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Sample records for agranular insular cortex

  1. Correlation Between Activation of the Prelimbic Cortex, Basolateral Amygdala, and Agranular Insular Cortex During Taste Memory Formation.

    PubMed

    Uematsu, Akira; Kitamura, Akihiko; Iwatsuki, Ken; Uneyama, Hisayuki; Tsurugizawa, Tomokazu

    2015-09-01

    Conditioned taste aversion (CTA) is a well-established learning paradigm, whereby animals associate tastes with subsequent visceral illness. The prelimbic cortex (PL) has been shown to be involved in the association of events separated by time. However, the nature of PL activity and its functional network in the whole brain during CTA learning remain unknown. Here, using awake functional magnetic resonance imaging and fiber tracking, we analyzed functional brain connectivity during the association of tastes and visceral illness. The blood oxygen level-dependent (BOLD) signal significantly increased in the PL after tastant and lithium chloride (LiCl) infusions. The BOLD signal in the PL significantly correlated with those in the amygdala and agranular insular cortex (IC), which we found were also structurally connected to the PL by fiber tracking. To precisely examine these data, we then performed double immunofluorescence with a neuronal activity marker (c-Fos) and an inhibitory neuron marker (GAD67) combined with a fluorescent retrograde tracer in the PL. During CTA learning, we found an increase in the activity of excitatory neurons in the basolateral amygdala (BLA) or agranular IC that project to the PL. Taken together, these findings clearly identify a role of synchronized PL, agranular IC, and BLA activity in CTA learning. PMID:24735672

  2. Moderate Prenatal Alcohol Exposure Enhances GluN2B Containing NMDA Receptor Binding and Ifenprodil Sensitivity in Rat Agranular Insular Cortex

    PubMed Central

    Bird, Clark W.; Candelaria-Cook, Felicha T.; Magcalas, Christy M.; Davies, Suzy; Valenzuela, C. Fernando; Savage, Daniel D.; Hamilton, Derek A.

    2015-01-01

    Prenatal exposure to alcohol affects the expression and function of glutamatergic neurotransmitter receptors in diverse brain regions. The present study was undertaken to fill a current gap in knowledge regarding the regional specificity of ethanol-related alterations in glutamatergic receptors in the frontal cortex. We quantified subregional expression and function of glutamatergic neurotransmitter receptors (AMPARs, NMDARs, GluN2B-containing NMDARs, mGluR1s, and mGluR5s) by radioligand binding in the agranular insular cortex (AID), lateral orbital area (LO), prelimbic cortex (PrL) and primary motor cortex (M1) of adult rats exposed to moderate levels of ethanol during prenatal development. Increased expression of GluN2B-containing NMDARs was observed in AID of ethanol-exposed rats compared to modest reductions in other regions. We subsequently performed slice electrophysiology measurements in a whole-cell patch-clamp preparation to quantify the sensitivity of evoked NMDAR-mediated excitatory postsynaptic currents (EPSCs) in layer II/III pyramidal neurons of AID to the GluN2B negative allosteric modulator ifenprodil. Consistent with increased GluN2B expression, ifenprodil caused a greater reduction in NMDAR-mediated EPSCs from prenatal alcohol-exposed rats than saccharin-exposed control animals. No alterations in AMPAR-mediated EPSCs or the ratio of AMPARs/NMDARs were observed. Together, these data indicate that moderate prenatal alcohol exposure has a significant and lasting impact on GluN2B-containing receptors in AID, which could help to explain ethanol-related alterations in learning and behaviors that depend on this region. PMID:25747876

  3. The Dorsal Agranular Insular Cortex Regulates the Cued Reinstatement of Cocaine-Seeking, but not Food-Seeking, Behavior in Rats

    PubMed Central

    Cosme, Caitlin V; Gutman, Andrea L; LaLumiere, Ryan T

    2015-01-01

    Prior studies suggest that the insular cortex (IC), and particularly its posterior region (the PIc), is involved in nicotine craving and relapse in humans and rodents. The present experiments were conducted to determine whether the IC and its different subregions regulate relapse to cocaine-seeking behavior in rats. To address this issue, male Sprague–Dawley rats underwent cocaine self-administration followed by extinction training and reinstatement tests. Before each reinstatement, the PIc or the more anterior dorsal agranular IC (AId) was inactivated to determine their roles in the reinstatement to cocaine seeking. In contrast to the nicotine findings, PIc inactivation had no effect on cue-induced reinstatement for cocaine seeking. However, AId inactivation reduced cued reinstatement while having no effect on cocaine-prime reinstatement. AId inactivation had no effect on reinstatement of food-seeking behavior induced by cues, a food-prime, or cues+food-prime. Based on previous work hypothesizing a role for corticotropin-releasing factor (CRF) in the IC during craving and relapse, a subsequent experiment found that CRF receptor-1 (CRF1) blockade in the AId similarly reduced cued reinstatement. Our results suggest that the AId, along with CRF1 receptors in this region, regulates reinstatement to cocaine seeking, but not food seeking, depending on the type of reinstatement, whereas PIc activity does not influence cue-induced reinstatement. PMID:25837282

  4. Differential Involvement of the Agranular vs Granular Insular Cortex in the Acquisition and Performance of Choice Behavior in a Rodent Gambling Task.

    PubMed

    Pushparaj, Abhiram; Kim, Aaron S; Musiol, Martin; Zangen, Abraham; Daskalakis, Zafiris J; Zack, Martin; Winstanley, Catharine A; Le Foll, Bernard

    2015-11-01

    Substance-related and addictive disorders, in particular gambling disorder, are known to be associated with risky decision-making behavior. Several neuroimaging studies have identified the involvement of the insular cortex in decision-making under risk. However, the extent of this involvement remains unclear and the specific contributions of two distinct insular subregions, the rostral agranular (RAIC) and the caudal granular (CGIC), have yet to be examined. Animals were trained to perform a rat gambling task (rGT), in which subjects chose between four options that differed in the magnitude and probability of rewards and penalties. In order to address the roles of the RAIC and CGIC in established choice behavior, pharmacological inactivations of these two subregions via local infusions of GABA receptor agonists were performed following 30 rGT training sessions. The contribution made by the RAIC or CGIC to the acquisition of choice behavior was also determined by lesioning these areas before behavioral training. Inactivation of the RAIC, but not of the CGIC, shifted rats' preference toward options with greater reward frequency and lower punishment. Before rGT acquisition, lesions of the RAIC, but not the CGIC, likewise resulted in a higher preference for options with greater reward frequency and lower punishment, and this persisted throughout the 30 training sessions. Our results provide confirmation of the involvement of the RAIC in rGT choice behavior and suggest that the RAIC may mediate detrimental risky decision-making behavior, such as that associated with addiction and gambling disorder. PMID:25953358

  5. Differential Involvement of the Agranular vs Granular Insular Cortex in the Acquisition and Performance of Choice Behavior in a Rodent Gambling Task

    PubMed Central

    Pushparaj, Abhiram; Kim, Aaron S; Musiol, Martin; Zangen, Abraham; Daskalakis, Zafiris J; Zack, Martin; Winstanley, Catharine A; Le Foll, Bernard

    2015-01-01

    Substance-related and addictive disorders, in particular gambling disorder, are known to be associated with risky decision-making behavior. Several neuroimaging studies have identified the involvement of the insular cortex in decision-making under risk. However, the extent of this involvement remains unclear and the specific contributions of two distinct insular subregions, the rostral agranular (RAIC) and the caudal granular (CGIC), have yet to be examined. Animals were trained to perform a rat gambling task (rGT), in which subjects chose between four options that differed in the magnitude and probability of rewards and penalties. In order to address the roles of the RAIC and CGIC in established choice behavior, pharmacological inactivations of these two subregions via local infusions of GABA receptor agonists were performed following 30 rGT training sessions. The contribution made by the RAIC or CGIC to the acquisition of choice behavior was also determined by lesioning these areas before behavioral training. Inactivation of the RAIC, but not of the CGIC, shifted rats' preference toward options with greater reward frequency and lower punishment. Before rGT acquisition, lesions of the RAIC, but not the CGIC, likewise resulted in a higher preference for options with greater reward frequency and lower punishment, and this persisted throughout the 30 training sessions. Our results provide confirmation of the involvement of the RAIC in rGT choice behavior and suggest that the RAIC may mediate detrimental risky decision-making behavior, such as that associated with addiction and gambling disorder. PMID:25953358

  6. The insular cortex: a review.

    PubMed

    Nieuwenhuys, Rudolf

    2012-01-01

    The human insular cortex forms a distinct, but entirely hidden lobe, situated in the depth of the Sylvian fissure. Here, we first review the recent literature on the connectivity and the functions of this structure. It appears that this small lobe, taking up less than 2% of the total cortical surface area, receives afferents from some sensory thalamic nuclei, is (mostly reciprocally) connected with the amygdala and with many limbic and association cortical areas, and is implicated in an astonishingly large number of widely different functions, ranging from pain perception and speech production to the processing of social emotions. Next, we embark on a long, adventurous journey through the voluminous literature on the structural organization of the insular cortex. This journey yielded the following take-home messages: (1) The meticulous, but mostly neglected publications of Rose (1928) and Brockhaus (1940) are still invaluable for our understanding of the architecture of the mammalian insular cortex. (2) The relation of the insular cortex to the adjacent claustrum is neither ontogenetical nor functional, but purely topographical. (3) The insular cortex has passed through a spectacular progressive differentiation during hominoid evolution, but the assumption of Craig (2009) that the human anterior insula has no homologue in the rhesus monkey is untenable. (4) The concept of Mesulam and Mufson (1985), that the primate insula is essentially composed of three concentrically arranged zones, agranular, dysgranular, and granular, is presumably correct, but there is at present much confusion concerning the more detailed architecture of the anterior insular cortex. (5) The large spindle-shaped cells in the fifth layer of the insular cortex, currently known as von Economo neurons (VENs), are not only confined to large-brained mammals, such as whales, elephants, apes, and humans, but also occur in monkeys and prosimians, as well as in the pygmy hippopotamus, the Atlantic

  7. Reflections on agranular architecture: predictive coding in the motor cortex

    PubMed Central

    Shipp, Stewart; Adams, Rick A.; Friston, Karl J.

    2013-01-01

    The agranular architecture of motor cortex lacks a functional interpretation. Here, we consider a ‘predictive coding’ account of this unique feature based on asymmetries in hierarchical cortical connections. In sensory cortex, layer 4 (the granular layer) is the target of ascending pathways. We theorise that the operation of predictive coding in the motor system (a process termed ‘active inference’) provides a principled rationale for the apparent recession of the ascending pathway in motor cortex. The extension of this theory to interlaminar circuitry also accounts for a sub-class of ‘mirror neuron’ in motor cortex – whose activity is suppressed when observing an action –explaining how predictive coding can gate hierarchical processing to switch between perception and action. PMID:24157198

  8. A volumetric comparison of the insular cortex and its subregions in primates

    PubMed Central

    Bauernfeind, Amy L.; de Sousa, Alexandra A.; Avasthi, Tanvi; Dobson, Seth D.; Raghanti, Mary Ann; Lewandowski, Albert H.; Zilles, Karl; Semendeferi, Katerina; Allman, John M.; (Bud) Craig, Arthur D.; Hof, Patrick R.; Sherwood, Chet C.

    2013-01-01

    The neuronal composition of the insula in primates displays a gradient, transitioning from granular neocortex in the posterior-dorsal insula to agranular neocortex in the anterior-ventral insula with an intermediate zone of dysgranularity. Additionally, apes and humans exhibit a distinctive subdomain in the agranular insula, the frontoinsular cortex (FI), defined by the presence of clusters of von Economo neurons (VENs). Studies in humans indicate that the ventral anterior insula, including agranular insular cortex and FI, is involved in social awareness, and that the posterodorsal insula, including granular and dysgranular cortices, produces an internal representation of the body’s homeostatic state. We examined the volumes of these cytoarchitectural areas of insular cortex in 30 primate species, including the volume of FI in apes and humans. Results indicate that the whole insula scales hyperallometrically (exponent = 1.13) relative to total brain mass, and the agranular insula (including FI) scales against total brain mass with even greater positive allometry (exponent = 1.23), providing a potential neural basis for enhancement of social cognition in association with increased brain size. The relative volumes of the subdivisions of the insular cortex, after controlling for total brain volume, are not correlated with species typical social group size. Although its size is predicted by primate-wide allometric scaling patterns, we found that the absolute volume of the left and right agranular insula and left FI are among the most differentially expanded of the human cerebral cortex compared to our closest living relative, the chimpanzee. PMID:23466178

  9. Microcircuitry of Agranular Frontal Cortex: Testing the Generality of the Canonical Cortical Microcircuit

    PubMed Central

    Godlove, David C.; Maier, Alexander; Woodman, Geoffrey F.

    2014-01-01

    We investigated whether a frontal area that lacks granular layer IV, supplementary eye field, exhibits features of laminar circuitry similar to those observed in primary sensory areas. We report, for the first time, visually evoked local field potentials (LFPs) and spiking activity recorded simultaneously across all layers of agranular frontal cortex using linear electrode arrays. We calculated current source density from the LFPs and compared the laminar organization of evolving sinks to those reported in sensory areas. Simultaneous, transient synaptic current sinks appeared first in layers III and V followed by more prolonged current sinks in layers I/II and VI. We also found no variation of single- or multi-unit visual response latency across layers, and putative pyramidal neurons and interneurons displayed similar response latencies. Many units exhibited pronounced discharge suppression that was strongest in superficial relative to deep layers. Maximum discharge suppression also occurred later in superficial than in deep layers. These results are discussed in the context of the canonical cortical microcircuit model originally formulated to describe early sensory cortex. The data indicate that agranular cortex resembles sensory areas in certain respects, but the cortical microcircuit is modified in nontrivial ways. PMID:24719113

  10. The insular cortex: a comparative perspective.

    PubMed

    Butti, Camilla; Hof, Patrick R

    2010-06-01

    The human insular cortex is involved in a variety of viscerosensory, visceromotor, and interoceptive functions, and plays a role in complex processes such as emotions, music, and language. Across mammals, the insula has considerable morphologic variability. We review the structure and connectivity of the insula in laboratory animals (mouse, domestic cat, macaque monkey), and we present original data on the morphology and cytoarchitecture of insular cortex in less common species including a large carnivore (the Atlantic walrus, Odobenus rosmarus), two artiodactyls (the pigmy hippopotamus, Hexaprotodon liberiensis, and the Western bongo, Tragelaphus eurycerus), two cetaceans (the beluga whale, Delphinapterus leucas, and the minke whale, Balaenoptera acutorostrata), and a sirenian (the Florida manatee, Trichechus manatus latirostris). The insula shows substantial variability in shape, extent, and gyral and sulcal patterns, as well as differences in laminar organization, cellular specialization, and structural association with the claustrum. Our observations reveal that the insular cortex is extremely variable among mammals. These differences could be related to the role exerted by specific and selective pressures on cortical structure during evolution. We conclude that it is not possible to identify a general model of organization for the mammalian insular cortex. PMID:20512368

  11. A comparison of multiple-unit activity in the medial prefrontal and agranular insular cortices during Pavlovian heart rate conditioning in rabbits.

    PubMed

    Gibbs, C M; Prescott, L B; Powell, D A

    1992-01-01

    Multiple-unit activity (MUA) was recorded from chronically implanted electrodes in the medial prefrontal cortex (PFCm) and the agranular insular cortex (Iag) in separate groups of rabbits during habituation training, followed by aversive Pavlovian conditioning and subsequent extinction training. Control animals received explicitly unpaired presentations of the tone conditioned stimulus (CS) and eye-shock unconditioned stimulus (US). Both the cardiac orientating reflex and the conditioned heart rate response (HR CR) consisted of bradycardia, whereas tone-evoked tachycardia was observed in animals that received unpaired stimuli. Short-latency (less than 20-60 ms), tone-evoked increases in PFCm MUA were observed during the initial trials of habituation training, with their magnitude declining predictably across repeated tone-alone presentations. Subsequent CS/US pairings, however, served systematically to reinstate and enhance this CS-evoked MUA, while both non-associative (unpaired CS/US) and extinction (CS alone) training resulted in significant attenuation of such activity. Unconditioned tone-evoked increases in MUA were also observed in the Iag during habituation; however, such unit responses appeared to be more variable than their PFCm counterparts and were of considerably lesser magnitude. Moreover, in striking contrast to the above PFCm findings, conditioning and non-associative training did not differentially affect overall mean evoked MUA in the Iag, although different post-tone patterns of activity were obtained with the two procedures. The contrasting training effects observed in animals with PFCm vs. Iag electrode placements did not appear to be attributable to differences in regional sensitivity to the US, since excitatory patterns of MUA were elicited by unsignalled presentations of eye-shock at most placements within each cortical field. Accordingly, the present findings are consistent with our previous lesion data in suggesting that, although training

  12. The importance of being agranular: a comparative account of visual and motor cortex

    PubMed Central

    Shipp, Stewart

    2005-01-01

    The agranular cortex is an important landmark—anatomically, as the architectural flag of mammalian motor cortex, and historically, as a spur to the development of theories of localization of function. But why, exactly, do agranularity and motor function go together? To address this question, it should be noted that not only does motor cortex lack granular layer four, it also has a relatively thinner layer three. Therefore, it is the two layers which principally constitute the ascending pathways through the sensory (granular) cortex that have regressed in motor cortex: simply stated, motor cortex does not engage in serial reprocessing of incoming sensory data. But why should a granular architecture not be demanded by the downstream relay of motor instructions through the motor cortex? The scant anatomical evidence available regarding laminar patterns suggests that the pathways from frontal and premotor areas to the primary motor cortex actually bear a greater resemblance to the descending, or feedback connections of sensory cortex that avoid the granular layer. The action of feedback connections is generally described as ‘modulatory’ at a cellular level, or ‘selective’ in terms of systems analysis. By contrast, ascending connections may be labelled ‘driving’ or ‘instructive’. Where the motor cortex uses driving inputs, they are most readily identified as sensory signals instructing the visual location of targets and the kinaesthetic state of the body. Visual signals may activate motor concepts, e.g. ‘mirror neurons’, and the motor plan must select the appropriate muscles and forces to put the plan into action, if the decision to move is taken. This, perhaps, is why ‘driving’ motor signals might be inappropriate—the optimal selection and its execution are conditional upon both kinaesthetic and motivational factors. The argument, summarized above, is constructed in honour of Korbinian Brodmann's centenary, and follows two of the fundamental

  13. Microcircuitry of agranular frontal cortex: contrasting laminar connectivity between occipital and frontal areas.

    PubMed

    Ninomiya, Taihei; Dougherty, Kacie; Godlove, David C; Schall, Jeffrey D; Maier, Alexander

    2015-05-01

    Neocortex is striking in its laminar architecture. Tracer studies have uncovered anatomical connectivity among laminae, but the functional connectivity between laminar compartments is still largely unknown. Such functional connectivity can be discerned through spontaneous neural correlations during rest. Previous work demonstrated a robust pattern of mesoscopic resting-state connectivity in macaque primary visual cortex (V1) through interlaminar cross-frequency coupling. Here we investigated whether this pattern generalizes to other cortical areas by comparing resting-state laminar connectivity between V1 and the supplementary eye field (SEF), a frontal area lacking a granular layer 4 (L4). Local field potentials (LFPs) were recorded with linear microelectrode arrays from all laminae of granular V1 and agranular SEF while monkeys rested in darkness. We found substantial differences in the relationship between the amplitude of gamma-band (>30 Hz) LFP and the phase of alpha-band (7-14 Hz) LFP between these areas. In V1, gamma amplitudes in L2/3 and L5 were coupled with alpha-band LFP phase in L5, as previously described. In contrast, in SEF phase-amplitude coupling was prominent within L3 and much weaker across layers. These results suggest that laminar interactions in agranular SEF are unlike those in granular V1. Thus the intrinsic functional connectivity of the cortical microcircuit does not seem to generalize across cortical areas. PMID:25744881

  14. Pathomechanisms of atrophy in insular cortex in Alzheimer's disease.

    PubMed

    Moon, Yeonsil; Moon, Won-Jin; Han, Seol-Heui

    2015-08-01

    The insular cortex is associated with neuropsychiatric symptoms, changes in cardiovascular and autonomic control, and mortality in Alzheimer's dementia. However, the insular cortex does not provide information on the contribution of the other cortices to cognitive decline. We hypothesized that the factors that affect to atrophy in insular cortex are different from other cortical regions. A total of 42 patients with probable Alzheimer's dementia were included in the analyses. The manual drawing of regions of interest was used to detect insular cortex located in the deep gray matter and to avoid coatrophy. Covariates, which could affect to the atrophy of the cerebral cortex, were selected based on previous studies. Any of the demographic factors, vascular risk factors, and the severity scales of dementia was not associated with any insular volume ratio. We suggest that the pathomechanisms of atrophy in insular cortex are different from those of other cortex regions in Alzheimer's disease. PMID:25596207

  15. Anterior Insular Cortex and Emotional Awareness

    PubMed Central

    Gu, Xiaosi; Hof, Patrick R.; Friston, Karl J.; Fan, Jin

    2014-01-01

    This paper reviews the foundation for a role of the human anterior insular cortex (AIC) in emotional awareness, defined as the conscious experience of emotions. We first introduce the neuroanatomical features of AIC and existing findings on emotional awareness. Using empathy, the awareness and understanding of other people’s emotional states, as a test case, we then present evidence to demonstrate: 1) AIC and anterior cingulate cortex (ACC) are commonly coactivated as revealed by a meta-analysis, 2) AIC is functionally dissociable from ACC, 3) AIC integrates stimulus-driven and top-down information, and 4) AIC is necessary for emotional awareness. We propose a model in which AIC serves two major functions: integrating bottom-up interoceptive signals with top-down predictions to generate a current awareness state and providing descending predictions to visceral systems that provide a point of reference for autonomic reflexes. We argue that AIC is critical and necessary for emotional awareness. PMID:23749500

  16. Anterior insular cortex and emotional awareness.

    PubMed

    Gu, Xiaosi; Hof, Patrick R; Friston, Karl J; Fan, Jin

    2013-10-15

    This paper reviews the foundation for a role of the human anterior insular cortex (AIC) in emotional awareness, defined as the conscious experience of emotions. We first introduce the neuroanatomical features of AIC and existing findings on emotional awareness. Using empathy, the awareness and understanding of other people's emotional states, as a test case, we then present evidence to demonstrate: 1) AIC and anterior cingulate cortex (ACC) are commonly coactivated as revealed by a meta-analysis, 2) AIC is functionally dissociable from ACC, 3) AIC integrates stimulus-driven and top-down information, and 4) AIC is necessary for emotional awareness. We propose a model in which AIC serves two major functions: integrating bottom-up interoceptive signals with top-down predictions to generate a current awareness state and providing descending predictions to visceral systems that provide a point of reference for autonomic reflexes. We argue that AIC is critical and necessary for emotional awareness. PMID:23749500

  17. A heterogeneous population code for elapsed time in rat medial agranular cortex

    PubMed Central

    Matell, Matthew S.; Shea-Brown, Eric; Gooch, Cindy; Wilson, A. George; Rinzel, John

    2010-01-01

    The neural mechanisms underlying the temporal control of behavior are largely unknown. Here we recorded from the medial agranular cortex in rats trained to respond on a temporal production procedure for probabilistically available food reward. Due to variability in estimating the time of food availability, robust responding typically bracketed the expected duration, starting some time before and ending some time after the signaled delay. This response period provided an analytic “steady-state” window during which the subject actively timed their behavior. Remarkably, during these response periods, a variety of firing patterns were seen which could be broadly described as ramps, peaks, and dips, with different slopes, directions, and times at which maxima or minima occur. Regularized linear discriminant analysis indicated that these patterns provided sufficiently reliable information to discriminate the elapsed duration of responding within these response periods. Modeling this across neuron variability showed that the utilization of ramps, dips, and peaks with different slopes and minimal/maximal rates at different times led to a substantial improvement in temporal prediction errors, suggesting that heterogeneity in the neural representation of elapsed time may facilitate temporally controlled behavior. PMID:21319888

  18. Distinctive Roles of 5-aza-2′-deoxycytidine in Anterior Agranular Insular and Basolateral Amygdala in Reconsolidation of Aversive Memory Associated with Morphine in Rats

    PubMed Central

    Liu, Peng; Zhang, JianJun; Li, Ming; Sui, Nan

    2016-01-01

    5-aza-2′-deoxycytidine (5-aza), an inhibitor of DNA methyltransferases (DNMTs), has been implicated in aversive memory and the function of brain region involved in processing emotion. However, little is known about the role of 5-aza in the reconsolidation of opiate withdrawal memory. In the present study, using the morphine-naloxone induced conditioned place aversion (CPA) model in rats, we injected 5-aza into agranular insular (AI), granular insular (GI), basolateral amygdala (BLA) and central amygdala (CeA) immediately after the memory retrieval and tested the behavioral consequences at 24 h, 7 and 14 days after retrieval test. We found that 5-aza injection into AI disrupted the reconsolidation of morphine-associated withdrawal memory, but 5-aza injection into GI had no impact on the reconsolidation. Meanwhile, 5-aza injection into BLA but not CeA attenuated the withdrawal memory trace 14 days later. However, 5-aza administration to rats, in the absence of memory reactivation, had no effect on morphine-associated withdrawal memory. These findings suggest that 5-aza interferes with the reconsolidation of opiate withdrawal memory, and the roles of insular and amygdala in reconsolidation are distinctive. PMID:27014010

  19. The Role of the Insular Cortex in Retaliation.

    PubMed

    Emmerling, Franziska; Schuhmann, Teresa; Lobbestael, Jill; Arntz, Arnoud; Brugman, Suzanne; Sack, Alexander Thomas

    2016-01-01

    The insular cortex has consistently been associated with various aspects of emotion regulation and social interaction, including anger processing and overt aggression. Aggression research distinguishes proactive or instrumental aggression from retaliation, i.e. aggression in response to provocation. Here, we investigated the specific role of the insular cortex during retaliation, employing a controlled behavioral aggression paradigm implementing different levels of provocation. Fifteen healthy male volunteers underwent whole brain functional magnetic resonance imaging (fMRI) to identify brain regions involved in interaction with either a provoking or a non-provoking opponent. FMRI group analyses were complemented by examining the parametric modulations of brain activity related to the individual level of displayed aggression. These analyses identified a hemispheric lateralization as well as an anatomical segregation of insular cortex with specifically the left posterior part being involved in retaliation. The left-lateralization of insular activity during retaliation is in accordance with evidence from electro-physiological studies, suggesting left-lateralized fronto-cortical dominance during anger processing and aggressive acts. The posterior localization of insular activity, on the other hand, suggests a spatial segregation within insular cortex with particularly the posterior part being involved in the processing of emotions that trigger intense bodily sensations and immediate action tendencies. PMID:27096431

