidus and thalamus, compared with healthy controls. There were no statistically significant differences in brain activation between the three patient groups. State anxiety was negatively correlated with dorsal frontal-striatal activation. Task performance was positively correlated with dorsal frontal-striatal recruitment and negatively correlated with limbic and ventral frontal-striatal recruitment. Multiple regression models showed that adequate task performance was best explained by independent contributions from dorsolateral prefrontal cortex (positive correlation) and amygdala (negative correlation), even after controlling for state anxiety. Patients with OCD, panic disorder and hypochondriasis share similar alterations in frontal-striatal brain regions during a planning task, presumably partly related to increased limbic activation.