  20. The Role of the Insular Cortex in Retaliation

    PubMed Central

    Lobbestael, Jill; Arntz, Arnoud; Brugman, Suzanne; Sack, Alexander Thomas

    2016-01-01

    The insular cortex has consistently been associated with various aspects of emotion regulation and social interaction, including anger processing and overt aggression. Aggression research distinguishes proactive or instrumental aggression from retaliation, i.e. aggression in response to provocation. Here, we investigated the specific role of the insular cortex during retaliation, employing a controlled behavioral aggression paradigm implementing different levels of provocation. Fifteen healthy male volunteers underwent whole brain functional magnetic resonance imaging (fMRI) to identify brain regions involved in interaction with either a provoking or a non-provoking opponent. FMRI group analyses were complemented by examining the parametric modulations of brain activity related to the individual level of displayed aggression. These analyses identified a hemispheric lateralization as well as an anatomical segregation of insular cortex with specifically the left posterior part being involved in retaliation. The left-lateralization of insular activity during retaliation is in accordance with evidence from electro-physiological studies, suggesting left-lateralized fronto-cortical dominance during anger processing and aggressive acts. The posterior localization of insular activity, on the other hand, suggests a spatial segregation within insular cortex with particularly the posterior part being involved in the processing of emotions that trigger intense bodily sensations and immediate action tendencies. PMID:27096431

  1. Macroscopic connection of rat insular cortex: anatomical bases underlying its physiological functions.

    PubMed

    Kobayashi, Masayuki

    2011-01-01

    The insular cortex (IC), which lies on the dorsal bank of the rhinal fissure, receives multi-modal sensory inputs, i.e. visceral, gustatory, nociceptive and thermal information from the sensory thalamic nuclei. In contrast to other primary sensory cortices such as visual, auditory and somatosensory areas, the anatomical features of the IC are quite distinctive; more than a half of the IC is composed of agranular or dysgranular cortex, which lacks a complete granular layer (layer IV). In addition to the characteristic layer structures, the IC has dense reciprocal innervations with the limbic structures, including the amygdala and hypothalamus. Such connectivity implies that sensory information processed in the IC is profoundly related to limbic information. By enabling the visualization of functional connectivity in the central nervous system, recent advancements in optical imaging techniques have opened the possibility to elucidate the mechanisms of sensory information processing from a macroscopic perspective. In this review, anatomical and functional features of the IC are overviewed from the aspect of gustatory processing, a typical sensation processed in the IC. In addition, the recently developed optical imaging techniques and their findings in gustatory information processing are summarized. We discuss how these characteristic features of excitatory propagation in the IC play functional roles in transmitting neural excitation arising from the limbic structures to the frontal and orbital cortices. PMID:21708315

  2. CREB regulates memory allocation in the insular cortex.

    PubMed

    Sano, Yoshitake; Shobe, Justin L; Zhou, Miou; Huang, Shan; Shuman, Tristan; Cai, Denise J; Golshani, Peyman; Kamata, Masakazu; Silva, Alcino J

    2014-12-01

    The molecular and cellular mechanisms of memory storage have attracted a great deal of attention. By comparison, little is known about memory allocation, the process that determines which specific neurons in a neural network will store a given memory. Previous studies demonstrated that memory allocation is not random in the amygdala; these studies showed that amygdala neurons with higher levels of the cyclic-AMP-response-element-binding protein (CREB) are more likely to be recruited into encoding and storing fear memory. To determine whether specific mechanisms also regulate memory allocation in other brain regions and whether CREB also has a role in this process, we studied insular cortical memory representations for conditioned taste aversion (CTA). In this task, an animal learns to associate a taste (conditioned stimulus [CS]) with the experience of malaise (such as that induced by LiCl; unconditioned stimulus [US]). The insular cortex is required for CTA memory formation and retrieval. CTA learning activates a subpopulation of neurons in this structure, and the insular cortex and the basolateral amygdala (BLA) interact during CTA formation. Here, we used a combination of approaches, including viral vector transfections of insular cortex, arc fluorescence in situ hybridization (FISH), and designer receptors exclusively activated by designer drugs (DREADD) system, to show that CREB levels determine which insular cortical neurons go on to encode a given conditioned taste memory. PMID:25454591

  3. Insular cortex activity and the evocation of laughter.

    PubMed

    Wattendorf, Elise; Westermann, Birgit; Lotze, Martin; Fiedler, Klaus; Celio, Marco R

    2016-06-01

    The insular cortex is fundamentally involved in the processing of interoceptive information. It has been postulated that the integrative monitoring of the bodily responses to environmental stimuli is crucial for the recognition and experience of emotions. Because emotional arousal is known to be closely coupled to functions of the anterior insula, we suspected laughter to be associated primarily with neuronal activity in this region. An anatomically constrained re-analysis of our imaging data pertaining to ticklish laughter, to inhibited ticklish laughter, and to voluntary laughter revealed regional differences in the levels of neuronal activity in the posterior and mid-/anterior portions of the insula. Ticklish laughter was associated specifically with right ventral anterior insular activity, which was not detected under the other two conditions. Hence, apparently, only laughter that is evoked as an emotional response bears the signature of autonomic arousal in the insular cortex. J. Comp. Neurol. 524:1608-1615, 2016. © 2015 Wiley Periodicals, Inc. PMID:26287648

  4. Neural processing of gustatory information in insular circuits.

    PubMed

    Maffei, Arianna; Haley, Melissa; Fontanini, Alfredo

    2012-08-01

    The insular cortex is the primary cortical site devoted to taste processing. A large body of evidence is available for how insular neurons respond to gustatory stimulation in both anesthetized and behaving animals. Most of the reports describe broadly tuned neurons that are involved in processing the chemosensory, physiological and psychological aspects of gustatory experience. However little is known about how these neural responses map onto insular circuits. Particularly mysterious is the functional role of the three subdivisions of the insular cortex: the granular, the dysgranular and the agranular insular cortices. In this article we review data on the organization of the local and long-distance circuits in the three subdivisions. The functional significance of these results is discussed in light of the latest electrophysiological data. A view of the insular cortex as a functionally integrated system devoted to processing gustatory, multimodal, cognitive and affective information is proposed. PMID:22554880

  5. Insular Cortex Metabolite Changes in Obstructive Sleep Apnea

    PubMed Central

    Yadav, Santosh K.; Kumar, Rajesh; Macey, Paul M.; Woo, Mary A.; Yan-Go, Frisca L.; Harper, Ronald M.

    2014-01-01

    likely indicates increased inflammatory action that may induce more neuronal injury, and suggests separate approaches for glial and neuronal protection. Citation: Yadav SK, Kumar R, Macey PM, Woo MA, Yan-Go FL, Harper RM. Insular cortex metabolite changes in obstructive sleep apnea. SLEEP 2014;37(5):951-958. PMID:24790274

  6. Spatiotemporal dynamics of excitation in rat insular cortex: intrinsic corticocortical circuit regulates caudal-rostro excitatory propagation from the insular to frontal cortex.

    PubMed

    Fujita, S; Adachi, K; Koshikawa, N; Kobayashi, M

    2010-01-13

    The insular cortex (IC), composing unique anatomical connections, receives multi-modal sensory inputs including visceral, gustatory and somatosensory information from sensory thalamic nuclei. Axonal projections from the limbic structures, which have a profound influence on induction of epileptic activity, also converge onto the IC. However, functional connectivity underlying the physiological and pathological roles characteristic to the IC still remains unclear. The present study sought to elucidate the spatiotemporal dynamics of excitatory propagation and their cellular mechanisms in the IC using optical recording in urethane-anesthetized rats. Repetitive electrical stimulations of the IC at 50 Hz demonstrated characteristic patterns of excitatory propagation depending on the stimulation sites. Stimulation of the granular zone of the IC (GI) and other surrounding cortices such as the motor/primary sensory/secondary sensory cortices evoked round-shaped excitatory propagations, which often extended over the borders of adjacent areas, whereas excitation of the agranular and dysgranular zones in the IC (AI and DI, respectively) spread along the rostrocaudal axis parallel to the rhinal fissure. Stimulation of AI/DI often evoked excitation in the dorsolateral orbital cortex, which exhibited spatially discontinuous topography of excitatory propagation in the IC. Pharmacological manipulations using 6,7-dinitroquinoxaline-2,3(1H,4H)-dione (DNQX), a non-NMDA receptor antagonist, D-2-amino-5-phosphonovaleric acid (D-APV), an NMDA receptor antagonist, and bicuculline methiodide, a GABA(A) receptor antagonist, indicate that excitatory propagation was primarily regulated by non-NMDA and GABA(A) receptors. Microinjection of lidocaine or incision of the supragranular layers of the rostrocaudally middle part of excitatory regions suppressed excitation in the remote regions from the stimulation site, suggesting that the excitatory propagation in the IC is largely mediated by

  7. Altered functional connectivity of the insular cortex across prefrontal networks in cocaine addiction.

    PubMed

    Cisler, Josh M; Elton, Amanda; Kennedy, Ashley P; Young, Jonathan; Smitherman, Sonet; Andrew James, George; Kilts, Clinton D

    2013-07-30

    Interoception is theorized to be an important process mediating substance use disorders, and the insular cortex is recognized as a core neural region supporting interoception. The purpose of this study was to compare the integration of the insular cortex into prefrontal-related resting-state networks between individuals with cocaine dependence and healthy controls. Participants comprised 41 patients with cocaine dependence and 19 controls who underwent a resting-state 3-T functional magnetic resonance imaging scan. Individuals with cocaine dependence demonstrated altered functional connectivity of the insular cortex, predominantly the right insular cortex, with all eight prefrontal-related resting-state networks identified through Independent Component Analysis (ICA). A conjunction analysis demonstrated that the right insular cortex was the neural region with the highest number of common group differences across the networks. There was no evidence that insular cortex connectivity commonly differed between groups for non-prefrontal-related networks. Further, seed-based functional connectivity analyses extended the network analyses and indicated that cocaine dependence was associated with greater connectivity of the right insula with the dorsomedial prefrontal cortex, inferior frontal gyrus, and bilateral dorsolateral prefrontal cortex. These data support the hypothesis that cocaine dependence is related to altered functional interactions of the insular cortex with prefrontal networks. The results suggest possible neural mechanisms by which the insular cortex and interoceptive information influence cognitive control and decision-making processes presumably mediated by prefrontal networks in the cocaine dependence process. PMID:23684980

  8. Altered Functional Connectivity of the Insular Cortex across Prefrontal Networks in Cocaine Addiction

    PubMed Central

    Cisler, Josh M.; Elton, Amanda; Kennedy, Ashley P.; Young, Jonathan; Smitherman, Sonet; James, George Andrew; Kilts, Clinton D.

    2013-01-01

    Interoception is theorized to be an important process mediating substance use disorders, and the insular cortex is recognized as a core neural region supporting interoception. The purpose of this study was to compare the integration of the insular cortex into prefrontal-related resting-state networks between individuals with cocaine dependence and healthy controls. 41 participants with cocaine dependence and 19 control participants underwent a resting-state 3T fMRI scan. Individuals with cocaine dependence demonstrated altered functional connectivity of the insular cortex, predominantly the right insular cortex, with all eight prefrontal-related resting-state networks identified through Independent Component Analysis (ICA). A conjunction analysis demonstrated that the right insular cortex was the neural region with the highest number of common group differences across the networks. There was no evidence that insular cortex connectivity commonly differed between groups for non-prefrontal-related networks. Further, seed-based functional connectivity analyses extended the network analyses and indicated that cocaine dependence was associated with greater connectivity of the right insula with the dorsomedial PFC, inferior frontal gyrus, and bilateral dlPFC. These data support the hypothesis that cocaine dependence is related to altered functional interactions of the insular cortex with prefrontal networks. The results suggest possible neural mechanisms by which the insular cortex and interoceptive information influence cognitive control and decision-making processes presumably mediated by prefrontal networks in the cocaine dependence process. PMID:23684980

  9. Gustatory insular cortex, aversive taste memory and taste neophobia

    PubMed Central

    Lin, Jian-You; Arthurs, Joe; Reilly, Steve

    2015-01-01

    Prior research indicates a role for the gustatory insular cortex (GC) in taste neophobia. Rats with lesions of the GC show much weaker avoidance to a novel and potentially dangerous taste than do neurologically intact animals. The current study used the retention of conditioned taste aversion (CTA) as a tool to determine whether the GC modulates neophobia by processing taste novelty or taste danger. The results show that GC lesions attenuate CTA retention (Experiment 1) and impair taste neophobia (Experiment 2). Given that normal CTA retention does not involve the processing of taste novelty, the pattern of results suggests that the GC is involved in taste neophobia via its function in processing the danger conveyed by a taste stimulus. PMID:25617666

  10. Insular Cortex and Consummatory Successive Negative Contrast in the Rat

    PubMed Central

    Lin, Jian-You; Roman, Christopher; Reilly, Steve

    2009-01-01

    Rats that are expecting a high value reward (e.g., 1.0 M sucrose) show an exaggerated underresponding when they are instead given a low value reward (e.g., 0.15% saccharin), an effect termed successive negative contrast (SNC). In the present experiment, insular cortex-lesioned (ICX) rats showed normal responsivity to sucrose and saccharin prior to the reward downshift. However, when switched from sucrose to saccharin during the postshift trials these rats displayed no evidence of SNC. Indeed, over the downshift trials these ICX rats consistently drank more saccharin than the ICX rats maintained on saccharin throughout the experiment. Potential interpretations are discussed including a lesion-induced impairment in the ability to accurately recognize the novelty of the postshift saccharin stimulus. PMID:19634939

  11. Roles of the Insular Cortex in the Modulation of Pain: Insights from Brain Lesions

    PubMed Central

    Starr, Christopher J.; Sawaki, Lumy; Wittenberg, George F.; Burdette, Jonathan H.; Oshiro, Yoshitetsu; Quevedo, Alexandre S.; Coghill, Robert C.

    2009-01-01

    Subjective sensory experiences are constructed by the integration of afferent sensory information with information about the uniquely personal internal cognitive state. The insular cortex is anatomically positioned to serve as one potential interface between afferent processing mechanisms and more cognitively-oriented modulatory systems. However, the role of the insular cortex in such modulatory processes remain poorly understood. Two individuals with extensive lesions to the insula were examined to better understand the contribution of this brain region to the generation of subjective sensory experiences. Despite substantial differences in the extent of the damage to the insular cortex, three findings were common to both individuals. First, both subjects had substantially higher pain intensity ratings of acute experimental noxious stimuli than age-matched control subjects. Second, when pain-related activation of the primary somatosensory cortex was examined during left and right-sided stimulation, both individuals exhibited dramatically elevated activity of the primary somatosensory cortex ipsilateral to the lesioned insula in relation to healthy control subjects. Finally, both individuals retained the ability to evaluate pain despite substantial insular damage and no evidence of detectible insular activity. Taken together, these results indicate that the insula may be importantly involved in tuning cortical regions to appropriately utilize prior cognitive information during afferent processing. Finally, these data suggest that a subjectively available experience of pain can be instantiated by brain mechanisms that do not require the insular cortex. PMID:19261863

  12. Differential Effects of Insular and Ventromedial Prefrontal Cortex Lesions on Risky Decision-Making

    ERIC Educational Resources Information Center

    Clark, L.; Bechara, A.; Damasio, H.; Aitken, M. R. F.; Sahakian, B. J.; Robbins, T. W.

    2008-01-01

    The ventromedial prefrontal cortex (vmPFC) and insular cortex are implicated in distributed neural circuitry that supports emotional decision-making. Previous studies of patients with vmPFC lesions have focused primarily on decision-making under uncertainty, when outcome probabilities are ambiguous (e.g. the Iowa Gambling Task). It remains unclear…

  13. Conditioned place preference induced by electrical stimulation of the insular cortex: effects of naloxone.

    PubMed

    García, Raquel; Simón, María J; Puerto, Amadeo

    2013-04-01

    The insular cortex has been related to various sensory, regulatory, and learning processes, which frequently include affective-emotional components. The objective of this study was to investigate the possibility of inducing reinforcing effects by electrical stimulation of this cortical region in Wistar rats. Concurrent conditioned place preference tasks were conducted for this purpose, using two rectangular mazes that differed in dimensions, texture, and spatial orientation. A significant correlation was found in the preferences induced by insular cortex electrical stimulation between the two mazes. Animals showed consistent preference or avoidance behaviors associated with simultaneous insular cortex stimulation. No electrical self-stimulation was achieved. In a second experiment, animals that showed consistent place preference after the simultaneous insular cortex electrical stimulation were administered with 4 mg/ml/kg of naloxone. The results revealed that this opiate antagonist blocked concurrent place preference learning when the task was conducted in a new maze but not when it was conducted in the same maze as that in which the animals had learned the task. These results are discussed in terms of the participation of the insular cortex in various reward and aversion modalities. PMID:23377149

  14. A Rapid Sound-Action Association Effect in Human Insular Cortex

    PubMed Central

    Schulze-Bonhage, Andreas; Glauche, Volkmar; Demandt, Evariste; Speck, Oliver

    2007-01-01

    Background Learning to play a musical piece is a prime example of complex sensorimotor learning in humans. Recent studies using electroencephalography (EEG) and transcranial magnetic stimulation (TMS) indicate that passive listening to melodies previously rehearsed by subjects on a musical instrument evokes differential brain activation as compared with unrehearsed melodies. These changes were already evident after 20–30 minutes of training. The exact brain regions involved in these differential brain responses have not yet been delineated. Methodology/Principal Finding Using functional MRI (fMRI), we investigated subjects who passively listened to simple piano melodies from two conditions: In the ‘actively learned melodies’ condition subjects learned to play a piece on the piano during a short training session of a maximum of 30 minutes before the fMRI experiment, and in the ‘passively learned melodies’ condition subjects listened passively to and were thus familiarized with the piece. We found increased fMRI responses to actively compared with passively learned melodies in the left anterior insula, extending to the left fronto-opercular cortex. The area of significant activation overlapped the insular sensorimotor hand area as determined by our meta-analysis of previous functional imaging studies. Conclusions/Significance Our results provide evidence for differential brain responses to action-related sounds after short periods of learning in the human insular cortex. As the hand sensorimotor area of the insular cortex appears to be involved in these responses, re-activation of movement representations stored in the insular sensorimotor cortex may have contributed to the observed effect. The insular cortex may therefore play a role in the initial learning phase of action-perception associations. PMID:17327919

  15. Mindfulness training modulates value signals in ventromedial prefrontal cortex through input from insular cortex

    PubMed Central

    Kirk, Ulrich; Gu, Xiaosi; Harvey, Ann H.; Fonagy, Peter; Montague, P. Read

    2014-01-01

    Neuroimaging research has demonstrated that ventromedial prefrontal cortex (vmPFC) encodes value signals that can be modulated by top-down cognitive input such as semantic knowledge, price incentives, and monetary favors suggesting that such biases may have an identified biological basis. It has been hypothesized that mindfulness training (MT) provides one path for gaining control over such top-down influences; yet, there have been no direct tests of this hypothesis. Here, we probe the behavioral and neural effects of MT on value signals in vmPFC in a randomized longitudinal design of 8 weeks of MT on an initially naïve subject cohort. The impact of this within-subject training was assessed using two paradigms: one that employed primary rewards (fruit juice) in a simple conditioning task and another that used a well-validated art-viewing paradigm to test bias of monetary favors on preference. We show that MT behaviorally censors the top-down bias of monetary favors through a measurable influence on value signals in vmPFC. MT also modulates value signals in vmPFC to primary reward delivery. Using a separate cohort of subjects we show that 8 weeks of active control training (ACT) generates the same behavioral impact also through an effect on signals in the vmPFC. Importantly, functional connectivity analyses show that value signals in vmPFC are coupled with bilateral posterior insula in the MT groups in both paradigms, but not in the ACT groups. These results suggest that MT integrates interoceptive input from insular cortex in the context of value computations of both primary and secondary rewards. PMID:24956066

  16. Activation of the insular cortex is affected by the intensity of exercise.

    PubMed

    Williamson, J W; McColl, R; Mathews, D; Ginsburg, M; Mitchell, J H

    1999-09-01

    The purpose of this investigation was to determine whether there were differences in the magnitude of insular cortex activation across varying intensities of static and dynamic exercise. Eighteen healthy volunteers were studied: eight during two intensities of leg cycling and ten at different time periods during sustained static handgrip at 25% maximal voluntary contraction or postexercise cuff occlusion. Heart rate, blood pressure (BP), perceived exertion, and regional cerebral blood flow (rCBF) distribution data were collected. There were significantly greater increases in insular rCBF during lower (6.3 +/- 1.7%; P < 0.05) and higher (13.3 +/- 3.8%; P < 0.05) intensity cycling and across time during static handgrip (change from rest for right insula at 2-3 min, 3.8 +/- 1.1%, P < 0.05; and at 4-5 min, 8.6 +/- 2.8%, P < 0.05). Insular rCBF was decreased during postexercise cuff occlusion (-5.5 +/- 1.2%; P < 0.05) with BP sustained at exercise levels. Right insular rCBF data, but not left, were significantly related, with individual BP changes (r(2) = 0.80; P < 0.001) and with ratings of perceived exertion (r(2) = 0.79; P < 0.01) during exercise. These results suggest that the magnitude of insular activation varies with the intensity of exercise, which may be further related to the level of perceived effort or central command. PMID:10484598

  17. Node Detection Using High-Dimensional Fuzzy Parcellation Applied to the Insular Cortex

    PubMed Central

    Vercelli, Ugo; Diano, Matteo; Costa, Tommaso; Nani, Andrea; Duca, Sergio; Geminiani, Giuliano; Vercelli, Alessandro; Cauda, Franco

    2016-01-01

    Several functional connectivity approaches require the definition of a set of regions of interest (ROIs) that act as network nodes. Different methods have been developed to define these nodes and to derive their functional and effective connections, most of which are rather complex. Here we aim to propose a relatively simple “one-step” border detection and ROI estimation procedure employing the fuzzy c-mean clustering algorithm. To test this procedure and to explore insular connectivity beyond the two/three-region model currently proposed in the literature, we parcellated the insular cortex of 20 healthy right-handed volunteers scanned in a resting state. By employing a high-dimensional functional connectivity-based clustering process, we confirmed the two patterns of connectivity previously described. This method revealed a complex pattern of functional connectivity where the two previously detected insular clusters are subdivided into several other networks, some of which are not commonly associated with the insular cortex, such as the default mode network and parts of the dorsal attentional network. Furthermore, the detection of nodes was reliable, as demonstrated by the confirmative analysis performed on a replication group of subjects. PMID:26881093

  18. Node Detection Using High-Dimensional Fuzzy Parcellation Applied to the Insular Cortex.

    PubMed

    Vercelli, Ugo; Diano, Matteo; Costa, Tommaso; Nani, Andrea; Duca, Sergio; Geminiani, Giuliano; Vercelli, Alessandro; Cauda, Franco

    2016-01-01

    Several functional connectivity approaches require the definition of a set of regions of interest (ROIs) that act as network nodes. Different methods have been developed to define these nodes and to derive their functional and effective connections, most of which are rather complex. Here we aim to propose a relatively simple "one-step" border detection and ROI estimation procedure employing the fuzzy c-mean clustering algorithm. To test this procedure and to explore insular connectivity beyond the two/three-region model currently proposed in the literature, we parcellated the insular cortex of 20 healthy right-handed volunteers scanned in a resting state. By employing a high-dimensional functional connectivity-based clustering process, we confirmed the two patterns of connectivity previously described. This method revealed a complex pattern of functional connectivity where the two previously detected insular clusters are subdivided into several other networks, some of which are not commonly associated with the insular cortex, such as the default mode network and parts of the dorsal attentional network. Furthermore, the detection of nodes was reliable, as demonstrated by the confirmative analysis performed on a replication group of subjects. PMID:26881093

  19. Variable temporo-insular cortex neuroanatomy in primates suggests a bottleneck effect in eastern gorillas

    PubMed Central

    Barks, Sarah K.; Bauernfeind, Amy L.; Bonar, Christopher J.; Cranfield, Michael R.; de Sousa, Alexandra A.; Erwin, Joseph M.; Hopkins, William D.; Lewandowski, Albert H.; Mudakikwa, Antoine; Phillips, Kimberley A.; Raghanti, Mary Ann; Stimpson, Cheryl D.; Hof, Patrick R.; Zilles, Karl; Sherwood, Chet C.

    2013-01-01

    In this study, we describe an atypical neuroanatomical feature present in several primate species that involves a fusion between the temporal lobe (often including Heschl’s gyrus in great apes) and the posterior dorsal insula, such that a portion of insular cortex forms an isolated pocket medial to the Sylvian fissure. We assessed the frequency of this fusion in 56 primate species (including apes, Old World monkeys, New World monkeys, and strepsirrhines) using either magnetic resonance images or histological sections. A fusion between temporal cortex and posterior insula was present in 22 species (7 apes, 2 Old World monkeys, 4 New World monkeys, and 9 strepsirrhines). The temporo-insular fusion was observed in most eastern gorilla (Gorilla beringei beringei and G. b. graueri) specimens (62% and 100% of cases, respectively) but less frequently in other great apes and was never found in humans. We further explored the histology of this fusion in eastern gorillas by examining the cyto- and myeloarchitecture within this region, and observed that the degree to which deep cortical layers and white matter are incorporated into the fusion varies among individuals within a species. We suggest that fusion between temporal and insular cortex is an example of a relatively rare neuroanatomical feature that has become more common in eastern gorillas, possibly as the result of a population bottleneck effect. Characterizing the phylogenetic distribution of this morphology highlights a derived feature of these great apes. PMID:23939630

  20. The Insular Cortex and the Regulation of Cardiac Function.

    PubMed

    Oppenheimer, Stephen; Cechetto, David

    2016-04-01

    Cortical representation of the heart challenges the orthodox view that cardiac regulation is confined to stereotyped, preprogrammed and rigid responses to exteroceptive or interoceptive environmental stimuli. The insula has been the region most studied in this regard; the results of clinical, experimental, and functional radiological studies show a complex interweave of activity with patterns dynamically varying regarding lateralization and antero-posterior distribution of responsive insular regions. Either acting alone or together with other cortical areas including the anterior cingulate, medial prefrontal, and orbito-frontal cortices as part of a concerted network, the insula can imbue perceptions with autonomic color providing emotional salience, and aiding in learning and behavioral decision choice. In these functions, cardiovascular input and the right anterior insula appear to play an important, if not pivotal role. At a more basic level, the insula gauges cardiovascular responses to exteroceptive and interoceptive stimuli, taking into account memory, cognitive, and reflexive constructs thereby ensuring appropriate survival responses and maintaining emotional and physiological homeostasis. When acquired derangements to the insula occur after stroke, during a seizure or from abnormal central processing of interoceptive or exteroceptive environmental cues as in psychiatric disorders, serious consequences can arise including cardiac electrophysiological, structural and contractile dysfunction and sudden cardiac death. PMID:27065176

  1. Anterior insular cortex activity to emotional salience of voices in a passive oddball paradigm

    PubMed Central

    Chen, Chenyi; Lee, Yu-Hsuan; Cheng, Yawei

    2014-01-01

    The human voice, which has a pivotal role in communication, is processed in specialized brain regions. Although a general consensus holds that the anterior insular cortex (AIC) plays a critical role in negative emotional experience, previous studies have not observed AIC activation in response to hearing disgust in voices. We used magnetoencephalography to measure the magnetic counterparts of mismatch negativity (MMNm) and P3a (P3am) in healthy adults while the emotionally meaningless syllables dada, spoken as neutral, happy, or disgusted prosodies, along with acoustically matched simple and complex tones, were presented in a passive oddball paradigm. The results revealed that disgusted relative to happy syllables elicited stronger MMNm-related cortical activities in the right AIC and precentral gyrus along with the left posterior insular cortex, supramarginal cortex, transverse temporal cortex, and upper bank of superior temporal cortex. The AIC activity specific to disgusted syllables (corrected p < 0.05) was associated with the hit rate of the emotional categorization task. These findings may clarify the neural correlates of emotional MMNm and lend support to the role of AIC in the processing of emotional salience already at the preattentive level. PMID:25346670

  2. Anterior insular cortex regulation in autism spectrum disorders.

    PubMed

    Caria, Andrea; de Falco, Simona

    2015-01-01

    Autism spectrum disorders (ASDs) comprise a heterogeneous set of neurodevelopmental disorders characterized by dramatic impairments of interpersonal behavior, communication, and empathy. Recent neuroimaging studies suggested that ASD are disorders characterized by widespread abnormalities involving distributed brain network, though clear evidence of differences in large-scale brain network interactions underlying the cognitive and behavioral symptoms of ASD are still lacking. Consistent findings of anterior insula cortex hypoactivation and dysconnectivity during tasks related to emotional and social processing indicates its dysfunctional role in ASD. In parallel, increasing evidence showed that successful control of anterior insula activity can be attained using real-time fMRI paradigms. More importantly, successful regulation of this region was associated with changes in behavior and brain connectivity in both healthy individuals and psychiatric patients. Building on these results we here propose and discuss the use of real-time fMRI neurofeedback in ASD aiming at improving emotional and social behavior. PMID:25798096

  3. Anterior insular cortex regulation in autism spectrum disorders

    PubMed Central

    Caria, Andrea; de Falco, Simona

    2015-01-01

    Autism spectrum disorders (ASDs) comprise a heterogeneous set of neurodevelopmental disorders characterized by dramatic impairments of interpersonal behavior, communication, and empathy. Recent neuroimaging studies suggested that ASD are disorders characterized by widespread abnormalities involving distributed brain network, though clear evidence of differences in large-scale brain network interactions underlying the cognitive and behavioral symptoms of ASD are still lacking. Consistent findings of anterior insula cortex hypoactivation and dysconnectivity during tasks related to emotional and social processing indicates its dysfunctional role in ASD. In parallel, increasing evidence showed that successful control of anterior insula activity can be attained using real-time fMRI paradigms. More importantly, successful regulation of this region was associated with changes in behavior and brain connectivity in both healthy individuals and psychiatric patients. Building on these results we here propose and discuss the use of real-time fMRI neurofeedback in ASD aiming at improving emotional and social behavior. PMID:25798096

  4. Hyperacusis following unilateral damage to the insular cortex: a three-case report.

    PubMed

    Boucher, Olivier; Turgeon, Christine; Champoux, Sara; Ménard, Lucie; Rouleau, Isabelle; Lassonde, Maryse; Lepore, Franco; Nguyen, Dang K

    2015-05-01

    The insula is a multisensory area involved in various brain functions, including central auditory processing. However, its specific role in auditory function remains unclear. Here we report three cases of persistent hypersensitivity to auditory stimuli following damage to the insular cortex, using behavioral and neurophysiological measures. Two patients who complained of auditory disturbance since they suffered an isolated unilateral insular stroke, and one epileptic patient who underwent right insular resection for control of drug-resistant seizures, were involved in this study. These patients, all young adult women, were tested for auditory function more than one year after brain injury, and were compared to 10 healthy control participants matched for age, sex, and education. The assessment included pure-tone detection and speech detection in quiet, loudness discomfort levels, random gap detection, recognition of frequency and duration patterns, binaural separation, dichotic listening, as well as late-latency auditory event-related potentials (ERPs). Each patient showed mild or moderate hyperacusis, as revealed by decreased loudness discomfort levels, which was more important on the side of lesion in two cases. Tests of temporal processing also revealed impairments, in concordance with previous findings. ERPs of two patients were characterised by increased amplitude of the P3b component elicited during a two-tone auditory oddball detection task. This study is the first to report cases of persistent hyperacusis following damage to the insular cortex, and suggests that the insula is involved in modulating the perceived intensity of the incoming auditory stimuli during late-stage processing. PMID:25721796

  5. Corticotrigeminal Projections from the Insular Cortex to the Trigeminal Caudal Subnucleus Regulate Orofacial Pain after Nerve Injury via Extracellular Signal-Regulated Kinase Activation in Insular Cortex Neurons

    PubMed Central

    Wang, Jian; Li, Zhi-Hua; Feng, Ban; Zhang, Ting; Zhang, Han; Li, Hui; Chen, Tao; Cui, Jing; Zang, Wei-Dong; Li, Yun-Qing

    2015-01-01

    Cortical neuroplasticity alterations are implicated in the pathophysiology of chronic orofacial pain. However, the relationship between critical cortex excitability and orofacial pain maintenance has not been fully elucidated. We recently demonstrated a top-down corticospinal descending pain modulation pathway from the anterior cingulate cortex (ACC) to the spinal dorsal horn that could directly regulate nociceptive transmission. Thus, we aimed to investigate possible corticotrigeminal connections that directly influence orofacial nociception in rats. Infraorbital nerve chronic constriction injury (IoN-CCI) induced significant orofacial nociceptive behaviors as well as pain-related negative emotions such as anxiety/depression in rats. By combining retrograde and anterograde tract tracing, we found powerful evidence that the trigeminal caudal subnucleus (Vc), especially the superficial laminae (I/II), received direct descending projections from granular and dysgranular parts of the insular cortex (IC). Extracellular signal-regulated kinase (ERK), an important signaling molecule involved in neuroplasticity, was significantly activated in the IC following IoN-CCI. Moreover, in IC slices from IoN-CCI rats, U0126, an inhibitor of ERK activation, decreased both the amplitude and the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) and reduced the paired-pulse ratio (PPR) of Vc-projecting neurons. Additionally, U0126 also reduced the number of action potentials in the Vc-projecting neurons. Finally, intra-IC infusion of U0126 obviously decreased Fos expression in the Vc, accompanied by the alleviation of both nociceptive behavior and negative emotions. Thus, the corticotrigeminal descending pathway from the IC to the Vc could directly regulate orofacial pain, and ERK deactivation in the IC could effectively alleviate neuropathic pain as well as pain-related negative emotions in IoN-CCI rats, probably through this top–down pathway. These findings may

  6. Direction-dependent activation of the insular cortex during vertical and horizontal hand movements.

    PubMed

    Rousseau, C; Fautrelle, L; Papaxanthis, C; Fadiga, L; Pozzo, T; White, O

    2016-06-14

    The planning of any motor action requires a complex multisensory processing by the brain. Gravity - immutable on Earth - has been shown to be a key input to these mechanisms. Seminal fMRI studies performed during visual perception of falling objects and self-motion demonstrated that humans represent the action of gravity in parts of the cortical vestibular system; in particular, the insular cortex and the cerebellum. However, little is known as to whether a specific neural network is engaged when processing non-visual signals relevant to gravity. We asked participants to perform vertical and horizontal hand movements without visual control, while lying in a 3T-MRI scanner. We highlighted brain regions activated in the processing of vertical movements, for which the effects of gravity changed during execution. Precisely, the left insula was activated in vertical movements and not in horizontal movements. Moreover, the network identified by contrasting vertical and horizontal movements overlapped with neural correlates previously associated to the processing of simulated self-motion and visual perception of the vertical direction. Interestingly, we found that the insular cortex activity is direction-dependent which suggests that this brain region processes the effects of gravity on the moving limbs through non-visual signals. PMID:27001175

  7. Structural basis of empathy and the domain general region in the anterior insular cortex

    PubMed Central

    Mutschler, Isabella; Reinbold, Céline; Wankerl, Johanna; Seifritz, Erich; Ball, Tonio

    2013-01-01

    Empathy is key for healthy social functioning and individual differences in empathy have strong implications for manifold domains of social behavior. Empathy comprises of emotional and cognitive components and may also be closely linked to sensorimotor processes, which go along with the motivation and behavior to respond compassionately to another person's feelings. There is growing evidence for local plastic change in the structure of the healthy adult human brain in response to environmental demands or intrinsic factors. Here we have investigated changes in brain structure resulting from or predisposing to empathy. Structural MRI data of 101 healthy adult females was analyzed. Empathy in fictitious as well as real-life situations was assessed using a validated self-evaluation measure. Furthermore, empathy-related structural effects were also put into the context of a functional map of the anterior insular cortex (AIC) determined by activation likelihood estimate (ALE) meta-analysis of previous functional imaging studies. We found that gray matter (GM) density in the left dorsal AIC correlates with empathy and that this area overlaps with the domain general region (DGR) of the anterior insula that is situated in-between functional systems involved in emotion–cognition, pain, and motor tasks as determined by our meta-analysis. Thus, we propose that this insular region where we find structural differences depending on individual empathy may play a crucial role in modulating the efficiency of neural integration underlying emotional, cognitive, and sensorimotor information which is essential for global empathy. PMID:23675334

  8. Morphine-induced suppression of conditioned stimulus intake: Effects of stimulus type and insular cortex lesions

    PubMed Central

    Lin, Jian-You; Roman, Christopher; Reilly, Steve

    2009-01-01

    Intake of an unconditionally preferred taste stimulus (e.g., saccharin) is reduced by contingent administration of a drug of abuse (e.g., morphine). We examined the influence of insular cortex (IC) lesions on morphine-induced suppression of an olfactory cue and two taste stimuli with different levels of perceived innate reward value. Two major findings emerged from this study. First, morphine suppressed intake of an aqueous odor as well as each taste stimulus in neurologically intact rats. Second, IC lesions disrupted morphine-induced suppression of the taste stimuli but not the aqueous odor cue. These results indicate that the perceived innate reward value of the CS is not a factor that governs drug-induced intake suppression. PMID:19631620

  9. Insular Cortex is Critical for the Perception, Modulation, and Chronification of Pain.

    PubMed

    Lu, Changbo; Yang, Tao; Zhao, Huan; Zhang, Ming; Meng, Fancheng; Fu, Hao; Xie, Yingli; Xu, Hui

    2016-04-01

    An increasing body of neuroimaging and electrophysiological studies of the brain suggest that the insular cortex (IC) integrates multimodal salient information ranging from sensation to cognitive-affective events to create conscious interoception. Especially with regard to pain experience, the IC has been supposed to participate in both sensory-discriminative and affective-motivational aspects of pain. In this review, we discuss the latest data proposing that subregions of the IC are involved in isolated pain networks: the posterior sensory circuit and the anterior emotional network. Due to abundant connections with other brain areas, the IC is likely to serve as an interface where cross-modal shaping of pain occurs. In chronic pain, however, this mode of emotional awareness and the modulation of pain are disrupted. We highlight some of the molecular mechanisms underlying the changes of the pain modulation system that contribute to the transition from acute to chronic pain in the IC. PMID:26898298

  10. Dopaminergic and serotonergic modulation of anterior insular and orbitofrontal cortex function in risky decision making.

    PubMed

    Ishii, Hironori; Ohara, Shinya; Tobler, Philippe N; Tsutsui, Ken-Ichiro; Iijima, Toshio

    2015-03-01

    Systemic manipulations have shown that dopamine and serotonin systems are involved in risky decision making. However, how they work within the regions that implement risky choices remains unclear. The present study investigated the role of dopamine and serotonin in the rat anterior insular cortex (AIC) and orbitofrontal cortex (OFC), which make different contributions to risky decision making. We examined the effects of local injection of the D1 (SCH23390), D2 (eticlopride), 5-HT1A (WAY100635) and 5-HT2A (M100907) receptor antagonists into the AIC or OFC on risk preference in a gambling task. We found that different dopamine and serotonin receptor subtypes in the AIC and OFC differentially influence risky decision making: intra-AIC injection of D2R or 5-HT1AR blockers increased risk preference whereas intra-OFC injection of the 5-HT1AR blocker decreased it. Risk preference was not altered by intra-AIC injection of D1R and 5-HT2AR blockers or by intra-OFC injection of D1R, D2R, and 5-HT2AR blockers. Furthermore, additional analyses revealed that dopamine and serotonin signaling in the AIC have outcome history-dependent effects on risk taking: intra-AIC injection of the D2R blocker increased risk preference particularly after winning in a previous risky choice, whereas intra-AIC injection of the 5-HT1AR blocker increased risk preference after losing. PMID:25481848

  11. Sex Differences in Insular Cortex Gyri Responses to the Valsalva Maneuver.

    PubMed

    Macey, Paul M; Rieken, Nicholas S; Kumar, Rajesh; Ogren, Jennifer A; Middlekauff, Holly R; Wu, Paula; Woo, Mary A; Harper, Ronald M

    2016-01-01

    Sex differences in autonomic regulation may underlie cardiovascular disease variations between females and males. One key autonomic brain region is the insular cortex, which typically consists of five main gyri in each hemisphere, and shows a topographical organization of autonomic function across those gyri. The present study aims to identify possible sex differences in organization of autonomic function in the insula. We studied brain functional magnetic resonance imaging (fMRI) responses to a series of four 18-s Valsalva maneuvers in 22 healthy females (age ± SD: 50.0 ± 7.9 years) and 36 healthy males (45.3 ± 9.2 years). Comparisons of heart rate (HR) and fMRI signals were performed with repeated measures ANOVA (threshold P < 0.05 for all findings). All subjects achieved the target 30 mmHg expiratory pressure for all challenges. Typical HR responses were elicited by the maneuver, including HR increases from ~4 s into the strain period (Phase II) and rapid declines to below baseline 5-10 s, following strain release (Phase IV). Small, but significant, sex differences in HR percent change occurred during the sympathetic-dominant Phase II (female < male) and parasympathetic-dominant Phase IV (female > male, i.e., greater undershoot in males). The insular cortices showed similar patterns in all gyri, with greater signal decreases in males than females. Both sexes exhibited an anterior-posterior topographical organization of insular responses during Phase II, with anterior gyri showing higher responses than more posterior gyri. The exception was the right anterior-most gyrus in females, which had lower responses than the four other right gyri. Responses were lateralized, with right-sided dominance during Phase II in both sexes, except the right anterior-most gyrus in females, which showed lower responses than the left. The findings confirm the anterior and right-sided sympathetic dominance of the insula. Although sex differences

  12. Sex Differences in Insular Cortex Gyri Responses to the Valsalva Maneuver

    PubMed Central

    Macey, Paul M.; Rieken, Nicholas S.; Kumar, Rajesh; Ogren, Jennifer A.; Middlekauff, Holly R.; Wu, Paula; Woo, Mary A.; Harper, Ronald M.

    2016-01-01

    Sex differences in autonomic regulation may underlie cardiovascular disease variations between females and males. One key autonomic brain region is the insular cortex, which typically consists of five main gyri in each hemisphere, and shows a topographical organization of autonomic function across those gyri. The present study aims to identify possible sex differences in organization of autonomic function in the insula. We studied brain functional magnetic resonance imaging (fMRI) responses to a series of four 18-s Valsalva maneuvers in 22 healthy females (age ± SD: 50.0 ± 7.9 years) and 36 healthy males (45.3 ± 9.2 years). Comparisons of heart rate (HR) and fMRI signals were performed with repeated measures ANOVA (threshold P < 0.05 for all findings). All subjects achieved the target 30 mmHg expiratory pressure for all challenges. Typical HR responses were elicited by the maneuver, including HR increases from ~4 s into the strain period (Phase II) and rapid declines to below baseline 5–10 s, following strain release (Phase IV). Small, but significant, sex differences in HR percent change occurred during the sympathetic-dominant Phase II (female < male) and parasympathetic-dominant Phase IV (female > male, i.e., greater undershoot in males). The insular cortices showed similar patterns in all gyri, with greater signal decreases in males than females. Both sexes exhibited an anterior–posterior topographical organization of insular responses during Phase II, with anterior gyri showing higher responses than more posterior gyri. The exception was the right anterior-most gyrus in females, which had lower responses than the four other right gyri. Responses were lateralized, with right-sided dominance during Phase II in both sexes, except the right anterior-most gyrus in females, which showed lower responses than the left. The findings confirm the anterior and right-sided sympathetic dominance of the insula. Although sex

  13. Parental Praise Correlates with Posterior Insular Cortex Gray Matter Volume in Children and Adolescents

    PubMed Central

    Matsudaira, Izumi; Yokota, Susumu; Hashimoto, Teruo; Takeuchi, Hikaru; Asano, Kohei; Asano, Michiko; Sassa, Yuko; Taki, Yasuyuki; Kawashima, Ryuta

    2016-01-01

    A positive parenting style affects psychological and cognitive development in children. Neuroimaging studies revealed that a positive parenting style influenced brain structure in children. Parental praise is a concrete behavior observed in positive parenting. Although previous psychological studies revealed a positive effect of parental praise on children, little is known about the relationship between parental praise and brain structure in children. Thus, the purpose of the present study was to determine whether there was a correlation between the parental attitude towards praising their child and gray matter volume in the children (116 boys and 109 girls; mean age, 10.6 years old). We examined the correlation between regional gray matter volume and parental praise using voxel-based morphometry (VBM) following magnetic resonance imaging (MRI). In addition, to confirm the positive effects of parental praise, we analyzed the correlation between the frequency of parental praise and personality traits in children. We showed that the parental attitude towards praising their child was significantly and positively correlated with the gray matter volume of the left posterior insular cortex in children. Moreover, we found a significant positive correlation between parental attitude towards praising their child and the personality traits of conscientiousness and openness to experience in the children. Prior studies said that gray matter volume in the posterior insula was correlated with empathy, and the functional connectivity between this area and the amygdala was associated with emotional regulation. Furthermore, the posterior insula relates to auditory function, and therefore, was likely involved in the processing of parental praise. Considering the possibility of experience-dependent plasticity, frequent parental praise would lead to increased posterior insular gray matter volume in children. Our study is the first to elucidate the relationship between a specific

  14. Parental Praise Correlates with Posterior Insular Cortex Gray Matter Volume in Children and Adolescents.

    PubMed

    Matsudaira, Izumi; Yokota, Susumu; Hashimoto, Teruo; Takeuchi, Hikaru; Asano, Kohei; Asano, Michiko; Sassa, Yuko; Taki, Yasuyuki; Kawashima, Ryuta

    2016-01-01

    A positive parenting style affects psychological and cognitive development in children. Neuroimaging studies revealed that a positive parenting style influenced brain structure in children. Parental praise is a concrete behavior observed in positive parenting. Although previous psychological studies revealed a positive effect of parental praise on children, little is known about the relationship between parental praise and brain structure in children. Thus, the purpose of the present study was to determine whether there was a correlation between the parental attitude towards praising their child and gray matter volume in the children (116 boys and 109 girls; mean age, 10.6 years old). We examined the correlation between regional gray matter volume and parental praise using voxel-based morphometry (VBM) following magnetic resonance imaging (MRI). In addition, to confirm the positive effects of parental praise, we analyzed the correlation between the frequency of parental praise and personality traits in children. We showed that the parental attitude towards praising their child was significantly and positively correlated with the gray matter volume of the left posterior insular cortex in children. Moreover, we found a significant positive correlation between parental attitude towards praising their child and the personality traits of conscientiousness and openness to experience in the children. Prior studies said that gray matter volume in the posterior insula was correlated with empathy, and the functional connectivity between this area and the amygdala was associated with emotional regulation. Furthermore, the posterior insula relates to auditory function, and therefore, was likely involved in the processing of parental praise. Considering the possibility of experience-dependent plasticity, frequent parental praise would lead to increased posterior insular gray matter volume in children. Our study is the first to elucidate the relationship between a specific

  15. Learning touch preferences with a tactile robot using dopamine modulated STDP in a model of insular cortex

    PubMed Central

    Chou, Ting-Shuo; Bucci, Liam D.; Krichmar, Jeffrey L.

    2015-01-01

    Neurorobots enable researchers to study how behaviors are produced by neural mechanisms in an uncertain, noisy, real-world environment. To investigate how the somatosensory system processes noisy, real-world touch inputs, we introduce a neurorobot called CARL-SJR, which has a full-body tactile sensory area. The design of CARL-SJR is such that it encourages people to communicate with it through gentle touch. CARL-SJR provides feedback to users by displaying bright colors on its surface. In the present study, we show that CARL-SJR is capable of learning associations between conditioned stimuli (CS; a color pattern on its surface) and unconditioned stimuli (US; a preferred touch pattern) by applying a spiking neural network (SNN) with neurobiologically inspired plasticity. Specifically, we modeled the primary somatosensory cortex, prefrontal cortex, striatum, and the insular cortex, which is important for hedonic touch, to process noisy data generated directly from CARL-SJR's tactile sensory area. To facilitate learning, we applied dopamine-modulated Spike Timing Dependent Plasticity (STDP) to our simulated prefrontal cortex, striatum, and insular cortex. To cope with noisy, varying inputs, the SNN was tuned to produce traveling waves of activity that carried spatiotemporal information. Despite the noisy tactile sensors, spike trains, and variations in subject hand swipes, the learning was quite robust. Further, insular cortex activities in the incremental pathway of dopaminergic reward system allowed us to control CARL-SJR's preference for touch direction without heavily pre-processed inputs. The emerged behaviors we found in this model match animal's behaviors wherein they prefer touch in particular areas and directions. Thus, the results in this paper could serve as an explanation on the underlying neural mechanisms for developing tactile preferences and hedonic touch. PMID:26257639

  16. Central role for the insular cortex in mediating conditioned responses to anticipatory cues

    PubMed Central

    Kusumoto-Yoshida, Ikue; Liu, Haixin; Chen, Billy T.; Fontanini, Alfredo; Bonci, Antonello

    2015-01-01

    Reward-related circuits are fundamental for initiating feeding on the basis of food-predicting cues, whereas gustatory circuits are believed to be involved in the evaluation of food during consumption. However, accumulating evidence challenges such a rigid separation. The insular cortex (IC), an area largely studied in rodents for its role in taste processing, is involved in representing anticipatory cues. Although IC responses to anticipatory cues are well established, the role of IC cue-related activity in mediating feeding behaviors is poorly understood. Here, we examined the involvement of the IC in the expression of cue-triggered food approach in mice trained with a Pavlovian conditioning paradigm. We observed a significant change in neuronal firing during presentation of the cue. Pharmacological silencing of the IC inhibited food port approach. Such a behavior could be recapitulated by temporally selective inactivation during the cue. These findings represent the first evidence, to our knowledge, that cue-evoked neuronal activity in the mouse IC modulates behavioral output, and demonstrate a causal link between cue responses and feeding behaviors. PMID:25583486

  17. Taste intensity modulates effective connectivity from the insular cortex to the thalamus in humans.

    PubMed

    Yeung, Andy Wai Kan; Tanabe, Hiroki C; Suen, Justin Long Kiu; Goto, Tazuko K

    2016-07-15

    Evaluation of taste intensity is one of the most important perceptual abilities in our daily life. In contrast with extensive research findings regarding the spatial representation of taste in the insula and thalamus, little is known about how the thalamus and insula communicate and reciprocally influence their activities for processing taste intensity. To examine this neurophysiological relationship, we investigated the modulatory effect of intensity of saltiness on connections in the network processing taste signals in the human brain. These "effective connectivity" relationships refer to the neurophysiological influence (including direction and strength of influence) of one brain region on another. Healthy adults (N=34), including 17 males and 17 females (mean age=21.3years, SD=2.4; mean body mass index (BMI)=20.2kg/m(2), SD=2.1) underwent functional magnetic resonance imaging as they tasted three concentrations of sodium chloride solutions. By effective connectivity analysis with dynamic causal modeling, we show that taste intensity enhances top-down signal transmission from the insular cortex to the thalamus. These results are the first to demonstrate the modulatory effect of taste intensity on the taste network in the human brain. PMID:27132544

  18. The von Economo neurons in fronto-insular and anterior cingulate cortex

    PubMed Central

    Allman, John M.; Tetreault, Nicole A.; Hakeem, Atiya Y.; Manaye, Kebreten F.; Semendeferi, Katerina; Erwin, Joseph M.; Park, Soyoung; Goubert, Virginie; Hof, Patrick R.

    2011-01-01

    The von Economo neurons (VENs) are large bipolar neurons located in fronto-insular cortex (FI) and anterior limbic area (LA) in great apes and humans but not in other primates. Our stereological counts of VENs in FI and LA show them to be more numerous in humans than in apes. In humans, small numbers of VENs appear the 36th week post conception, with numbers increasing during the first eight months after birth. There are significantly more VENs in the right hemisphere in postnatal brains; this may be related to asymmetries in the autonomic nervous system. VENs are also present in elephants and whales and may be a specialization related to very large brain size. The large size and simple dendritic structure of these projection neurons suggest that they rapidly send basic information from FI and LA to other parts of the brain, while slower neighboring pyramids send more detailed information. Selective destruction of VENs in early stages of fronto-temporal dementia implies that they are involved in empathy, social awareness, and self-control, consistent with evidence from functional imaging. PMID:21534993

  19. Differential coding of uncertain reward in rat insular and orbitofrontal cortex

    PubMed Central

    Jo, Suhyun; Jung, Min Whan

    2016-01-01

    Anterior insular and orbitofrontal cortex (AIC and OFC, respectively) are known to play important roles in decision making under risk. However, risk-related AIC neural activity has not been investigated and it is controversial whether the rodent OFC conveys genuine risk signals. To address these issues, we examined AIC and OFC neuronal activity in rats responding to five distinct auditory cues predicting water reward with different probabilities. Both structures conveyed significant neural signals for reward, value and risk, with value and risk signals conjunctively coded. However, value signals were stronger and appeared earlier in the OFC, and many risk-coding OFC neurons responded only to the cue predicting certain (100%) reward. Also, AIC neurons tended to increase their activity for a prolonged time following a negative outcome and according to previously expected value. These results show that both the AIC and OFC convey neural signals related to reward uncertainty, but in different ways. The OFC might play an important role in encoding certain reward-biased, risk-modulated subjective value, whereas the AIC might convey prolonged negative outcome and disappointment signals. PMID:27052943

  20. A molecular mechanism underlying gustatory memory trace for an association in the insular cortex

    PubMed Central

    Adaikkan, Chinnakkaruppan; Rosenblum, Kobi

    2015-01-01

    Events separated in time are associatively learned in trace conditioning, recruiting more neuronal circuits and molecular mechanisms than in delay conditioning. However, it remains unknown whether a given sensory memory trace is being maintained as a unitary item to associate. Here, we used conditioned taste aversion learning in the rat model, wherein animals associate a novel taste with visceral nausea, and demonstrate that there are two parallel memory traces of a novel taste: a short-duration robust trace, lasting approximately 3 hr, and a parallel long-duration weak one, lasting up to 8 hr, and dependent on the strong trace for its formation. Moreover, only the early robust trace is maintained by a NMDAR-dependent CaMKII- AMPAR pathway in the insular cortex. These findings suggest that a memory trace undergoes rapid modifications, and that the mechanisms underlying trace associative learning differ when items in the memory are experienced at different time points. DOI: http://dx.doi.org/10.7554/eLife.07582.001 PMID:26452094

  1. Intrinsic functional connectivity of insular cortex and symptoms of sickness during acute experimental inflammation.

    PubMed

    Lekander, Mats; Karshikoff, Bianka; Johansson, Emilia; Soop, Anne; Fransson, Peter; Lundström, Johan N; Andreasson, Anna; Ingvar, Martin; Petrovic, Predrag; Axelsson, John; Nilsonne, Gustav

    2016-08-01

    Task-based fMRI has been used to study the effects of experimental inflammation on the human brain, but it remains unknown whether intrinsic connectivity in the brain at rest changes during a sickness response. Here, we investigated the effect of experimental inflammation on connectivity between areas relevant for monitoring of bodily states, motivation, and subjective symptoms of sickness. In a double-blind randomized controlled experiment, 52 healthy volunteers were injected with 0.6ng/kg LPS (lipopolysaccharide) or placebo, and participated in a resting state fMRI experiment after approximately 2h 45min. Resting state fMRI data were available from 48 participants, of which 28 received LPS and 20 received placebo. Bilateral anterior and bilateral posterior insula sections were used as seed regions and connectivity with bilateral orbitofrontal and cingulate (anterior and middle) cortices was investigated. Back pain, headache and global sickness increased significantly after as compared to before LPS, while a non-significant trend was shown for increased nausea. Compared to placebo, LPS was followed by increased connectivity between left anterior insula and left midcingulate cortex. This connectivity was significantly correlated to increase in back pain after LPS and tended to be related to increased global sickness, but was not related to increased headache or nausea. LPS did not affect the connectivity from other insular seeds. In conclusion, the finding of increased functional connectivity between left anterior insula and middle cingulate cortex suggests a potential neurophysiological mechanism that can be further tested to understand the subjective feeling of malaise and discomfort during a sickness response. PMID:26732827

  2. Macaque Parieto-Insular Vestibular Cortex: Responses to self-motion and optic flow

    PubMed Central

    Chen, Aihua; DeAngelis, Gregory C.; Angelaki, Dora E.

    2011-01-01

    The parieto-insular vestibular cortex (PIVC) is thought to contain an important representation of vestibular information. Here we describe responses of macaque PIVC neurons to three-dimensional (3D) vestibular and optic flow stimulation. We found robust vestibular responses to both translational and rotational stimuli in the retroinsular (Ri) and adjacent secondary somatosensory (S2) cortices. PIVC neurons did not respond to optic flow stimulation, and vestibular responses were similar in darkness and during visual fixation. Cells in the upper bank and tip of the lateral sulcus (Ri and S2) responded to sinusoidal vestibular stimuli with modulation at the first harmonic frequency, and were directionally tuned. Cells in the lower bank of the lateral sulcus (mostly Ri) often modulated at the second harmonic frequency, and showed either bimodal spatial tuning or no tuning at all. All directions of 3D motion were represented in PIVC, with direction preferences distributed roughly uniformly for translation, but showing a preference for roll rotation. Spatio-temporal profiles of responses to translation revealed that half of PIVC cells followed the linear velocity profile of the stimulus, one-quarter carried signals related to linear acceleration (in the form of two peaks of direction selectivity separated in time), and a few neurons followed the derivative of linear acceleration (jerk). In contrast, mainly velocity-coding cells were found in response to rotation. Thus, PIVC comprises a large functional region in macaque areas Ri and S2, with robust responses to 3D rotation and translation, but is unlikely to play a significant role in visual/vestibular integration for self-motion perception. PMID:20181599

  3. Enhancement of Inhibitory Avoidance and Conditioned Taste Aversion Memory with Insular Cortex Infusions of 8-Br-cAMP: Involvement of the Basolateral Amygdala

    ERIC Educational Resources Information Center

    Miranda, Maria I.; McGaugh, James L.

    2004-01-01

    There is considerable evidence that in rats, the insular cortex (IC) and amygdala are involved in the learning and memory of aversively motivated tasks. The present experiments examined the effects of 8-Br-cAMP, an analog of cAMP, and oxotremorine, a muscarinic agonist, infused into the IC after inhibitory avoidance (IA) training and during the…

  4. Transient inhibition of protein synthesis in the rat insular cortex delays extinction of conditioned taste aversion with cyclosporine A.

    PubMed

    Hadamitzky, Martin; Orlowski, Kathrin; Schwitalla, Jan Claudius; Bösche, Katharina; Unteroberdörster, Meike; Bendix, Ivo; Engler, Harald; Schedlowski, Manfred

    2016-09-01

    Conditioned responses gradually weaken and eventually disappear when subjects are repeatedly exposed to the conditioned stimulus (CS) in the absence of the unconditioned stimulus (US), a process called extinction. Studies have demonstrated that extinction of conditioned taste aversion (CTA) can be prevented by interfering with protein synthesis in the insular cortex (IC). However, it remained unknown whether it is possible to pharmacologically stabilize the taste aversive memory trace over longer periods of time. Thus, the present study aimed at investigating the time frame during which extinction of CTA can be efficiently prevented by blocking protein synthesis in the IC. Employing an established conditioning paradigm in rats with saccharin as CS, and the immunosuppressant cyclosporine A (CsA) as US, we show here that daily bilateral intra-insular injections of the protein synthesis inhibitor anisomycin (120μg/μl) immediately after retrieval significantly diminished CTA extinction over a period of five retrieval days and subsequently reached levels of saline-infused controls. These findings demonstrate that it is possible to efficiently delay but not to fully prevent CTA extinction during repeated retrieval trials by blocking protein translation with daily bilateral infusions of anisomycin in the IC. These data confirm and extent earlier reports indicating that the role of protein synthesis in CTA extinction learning is not limited to gastrointestinal malaise-inducing drugs such as lithium chloride (LiCl). PMID:27311758

  5. Roles of the Different Sub-Regions of the Insular Cortex in Various Phases of the Decision-Making Process

    PubMed Central

    Droutman, Vita; Bechara, Antoine; Read, Stephen J.

    2015-01-01

    This paper presents a coherent account of the role of the insular cortex (IC) in decision-making. We follow a conceptualization of decision-making that is very close to one previously proposed by Ernst and Paulus (2005): that the decision process is a progression of four phases: (1) re-focusing attention; (2) evaluation; (3) action; and (4) outcome processing, and we present evidence for the insula’s role in all these phases. We review the existing work on insula’s functional anatomy that subdivides the IC into posterior, dorsal anterior and ventral anterior regions. We re-map the results provided by the existing literature into these subdivisions wherever possible, to identify the components’ role in each decision making phase. In addition, we identify a self-regulating quality of the IC focused on harm avoidance. PMID:26635559

  6. Roles of the Different Sub-Regions of the Insular Cortex in Various Phases of the Decision-Making Process.

    PubMed

    Droutman, Vita; Bechara, Antoine; Read, Stephen J

    2015-01-01

    This paper presents a coherent account of the role of the insular cortex (IC) in decision-making. We follow a conceptualization of decision-making that is very close to one previously proposed by Ernst and Paulus (2005): that the decision process is a progression of four phases: (1) re-focusing attention; (2) evaluation; (3) action; and (4) outcome processing, and we present evidence for the insula's role in all these phases. We review the existing work on insula's functional anatomy that subdivides the IC into posterior, dorsal anterior and ventral anterior regions. We re-map the results provided by the existing literature into these subdivisions wherever possible, to identify the components' role in each decision making phase. In addition, we identify a self-regulating quality of the IC focused on harm avoidance. PMID:26635559

  7. The sensory insular cortex mediates the stress-buffering effects of safety signals but not behavioral control

    PubMed Central

    Christianson, J.P.; Benison, A.M.; Jennings, J.; Sandsmark, E.K.; Amat, J.; Kaufman, R.D.; Baratta, M.V.; Paul., E.D.; Campeau, S.; Watkins, L.R.; Barth, D.S.; Maier, S.F.

    2009-01-01

    Safety signals are learned cues that predict stress-free periods while behavioral control is the ability to modify a stressor by behavioral actions. Both serve to attenuate the effects of stressors such as uncontrollable shocks. Internal and external cues produced by a controlling behavior are followed by a stressor-free interval, and so it is possible that safety learning is fundamental to the effect of control. If this is the case then behavioral control and safety should recruit the same neural machinery. Interestingly, safety signals that prevented a behavioral outcome of stressor exposure that is also blocked by control (reduced social exploration) failed to inhibit activity in the dorsal raphé nucleus or utilize the ventromedial prefrontal cortex, the mechanisms by which behavioral control operates. However, bilateral lesions to a region of posterior insular cortex, termed the “sensory insula,” prevented the effect of safety but not of behavioral control, providing a double-dissociation. These results indicate that stressor-modulators can recruit distinct neural circuitry and imply a critical role of the sensory insula in safety learning. PMID:19074043

  8. Histaminergic modulation of cholinergic release from the nucleus basalis magnocellularis into insular cortex during taste aversive memory formation.

    PubMed

    Purón-Sierra, Liliana; Miranda, María Isabel

    2014-01-01

    The ability of acetylcholine (ACh) to alter specific functional properties of the cortex endows the cholinergic system with an important modulatory role in memory formation. For example, an increase in ACh release occurs during novel stimulus processing, indicating that ACh activity is critical during early stages of memory processing. During novel taste presentation, there is an increase in ACh release in the insular cortex (IC), a major structure for taste memory recognition. There is extensive evidence implicating the cholinergic efferents of the nucleus basalis magnocellularis (NBM) in cortical activity changes during learning processes, and new evidence suggests that the histaminergic system may interact with the cholinergic system in important ways. However, there is little information as to whether changes in cholinergic activity in the IC are modulated during taste memory formation. Therefore, in the present study, we evaluated the influence of two histamine receptor subtypes, H1 in the NBM and H3 in the IC, on ACh release in the IC during conditioned taste aversion (CTA). Injection of the H3 receptor agonist R-α-methylhistamine (RAMH) into the IC or of the H1 receptor antagonist pyrilamine into the NBM during CTA training impaired subsequent CTA memory, and simultaneously resulted in a reduction of ACh release in the IC. This study demonstrated that basal and cortical cholinergic pathways are finely tuned by histaminergic activity during CTA, since dual actions of histamine receptor subtypes on ACh modulation release each have a significant impact during taste memory formation. PMID:24625748

  9. Intracranial spectral amplitude dynamics of perceptual suppression in fronto-insular, occipito-temporal, and primary visual cortex

    PubMed Central

    Vidal, Juan R.; Perrone-Bertolotti, Marcela; Kahane, Philippe; Lachaux, Jean-Philippe

    2015-01-01

    If conscious perception requires global information integration across active distant brain networks, how does the loss of conscious perception affect neural processing in these distant networks? Pioneering studies on perceptual suppression (PS) described specific local neural network responses in primary visual cortex, thalamus and lateral prefrontal cortex of the macaque brain. Yet the neural effects of PS have rarely been studied with intracerebral recordings outside these cortices and simultaneously across distant brain areas. Here, we combined (1) a novel experimental paradigm in which we produced a similar perceptual disappearance and also re-appearance by using visual adaptation with transient contrast changes, with (2) electrophysiological observations from human intracranial electrodes sampling wide brain areas. We focused on broadband high-frequency (50–150 Hz, i.e., gamma) and low-frequency (8–24 Hz) neural activity amplitude modulations related to target visibility and invisibility. We report that low-frequency amplitude modulations reflected stimulus visibility in a larger ensemble of recording sites as compared to broadband gamma responses, across distinct brain regions including occipital, temporal and frontal cortices. Moreover, the dynamics of the broadband gamma response distinguished stimulus visibility from stimulus invisibility earlier in anterior insula and inferior frontal gyrus than in temporal regions, suggesting a possible role of fronto-insular cortices in top–down processing for conscious perception. Finally, we report that in primary visual cortex only low-frequency amplitude modulations correlated directly with perceptual status. Interestingly, in this sensory area broadband gamma was not modulated during PS but became positively modulated after 300 ms when stimuli were rendered visible again, suggesting that local networks could be ignited by top–down influences during conscious perception. PMID:25642199

  10. Intracranial spectral amplitude dynamics of perceptual suppression in fronto-insular, occipito-temporal, and primary visual cortex.

    PubMed

    Vidal, Juan R; Perrone-Bertolotti, Marcela; Kahane, Philippe; Lachaux, Jean-Philippe

    2014-01-01

    If conscious perception requires global information integration across active distant brain networks, how does the loss of conscious perception affect neural processing in these distant networks? Pioneering studies on perceptual suppression (PS) described specific local neural network responses in primary visual cortex, thalamus and lateral prefrontal cortex of the macaque brain. Yet the neural effects of PS have rarely been studied with intracerebral recordings outside these cortices and simultaneously across distant brain areas. Here, we combined (1) a novel experimental paradigm in which we produced a similar perceptual disappearance and also re-appearance by using visual adaptation with transient contrast changes, with (2) electrophysiological observations from human intracranial electrodes sampling wide brain areas. We focused on broadband high-frequency (50-150 Hz, i.e., gamma) and low-frequency (8-24 Hz) neural activity amplitude modulations related to target visibility and invisibility. We report that low-frequency amplitude modulations reflected stimulus visibility in a larger ensemble of recording sites as compared to broadband gamma responses, across distinct brain regions including occipital, temporal and frontal cortices. Moreover, the dynamics of the broadband gamma response distinguished stimulus visibility from stimulus invisibility earlier in anterior insula and inferior frontal gyrus than in temporal regions, suggesting a possible role of fronto-insular cortices in top-down processing for conscious perception. Finally, we report that in primary visual cortex only low-frequency amplitude modulations correlated directly with perceptual status. Interestingly, in this sensory area broadband gamma was not modulated during PS but became positively modulated after 300 ms when stimuli were rendered visible again, suggesting that local networks could be ignited by top-down influences during conscious perception. PMID:25642199

  11. Comparison of anterior cingulate vs. insular cortex as targets for real-time fMRI regulation during pain stimulation

    PubMed Central

    Emmert, Kirsten; Breimhorst, Markus; Bauermann, Thomas; Birklein, Frank; Van De Ville, Dimitri; Haller, Sven

    2014-01-01

    Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback allows learning voluntary control over specific brain areas by means of operant conditioning and has been shown to decrease pain perception. To further increase the effect of rt-fMRI neurofeedback on pain, we directly compared two different target regions of the pain network, notably the anterior insular cortex (AIC) and the anterior cingulate cortex (ACC). Participants for this prospective study were randomly assigned to two age-matched groups of 14 participants each (7 females per group) for AIC and ACC feedback. First, a functional localizer using block-design heat pain stimulation was performed to define the pain-sensitive target region within the AIC or ACC. Second, subjects were asked to down-regulate the BOLD activation in four neurofeedback runs during identical pain stimulation. Data analysis included task-related and functional connectivity analysis. At the behavioral level, pain ratings significantly decreased during feedback vs. localizer runs, but there was no difference between AIC and ACC groups. Concerning neuroimaging, ACC and AIC showed consistent involvement of the caudate nucleus for subjects that learned down-regulation (17/28) in both task-related and functional connectivity analysis. The functional connectivity toward the caudate nucleus is stronger for the ACC while the AIC is more heavily connected to the ventrolateral prefrontal cortex. Consequently, the ACC and AIC are suitable targets for real-time fMRI neurofeedback during pain perception as they both affect the caudate nucleus, although functional connectivity indicates that the direct connection seems to be stronger with the ACC. Additionally, the caudate, an important area involved in pain perception and suppression, could be a good rt-fMRI target itself. Future studies are needed to identify parameters characterizing successful regulators and to assess the effect of repeated rt-fMRI neurofeedback on pain

  12. Differential effects of hunger and satiety on insular cortex and hypothalamic functional connectivity.

    PubMed

    Wright, Hazel; Li, Xiaoyun; Fallon, Nicholas B; Crookall, Rebecca; Giesbrecht, Timo; Thomas, Anna; Halford, Jason C G; Harrold, Joanne; Stancak, Andrej

    2016-05-01

    The insula cortex and hypothalamus are implicated in eating behaviour, and contain receptor sites for peptides and hormones controlling energy balance. The insula encompasses multi-functional subregions, which display differential anatomical and functional connectivities with the rest of the brain. This study aimed to analyse the effect of fasting and satiation on the functional connectivity profiles of left and right anterior, middle, and posterior insula, and left and right hypothalamus. It was hypothesized that the profiles would be altered alongside changes in homeostatic energy balance. Nineteen healthy participants underwent two 7-min resting state functional magnetic resonance imaging scans, one when fasted and one when satiated. Functional connectivity between the left posterior insula and cerebellum/superior frontal gyrus, and between left hypothalamus and inferior frontal gyrus was stronger during fasting. Functional connectivity between the right middle insula and default mode structures (left and right posterior parietal cortex, cingulate cortex), and between right hypothalamus and superior parietal cortex was stronger during satiation. Differences in blood glucose levels between the scans accounted for several of the altered functional connectivities. The insula and hypothalamus appear to form a homeostatic energy balance network related to cognitive control of eating; prompting eating and preventing overeating when energy is depleted, and ending feeding or transferring attention away from food upon satiation. This study provides evidence of a lateralized dissociation of neural responses to energy modulations. PMID:26790868

  13. Neural correlates of the ‘good life’: eudaimonic well-being is associated with insular cortex volume

    PubMed Central

    Kanai, Ryota; Rees, Geraint; Bates, Timothy C.

    2014-01-01

    Eudaimonic well-being reflects traits concerned with personal growth, self-acceptance, purpose in life and autonomy (among others) and is a substantial predictor of life events, including health. Although interest in the aetiology of eudaimonic well-being has blossomed in recent years, little is known of the underlying neural substrates of this construct. To address this gap in our knowledge, here we examined whether regional gray matter (GM) volume was associated with eudaimonic well-being. Structural magnetic resonance images from 70 young, healthy adults who also completed Ryff’s 42-item measure of the six core facets of eudaimonia, were analysed with voxel-based morphometry techniques. We found that eudaimonic well-being was positively associated with right insular cortex GM volume. This association was also reflected in three of the sub-scales of eudaimonia: personal growth, positive relations and purpose in life. Positive relations also showed a significant association with left insula volume. No other significant associations were observed, although personal growth was marginally associated with left insula, and purpose in life exhibited a marginally significant negative association with middle temporal gyrus GM volume. These findings are the first to our knowledge linking eudaimonic well-being with regional brain structure. PMID:23512932

  14. Endocannabinoid regulation of nausea is mediated by 2-arachidonoylglycerol (2-AG) in the rat visceral insular cortex.

    PubMed

    Sticht, Martin A; Limebeer, Cheryl L; Rafla, Benjamin R; Abdullah, Rehab A; Poklis, Justin L; Ho, Winnie; Niphakis, Micah J; Cravatt, Benjamin F; Sharkey, Keith A; Lichtman, Aron H; Parker, Linda A

    2016-03-01

    Cannabinoid (CB) agonists suppress nausea in humans and animal models; yet, their underlying neural substrates remain largely unknown. Evidence suggests that the visceral insular cortex (VIC) plays a critical role in nausea. Given the expression of CB1 receptors and the presence of endocannabinoids in this brain region, we hypothesized that the VIC endocannabinoid system regulates nausea. In the present study, we assessed whether inhibiting the primary endocannabinoid hydrolytic enzymes in the VIC reduces acute lithium chloride (LiCl)-induced conditioned gaping, a rat model of nausea. We also quantified endocannabinoid levels during an episode of nausea, and assessed VIC neuronal activation using the marker, c-Fos. Local inhibition of monoacylglycerol lipase (MAGL), the main hydrolytic enzyme of 2-arachidonylglycerol (2-AG), reduced acute nausea through a CB1 receptor mechanism, whereas inhibition of fatty acid amide hydrolase (FAAH), the primary catabolic enzyme of anandamide (AEA), was without effect. Levels of 2-AG were also selectively elevated in the VIC during an episode of nausea. Inhibition of MAGL robustly increased 2-AG in the VIC, while FAAH inhibition had no effect on AEA. Finally, we demonstrated that inhibition of MAGL reduced VIC Fos immunoreactivity in response to LiCl treatment. Taken together, these findings provide compelling evidence that acute nausea selectively increases 2-AG in the VIC, and suggests that 2-AG signaling within the VIC regulates nausea by reducing neuronal activity in this forebrain region. PMID:26541329

  15. Plasticity-Related PKMζ Signaling in the Insular Cortex Is Involved in the Modulation of Neuropathic Pain after Nerve Injury

    PubMed Central

    Han, Jeongsoo; Kwon, Minjee; Cha, Myeounghoon; Tanioka, Motomasa; Hong, Seong-Karp; Bai, Sun Joon; Lee, Bae Hwan

    2015-01-01

    The insular cortex (IC) is associated with important functions linked with pain and emotions. According to recent reports, neural plasticity in the brain including the IC can be induced by nerve injury and may contribute to chronic pain. Continuous active kinase, protein kinase Mζ (PKMζ), has been known to maintain the long-term potentiation. This study was conducted to determine the role of PKMζ in the IC, which may be involved in the modulation of neuropathic pain. Mechanical allodynia test and immunohistochemistry (IHC) of zif268, an activity-dependent transcription factor required for neuronal plasticity, were performed after nerve injury. After ζ-pseudosubstrate inhibitory peptide (ZIP, a selective inhibitor of PKMζ) injection, mechanical allodynia test and immunoblotting of PKMζ, phospho-PKMζ (p-PKMζ), and GluR1 and GluR2 were observed. IHC demonstrated that zif268 expression significantly increased in the IC after nerve injury. Mechanical allodynia was significantly decreased by ZIP microinjection into the IC. The analgesic effect lasted for 12 hours. Moreover, the levels of GluR1, GluR2, and p-PKMζ were decreased after ZIP microinjection. These results suggest that peripheral nerve injury induces neural plasticity related to PKMζ and that ZIP has potential applications for relieving chronic pain. PMID:26457205

  16. Altered resting state connectivity of the insular cortex in individuals with fibromyalgia

    PubMed Central

    Ichesco, Eric; Schmidt-Wilcke, Tobias; Bhavsar, Rupal; Clauw, Daniel J.; Peltier, Scott J.; Kim, Jieun; Napadow, Vitaly; Hampson, Johnson P.; Kairys, Anson E.; Williams, David A.; Harris, Richard E.

    2014-01-01

    The insular (IC) and cingulate cortices (CC) are critically involved in pain perception. Previously we demonstrated that fibromyalgia (FM) patients have greater connectivity between the insula and Default Mode Network at rest, and that changes in the degree of this connectivity were associated with changes in the intensity of ongoing clinical pain. Here we more thoroughly evaluate the degree of resting state connectivity to multiple regions of the IC in individuals with FM and healthy controls (HC). We also investigated the relationship between connectivity, experimental pain and current clinical chronic pain. Functional connectivity was assessed using resting state functional magnetic resonance imaging in 18 FM patients and 18 age- and sex-matched HC using pre-defined seed regions in the anterior, middle and posterior IC. FM patients exhibited greater connectivity between: (1) right mid IC and right mid/posterior CC and right mid IC; (2) right posterior IC and the left CC; and (3) right anterior IC and left superior temporal gyrus. HCs displayed greater connectivity between: left anterior IC and the bilateral medial frontal gyrus/ACC; and left posterior IC and the right superior frontal gyrus. Within the FM group, greater connectivity between the IC and CC was associated with decreased pressure-pain thresholds. Perspective These data provide further support for altered resting-state connectivity between the IC and other brain regions known to participate in pain perception/modulation playing a pathogenic role in conditions such as FM. We speculate that altered IC connectivity is associated with the experience of chronic pain in individuals with fibromyalgia. PMID:24815079

  17. Noradrenergic activation of the basolateral amygdala enhances object recognition memory and induces chromatin remodeling in the insular cortex

    PubMed Central

    Beldjoud, Hassiba; Barsegyan, Areg; Roozendaal, Benno

    2015-01-01

    It is well established that arousal-induced memory enhancement requires noradrenergic activation of the basolateral complex of the amygdala (BLA) and modulatory influences on information storage processes in its many target regions. While this concept is well accepted, the molecular basis of such BLA effects on neural plasticity changes within other brain regions remains to be elucidated. The present study investigated whether noradrenergic activation of the BLA after object recognition training induces chromatin remodeling through histone post-translational modifications in the insular cortex (IC), a brain region that is importantly involved in object recognition memory. Male Sprague—Dawley rats were trained on an object recognition task, followed immediately by bilateral microinfusions of norepinephrine (1.0 μg) or saline administered into the BLA. Saline-treated control rats exhibited poor 24-h retention, whereas norepinephrine treatment induced robust 24-h object recognition memory. Most importantly, this memory-enhancing dose of norepinephrine induced a global reduction in the acetylation levels of histone H3 at lysine 14, H2B and H4 in the IC 1 h later, whereas it had no effect on the phosphorylation of histone H3 at serine 10 or tri-methylation of histone H3 at lysine 27. Norepinephrine administered into the BLA of non-trained control rats did not induce any changes in the histone marks investigated in this study. These findings indicate that noradrenergic activation of the BLA induces training-specific effects on chromatin remodeling mechanisms, and presumably gene transcription, in its target regions, which may contribute to the understanding of the molecular mechanisms of stress and emotional arousal effects on memory consolidation. PMID:25972794

  18. Altered Cingulate and Insular Cortex Activation During Risk-Taking in Methamphetamine Dependence: Losses Lose Impact

    PubMed Central

    Gowin, Joshua L.; Stewart, Jennifer L.; May, April C.; Ball, Tali M.; Wittmann, Marc; Tapert, Susan F.; Paulus, Martin P.

    2013-01-01

    Aims To determine if methamphetamine-dependent (MD) individuals exhibit behavioral or neural processing differences in risk-taking relative to healthy comparison participants (CTL). Design This was a cross-sectional study comparing two groups’ behavior on a risk-taking task and neural processing as assessed using functional magnetic resonance imaging (fMRI). Settings The study was conducted in an inpatient treatment center and a research fMRI facility in the United States. Participants Sixty-eight recently abstinent MD individuals recruited from a treatment program and forty CTL recruited from the community completed the study. Measurements The study assessed risk-taking behavior (overall and post-loss) using the Risky Gains Task (RGT), sensation-seeking, impulsivity and blood-oxygenation level dependent activation in the brain during the decision phase of the RGT. Findings Relative to CTL, MD displayed decreased activation in the bilateral rostral anterior cingulate cortex (ACC) and greater activation in the left insula across risky and safe decisions (p<.05). Right mid insula activation among CTL did not vary between risky and safe decisions, but among MD it was higher during risky relative to safe decisions (p<.05). Among MD, lower activation in the right rostral ACC (r=−.39, p<.01) and higher activation in the right mid insula (r=.35, p<.01) during risky decisions were linked to a higher likelihood of choosing a risky option following a loss. Conclusions Methamphetamine-dependent individuals show disrupted risk-related processing in both anterior cingulate and insula, brain areas that have been implicated in cognitive control and interoceptive processing. Attenuated neural processing of risky options may lead to risk-taking despite experiencing negative consequences. PMID:24033715

  19. Cholinergic Neurotransmission in the Posterior Insular Cortex Is Altered in Preclinical Models of Neuropathic Pain: Key Role of Muscarinic M2 Receptors in Donepezil-Induced Antinociception

    PubMed Central

    Ferrier, Jérémy; Bayet-Robert, Mathilde; Dalmann, Romain; El Guerrab, Abderrahim; Aissouni, Youssef; Graveron-Demilly, Danielle; Chalus, Maryse; Pinguet, Jérémy; Eschalier, Alain; Richard, Damien; Daulhac, Laurence; Balayssac, David

    2015-01-01

    Neuropathic pain is one of the most debilitating pain conditions, yet no therapeutic strategy has been really effective for its treatment. Hence, a better understanding of its pathophysiological mechanisms is necessary to identify new pharmacological targets. Here, we report important metabolic variations in brain areas involved in pain processing in a rat model of oxaliplatin-induced neuropathy using HRMAS 1H-NMR spectroscopy. An increased concentration of choline has been evidenced in the posterior insular cortex (pIC) of neuropathic animal, which was significantly correlated with animals' pain thresholds. The screening of 34 genes mRNA involved in the pIC cholinergic system showed an increased expression of the high-affinity choline transporter and especially the muscarinic M2 receptors, which was confirmed by Western blot analysis in oxaliplatin-treated rats and the spared nerve injury model (SNI). Furthermore, pharmacological activation of M2 receptors in the pIC using oxotremorine completely reversed oxaliplatin-induced mechanical allodynia. Consistently, systemic treatment with donepezil, a centrally active acetylcholinesterase inhibitor, prevented and reversed oxaliplatin-induced cold and mechanical allodynia as well as social interaction impairment. Intracerebral microdialysis revealed a lower level of acetylcholine in the pIC of oxaliplatin-treated rats, which was significantly increased by donepezil. Finally, the analgesic effect of donepezil was markedly reduced by a microinjection of the M2 antagonist, methoctramine, within the pIC, in both oxaliplatin-treated rats and spared nerve injury rats. These findings highlight the crucial role of cortical cholinergic neurotransmission as a critical mechanism of neuropathic pain, and suggest that targeting insular M2 receptors using central cholinomimetics could be used for neuropathic pain treatment. SIGNIFICANCE STATEMENT Our study describes a decrease in cholinergic neurotransmission in the posterior insular

  20. Single Neurons in the Insular Cortex of a Macaque Monkey Respond to Skin Brushing: Preliminary Data of the Possible Representation of Pleasant Touch

    PubMed Central

    Grandi, Laura Clara; Gerbella, Marzio

    2016-01-01

    Pleasant touch may serve as a foundation for affiliative behavior, providing a mechanism for the formation and maintenance of social bonds among conspecifics. In humans, this touch is usually referred to as the caress. Dynamic caressing performed on the hairy skin with a velocity of 1–10 cm/s is perceived as being pleasant and determines positive cardio-physiological effects. Furthermore, imaging human studies show that affiliative touch activates the posterior insular cortex (pIC). Recently, it was demonstrated that pleasant touch in monkeys (i.e., sweeping in a grooming-like manner) is performed with velocities similar to those characteristics of human caress (9.31 cm/s), and causes similarly positive autonomic effects, if performed with velocity of 5 cm/s and 10 cm/s, but not lower or higher. Due to similarities between the human caress and non-human primate sweeping, we investigated for the first time whether single neurons of the perisylvian regions (secondary somatosensory cortex [SII] and pIC) of a rhesus monkey can process sweeping touch differently depending on the stimulus speed. We applied stimulation with two speeds: one that optimally induces positive cardio-physiological effects in the monkey who receives it, and includes the real speed of sweep (5–15 cm/s, sweep fast), and a non-optimal speed (1–5 cm/s, sweep slow). The results show that single neurons of insular cortex differently encode the stimulus speed. In particular, even the majority of recorded somatosensory neurons (82.96%) did not discriminate the two speeds, a small set of neurons (16.59%) were modulated just during the sweep fast. These findings represent the first evidence that single neurons of the non-human primates insular cortex can code affiliative touch, highlighting the similarity between human and non-human primates’ social touch systems. This study constitutes an important starting point to carry out deeper investigation on neuronal processing of pleasant sweeping in the

  1. Single Neurons in the Insular Cortex of a Macaque Monkey Respond to Skin Brushing: Preliminary Data of the Possible Representation of Pleasant Touch.

    PubMed

    Grandi, Laura Clara; Gerbella, Marzio

    2016-01-01

    Pleasant touch may serve as a foundation for affiliative behavior, providing a mechanism for the formation and maintenance of social bonds among conspecifics. In humans, this touch is usually referred to as the caress. Dynamic caressing performed on the hairy skin with a velocity of 1-10 cm/s is perceived as being pleasant and determines positive cardio-physiological effects. Furthermore, imaging human studies show that affiliative touch activates the posterior insular cortex (pIC). Recently, it was demonstrated that pleasant touch in monkeys (i.e., sweeping in a grooming-like manner) is performed with velocities similar to those characteristics of human caress (9.31 cm/s), and causes similarly positive autonomic effects, if performed with velocity of 5 cm/s and 10 cm/s, but not lower or higher. Due to similarities between the human caress and non-human primate sweeping, we investigated for the first time whether single neurons of the perisylvian regions (secondary somatosensory cortex [SII] and pIC) of a rhesus monkey can process sweeping touch differently depending on the stimulus speed. We applied stimulation with two speeds: one that optimally induces positive cardio-physiological effects in the monkey who receives it, and includes the real speed of sweep (5-15 cm/s, sweep fast), and a non-optimal speed (1-5 cm/s, sweep slow). The results show that single neurons of insular cortex differently encode the stimulus speed. In particular, even the majority of recorded somatosensory neurons (82.96%) did not discriminate the two speeds, a small set of neurons (16.59%) were modulated just during the sweep fast. These findings represent the first evidence that single neurons of the non-human primates insular cortex can code affiliative touch, highlighting the similarity between human and non-human primates' social touch systems. This study constitutes an important starting point to carry out deeper investigation on neuronal processing of pleasant sweeping in the central

  2. Caudal granular insular cortex is sufficient and necessary for the long-term maintenance of allodynic behavior in the rat due to mononeuropathy

    PubMed Central

    Benison, Alexander M.; Chumachenko, Serhiy; Harrison, Jacqueline A.; Maier, Steven F.; Falci, Scott P.; Watkins, Linda R.; Barth, Daniel S.

    2011-01-01

    Mechanical allodynia, the perception of innocuous tactile stimulation as painful, is a severe symptom of chronic pain often produced by damage to peripheral nerves. Allodynia affects millions of people and remains highly resistant to classic analgesics and therapies. Neural mechanisms for the development and maintenance of allodynia have been investigated in the spinal cord, brainstem, thalamus, and forebrain, but manipulations of these regions rarely produce lasting effects. We found that long-term alleviation of allodynic manifestations is produced by discreetly lesioning a newly discovered somatosensory representation in caudal granular insular cortex (CGIC) in the rat, either before or after a chronic constriction injury of the sciatic nerve. However, CGIC lesions alone have no effect on normal mechanical stimulus thresholds. In addition, using electrophysiological techniques, we reveal a corticospinal loop that could be the anatomical source of CGIC’s influence on allodynia. PMID:21525272

  3. Unconditioned oromotor taste reactivity elicited by sucrose and quinine is unaffected by extensive bilateral damage to the gustatory zone of the insular cortex in rats.

    PubMed

    King, Camille Tessitore; Hashimoto, Koji; Blonde, Ginger D; Spector, Alan C

    2015-03-01

    Rats display stereotypical oromotor and somatic responses to small volumes of intraorally infused taste solutions. These behaviors, known as taste reactivity, are categorized by their association with ingestion or rejection and are thought to reflect the palatability of the stimulus. Because supracollicular decerebrate rats display normal taste reactivity responses, it would appear that forebrain structures are not necessary for generating them. However, because moving the plane of transection rostrally, or damaging or manipulating specific ventral forebrain sites disrupts normal taste reactivity behavior, lesions of the gustatory cortex, a region that has been suggested to be involved with palatability processing, may do the same. In the current study, rats received two injections of either ibotenic acid (N=12) or vehicle (N=8), targeting the conventionally defined gustatory cortex in each hemisphere, and were implanted with intraoral cannulae. Following recovery, their responses to intraoral infusions (0.23ml in 1min) of dH2O, sucrose (1.0M and 0.1M), and quinine hydrochloride (3mM and 0.3mM) were video recorded. Analysis of brains with sufficient bilateral lesions (N=10) revealed that, on average, approximately 94% of the gustatory cortex was destroyed. These extensive bilateral lesions had no significant effect on taste reactivity; the numbers of ingestive and aversive responses to sucrose and quinine were similar between groups. Though these findings do not rule out involvement of the gustatory cortex in palatability processing, they make evident that the region of insular cortex destroyed is not necessary for the normal expression of unconditioned affective behavioral responses to taste stimuli. PMID:25536305

  4. Extensive lesions in rat insular cortex significantly disrupt taste sensitivity to NaCl and KCl and slow salt discrimination learning.

    PubMed

    Blonde, Ginger D; Bales, Michelle B; Spector, Alan C

    2015-01-01

    While studies of the gustatory cortex (GC) mostly focus on its role in taste aversion learning and memory, the necessity of GC for other fundamental taste-guided behaviors remains largely untested. Here, rats with either excitotoxic lesions targeting GC (n = 26) or sham lesions (n = 14) were assessed for postsurgical retention of a presurgically LiCl-induced conditioned taste aversion (CTA) to 0.1M sucrose using a brief-access taste generalization test in a gustometer. The same animals were then trained in a two-response operant taste detection task and psychophysically tested for their salt (NaCl or KCl) sensitivity. Next, the rats were trained and tested in a NaCl vs. KCl taste discrimination task with concentrations varied. Rats meeting our histological inclusion criterion had large lesions (resulting in a group averaging 80% damage to GC and involving surrounding regions) and showed impaired postsurgical expression of the presurgical CTA (LiCl-injected, n = 9), demonstrated rightward shifts in the NaCl (0.54 log10 shift) and KCl (0.35 log10 shift) psychometric functions, and displayed retarded salt discrimination acquisition (n = 18), but eventually learned and performed the discrimination comparable to sham-operated animals. Interestingly, the degree of deficit between tasks correlated only modestly, if at all, suggesting that idiosyncratic differences in insular cortex lesion topography were the root of the individual differences in the behavioral effects demonstrated here. This latter finding hints at some degree of interanimal variation in the functional topography of insular cortex. Overall, GC appears to be necessary to maintain normal taste sensitivity to NaCl and KCl and for salt discrimination learning. However, higher salt concentrations can be detected and discriminated by rats with extensive damage to GC suggesting that the other resources of the gustatory system are sufficient to maintain partial competence in these tasks, supporting the view that

  5. Extensive Lesions in Rat Insular Cortex Significantly Disrupt Taste Sensitivity to NaCl and KCl and Slow Salt Discrimination Learning

    PubMed Central

    Blonde, Ginger D.; Bales, Michelle B.; Spector, Alan C.

    2015-01-01

    While studies of the gustatory cortex (GC) mostly focus on its role in taste aversion learning and memory, the necessity of GC for other fundamental taste-guided behaviors remains largely untested. Here, rats with either excitotoxic lesions targeting GC (n = 26) or sham lesions (n = 14) were assessed for postsurgical retention of a presurgically LiCl-induced conditioned taste aversion (CTA) to 0.1M sucrose using a brief-access taste generalization test in a gustometer. The same animals were then trained in a two-response operant taste detection task and psychophysically tested for their salt (NaCl or KCl) sensitivity. Next, the rats were trained and tested in a NaCl vs. KCl taste discrimination task with concentrations varied. Rats meeting our histological inclusion criterion had large lesions (resulting in a group averaging 80% damage to GC and involving surrounding regions) and showed impaired postsurgical expression of the presurgical CTA (LiCl-injected, n = 9), demonstrated rightward shifts in the NaCl (0.54 log10 shift) and KCl (0.35 log10 shift) psychometric functions, and displayed retarded salt discrimination acquisition (n = 18), but eventually learned and performed the discrimination comparable to sham-operated animals. Interestingly, the degree of deficit between tasks correlated only modestly, if at all, suggesting that idiosyncratic differences in insular cortex lesion topography were the root of the individual differences in the behavioral effects demonstrated here. This latter finding hints at some degree of interanimal variation in the functional topography of insular cortex. Overall, GC appears to be necessary to maintain normal taste sensitivity to NaCl and KCl and for salt discrimination learning. However, higher salt concentrations can be detected and discriminated by rats with extensive damage to GC suggesting that the other resources of the gustatory system are sufficient to maintain partial competence in these tasks, supporting the view that

  6. Topographically Organized Projection to Posterior Insular Cortex from the Posterior Portion of the Ventral Medial Nucleus (VMpo) in the Long-tailed Macaque Monkey

    PubMed Central

    Craig, A.D. (Bud)

    2014-01-01

    Prior anterograde tracing work identified somatotopically organized lamina I trigemino- and spino-thalamic terminations in a cytoarchitectonically distinct portion of posterolateral thalamus of the macaque monkey, named the posterior part of the ventral medial nucleus (VMpo; Craig, 2004b). Microelectrode recordings from clusters of selectively thermoreceptive or nociceptive neurons were used to guide precise micro-injections of various tracers in VMpo. A prior report (Craig and Zhang, 2006) described retrograde tracing results, which confirmed the selective lamina I input to VMpo and the antero-posterior (head to foot) topography. The present report describes the results of micro-injections of anterograde tracers placed at different levels in VMpo, based on the antero-posterior topographic organization of selectively nociceptive units and clusters over nearly the entire extent of VMpo. Each injection produced dense, patchy terminal labeling in a single coherent field within a distinct granular cortical area centered in the fundus of the superior limiting sulcus. The terminations were distributed with a consistent antero-posterior topography over the posterior half of the superior limiting sulcus. These observations demonstrate a specific VMpo projection area in dorsal posterior insular cortex that provides the basis for a somatotopic representation of selectively nociceptive lamina I spinothalamic activity. These results also identify the VMpo terminal area as the posterior half of interoceptive cortex; the anterior half receives input from the vagal-responsive and gustatory neurons in the basal part of the ventral medial nucleus (VMb). PMID:23853108

  7. The insular cortex: relationship to skin conductance responses to facial expression of emotion in temporal lobe epilepsy.

    PubMed

    Banks, Sarah J; Bellerose, Jenny; Douglas, Danielle; Jones-Gotman, Marilyn

    2014-03-01

    The insula plays an important role both in emotion processing and in the generation of epileptic seizures. In the current study we examined thickness of insular cortices and bilateral skin conductance responses (SCR) in healthy subjects in addition to a small number of patients with temporal lobe epilepsy. SCR measures arousal and is used to assess non-conscious responses to emotional stimuli. We used two emotion tasks, one explicitly about emotion and the other implicit. The explicit task required judgments about emotions being expressed in photographs of faces, while the implicit one required judgments about the age of the people in the photographs. Patients and healthy differed in labeling neutral faces, but not other emotions. They also differed in their SCR to emotions, though the profile depended on which hand the recordings were from. Finally, we found relationships between the thickness of the insula and SCR to each task: in the healthy group the thickness of the left insula was related to SCR to the emotion-labeling task; in the patient group it was between the thickness of the right insula and SCR in the age-labeling task. These patterns were evident only for the right hand recordings, thus underscoring the importance of bilateral recordings. PMID:24170157

  8. Elevation of 2-AG by monoacylglycerol lipase inhibition in the visceral insular cortex interferes with anticipatory nausea in a rat model.

    PubMed

    Limebeer, Cheryl L; Rock, Erin M; Puvanenthirarajah, Nirushan; Niphakis, Micah J; Cravatt, Benjamin F; Parker, Linda A

    2016-04-01

    Anticipatory nausea (AN) is a conditioned nausea reaction experienced by chemotherapy patients upon returning to the clinic. Currently, there are no specific treatments for this phenomenon, with the classic antiemetic treatments (e.g., ondansetron) providing no relief. The rat model of AN, contextually elicited conditioned gaping reactions in rats, provides a tool for assessing potential treatments for this difficult to treat disorder. Systemically administered drugs which elevate the endocannabinoids, anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), by interfering with their respective degrading enzymes, fatty acid amide hydrolase (FAAH) and monoacyl glycerol lipase (MAGL) interfere with AN in the rat model. We have shown that MAGL inhibition within the visceral insular cortex (VIC) interferes with acute nausea in the gaping model (Sticht et al., 2015). Here we report that bilateral infusion of the MAGL inhibitor, MJN110 (but neither the FAAH inhibitor, PF3845, nor ondansetron) into the VIC suppressed contextually elicited conditioned gaping, and this effect was reversed by coadministration of the CB1 antagonist, AM251. These findings suggest that 2-AG within the VIC plays a critical role in the regulation of both acute nausea and AN. Because there are currently no specific therapeutics for chemotherapy patients that develop anticipatory nausea, MAGL inhibition by MJN110 may be a candidate treatment. (PsycINFO Database Record PMID:26974857

  9. Conditioned taste aversion prevents the long-lasting BDNF-induced enhancement of synaptic transmission in the insular cortex: A metaplastic effect.

    PubMed

    Rivera-Olvera, Alejandro; Rodríguez-Durán, Luis F; Escobar, Martha L

    2016-04-01

    Homeostatic plasticity mechanisms dynamically adjust synaptic strengths to promote stability that is crucial for memory storage. Metaplasticity is an example of these forms of plasticity that modify the capacity of synapses to experience subsequent Hebbian modifications. In particular, training in several behavioral tasks modifies the ability to induce long-term potentiation (LTP). Recently, we have reported that prior training in conditioned taste aversion (CTA) prevents the subsequent induction of LTP generated by high frequency stimulation in the projection from the basolateral nucleus of the amygdala (Bla) to the insular cortex (IC). One of the key molecular players that underlie long-term synaptic plasticity is brain-derived neurotrophic factor (BDNF). Previous studies from our group reported that acute microinfusion of BDNF in the IC induces a lasting potentiation of synaptic efficacy at the Bla-IC projection. Thus, the aim of the present study was to analyze whether CTA training modifies the ability to induce subsequent BDNF-induced potentiation of synaptic transmission in the Bla-IC projection in vivo. Accordingly, CTA trained rats received intracortical microinfusion of BDNF in order to induce lasting potentiation 48h after the aversion test. Our results show that CTA training prevents the induction of in vivo BDNF-LTP in the Bla-IC projection. The present results provide evidence that CTA modulates BDNF-dependent changes in IC synaptic strength. PMID:26854904

  10. Felt and seen pain evoke the same local patterns of cortical activity in insular and cingulate cortex.

    PubMed

    Corradi-Dell'Acqua, Corrado; Hofstetter, Christoph; Vuilleumier, Patrik

    2011-12-01

    The discovery of regions in the human brain (e.g., insula and cingulate cortex) that activate both under direct exposure to pain and when perceiving pain in others has been interpreted as a neural signature of empathy. However, this overlap raises the question of whether it may reflect a unique distributed population of bimodal neurons or, alternatively, the activity of intermingled but independent populations. We used fMRI on 28 female volunteers and used multivariate pattern analysis techniques to probe for more fine-grain spatial representations of seen and felt pain. Using a whole-brain approach, we found that only in the anterior insula (bilaterally) the distribution of cortical activity evoked by seeing another person's hand in pain was spatially similar to that of pain felt on one's own hand. Subsequent region of interest analyses also implicated the middle insula (right hemisphere) and the middle cingulate cortex. Furthermore, for the anterior insula, the spatial distribution of activity associated with one's pain also replicates that of the perception of negative but painless stimuli. Our data show how the neural representations of aversive events affecting oneself are also recruited when the same events affect others, and provide the stronger evidence thus far of a unique distributed cortical ensemble coding for aversive events regardless of the subject who is affected. PMID:22159113

  11. Intra-visceral insular cortex 2-arachidonoylglycerol, but not N-arachidonoylethanolamide, suppresses acute nausea-induced conditioned gaping in rats.

    PubMed

    Sticht, M A; Limebeer, C L; Rafla, B R; Parker, L A

    2015-02-12

    The visceral insular cortex (VIC) has previously been shown to play a critical role during acute nausea-induced conditioned gaping in rats. Specifically, localized administration of the conventional anti-emetic, ondansetron or the synthetic cannabinoid, HU210, interferes with the establishment of conditioned gaping, likely by reducing the effects of an illness-inducing treatment. However the precise role of the VIC in endocannabinoid-suppression of nausea remains unknown; thus we investigated the potential of localized intra-VIC endocannabinoid administration to interfere with acute nausea-induced conditioned gaping behavior in male Sprague-Dawley rats. Animals received an intraoral infusion of saccharin (0.1%) followed by intra-VIC exogenous N-arachidonoylethanolamide (AEA; 0.4, 4 μg) or 2-arachidonoylglycerol (2-AG; 0.5, 1 μg), and were subsequently injected with nausea-inducing LiCl (0.15M) 15 min later. Bilateral intra-VIC infusions of 2-AG (1 μg, but not 0.5 μg) dose-dependently suppressed conditioned gaping, whereas exogenous AEA was without effect. Interestingly, 2-AG reduced conditioned gaping despite additional pretreatment with the selective cannabinoid receptor type 1 (CB1) antagonist, AM-251; however, concomitant pretreatment with the cyclooxygenase inhibitor, indomethacin (0.5 μg), blocked the suppressive effects of intra-VIC 2-AG. These findings suggest that the modulatory role of the endocannabinoid system during nausea is driven largely by the endocannabinoid, 2-AG, and that its anti-nausea effects may be partly independent of CB1-receptor signaling through metabolic products of the endocannabinoid system. PMID:25499318

  12. Cross-modal representations of first-hand and vicarious pain, disgust and fairness in insular and cingulate cortex

    PubMed Central

    Corradi-Dell'Acqua, Corrado; Tusche, Anita; Vuilleumier, Patrik; Singer, Tania

    2016-01-01

    The anterior insula (AI) and mid-anterior cingulate cortex (mACC) have repeatedly been implicated in first-hand and vicarious experiences of pain, disgust and unfairness. However, it is debated whether these regions process different aversive events through a common modality-independent code, reflecting the shared unpleasantness of the experiences or through independent modality-specific representations. Using functional magnetic resonance imaging, we subjected 19 participants (and 19 confederates) to equally unpleasant painful and disgusting stimulations, as well as unfair monetary treatments. Multivoxel pattern analysis identified modality-independent activation maps in the left AI and mACC, pointing to common coding of affective unpleasantness, but also response patterns specific for the events' sensory properties and the person to whom it was addressed, particularly in the right AI. Our results provide evidence of both functional specialization and integration within AI and mACC, and support a comprehensive role of this network in processing aversive experiences for self and others. PMID:26988654

  13. Cross-modal representations of first-hand and vicarious pain, disgust and fairness in insular and cingulate cortex.

    PubMed

    Corradi-Dell'Acqua, Corrado; Tusche, Anita; Vuilleumier, Patrik; Singer, Tania

    2016-01-01

    The anterior insula (AI) and mid-anterior cingulate cortex (mACC) have repeatedly been implicated in first-hand and vicarious experiences of pain, disgust and unfairness. However, it is debated whether these regions process different aversive events through a common modality-independent code, reflecting the shared unpleasantness of the experiences or through independent modality-specific representations. Using functional magnetic resonance imaging, we subjected 19 participants (and 19 confederates) to equally unpleasant painful and disgusting stimulations, as well as unfair monetary treatments. Multivoxel pattern analysis identified modality-independent activation maps in the left AI and mACC, pointing to common coding of affective unpleasantness, but also response patterns specific for the events' sensory properties and the person to whom it was addressed, particularly in the right AI. Our results provide evidence of both functional specialization and integration within AI and mACC, and support a comprehensive role of this network in processing aversive experiences for self and others. PMID:26988654

  14. Agranular platelets as a cardinal feature of ARC syndrome.

    PubMed

    Kim, Seong Min; Chang, Hye Kyung; Song, Jae Woo; Koh, Hong; Han, Seok Joo

    2010-05-01

    We aimed to describe abnormal platelet morphology and its clinical significance in infants who were diagnosed with arthrogryposis renal dysfunction and cholestasis (ARC) syndrome. We collected all of the cases of ARC syndrome referred to a single pediatric referral center. In all patients, platelet counts and analysis of platelet morphology were performed with peripheral blood smear specimens. Electron microscopy images were obtained to examine the ultrastructure of the platelets. Over the 12-year period, 12 cases of ARC syndrome were identified. The sex ratio (male:female) was 1:1. The median birth weight was 3.15 kg (range, 2.3 to 3.8 kg). Failure to thrive was observed in all the patients. The major cause of death was recurrent febrile illness and pneumonia. The median age at death was 8.9 months (range, 2.6 to 28.8 kg). Their median body weight at death was 3.1 kg (range, 2.6 to 6.0 kg). Close examination of their peripheral blood smear (n=11) specimens showed large, pale, agranular platelets similar to those seen in gray platelet syndrome. Electron microscopic images of the platelets (n=7) revealed a lack of alpha; granules. Agranular platelets are a common finding in ARC syndrome. Agranular platelets should be considered as a cardinal feature of ARC syndrome and can be useful as a noninvasive diagnostic marker for ARC syndrome. PMID:20224444

  15. Multidimensional assessment of empathic abilities in patients with insular glioma.

    PubMed

    Chen, Peng; Wang, Guangming; Ma, Ru; Jing, Fang; Zhang, Yongjun; Wang, Ying; Zhang, Peng; Niu, Chaoshi; Zhang, Xiaochu

    2016-10-01

    Recent studies have provided evidence that there are two possible systems for empathy: affective empathy (AE) and cognitive empathy (CE). Neuroimaging paradigms have proven that the insular cortex is involved in empathy processing, particularly in AE. However, these observations do not provide causal evidence for the role of the insula in empathy. Although impairments in empathy have been described following insular damage in a few case studies, it is not clear whether insular cortex is involved in CE and whether these two systems are impaired independently or laterally in patients with insular gliomas. In this study, we assessed 17 patients with an insular glioma, 17 patients with a noninsular glioma, and 30 healthy controls using a method that combined a self-report empathy questionnaire with the emotion recognition task, assessment of empathy for others' pain, and the emotional perspective-taking paradigm. We found that patients with an insular glioma had lower scores for empathic concern and perspective taking than did either healthy controls or lesion controls. The patients' abilities to recognize facial emotions, perceive others' pain, and understand the emotional perspectives of others were also significantly impaired. Furthermore, we did not observe a laterality effect on either AE or CE among those with insular lesions. These findings revealed that both AE and CE are impaired in patients with an insular glioma and that the insular cortex may be a central neuroanatomical structure in both the AE and CE systems. PMID:27456973

  16. NADPH-diaphorase activity and neurovascular coupling in the rat cerebral cortex.

    PubMed

    Vlasenko, O V; Maisky, V A; Maznychenko, A V; Pilyavskii, A I

    2008-01-01

    The distribution of NADPH-diaphorase-reactive (NADPH-dr) neurons and neuronal processes in the cerebral cortex and basal forebrain and their association with parenchymal vessels were studied in normal adult rats using NADPH-d histochemical protocol. The intensely stained cortical interneurons and reactive subcortically originating afferents, and stained microvessels were examined through a light microscope at law (x250) and high (x630) magnifications. NADPH-dr interneurons were concentrated in layers 2-6 of the M1 and M2 areas. However, clear predominance in their concentration (14 +/- 0.8 P < 0.05 per section) was found in layer 6. A mean number of labeled neurons in auditory (AuV), granular and agranular (GI, AIP) areas of the insular cortex was calculated to reach 12.3 +/- 0.7, 18.5 +/- 1.0 and 23.3 +/- 1.7 units per section, respectively (P < 0.05). The distinct apposition of labelled neurons to intracortical vessels was found in the M1, M2. The order of frequency of neurovascular coupling in different zones of the cerebral cortex was as following sequence: AuV (31.2%, n = 1040) > GI (18.0%, n = 640) > S1 (13.3%, n = 720) > M1 (6.3%, n = 1360). A large number of structural associations between labeled cells and vessels in the temporal and insular cortex indicate that NADPH-d-reactive interneurons can contribute to regulation of the cerebral regional blood flow in these areas. PMID:18416183

  17. Double Dissociation of Monoacylglycerol Lipase Inhibition and CB1 Antagonism in the Central Amygdala, Basolateral Amygdala, and the Interoceptive Insular Cortex on the Affective Properties of Acute Naloxone-Precipitated Morphine Withdrawal in Rats.

    PubMed

    Wills, Kiri L; Petrie, Gavin N; Millett, Geneva; Limebeer, Cheryl L; Rock, Erin M; Niphakis, Micah J; Cravatt, Benjamin F; Parker, Linda A

    2016-06-01

    Both CB1 receptor antagonism and agonism, in particular by 2-arachidonyl glycerol (2-AG), have been shown to reduce somatic symptoms of morphine withdrawal (MWD). Here we evaluated the effects of both systemic pretreatment with the monoacylglycerol lipase (MAGL) inhibitor MJN110 (which selectively elevates 2-AG) and central administration of both MJN110 and the CB1 antagonist (AM251) on the affective properties of MWD. Acute MWD induced place aversion occurs when naloxone is administered 24 h following a single exposure to a high dose of morphine. Systemic pretreatment with the MAGL inhibitor, MJN110, prevented the aversive effects of acute MWD by a CB1 receptor-dependent mechanism. Furthermore, in a double dissociation, AM251 infusions into the central amygdala, but MJN110 infusions into the basolateral amygdala, interfered with the naloxone-precipitated MWD induced place aversion. As well, MJN110, but not AM251, infusions into the interoceptive insular cortex (a region known to be activated in acute MWD) also prevented the establishment of the place aversion by a CB1 mechanism of action. These findings reveal the respective sites of action of systemically administered MJN110 and AM251 in regulating the aversive effects of MWD. PMID:26647976

  18. Structural and Functional Alterations in Right Dorsomedial Prefrontal and Left Insular Cortex Co-Localize in Adolescents with Aggressive Behaviour: An ALE Meta-Analysis

    PubMed Central

    Raschle, Nora Maria; Menks, Willeke Martine; Fehlbaum, Lynn Valérie; Tshomba, Ebongo; Stadler, Christina

    2015-01-01

    Recent neuroimaging work has suggested that aggressive behaviour (AB) is associated with structural and functional brain abnormalities in processes subserving emotion processing and regulation. However, most neuroimaging studies on AB to date only contain relatively small sample sizes. To objectively investigate the consistency of previous structural and functional research in adolescent AB, we performed a systematic literature review and two coordinate-based activation likelihood estimation meta-analyses on eight VBM and nine functional neuroimaging studies in a total of 783 participants (408 [224AB/184 controls] and 375 [215 AB/160 controls] for structural and functional analysis respectively). We found 19 structural and eight functional foci of significant alterations in adolescents with AB, mainly located within the emotion processing and regulation network (including orbitofrontal, dorsomedial prefrontal and limbic cortex). A subsequent conjunction analysis revealed that functional and structural alterations co-localize in right dorsomedial prefrontal cortex and left insula. Our results are in line with meta-analytic work as well as structural, functional and connectivity findings to date, all of which make a strong point for the involvement of a network of brain areas responsible for emotion processing and regulation, which is disrupted in AB. Increased knowledge about the behavioural and neuronal underpinnings of AB is crucial for the development of novel and implementation of existing treatment strategies. Longitudinal research studies will have to show whether the observed alterations are a result or primary cause of the phenotypic characteristics in AB. PMID:26339798

  19. Attenuated sensitivity to the emotions of others by insular lesion.

    PubMed

    Terasawa, Yuri; Kurosaki, Yoshiko; Ibata, Yukio; Moriguchi, Yoshiya; Umeda, Satoshi

    2015-01-01

    The insular cortex has been considered to be the neural base of visceral sensation for many years. Previous studies in psychology and cognitive neuroscience have accumulated evidence indicating that interoception is an essential factor in the subjective feeling of emotion. Recent neuroimaging studies have demonstrated that anterior insular cortex activation is associated with accessing interoceptive information and underpinning the subjective experience of emotional state. Only a small number of studies have focused on the influence of insular damage on emotion processing and interoceptive awareness. Moreover, disparate hypotheses have been proposed for the alteration of emotion processing by insular lesions. Some studies show that insular lesions yield an inability for understanding and representing disgust exclusively, but other studies suggest that such lesions modulate arousal and valence judgments for both positive and negative emotions. In this study, we examined the alteration in emotion recognition in three right insular and adjacent area damaged cases with well-preserved higher cognitive function. Participants performed an experimental task using morphed photos that ranged between neutral and emotional facial expressions (i.e., anger, sadness, disgust, and happiness). Recognition rates of particular emotions were calculated to measure emotional sensitivity. In addition, they performed heartbeat perception task for measuring interoceptive accuracy. The cases identified emotions that have high arousal level (e.g., anger) as less aroused emotions (e.g., sadness) and a case showed remarkably low interoceptive accuracy. The current results show that insular lesions lead to attenuated emotional sensitivity across emotions, rather than category-specific impairments such as to disgust. Despite the small number of cases, our findings suggest that the insular cortex modulates recognition of emotional saliency and mediates interoceptive and emotional awareness. PMID

  20. Attenuated sensitivity to the emotions of others by insular lesion

    PubMed Central

    Terasawa, Yuri; Kurosaki, Yoshiko; Ibata, Yukio; Moriguchi, Yoshiya; Umeda, Satoshi

    2015-01-01

    The insular cortex has been considered to be the neural base of visceral sensation for many years. Previous studies in psychology and cognitive neuroscience have accumulated evidence indicating that interoception is an essential factor in the subjective feeling of emotion. Recent neuroimaging studies have demonstrated that anterior insular cortex activation is associated with accessing interoceptive information and underpinning the subjective experience of emotional state. Only a small number of studies have focused on the influence of insular damage on emotion processing and interoceptive awareness. Moreover, disparate hypotheses have been proposed for the alteration of emotion processing by insular lesions. Some studies show that insular lesions yield an inability for understanding and representing disgust exclusively, but other studies suggest that such lesions modulate arousal and valence judgments for both positive and negative emotions. In this study, we examined the alteration in emotion recognition in three right insular and adjacent area damaged cases with well-preserved higher cognitive function. Participants performed an experimental task using morphed photos that ranged between neutral and emotional facial expressions (i.e., anger, sadness, disgust, and happiness). Recognition rates of particular emotions were calculated to measure emotional sensitivity. In addition, they performed heartbeat perception task for measuring interoceptive accuracy. The cases identified emotions that have high arousal level (e.g., anger) as less aroused emotions (e.g., sadness) and a case showed remarkably low interoceptive accuracy. The current results show that insular lesions lead to attenuated emotional sensitivity across emotions, rather than category-specific impairments such as to disgust. Despite the small number of cases, our findings suggest that the insular cortex modulates recognition of emotional saliency and mediates interoceptive and emotional awareness. PMID

  1. Three Systems of Insular Functional Connectivity Identified with Cluster Analysis

    PubMed Central

    Pitskel, Naomi B.; Pelphrey, Kevin A.

    2011-01-01

    Despite much research on the function of the insular cortex, few studies have investigated functional subdivisions of the insula in humans. The present study used resting-state functional connectivity magnetic resonance imaging (MRI) to parcellate the human insular lobe based on clustering of functional connectivity patterns. Connectivity maps were computed for each voxel in the insula based on resting-state functional MRI (fMRI) data and segregated using cluster analysis. We identified 3 insular subregions with distinct patterns of connectivity: a posterior region, functionally connected with primary and secondary somatomotor cortices; a dorsal anterior to middle region, connected with dorsal anterior cingulate cortex, along with other regions of a previously described control network; and a ventral anterior region, primarily connected with pregenual anterior cingulate cortex. Applying these regions to a separate task data set, we found that dorsal and ventral anterior insula responded selectively to disgusting images, while posterior insula did not. These results demonstrate that clustering of connectivity patterns can be used to subdivide cerebral cortex into anatomically and functionally meaningful subregions; the insular regions identified here should be useful in future investigations on the function of the insula. PMID:21097516

  2. Spatial Organization of Direct Hippocampal Field CA1 Axonal Projections To the Rest of the Cerebral Cortex

    PubMed Central

    CENQUIZCA, LEE A.; SWANSON, LARRY W.

    2007-01-01

    The spatial distribution of axonal projections descending from rat field CA1 to thalamus and hypothalamus was analyzed previously with the PHAL method (Cenquizca and Swanson, 2006). The same experimental material was used here to define the topography of field CA1 association projections to other cerebral cortical areas. First, the results confirm and extend known intrahippocampal formation inputs to dentate gyrus, subiculum, presubiculum, parasubiculum, and entorhinal area, which are arranged generally along the formation’s transverse axis and dominated by the subicular projection—by far the densest established by field CA1 anywhere in the brain. And second, field CA1 innervates a virtually complete ring of extrahippocampal formation cortex via three routes. A dorsal pathway from the dorsal third of field CA1 innervates moderately the retrosplenial area; a moderately strong ventral pathway from the ventral two-thirds of field CA1 passing through the longitudinal association bundle sends offshoots to visual, auditory, somatosensory, gustatory, main and accessory olfactory, and visceral areas—as well as the basolateral amygdalar complex and the agranular insular and orbital areas; and a cortical-subcortical-cortical pathway through the fornix from the whole longitudinal extent of field CA1 innervates rather strongly a rostral region that includes the tenia tecta along with the anterior cingulate, prelimbic, infralimbic, and orbital areas. The functional consequences of long-term potentiation in field CA1 projection neurons remain to be explored. PMID:17559940

  3. Magnetoencephalographic signatures of insular epileptic spikes based on functional connectivity.

    PubMed

    Zerouali, Younes; Pouliot, Philippe; Robert, Manon; Mohamed, Ismail; Bouthillier, Alain; Lesage, Frédéric; Nguyen, Dang K

    2016-09-01

    Failure to recognize insular cortex seizures has recently been identified as a cause of epilepsy surgeries targeting the temporal, parietal, or frontal lobe. Such failures are partly due to the fact that current noninvasive localization techniques fare poorly in recognizing insular epileptic foci. Our group recently demonstrated that magnetoencephalography (MEG) is sensitive to epileptiform spikes generated by the insula. In this study, we assessed the potential of distributed source imaging and functional connectivity analyses to distinguish insular networks underlying the generation of spikes. Nineteen patients with operculo-insular epilepsy were investigated. Each patient underwent MEG as well as T1-weighted magnetic resonance imaging (MRI) as part of their standard presurgical evaluation. Cortical sources of MEG spikes were reconstructed with the maximum entropy on the mean algorithm, and their time courses served to analyze source functional connectivity. The results indicate that the anterior and posterior subregions of the insula have specific patterns of functional connectivity mainly involving frontal and parietal regions, respectively. In addition, while their connectivity patterns are qualitatively similar during rest and during spikes, couplings within these networks are much stronger during spikes. These results show that MEG can establish functional connectivity-based signatures that could help in the diagnosis of different subtypes of insular cortex epilepsy. Hum Brain Mapp 37:3250-3261, 2016. © 2016 Wiley Periodicals, Inc. PMID:27220112

  4. Electrical stimulation of the insular region attenuates nicotine-taking and nicotine-seeking behaviors.

    PubMed

    Pushparaj, Abhiram; Hamani, Clement; Yu, Wilson; Shin, Damian S; Kang, Bin; Nobrega, José N; Le Foll, Bernard

    2013-03-01

    Pharmacological inactivation of the granular insular cortex is able to block nicotine-taking and -seeking behaviors in rats. In this study, we explored the potential of modulating activity in the insular region using electrical stimulation. Animals were trained to self-administer nicotine (0.03 mg/kg per infusion) under a fixed ratio-5 (FR-5) schedule of reinforcement followed by a progressive ratio (PR) schedule. Evaluation of the effect of stimulation in the insular region was performed on nicotine self-administration under FR-5 and PR schedules, as well on reinstatement of nicotine-seeking behavior induced by nicotine-associated cues or nicotine-priming injections. The effect of stimulation was also examined in brain slices containing insular neurons. Stimulation significantly attenuated nicotine-taking, under both schedules of reinforcement, as well as nicotine-seeking behavior induced by cues and priming. These effects appear to be specific to nicotine-associated behaviors, as stimulation did not have any effect on food-taking behavior. They appear to be anatomically specific, as stimulation surrounding the insular region had no effect on behavior. Stimulation of brain slices containing the insular region was found to inactivate insular neurons. Our results suggest that deep brain stimulation to modulate insular activity should be further explored. PMID:23249816

  5. Differential columnar processing in local circuits of barrel and insular cortices.

    PubMed

    Sato, Hajime; Shimanuki, Yasushi; Saito, Mitsuru; Toyoda, Hiroki; Nokubi, Takashi; Maeda, Yoshinobu; Yamamoto, Takashi; Kang, Youngnam

    2008-03-19

    The columnar organization is most apparent in the whisker barrel cortex but seems less apparent in the gustatory insular cortex. We addressed here whether there are any differences between the two cortices in columnar information processing by comparing the spatiotemporal patterns of excitation spread in the two cortices using voltage-sensitive dye imaging. In contrast to the well known excitation spread in the horizontal direction in layer II/III induced in the barrel cortex by layer IV stimulation, the excitation caused in the insular cortex by stimulation of layer IV spread bidirectionally in the vertical direction into layers II/III and V/VI, displaying a columnar image pattern. Bicuculline or picrotoxin markedly extended the horizontal excitation spread in layer II/III in the barrel cortex, leading to a generation of excitation in the underlying layer V/VI, whereas those markedly increased the amplitude of optical responses throughout the whole column in the insular cortex, subsequently widening the columnar image pattern. Such synchronous activities as revealed by the horizontal and vertical excitation spreads were consistently induced in the barrel and insular cortices, respectively, even by stimulation of different layers with varying intensities. Thus, a unique functional column existed in the insular cortex, in which intracolumnar communication between the superficial and deep layers was prominent, and GABA(A) action is involved in the inhibition of the intracolumnar communication in contrast to its involvement in intercolumnar lateral inhibition in the barrel cortex. These results suggest that the columnar information processing may not be universal across the different cortical areas. PMID:18354011

  6. Relation of the insular claustrum to the neocortex in Insectivora.

    PubMed

    Narkiewicz, O; Mamos, L

    1990-01-01

    The claustra of 9 species of Insectivora (Sorex araneus, Sorex minutus, Tenrec ecaudatus, Solenodon paradoxus, Neomys fodiens, Erinaceus europaeus, Talpa europaea, Desmana moschata, Potamogale velox) were investigated. In all examined animals we found two parts of the insular claustrum: the main part called by us the pars principalis and more medially situated lamina profunda claustri. In the "basal" Insectivora the main part is in close contact with the layer VIa of the neocortex. In some more developed "basal" and in all "progressive" Insectivora the area capsularis appears. Dorsolaterally it separates the main part of the insular claustrum from the neocortex and possesses, besides neurons, also numerous fibers of the extreme capsule. The above data strongly suggest that in the phylogenesis the insular claustrum originates from the cortex from which it gets separated by the extreme capsule. Lamina profunda claustri is rather a narrow band of neurons situated on the medial side of the pars principalis and mostly separated from it by a thin lamina of white substance. Lamina profunda is continuous with the layer VIb of the neocortex. PMID:1707077

  7. Prenatal exposure to moderate levels of ethanol alters social behavior in adult rats: Relationship to structural plasticity and immediate early gene expression in frontal cortex

    PubMed Central

    Hamilton, Derek A.; Akers, Katherine G.; Rice, James P.; Johnson, Travis E.; Candelaria-Cook, Felicha T.; Maes, Levi I.; Rosenberg, Martina; Valenzuela, C. Fernando; Savage, Daniel D.

    2009-01-01

    The goals of the present study were to characterize the effects of prenatal exposure to moderate levels of ethanol on adult social behavior, and to evaluate fetal-ethanol-related effects on dendritic morphology, structural plasticity and activity-related immediate early gene (IEG) expression in the agranular insular (AID) and prelimbic (Cg3) regions of frontal cortex. Baseline fetal-ethanol-related alterations in social behavior were limited to reductions in social investigation in males. Repeated experience with novel cage-mates resulted in comparable increases in wrestling and social investigation among saccharin- and ethanol-exposed females, whereas social behavioral effects among males were more evident in ethanol-exposed animals. Male ethanol-exposed rats also displayed profound increases in wrestling when social interaction was motivated by 24 hours of isolation. Baseline decreases in dendritic length and spine density in AID were observed in ethanol-exposed rats that were always housed with the same cage-mate. Modest experience-related decreases in dendritic length and spine density in AID were observed in saccharin-exposed rats housed with various cage-mates. In contrast, fetal-ethanol-exposed rats displayed experience-related increases in dendritic length in AID, and no experience-related changes in spine density. The only effect observed in Cg3 was a baseline increase in basilar dendritic length among male ethanol-exposed rats. Robust increases in activity-related IEG expression in AID (c-fos and Arc) and Cg3 (c-fos) were observed following social interaction in saccharin-exposed rats, however, activity-related increases in IEG expression were not observed in fetal-ethanol-exposed rats in either region. The results indicate that deficits in social behavior are among the long-lasting behavioral consequences of moderate ethanol exposure during brain development, and implicate AID, and to a lesser degree Cg3, in fetal-ethanol-related social behavior

  8. The Cortical Signature of Central Poststroke Pain: Gray Matter Decreases in Somatosensory, Insular, and Prefrontal Cortices.

    PubMed

    Krause, T; Asseyer, S; Taskin, B; Flöel, A; Witte, A V; Mueller, K; Fiebach, J B; Villringer, K; Villringer, A; Jungehulsing, G J

    2016-01-01

    It has been proposed that cortical structural plasticity plays a crucial role in the emergence and maintenance of chronic pain. Various distinct pain syndromes have accordingly been linked to specific patterns of decreases in regional gray matter volume (GMV). However, it is not known whether central poststroke pain (CPSP) is also associated with cortical structural plasticity. To determine this, we employed T1-weighted magnetic resonance imaging at 3 T and voxel-based morphometry in 45 patients suffering from chronic subcortical sensory stroke with (n = 23) and without CPSP (n = 22), and healthy matched controls (n = 31). CPSP patients showed decreases in GMV in comparison to healthy controls, involving secondary somatosensory cortex (S2), anterior as well as posterior insular cortex, ventrolateral prefrontal and orbitofrontal cortex, temporal cortex, and nucleus accumbens. Comparing CPSP patients to nonpain patients revealed a similar but more restricted pattern of atrophy comprising S2, ventrolateral prefrontal and temporal cortex. Additionally, GMV in the ventromedial prefrontal cortex negatively correlated to pain intensity ratings. This shows for the first time that CPSP is accompanied by a unique pattern of widespread structural plasticity, which involves the sensory-discriminative areas of insular/somatosensory cortex, but also expands into prefrontal cortex and ventral striatum, where emotional aspects of pain are processed. PMID:25129889

  9. Disrupted resting-state insular subregions functional connectivity in post-traumatic stress disorder.

    PubMed

    Zhang, Youxue; Xie, Bing; Chen, Heng; Li, Meiling; Guo, Xiaonan; Chen, Huafu

    2016-07-01

    Post-traumatic stress disorder (PTSD) is suggested to be a structural and functional abnormality in the insula. The insula, which consists of distinct subregions with various patterns of connectivity, displays complex and diverse functions. However, whether these insular subregions have different patterns of connectivity in PTSD remains unclear. Investigating the abnormal functional connectivity of the insular subregions is crucial to reveal its potential effect on diseases specifically PTSD. This study uses a seed-based method to investigate the altered resting-state functional connectivity of insular subregions in PTSD. We found that patients with PTSD showed reduced functional connectivity compared with healthy controls (HCs) between the left ventral anterior insula and the anterior cingulate cortex. The patients with PTSD also exhibited decreased functional connectivity between the right posterior insula and left inferior parietal lobe, and the postcentral gyrus relative to HCs. These results suggest the involvement of altered functional connectivity of insular subregions in the abnormal regulation of emotion and processing of somatosensory information in patients with PTSD. Such impairments in functional connectivity patterns of the insular subregions may advance our understanding of the pathophysiological basis underlying PTSD. PMID:27399097

  10. Microglia in the Cerebral Cortex in Autism

    ERIC Educational Resources Information Center

    Tetreault, Nicole A.; Hakeem, Atiya Y.; Jiang, Sue; Williams, Brian A.; Allman, Elizabeth; Wold, Barbara J.; Allman, John M.

    2012-01-01

    We immunocytochemically identified microglia in fronto-insular (FI) and visual cortex (VC) in autopsy brains of well-phenotyped subjects with autism and matched controls, and stereologically quantified the microglial densities. Densities were determined blind to phenotype using an optical fractionator probe. In FI, individuals with autism had…

  11. Insular erosion, isostasy, and subsidence.

    PubMed

    Menard, H W

    1983-05-27

    Organic reefs and shore erosion record the intersection of sea level with islands. From this record it is possible to reconstruct the history of vertical movement of the islands and the adjacent deep sea floor, including midplate swells. As judged by coral thickness, islands with barrier reefs sink as though they were on thermally youthful crust regardless of the actual age. Reefless islands do not sink until truncated by erosion. Apparently, thermal subsidence is balanced by isostatic uplift in response to erosion. Barrier reefs prevent wave erosion of encircled volcanoes and capture products of stream erosion so that isostatic uplift is eliminated. Insular shelves widen initially at rates of 0.6 to 1.7 kilometers per million years; the rates decrease with time. Thus the subsidence of islands depends on the size of the is land and the presence of reefs, and it may not always be the same as that of the surrounding oceanic crust. PMID:17816008

  12. Perception of odor-induced tastes following insular cortex lesion.

    PubMed

    Stevenson, Richard J; Miller, Laurie A; McGrillen, Ky

    2015-02-01

    Lesions of the insula can affect olfaction and gustation. Here, we examined the effect of insula lesions on taste and taste-like experiences generated via smelling (i.e., odor-induced tastes) in patients with focal insula lesions and intact olfaction. From a set of 16 patients with lesions to the insula, we found 7 (6 with right-sided lesions) who performed normally on various olfactory measures. These were compared to 42 normal control subjects on tests of gustatory and odor-induced taste perception as well as control measures. The patients were impaired relative to controls on most gustatory measures. They were also impaired on tests of odor-induced taste perception, primarily for stimuli presented on the left side. Examining cases individually revealed evidence of a dissociation: two patients exhibited no impairment in odor-induced taste perception in spite of gustatory deficits. Together, these findings suggest that the insula mediates taste recognition, hedonics, and intensity judgments as well as odor-induced taste perception. However, the areas responsible for aspects of taste perception and those responsible for odor-induced taste do not fully overlap each other and they are also independent of olfactory areas. PMID:24308589

  13. Altered insular activation and increased insular functional connectivity during sad and happy face processing in adolescent major depressive disorder

    PubMed Central

    Blom, Eva Henje; Connolly, Colm G.; Ho, Tiffany C.; LeWinn, Kaja Z.; Mobayed, Nisreen; Han, Laura; Paulus, Martin P.; Wu, Jing; Simmons, Alan N.; Yang, Tony T.

    2015-01-01

    Background Major depressive disorder (MDD) is a leading cause of disability worldwide and occurs commonly first during adolescence. The insular cortex (IC) plays an important role in integrating emotion processing with interoception and has been implicated recently in the pathophysiology of adult and adolescent MDD. However, no studies have yet specifically examined the IC in adolescent MDD during processing of faces in the sad- happy continuum. Thus, the aim of the present study is to investigate the IC during sad and happy face processing in adolescents with MDD compared to healthy controls (HCL). Methods Thirty-one adolescents (22 female) with MDD and 36 (23 female) HCL underwent a well-validated emotional processing fMRI paradigm that included sad and happy face stimuli. Results The MDD group showed significantly less differential activation of the anterior/middle insular cortex (AMIC) in response to sad versus happy faces compared to the HCL group. AMIC also showed greater functional connectivity with right fusiform gyrus, left middle frontal gyrus, and right amygdala/parahippocampal gyrus in the MDD compared to HCL group. Moreover, differential activation to sad and happy faces in AMIC correlated negatively with depression severity within the MDD group. Limitations Small age-range and cross-sectional nature precluded assessment of development of the AMIC in adolescent depression. Conclusions Given the role of the IC in integrating bodily stimuli with conscious cognitive and emotional processes, our findings of aberrant AMIC function in adolescent MDD provide a neuroscientific rationale for targeting the AMIC in the development of new treatment modalities. PMID:25827506

  14. Architectonic Distribution of the Serotonin Transporter within the Orbitofrontal Cortex of the Vervet Monkey

    PubMed Central

    Way, Baldwin M.; Laćan, Goran; Fairbanks, Lynn A.; Melega, William P.

    2007-01-01

    To elucidate the organization of the serotoninergic innervation within the orbitofrontal cortex (OFC), serotonin transporter (SERT) density was quantified by autoradiography using [3H]cyanoimipramine binding. In six adult vervet monkeys, 15 architectonic areas were delineated according to cytoarchitectonic (Nissl), myeloarchitectonic (Gallyas) and chemoarchitectonic (Acetylcholinesterase) criteria to assess SERT distribution at two levels of organization: cortical area and cortical type. For cortical type, the 15 areas were evenly divided into three different categories primarily based upon the degree of granularization of layer IV: agranular, dysgranular, and granular. Within agranular and dysgranular, but not granular cortical types, SERT density was area-specific and progressively decreased in a medial to lateral gradient. Across cortical types, SERT density decreased in a caudal to rostral gradient: agranular > dysgranular > granular. A similar caudal to rostral gradient was seen when serotonin content was measured (using HPLC) in areas representative of each cortical type. Collectively, these results suggest that the serotoninergic innervation is organized according to both cortical type and area, and is thus structured to differentially modulate information processing within the OFC. PMID:17766046

  15. Impaired anterior insular activation during risky decision making in young adults with internet gaming disorder.

    PubMed

    Lee, Deokjong; Lee, Junghan; Yoon, Kang Joon; Kee, Namkoong; Jung, Young-Chul

    2016-05-25

    Internet gaming disorder is defined as excessive and compulsive use of the internet to engage in games that leads to clinically significant psychosocial impairment. We tested the hypothesis that individuals with internet gaming disorder would be less sensitive to high-risk situations and show aberrant brain activation related to risk prediction processing. Young adults with internet gaming disorder underwent functional MRI while performing a risky decision-making task. The healthy control group showed stronger activations within the dorsal attention network and the anterior insular cortex, which were not found in the internet gaming disorder group. Our findings imply that young adults with internet gaming disorder show impaired anterior insular activation during risky decision making, which might make them vulnerable when they need to adapt new behavioral strategies in high-risk situations. PMID:27092470

  16. Rat whisker motor cortex is subdivided into sensory-input and motor-output areas

    PubMed Central

    Smith, Jared B.; Alloway, Kevin D.

    2013-01-01

    Rodent whisking is an exploratory behavior that can be modified by sensory feedback. Consistent with this, many whisker-sensitive cortical regions project to agranular motor [motor cortex (MI)] cortex, but the relative topography of these afferent projections has not been established. Intracortical microstimulation (ICMS) evokes whisker movements that are used to map the functional organization of MI, but no study has compared the whisker-related inputs to MI with the ICMS sites that evoke whisker movements. To elucidate this relationship, anterograde tracers were placed in posterior parietal cortex (PPC) and in the primary somatosensory (SI) and secondary somatosensory (SII) cortical areas so that their labeled projections to MI could be analyzed with respect to ICMS sites that evoke whisker movements. Projections from SI and SII terminate in a narrow zone that marks the transition between the medial agranular (AGm) and lateral agranular (AGl) cortical areas, but PPC projects more medially and terminates in AGm proper. Paired recordings of MI neurons indicate that the region between AGm and AGl is highly responsive to whisker deflections, but neurons in AGm display negligible responses to whisker stimulation. By contrast, AGm microstimulation is more effective in evoking whisker movements than microstimulation of the transitional region between AGm and AGl. The AGm region was also found to contain a larger concentration of corticotectal neurons, which could convey whisker-related information to the facial nucleus. These results indicate that rat whisker MI is comprised of at least two functionally distinct subregions: a sensory processing zone in the transitional region between AGm and AGl, and a motor-output region located more medially in AGm proper. PMID:23372545

  17. 27 CFR 479.121 - Insular possessions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Insular possessions. 479.121 Section 479.121 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND...

  18. 27 CFR 479.121 - Insular possessions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Insular possessions. 479.121 Section 479.121 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND...

  19. 27 CFR 479.121 - Insular possessions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Insular possessions. 479.121 Section 479.121 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND...

  20. 27 CFR 479.121 - Insular possessions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Insular possessions. 479.121 Section 479.121 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND...

  1. 27 CFR 479.121 - Insular possessions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Insular possessions. 479.121 Section 479.121 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND...

  2. Retrosplenial cortex in the rhesus monkey: a cytoarchitectonic and Golgi study.

    PubMed

    Vogt, B A

    1976-09-01

    The laminar and cellular structure of retrosplenial cortex in the rhesus monkey was studied with Nissl stained and rapid Golgi impregnated tissue and the results were used to evaluate morphological features of a cortical transition zone. The granular layer of retrosplenial granular cortex is composed primarily of small, density packed, star pyramidal cells. These cells branch within the granular layer itself, while the apical dendrite enters layer I where it branches infrequently or not at all. This cell type is similar to the star pyramid first described by Lorente de No except in its areal and laminar distribution. Cytoarchitectonic observations of retrosplenial agranular cortex show, that, although this area is relatively "agranular" in comparison to other cortical areas, it does possess an incipient layer II and layer IV. These layers are composed mainly of small and medium sized pyramidal cells, but many non-pyramidal cell types were found in these and other layers in this area in rapid Golgi preparations. Stellate cells with beaded or smooth, lightly spinous dendrites were found throughout layer I-IV, while fusiform cells with smooth or very lightly spinous dendrites appear in layers III-VI. Areas surrounding retrosplenial cortex in the posterior cingulate region were also evaluated in Nissl and Golgi preparations including the indusium griseum, subiculum (dorsal to the corpus callosum) and area 23. The laminar and cellular constitutents of retrosplenial cortex were then evaluated in the context of cortical architectonic transition. The transition from one cellular layer in the indusium griseum to five cellular layers in area 23 is made by the addition of layers II, III, IV and VI in retrosplenial cortex to the one ganglionic layer of the indusium griseum and subiculum. Besides the addition and subdivision of layers in retrosplenial cortex, two aspects of cell morphology were found to change in this region. First, the structure of pyramidal cells

  3. Right insular damage decreases heartbeat awareness and alters cardio-visual effects on bodily self-consciousness.

    PubMed

    Ronchi, Roberta; Bello-Ruiz, Javier; Lukowska, Marta; Herbelin, Bruno; Cabrilo, Ivan; Schaller, Karl; Blanke, Olaf

    2015-04-01

    Recent evidence suggests that multisensory integration of bodily signals involving exteroceptive and interoceptive information modulates bodily aspects of self-consciousness such as self-identification and self-location. In the so-called Full Body Illusion subjects watch a virtual body being stroked while they perceive tactile stimulation on their own body inducing illusory self-identification with the virtual body and a change in self-location towards the virtual body. In a related illusion, it has recently been shown that similar changes in self-identification and self-location can be observed when an interoceptive signal is used in association with visual stimulation of the virtual body (i.e., participants observe a virtual body illuminated in synchrony with their heartbeat). Although brain imaging and neuropsychological evidence suggest that the insular cortex is a core region for interoceptive processing (such as cardiac perception and awareness) as well as for self-consciousness, it is currently not known whether the insula mediates cardio-visual modulation of self-consciousness. Here we tested the involvement of insular cortex in heartbeat awareness and cardio-visual manipulation of bodily self-consciousness in a patient before and after resection of a selective right neoplastic insular lesion. Cardio-visual stimulation induced an abnormally enhanced state of bodily self-consciousness; in addition, cardio-visual manipulation was associated with an experienced loss of the spatial unity of the self (illusory bi-location and duplication of his body), not observed in healthy subjects. Heartbeat awareness was found to decrease after insular resection. Based on these data we propose that the insula mediates interoceptive awareness as well as cardio-visual effects on bodily self-consciousness and that insular processing of interoceptive signals is an important mechanism for the experienced unity of the self. PMID:25676677

  4. ADORA2A genotype modulates interoceptive and exteroceptive processing in a fronto-insular network.

    PubMed

    Geiger, Maximilian J; Domschke, Katharina; Homola, György A; Schulz, Stefan M; Nowak, Johannes; Akhrif, Atae; Pauli, Paul; Deckert, Jürgen; Neufang, Susanne

    2016-08-01

    Facilitated processing of interoceptive and exteroceptive information in the salience network is suggested to promote the development of anxiety and anxiety disorders. Here, it was investigated whether the adenosine 2 A receptor gene (ADORA2A) 1976T/C (rs5751876) variant - previously associated with anxiety disorders and anxiety-related phenotypes as well as general attentional efficiency -was involved in the regulation of this network. In detail, fMRI recordings of 65 healthy participants (female=35) were analyzed regarding ADORA2A genotype effects on brain connectivity related to (1) interoceptive processing in terms of functional connectivity resting-state fMRI, and (2) exteroceptive processing using dynamic causal modeling in task-based fMRI. In a subsample, cardiac interoceptive accuracy was furthermore measured via the Mental Tracking Task. ADORA2A genotype was found to modulate a fronto-insular network at rest (interoceptive processing) and while performing an executive control task (exteroceptive processing). Across both modalities, the ADORA2A TT risk genotype was associated with increased connectivity between the insula and the prefrontal cortex. The strength in connectivity correlated with interoceptive accuracy. It is concluded that alterations in fronto-insular connectivity are modulated by both the adenosinergic system and interoceptive accuracy. Thus, fronto-insular connectivity in synopsis with ADORA2A genotypic information could serve as combined biomarkers for personalized treatment approaches in anxiety disorders targeting exteroceptive and interoceptive dysfunction. PMID:27262510

  5. Insular neural system controls decision-making in healthy and methamphetamine-treated rats.

    PubMed

    Mizoguchi, Hiroyuki; Katahira, Kentaro; Inutsuka, Ayumu; Fukumoto, Kazuya; Nakamura, Akihiro; Wang, Tian; Nagai, Taku; Sato, Jun; Sawada, Makoto; Ohira, Hideki; Yamanaka, Akihiro; Yamada, Kiyofumi

    2015-07-21

    Patients suffering from neuropsychiatric disorders such as substance-related and addictive disorders exhibit altered decision-making patterns, which may be associated with their behavioral abnormalities. However, the neuronal mechanisms underlying such impairments are largely unknown. Using a gambling test, we demonstrated that methamphetamine (METH)-treated rats chose a high-risk/high-reward option more frequently and assigned higher value to high returns than control rats, suggestive of changes in decision-making choice strategy. Immunohistochemical analysis following the gambling test revealed aberrant activation of the insular cortex (INS) and nucleus accumbens in METH-treated animals. Pharmacological studies, together with in vivo microdialysis, showed that the insular neural system played a crucial role in decision-making. Moreover, manipulation of INS activation using designer receptor exclusively activated by designer drug technology resulted in alterations to decision-making. Our findings suggest that the INS is a critical region involved in decision-making and that insular neural dysfunction results in risk-taking behaviors associated with altered decision-making. PMID:26150496

  6. Insular neural system controls decision-making in healthy and methamphetamine-treated rats

    PubMed Central

    Mizoguchi, Hiroyuki; Katahira, Kentaro; Inutsuka, Ayumu; Fukumoto, Kazuya; Nakamura, Akihiro; Wang, Tian; Nagai, Taku; Sato, Jun; Sawada, Makoto; Ohira, Hideki; Yamanaka, Akihiro; Yamada, Kiyofumi

    2015-01-01

    Patients suffering from neuropsychiatric disorders such as substance-related and addictive disorders exhibit altered decision-making patterns, which may be associated with their behavioral abnormalities. However, the neuronal mechanisms underlying such impairments are largely unknown. Using a gambling test, we demonstrated that methamphetamine (METH)-treated rats chose a high-risk/high-reward option more frequently and assigned higher value to high returns than control rats, suggestive of changes in decision-making choice strategy. Immunohistochemical analysis following the gambling test revealed aberrant activation of the insular cortex (INS) and nucleus accumbens in METH-treated animals. Pharmacological studies, together with in vivo microdialysis, showed that the insular neural system played a crucial role in decision-making. Moreover, manipulation of INS activation using designer receptor exclusively activated by designer drug technology resulted in alterations to decision-making. Our findings suggest that the INS is a critical region involved in decision-making and that insular neural dysfunction results in risk-taking behaviors associated with altered decision-making. PMID:26150496

  7. Predictive coding accounts of shared representations in parieto-insular networks.

    PubMed

    Ishida, Hiroaki; Suzuki, Keisuke; Grandi, Laura Clara

    2015-04-01

    The discovery of mirror neurons in the ventral premotor cortex (area F5) and inferior parietal cortex (area PFG) in the macaque monkey brain has provided the physiological evidence for direct matching of the intrinsic motor representations of the self and the visual image of the actions of others. The existence of mirror neurons implies that the brain has mechanisms reflecting shared self and other action representations. This may further imply that the neural basis self-body representations may also incorporate components that are shared with other-body representations. It is likely that such a mechanism is also involved in predicting other's touch sensations and emotions. However, the neural basis of shared body representations has remained unclear. Here, we propose a neural basis of body representation of the self and of others in both human and non-human primates. We review a series of behavioral and physiological findings which together paint a picture that the systems underlying such shared representations require integration of conscious exteroception and interoception subserved by a cortical sensory-motor network involving parieto-inner perisylvian circuits (the ventral intraparietal area [VIP]/inferior parietal area [PFG]-secondary somatosensory cortex [SII]/posterior insular cortex [pIC]/anterior insular cortex [aIC]). Based on these findings, we propose a computational mechanism of the shared body representation in the predictive coding (PC) framework. Our mechanism proposes that processes emerging from generative models embedded in these specific neuronal circuits play a pivotal role in distinguishing a self-specific body representation from a shared one. The model successfully accounts for normal and abnormal shared body phenomena such as mirror-touch synesthesia and somatoparaphrenia. In addition, it generates a set of testable experimental predictions. PMID:25447372

  8. A cutaneous agranular CD2- CD4+ CD56+ "lymphoma": report of two cases and review of the literature.

    PubMed

    Kameoka, J; Ichinohasama, R; Tanaka, M; Miura, I; Tomiya, Y; Takahashi, S; Yamada, M; Ishikawa, I; Kadowaki, I; Sasaki, O; Kimura, J; Meguro, K; Ooya, K; Ito, S

    1998-10-01

    We report 2 cases of agranular CD2- CD4+ CD56+ non-Hodgkin lymphoma in which skin seemed to be the primary site. A 21-year-old woman's initial symptom was a skin nodule on the right cheek. She also had tumors in the nasopharynx, and the bone marrow subsequently became involved. No lymphadenopathy was present. She experienced complete remission after dose-intensified therapy with cyclophosphamide, hydroxydaunomycin, vincristine [Oncovin], and prednisone (CHOP), but the disease relapsed in the central nervous system 6 months later. An 81-year-old man experienced an 11-month history of skin nodules in the left forearm. On admission, he had a bone marrow infiltration of lymphoma cells. He died of pneumonia during chemotherapy. The malignant cells of the 2 patients had similar morphologic features, with a monocytoid nucleus and no cytoplasmic granules. The cells in both cases showed a unique phenotype: CD2-, CD3-, CD4+, CD8-, CD13-, CD14-, CD34-, CD16-, CD56+, CD57-, HLA-DR-positive. Staining for peroxidase and alpha-naphthyl butyrate esterase was negative. The T-cell receptor beta, gamma, delta, IgH, kappa, lambda genes were of germ line configurations. The DNA of Epstein-Barr virus was not detected from the bone marrow cells by polymerase chain reaction. Only 3 other cases with similar phenotypes have been reported; all had skin lesions. Although the origin of these cells remains unknown, we propose that this is a distinct clinicopathologic entity. PMID:9763034

  9. The orbitofrontal cortex: novelty, deviation from expectation, and memory.

    PubMed

    Petrides, Michael

    2007-12-01

    The orbitofrontal cortex is strongly connected with limbic areas of the medial temporal lobe that are critically involved in the establishment of declarative memories (entorhinal and perirhinal cortex and the hippocampal region) as well as the amygdala and the hypothalamus that are involved in emotional and motivational states. The present article reviews evidence regarding the role of the orbitofrontal cortex in the processing of novel information, breaches of expectation, and memory. Functional neuroimaging evidence is provided that there is a difference between the anterior and posterior orbitofrontal cortex in such processing. Exposure to novel information gives rise to a selective increase of activity in the granular anterior part of the orbitofrontal cortex (area 11) and this activity increases when subjects attempt to encode this information in memory. If the stimuli violate expectations (e.g., inspection of graffiti-like stimuli in the context of other regular stimuli) or are unpleasant (i.e., exposure to the sounds of car crashes), there is increased response in the posteromedial agranular/dysgranular area 13 of the orbitofrontal region. The anatomic data provide a framework within which to understand these functional neuroimaging findings. PMID:17872393

  10. Multiarchitectonic characterization of insular, perirhinal and related regions in a basal mammal, Echinops telfairi.

    PubMed

    Künzle, H; Radtke-Schuller, S

    2000-12-01

    The rhinal cortex was investigated in the Madagascan lesser hedgehog tenrec, a basal placental mammal. This region parallels the rhinal indentation and presumably contains the equivalents of the insular and perirhinal cortices. Using cyto- and myeloarchitectural, enzyme- and immunohistochemical criteria as well as data on the connections with the olfactory bulb, the rhinal cortex was subdivided tentatively along its rostrocaudal and dorsoventral planes. An area caudally adjacent to the rhinal cortex received a prominent input from the olfactory bulb and was also preliminarily characterized in this study. Because previous studies in insectivores remained controversial with regard to the identification of the claustrum, special attention was paid to the laminar organization of the rhinal cortex and its deep cell groups. The tenrec's claustrum was identified and delineated cytoarchitecturally and by its negative acetylcholinesterase stain. Latexin, a molecular marker for characterizing infragranular and claustral cells, also helped to differentiate the claustrum from the cell groups subjacent to it. Thus, the data indicate that in poorly differentiated mammals the claustrum occupies an intermediate deep position within the width of the rhinal cortex, i.e., it is separated from the subcortical white matter by additional, still unidentified, cell groups. PMID:11131017

  11. 38 CFR 3.40 - Philippine and Insular Forces.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Forces. 3.40 Section 3.40 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS... Insular Forces. (a) Regular Philippine Scouts. Service in the Philippine Scouts (except that described in paragraph (b) of this section), the Insular Force of the Navy, Samoan Native Guard, and Samoan Native...

  12. 38 CFR 3.40 - Philippine and Insular Forces.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Forces. 3.40 Section 3.40 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS... Insular Forces. (a) Regular Philippine Scouts. Service in the Philippine Scouts (except that described in paragraph (b) of this section), the Insular Force of the Navy, Samoan Native Guard, and Samoan Native...

  13. 38 CFR 3.40 - Philippine and Insular Forces.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Forces. 3.40 Section 3.40 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS... Insular Forces. (a) Regular Philippine Scouts. Service in the Philippine Scouts (except that described in paragraph (b) of this section), the Insular Force of the Navy, Samoan Native Guard, and Samoan Native...

  14. 38 CFR 3.40 - Philippine and Insular Forces.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Forces. 3.40 Section 3.40 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS... Insular Forces. (a) Regular Philippine Scouts. Service in the Philippine Scouts (except that described in paragraph (b) of this section), the Insular Force of the Navy, Samoan Native Guard, and Samoan Native...

  15. 38 CFR 3.40 - Philippine and Insular Forces.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Forces. 3.40 Section 3.40 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS... Insular Forces. (a) Regular Philippine Scouts. Service in the Philippine Scouts (except that described in paragraph (b) of this section), the Insular Force of the Navy, Samoan Native Guard, and Samoan Native...

  16. Cigarette smoking is associated with thinner cingulate and insular cortices in patients with severe mental illness

    PubMed Central

    Jørgensen, Kjetil Nordbø; Psychol, Cand; Skjærvø, Ingeborg; Mørch-Johnsen, Lynn; Haukvik, Unn Kristin; Lange, Elisabeth Heffermehl; Melle, Ingrid; Andreassen, Ole Andreas; Agartz, Ingrid

    2015-01-01

    Background Magnetic resonance imaging (MRI) studies show reduced cortical thickness in patients with schizophrenia and bipolar disorder. These subtle brain abnormalities may provide insight into illness mechanisms. However, environmental and lifestyle-related factors, such as cigarette smoking, may contribute to brain structure changes. Cigarette smoking is highly prevalent in patients with severe mental illness. In nonpsychiatric samples, smoking has been associated with reduced thickness in the anterior (ACC) and posterior cingulate cortices, the insular cortex (INS), the dorsolateral prefrontal cortex and the orbitofrontal cortex. Methods We examined MRI scans from patients with schizophrenia, other psychotic disorders or bipolar disorder and healthy controls using FreeSurfer. Results We included 506 patients (49% smokers) and 237 controls (20% smokers) in our study. We found reduced cortical thickness in the left rostral ACC and the left INS in smoking patients compared with nonsmoking patients, but this difference was not found among healthy controls. No dose–response relationship was found between amount of smoking and cortical thickness in these regions. Among patients, maps of thickness along the whole cortical surface revealed reduced insular thickness but no effects in other regions. Among healthy controls, similar analyses revealed increased age-related cortical thinning in the left occipital lobe among smokers compared with nonsmokers. Limitations The causal direction could not be determined owing to the cross-sectional design and lack of detailed data on smoking addiction and smoking history. Conclusion The effect of cigarette smoking should be considered in MRI studies of patients with severe mental illness. PMID:25672482

  17. Extensive Clonality and Strong Differentiation in the Insular Pacific Tree Santalum insulare: Implications for its Conservation

    PubMed Central

    LHUILLIER, EMELINE; BUTAUD, JEAN-FRANÇOIS; BOUVET, JEAN-MARC

    2006-01-01

    • Background and Aims The impact of evolutionary forces on insular systems is particularly exacerbated by the remoteness of islands, strong founder effects, small population size and the influence of biotic and abiotic factors. Patterns of molecular diversity were analysed in an island system with Santalum insulare, a sandalwood species endemic to eastern Polynesia. The aims were to evaluate clonality and to study the genetic diversity and structure of this species, in order to understand the evolutionary process and to define a conservation strategy. • Methods Eight nuclear microsatellites were used to investigate clonality, genetic variation and structure of the French Polynesian sandalwood populations found on ten islands distributed over three archipelagos. • Key Results It was found that 58 % of the 384 trees analysed were clones. The real size of the populations is thus dramatically reduced, with sometimes only one genet producing ramets by root suckering. The diversity parameters were low for islands (nA = 1·5–5·0; HE = 0·28–0·49). No departure from Hardy–Weinberg proportion was observed except within Tahiti island, where a significant excess of homozygotes was noted in the highland population. Genetic structure was characterized by high levels of differentiation between archipelagos (27 % of the total variation) and islands (FST = 0·50). The neighbour-joining tree did not discriminate the three archipelagos but separated the Society archipelago from the other two. • Conclusions This study shows that clonality is a frequent phenomenon in S. insulare. The genetic diversity within populations is lower than the values assessed in species distributed on the mainland, as a consequence of insularity. But this can also be explained by the overexploitation of sandalwood. The differentiation between archipelagos and islands within archipelagos is very high because of the limited gene flow due to oceanic barriers. Delineation of evolutionary

  18. Parasite richness and abundance in insular and mainland feral cats: insularity or density?

    PubMed

    Fromont, E; Morvilliers, L; Artois, M; Pontier, D

    2001-08-01

    Hosts living on islands carry few parasite species, and the prevalence and intensity of directly transmitted parasites are often higher in insular than in mainland populations. However, it is unclear whether density or other features of insular populations can be responsible for the pattern observed. We compared the parasite richness, prevalence and intensity of parasites between 2 feral populations of cats living either at low density on an island (Kerguelen) or at high density on the mainland (Lyon). Parasite richness was higher in Lyon than in Kerguelen, where only Toxocara cati was found. T. cati egg prevalence was higher in Kerguelen (71.1%) than in Lyon (58.0%). Because cat density cannot explain this pattern, we propose that the low number of parasite species, the diet and/or immunity of cats act to increase prevalence in Kerguelen. Moreover, prevalence, intensity and variance-to-mean ratio increased with age and body mass in Kerguelen whereas, in Lyon, prevalence decreased with age and body mass. We hypothesize that the pattern of exposure differs between populations, and that density-dependent parasite mortality is lower in Kerguelen than in Lyon. We discuss the consequences concerning the influence of parasites on insular host populations. PMID:11510679

  19. Impulsivity is Associated with Increased Metabolism in the Fronto-Insular Network in Parkinson’s Disease

    PubMed Central

    Tahmasian, Masoud; Rochhausen, Luisa; Maier, Franziska; Williamson, Kim L.; Drzezga, Alexander; Timmermann, Lars; Van Eimeren, Thilo; Eggers, Carsten

    2015-01-01

    Various neuroimaging studies demonstrated that the fronto-insular network is implicated in impulsive behavior. We compared glucose metabolism (as a proxy measure of neural activity) among 24 patients with Parkinson’s disease (PD) who presented with low or high levels of impulsivity based on the Barratt Impulsiveness Scale 11 (BIS) scores. Subjects underwent 18-fluorodeoxyglucose positron emission tomography (FDG-PET) and the voxel-wise group difference of FDG-metabolism was analyzed in Statistical Parametric Mapping (SPM8). Subsequently, we performed a partial correlation analysis between the FDG-metabolism and BIS scores, controlling for covariates (i.e., age, sex, severity of disease and levodopa equivalent daily doses). Voxel-wise group comparison revealed higher FDG-metabolism in the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), and right insula in patients with higher impulsivity scores. Moreover, there was a positive correlation between the FDG-metabolism and BIS scores. Our findings provide evidence that high impulsivity is associated with increased FDG-metabolism within the fronto-insular network in PD. PMID:26648853

  20. Report to Congress on Insular Area energy vulnerability

    SciTech Connect

    Not Available

    1994-05-01

    This report was prepared in response to Section 1406 of the Energy Policy Act of 1992 (Public Law 102-486), which directed the Department of Energy (DOE) to ``conduct a study of the implications of the unique vulnerabilities of the insular areas to an oil supply disruption,`` and to ``outline how the insular areas shall gain access to vital oil supplies during times of national emergency.`` The Act defines the insular areas to be the US Virgin Islands and Puerto Rico in the Caribbean, and Guam, American Samoa, the Commonwealth of the Northern Mariana Islands (CNMI), and Palau in the Pacific. In the study, ``unique vulnerabilities`` were defined as susceptibility to: (1) more frequent or more likely interruptions of oil supplies compared to the US Mainland, and/or (2) disproportionately larger or more likely economic losses in the event of an oil supply disruption. In order to assess unique vulnerabilities, the study examined the insular areas` experience during past global disruptions of oil supplies and during local emergencies caused by natural disasters. The effects of several possible future global disruptions and local emergencies were also analyzed. Analyses were based on historical data, simulations using energy and economic models, and interviews with officials in the insular governments and the energy industry.

  1. Lights and shadows in the evolutionary patterns of insular bovids.

    PubMed

    Rozzi, Roberto; Palombo, Maria Rita

    2014-03-01

    Endemic bovids are intriguing elements of insular faunas. The living species include the Japanese serow (Capricornis crispus) and the Formosan serow (C. swinhoei), the tamaraw from Mindoro, Philippines, (Bubalus mindorensis) and the anoas (B. depressicornis and B. quarlesi), 2 species of dwarf buffalos endemic to Sulawesi, Indonesia. Fossil endemic bovids are only recorded in some Asian, North American and Western Mediterranean islands. Here we present a comprehensive overview of the changes in body size and evolutionary patterns exhibited by both extant and extinct insular bovids. Our appraisal indicates that each insular representative of Bovidae shows its own peculiar evolutionary model, albeit some parallel trends exist (e.g. reduction in body size, allometric changes in limb bones, alteration of the life history traits). Some changes in morphology (e.g. the simplification of horn cores, the increase in hypsodonty, the acquisition of a 'low-gear' locomotion), for instance, appear as common, albeit not general, patterns triggered by a combination of selective forces. Body size patterns support the 'generality of the island rule' and suggest that biotic interaction had/have a major role in influencing body size evolution in these species, although in different ways on different islands. All things considered, available evidence suggest that a major role in the evolution of insular bovids is played by the structure of the insular community, the nature of available niches and by the dynamics of ecological interactions. PMID:24673764

  2. Distortion of time interval reproduction in an epileptic patient with a focal lesion in the right anterior insular/inferior frontal cortices.

    PubMed

    Monfort, Vincent; Pfeuty, Micha; Klein, Madelyne; Collé, Steffie; Brissart, Hélène; Jonas, Jacques; Maillard, Louis

    2014-11-01

    This case report on an epileptic patient suffering from a focal lesion at the junction of the right anterior insular cortex (AIC) and the adjacent inferior frontal cortex (IFC) provides the first evidence that damage to this brain region impairs temporal performance in a visual time reproduction task in which participants had to reproduce the presentation duration (3, 5 and 7s) of emotionally-neutral and -negative pictures. Strikingly, as compared to a group of healthy subjects, the AIC/IFC case considerably overestimated reproduction times despite normal variability. The effect was obtained in all duration and emotion conditions. Such a distortion in time reproduction was not observed in four other epileptic patients without insular or inferior frontal damage. Importantly, the absolute extent of temporal over-reproduction increased in proportion to the magnitude of the target durations, which concurs with the scalar property of interval timing, and points to an impairment of time-specific rather than of non temporal (such as motor) mechanisms. Our data suggest that the disability in temporal reproduction of the AIC/IFC case would result from a distorted memory representation of the encoded duration, occurring during the process of storage and/or of recovery from memory and leading to a deviation of the temporal judgment during the reproduction task. These findings support the recent proposal that the anterior insular/inferior frontal cortices would be involved in time interval representation. PMID:25223467

  3. Forest fires in the insular Caribbean.

    PubMed

    Robbins, A Marcus J; Eckelmann, Claus-Martin; Quiñones, Maya

    2008-12-01

    This paper presents a summary of the forest fire reports in the insular Caribbean derived from both management reports and an analysis of publicly available Moderate Resolution Imaging Spectrodiometer (MODIS) satellite active fire products from the region. A vast difference between the amount of fires reported by land managers and fire points in the MODIS Fire Information for Resource Management System data can be observed. Future research is recommended to better understand the nature of these differences. While there is a general lack of available statistical data on forest fires in the Caribbean, a few general observations can be made: Forest fires occur mainly in dry forest types (500 to 1000 mm of mean annual rainfall). These are also the areas where most human settlements are located. Lowland high forests and montane forests with higher rainfall (1000 and more mm y(-1)) are less susceptible to forest fire, but they can burn in exceptionally dry years. Most of the dry forest ecosystems in the Caribbean can be considered to be fire-sensitive ecosystems, while the pine forests in the Caribbean (Cuba, Dominican Republic, and the Bahamas) are maintained by wildfires. In fire-sensitive ecosystems, uncontrolled burning often encourages the spread of alien invasive species. A Caribbean Fire Management Cooperation Strategy was developed between 2005 and 2006 under auspices of the Food and Agriculture Organization of the United Nations. This regional strategy aims to strengthen Caribbean fire management networking by encouraging closer collaboration among countries with similar ecological conditions. The strategy for the Caribbean identifies a number of research, training, and management activities to improve wildfire management capacity in the Caribbean. PMID:19205174

  4. The anterior insular and anterior cingulate cortices in emotional processing for self-face recognition.

    PubMed

    Morita, Tomoyo; Tanabe, Hiroki C; Sasaki, Akihiro T; Shimada, Koji; Kakigi, Ryusuke; Sadato, Norihiro

    2014-05-01

    Individuals can experience embarrassment when exposed to self-feedback images, depending on the extent of the divergence from the internal representation of the standard self. Our previous work implicated the anterior insular cortex (AI) and the anterior cingulate cortex (ACC) in the processing of embarrassment; however, their exact functional contributions have remained uncertain. Here, we explored the effects of being observed by others while viewing self-face images on the extent of embarrassment, and the activation and connectivity patterns in the AI and ACC. We conducted functional magnetic resonance imaging hyperscanning in pairs of healthy participants using an interaction system that allowed an individual to be observed by a partner in real time. Being observed increased the extent of embarrassment reported when viewing self-face images; a corresponding increase in self-related activity in the right AI suggested that this region played a direct role in the subjective experience. Being observed also increased the functional connectivity between the caudal ACC and prefrontal regions, which are involved in processing the reflective self. The ACC might therefore serve as a hub, integrating information about the reflective self that is used in evaluating perceptual self-face images. PMID:23377900

  5. The anterior insular and anterior cingulate cortices in emotional processing for self-face recognition

    PubMed Central

    Morita, Tomoyo; Tanabe, Hiroki C.; Sasaki, Akihiro T.; Shimada, Koji; Kakigi, Ryusuke

    2014-01-01

    Individuals can experience embarrassment when exposed to self-feedback images, depending on the extent of the divergence from the internal representation of the standard self. Our previous work implicated the anterior insular cortex (AI) and the anterior cingulate cortex (ACC) in the processing of embarrassment; however, their exact functional contributions have remained uncertain. Here, we explored the effects of being observed by others while viewing self-face images on the extent of embarrassment, and the activation and connectivity patterns in the AI and ACC. We conducted functional magnetic resonance imaging hyperscanning in pairs of healthy participants using an interaction system that allowed an individual to be observed by a partner in real time. Being observed increased the extent of embarrassment reported when viewing self-face images; a corresponding increase in self-related activity in the right AI suggested that this region played a direct role in the subjective experience. Being observed also increased the functional connectivity between the caudal ACC and prefrontal regions, which are involved in processing the reflective self. The ACC might therefore serve as a hub, integrating information about the reflective self that is used in evaluating perceptual self-face images. PMID:23377900

  6. 24 CFR 570.405 - The insular areas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... met in accordance with 24 CFR 58.22, and with the understanding that HUD has no obligation whatsoever... under any of the following circumstances: (1) When local environmental reviews under 24 CFR part 58 have... 24 Housing and Urban Development 3 2011-04-01 2010-04-01 true The insular areas. 570.405...

  7. Ideas on the Margins: Professional Counseling and Ideological Insularity

    ERIC Educational Resources Information Center

    Hansen, James

    2010-01-01

    Efforts to professionalize counseling practice have yielded extraordinary benefits to counselors. However, professionalization has also caused counselors to adopt strict definitions of their education, practices, and ethics. In order to combat the ideological insularity brought on by professionalization, several marginalized ideas are considered.…

  8. 24 CFR 35.940 - Special requirements for insular areas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Special requirements for insular areas. 35.940 Section 35.940 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL...

  9. 24 CFR 35.940 - Special requirements for insular areas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Special requirements for insular areas. 35.940 Section 35.940 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL...

  10. 24 CFR 35.940 - Special requirements for insular areas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Special requirements for insular areas. 35.940 Section 35.940 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL...

  11. 24 CFR 35.940 - Special requirements for insular areas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Special requirements for insular areas. 35.940 Section 35.940 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL...

  12. 24 CFR 35.940 - Special requirements for insular areas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Special requirements for insular areas. 35.940 Section 35.940 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL...

  13. 75 FR 20237 - Interagency Group on Insular Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-19

    ..., 2010. [FR Doc. 2010-9078 Filed 4-16-10; 8:45 am] Billing code 3195-W0-P ...#0;#0; #0; #0;Title 3-- #0;The President ] Executive Order 13537 of April 14, 2010 Interagency Group... United States of America, it is hereby ordered as follows: Section 1. Interagency Group on Insular...

  14. Second Surgery in Insular Low-Grade Gliomas

    PubMed Central

    Ius, Tamara; Pauletto, Giada; Cesselli, Daniela; Isola, Miriam; Turella, Luca; Budai, Riccardo; DeMaglio, Giovanna; Eleopra, Roberto; Fadiga, Luciano; Lettieri, Christian; Pizzolitto, Stefano; Beltrami, Carlo Alberto; Skrap, Miran

    2015-01-01

    Background. Given the technical difficulties, a limited number of works have been published on insular gliomas surgery and risk factors for tumor recurrence (TR) are poorly documented. Objective. The aim of the study was to determine TR in adult patients with initial diagnosis of insular Low-Grade Gliomas (LGGs) that subsequently underwent second surgery. Methods. A consecutive series of 53 patients with insular LGGs was retrospectively reviewed; 23 patients had two operations for TR. Results. At the time of second surgery, almost half of the patients had experienced progression into high-grade gliomas (HGGs). Univariate analysis showed that TR is influenced by the following: extent of resection (EOR) (P < 0.002), ΔVT2T1 value (P < 0.001), histological diagnosis of oligodendroglioma (P = 0.017), and mutation of IDH1 (P = 0.022). The multivariate analysis showed that EOR at first surgery was the independent predictor for TR (P < 0.001). Conclusions. In patients with insular LGG the EOR at first surgery represents the major predictive factor for TR. At time of TR, more than 50% of cases had progressed in HGG, raising the question of the oncological management after the first surgery. PMID:26539503

  15. 24 CFR 570.441 - Citizen participation-insular areas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) General. An insular area jurisdiction submitting an abbreviated consolidated plan under 24 CFR 91.235... jurisdiction submitting a complete consolidated plan in accordance with 24 CFR 91.200 through 91.230 shall... Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  16. 24 CFR 570.441 - Citizen participation-insular areas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) General. An insular area jurisdiction submitting an abbreviated consolidated plan under 24 CFR 91.235... jurisdiction submitting a complete consolidated plan in accordance with 24 CFR 91.200 through 91.230 shall... Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  17. 24 CFR 570.442 - Reallocations-Insular Areas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Reallocations-Insular Areas. 570.442 Section 570.442 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  18. 24 CFR 570.441 - Citizen participation-insular areas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) General. An insular area jurisdiction submitting an abbreviated consolidated plan under 24 CFR 91.235... jurisdiction submitting a complete consolidated plan in accordance with 24 CFR 91.200 through 91.230 shall... Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  19. 24 CFR 570.441 - Citizen participation-insular areas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) General. An insular area jurisdiction submitting an abbreviated consolidated plan under 24 CFR 91.235... jurisdiction submitting a complete consolidated plan in accordance with 24 CFR 91.200 through 91.230 shall... Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  20. 24 CFR 570.442 - Reallocations-Insular Areas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 3 2011-04-01 2010-04-01 true Reallocations-Insular Areas. 570.442 Section 570.442 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT OF HOUSING...

  1. 24 CFR 570.442 - Reallocations-Insular Areas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 3 2014-04-01 2013-04-01 true Reallocations-Insular Areas. 570.442 Section 570.442 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT OF HOUSING...

  2. 24 CFR 570.442 - Reallocations-Insular Areas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 3 2012-04-01 2012-04-01 false Reallocations-Insular Areas. 570.442 Section 570.442 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  3. 24 CFR 570.441 - Citizen participation-insular areas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) General. An insular area jurisdiction submitting an abbreviated consolidated plan under 24 CFR 91.235... jurisdiction submitting a complete consolidated plan in accordance with 24 CFR 91.200 through 91.230 shall... Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  4. 24 CFR 570.442 - Reallocations-Insular Areas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 3 2013-04-01 2013-04-01 false Reallocations-Insular Areas. 570.442 Section 570.442 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  5. Asymmetrical intersection between the middle cerebral artery and rhinal vein suggests asymmetrical gustatory cortex location in rodent hemispheres.

    PubMed

    Kida, Ikuhiro; Enmi, Jun-Ichiro; Iida, Hidehiro; Yoshioka, Yoshichika

    2015-03-01

    The rodent gustatory cortex is located in the anterior part of the insular cortex, which is near the dorsal part of the rhinal vein (RHV) and the intersection of the anterior and posterior regions of the middle cerebral artery (MCA). Thus, the intersection between the RHV and MCA is used as a landmark for the rodent gustatory cortex. In our previous study, we employed functional magnetic resonance imaging (MRI) to demonstrate that tastants evoked bilateral responses in the rodent insular cortices, but that these representations were asymmetrical between the hemispheres. In the present study, to clarify the observed asymmetrical responses, we performed magnetic resonance angiography in a 7.0-Tesla MRI scanner to determine the anatomical position of the rodent gustatory cortex, which was identified using the intersection of the MCA and RHV. We successfully observed the intersection while administering carbogen as an inhaled gas and found that the intersection in the left hemisphere is more anterior compared to that in the right hemisphere. Taken together with the previous functional MRI results, this result indicates that the gustatory representation in relation to the intersection may be identically conserved in the insular cortex of both hemispheres; therefore, the rodent gustatory cortex may be asymmetrically located between the left and right hemispheres. The result also suggests that this landmark location needs to be verified when investigating gustatory representations and responses. PMID:25578950

  6. Body Size Evolution in Insular Speckled Rattlesnakes (Viperidae: Crotalus mitchellii)

    PubMed Central

    Meik, Jesse M.; Lawing, A. Michelle; Pires-daSilva, André

    2010-01-01

    Background Speckled rattlesnakes (Crotalus mitchellii) inhabit multiple islands off the coast of Baja California, Mexico. Two of the 14 known insular populations have been recognized as subspecies based primarily on body size divergence from putative mainland ancestral populations; however, a survey of body size variation from other islands occupied by these snakes has not been previously reported. We examined body size variation between island and mainland speckled rattlesnakes, and the relationship between body size and various island physical variables among 12 island populations. We also examined relative head size among giant, dwarfed, and mainland speckled rattlesnakes to determine whether allometric differences conformed to predictions of gape size (and indirectly body size) evolving in response to shifts in prey size. Methodology/Principal Findings Insular speckled rattlesnakes show considerable variation in body size when compared to mainland source subspecies. In addition to previously known instances of gigantism on Ángel de la Guarda and dwarfism on El Muerto, various degrees of body size decrease have occurred frequently in this taxon, with dwarfed rattlesnakes occurring mostly on small, recently isolated, land-bridge islands. Regression models using the Akaike information criterion (AIC) showed that mean SVL of insular populations was most strongly correlated with island area, suggesting the influence of selection for different body size optima for islands of different size. Allometric differences in head size of giant and dwarf rattlesnakes revealed patterns consistent with shifts to larger and smaller prey, respectively. Conclusions/Significance Our data provide the first example of a clear relationship between body size and island area in a squamate reptile species; among vertebrates this pattern has been previously documented in few insular mammals. This finding suggests that selection for body size is influenced by changes in community dynamics

  7. Indocyanine green as an adjunct for resection of insular gliomas

    PubMed Central

    Shah, Abhidha; Rangarajan, Vithal; Kaswa, Amol; Jain, Sonal; Goel, Atul

    2016-01-01

    Objective: Many controversies exist regarding the extent of resection for insular gliomas and the timing of resection. Several techniques and adjuncts are used to maximize safety during resection of these tumors. We describe the use of indocyanine green (ICG) to identify the branches of the middle cerebral artery and discuss its utility to increase safety for resection for insular gliomas. Materials and Methods: Five patients with insular gliomas were surgically treated by the authors from June 2013 to June 2014. The patients presented with complaints of either a headache or recurring episodes of convulsions. All the patients were operated with the aid of neuronavigation and tractography. The long perforating branches of the middle cerebral artery course through the insula and pass onward to supply the corona radiata. It is essential to preserve these vessels to prevent postoperative neurological deficits. ICG (Aurogreen) was used to identify and preserve the long perforating arteries of the middle cerebral artery. Results: ICG dye correctly identified the long perforating branches of the middle cerebral artery and easily distinguished these vessels from the short perforating branches. All the branches of the middle cerebral artery that coursed through the tumor and had an onward course were preserved in all the patients. Only one patient developed a transient right sided hemiparesis that had improved at follow-up. Conclusions: Surgery for insular gliomas is challenging due to its location adjacent to eloquent areas, important white fiber tracts and the course of the middle cerebral artery within it. ICG is useful to identify and preserve the long perforating branches of the middle cerebral artery that course through the tumor and traverse onward to supply the corona radiata. PMID:27366256

  8. Insular Volume Reduction in Patients with Social Anxiety Disorder

    PubMed Central

    Kawaguchi, Akiko; Nemoto, Kiyotaka; Nakaaki, Shutaro; Kawaguchi, Takatsune; Kan, Hirohito; Arai, Nobuyuki; Shiraishi, Nao; Hashimoto, Nobuhiko; Akechi, Tatsuo

    2016-01-01

    Despite the fact that social anxiety disorder (SAD) is highly prevalent, there have been only a few structural imaging studies. Moreover, most of them reported about a volume reduction in amygdale, which plays a key role in the neural function of SAD. Insula is another region of interest. Its hyperactivity in regard to processing negative emotional information or interoceptive awareness has been detected in patients with SAD. Referring to these studies, we hypothesized that insular volumes might reduce in patients with SAD and made a comparison of insular volumes between 13 patients with SAD and 18 healthy controls with matched age and gender using voxel-based morphometry. As a result, we found a significant volume reduction in insula in the SAD group. Our results suggest that the patients with SAD might have an insular volume reduction apart from amygdala. Since insula plays a critical role in the pathology of SAD, more attention should be paid not only to functional study but also morphometrical study of insula. PMID:26834652

  9. Glucocorticoids Enhance Taste Aversion Memory via Actions in the Insular Cortex and Basolateral Amygdala

    ERIC Educational Resources Information Center

    Miranda, Maria Isabel; Quirarte, Gina L.; Rodriguez-Garcia, Gabriela; McGaugh, James L.; Roozendaal, Benno

    2008-01-01

    It is well established that glucocorticoid hormones strengthen the consolidation of hippocampus-dependent spatial and contextual memory. The present experiments investigated glucocorticoid effects on the long-term formation of conditioned taste aversion (CTA), an associative learning task that does not depend critically on hippocampal function.…

  10. Role of thalamic nuclei in the modulation of Fos expression within the cerebral cortex during hypertonic saline-induced muscle nociception.

    PubMed

    Xiao, Y; Lei, J; Ye, G; Xu, H; You, H-J

    2015-09-24

    It has been proposed that thalamic mediodorsal (MD) and ventromedial (VM) nuclei form thalamic 'nociceptive discriminators' in discrimination of nociceptive afferents, and specifically govern endogenous descending facilitation and inhibition. The present study conducted in rats was to explore the role of thalamic MD and VM nuclei in modulation of cerebral neuronal activities by means of detection of spatiotemporal variations of Fos expression within the cerebral cortex. Following a unilateral intramuscular injection of 5.8% saline into the gastrocnemius muscle, Fos expression within the bilateral, different areas of the cerebral cortex except S2 was significantly increased (P<0.05). Particularly, the increases in Fos expression within the cingulate cortex and the insular cortex occurred at 0.5h, 4h and reached the peak level at 4h, 16h, respectively. Electrolytic lesion of the contralateral thalamic MD and VM nuclei significantly blocked the 5.8% saline intramuscularly induced increases in Fos expression within the bilateral cingulate and insular cortices, respectively. Additionally, the 5.8% saline-induced Fos expression in the cingulate cortex and the insular cortex were dose-dependently attenuated by microinjection of μ-opioid antagonist β-funaltrexamine hydrochloride into the thalamic MD and VM nuclei. It is suggested that (1) the neural circuits of 'thalamic MD nucleus - cingulate cortex' and 'thalamic VM nucleus - insular cortex' form two distinct pathways in the endogenous control of nociception, (2) mirror or contralateral pain is hypothesized to be related to cross-talk of neuronal activities within the bilateral cerebral cortices modulated by μ-opioid receptors within the thalamic MD and VM nuclei. PMID:26189794

  11. 76 FR 38370 - Western Pacific Fisheries; Approval of a Marine Conservation Plan for Pacific Insular Areas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-30

    ... National Oceanic and Atmospheric Administration RIN 0648-XA517 Western Pacific Fisheries; Approval of a Marine Conservation Plan for Pacific Insular Areas; Western Pacific Sustainable Fisheries Fund AGENCY... Pacific Insular Areas other than American Samoa, Guam, and the Northern Mariana Islands. DATES:...

  12. Isolated left posterior insular infarction and convergent roles in verbal fluency, language, memory, and executive function

    PubMed Central

    Ruthirago, Doungporn; DeToledo, John C.

    2016-01-01

    The posterior insular cortex—a complex structure interconnecting various brain regions for different functions—is a rare location for ischemic stroke. We report a patient with isolated left posterior insular infarction who presented with multiple cognitive impairment, including impairment in semantic and phonemic verbal fluency. PMID:27365876

  13. Insular avian adaptations on two Neotropical continental islands

    PubMed Central

    Wright, Natalie A.; Steadman, David W.

    2012-01-01

    Aim Most studies of avian insular adaptations have focused on oceanic islands, which may not allow characters that are insular adaptations to be teased apart from those that benefit dispersal and colonization. Using birds on continental islands, we investigated characters that evolved in situ in response to insular environments created by late Pleistocene sea level rise. Location Trinidad and Tobago, nearby Caribbean islands and continental South America. Methods We weighed fresh flight muscles and measured museum skeletal specimens of seven species of birds common to the continental islands of Trinidad and Tobago. Results When corrected for body size, study species exhibited significantly smaller flight muscles, sterna and sternal keels on Tobago than on larger Trinidad and continental South America. Tobago populations were more ‘insular’ in their morphologies than conspecifics on Trinidad or the continent in other ways as well, including having longer bills, longer wings, longer tails and longer legs. Main conclusions We hypothesize that the longer bills enhance foraging diversity, the longer wings and tails compensate for the smaller pectoral assemblage (allowing for retention of volancy, but with a probable reduction in flight power and speed), and the longer legs expand perching ability. Each of these differences is likely to be related to the lower diversity and fewer potential predators and competitors on Tobago compared with Trinidad. These patterns of smaller flight muscles and larger bills, legs, wings and tails in island birds are not the results of selection for island dispersal and colonization, but probably arose from selection pressures acting on populations already inhabiting these islands. PMID:23066173

  14. Left-insular damage, autonomic instability, and sudden unexpected death in epilepsy.

    PubMed

    Lacuey, Nuria; Zonjy, Bilal; Theerannaew, Wanchat; Loparo, Kenneth A; Tatsuoka, Curtis; Sahadevan, Jayakumar; Lhatoo, Samden D

    2016-02-01

    We analyzed the only two sudden unexpected death in epilepsy (SUDEP) cases from 320 prospectively recruited patients in the three-year Prevention and Risk Identification of SUDEP Mortality (PRISM) project. Both patients had surgically refractory epilepsy, evidence of left insular damage following previous temporal/temporo-insular resections, and progressive changes in heart rate variability (HRV) in monitored evaluations prior to death. Insular damage is known to cause autonomic dysfunction and increased mortality in acute stroke. This report suggests a possible role for the insula in the pathogenesis of SUDEP. The presence of intrinsic insular lesions or acquired insular damage in patients with refractory epilepsy may be an additional risk factor for SUDEP. PMID:26797084

  15. A genuine layer 4 in motor cortex with prototypical synaptic circuit connectivity.

    PubMed

    Yamawaki, Naoki; Borges, Katharine; Suter, Benjamin A; Harris, Kenneth D; Shepherd, Gordon M G

    2014-01-01

    The motor cortex (M1) is classically considered an agranular area, lacking a distinct layer 4 (L4). Here, we tested the idea that M1, despite lacking a cytoarchitecturally visible L4, nevertheless possesses its equivalent in the form of excitatory neurons with input-output circuits like those of the L4 neurons in sensory areas. Consistent with this idea, we found that neurons located in a thin laminar zone at the L3/5A border in the forelimb area of mouse M1 have multiple L4-like synaptic connections: excitatory input from thalamus, largely unidirectional excitatory outputs to L2/3 pyramidal neurons, and relatively weak long-range corticocortical inputs and outputs. M1-L4 neurons were electrophysiologically diverse but morphologically uniform, with pyramidal-type dendritic arbors and locally ramifying axons, including branches extending into L2/3. Our findings therefore identify pyramidal neurons in M1 with the expected prototypical circuit properties of excitatory L4 neurons, and question the traditional assumption that motor cortex lacks this layer. PMID:25525751

  16. Phylogeny and adaptation shape the teeth of insular mice.

    PubMed

    Ledevin, Ronan; Chevret, Pascale; Ganem, Guila; Britton-Davidian, Janice; Hardouin, Emilie A; Chapuis, Jean-Louis; Pisanu, Benoit; da Luz Mathias, Maria; Schlager, Stefan; Auffray, Jean-Christophe; Renaud, Sabrina

    2016-02-10

    By accompanying human travels since prehistorical times, the house mouse dispersed widely throughout the world, and colonized many islands. The origin of the travellers determined the phylogenetic source of the insular mice, which encountered diverse ecological and environmental conditions on the various islands. Insular mice are thus an exceptional model to disentangle the relative role of phylogeny, ecology and climate in evolution. Molar shape is known to vary according to phylogeny and to respond to adaptation. Using for the first time a three-dimensional geometric morphometric approach, compared with a classical two-dimensional quantification, the relative effects of size variation, phylogeny, climate and ecology were investigated on molar shape diversity across a variety of islands. Phylogeny emerged as the factor of prime importance in shaping the molar. Changes in competition level, mostly driven by the presence or absence of the wood mouse on the different islands, appeared as the second most important effect. Climate and size differences accounted for slight shape variation. This evidences a balanced role of random differentiation related to history of colonization, and of adaptation possibly related to resource exploitation. PMID:26842576

  17. Increase in c-Fos and Arc protein in retrosplenial cortex after memory-improving lateral hypothalamic electrical stimulation treatment.

    PubMed

    Kádár, Elisabeth; Vico-Varela, Eva; Aldavert-Vera, Laura; Huguet, Gemma; Morgado-Bernal, Ignacio; Segura-Torres, Pilar

    2016-02-01

    Post-training Intracranial self-stimulation (ICSS) of the lateral hypothalamus (LH), a kind of rewarding deep-brain stimulation, potentiates learning and memory and increases c-Fos protein expression in specific memory-related brain regions. In a previous study, Aldavert-Vera et al. (2013) reported that post-acquisition LH-ICSS improved 48 h retention of a delay two-way active avoidance conditioning (TWAA) and induced c-Fos expression increase in CA3 at 90 min after administration. Nevertheless, this c-Fos induction was only observed after the acquisition session and not after the retention test at 48 h, when the ICSS improving effect was observed on memory. This current study aims to examine the hypothesis that post-training ICSS treatment may stimulate c-Fos expression at the time of the TWAA retention test in retrosplenial cortex (RSC), a hippocampus-related brain region more closely related with long-lasting memory storage. Effects of ICSS on Arc protein, a marker of memory-associated synaptic plasticity, were also measured by immunohistochemistry in granular and agranular RSC. The most innovative results are that the ICSS treatment potentiates the c-Fos induction across TWAA conditions (no conditioning, acquisition and retention), specifically in layer V of the granular RSC, along with increases of Arc protein levels in the granular but not in agranular areas of RSC ipsilaterally few hours after ICSS. This leads us to suggest that plasticity-related protein activation in the granular RSC could be involved in the positive modulatory effects of ICSS on TWAA memory consolidation, opening a new approach for future research in ICSS memory facilitation. PMID:26774022

  18. Disrupted causal connectivity anchored on the anterior cingulate cortex in first-episode medication-naive major depressive disorder.

    PubMed

    Feng, Zhan; Xu, Shunliang; Huang, Manli; Shi, Yushu; Xiong, Bing; Yang, Hong

    2016-01-01

    In recent years, major depressive disorder (MDD) has been demonstrated to be associated with abnormalities in neural networks, particularly the prefrontal-limbic network (PLN). However, there are few current studies that have examined information flow in the PLN. In this study, Granger causality analysis (GCA), based on signed regression coefficient, was used to explore changes in causal connectivity in resting-state PLNs of MDD patients. A total of 23 first-episode medication-naïve MDD patients and 20 normal control participants were subjected to resting-state functional magnetic resonance imaging (RS-fMRI) scans. Increased causal effects of the right insular cortex, right putamen and right caudate on the rostral anterior cingulate cortex (rACC) and reduced causal effects of bilateral dorsolateral prefrontal cortex (DLPFC) and left orbitofrontal cortex (OFC) on the rACC were found in MDD patients compared to normal controls. The extensive reduction in the causal effect of the prefrontal cortex (PFC) demonstrates impaired top-down cognitive control in MDD patients. Changes in the causal relationship between the right insula and rACC suggest problems in coordination of the default mode network by the right anterior insular cortex (rAI). These findings provide valuable insight into MDD-related neural network disorders reported in previous RS-fMRI studies and may potentially guide clinical treatment of MDD in the future. PMID:26234517

  19. The association of insular stroke with lesion volume

    PubMed Central

    Kodumuri, Nishanth; Sebastian, Rajani; Davis, Cameron; Posner, Joseph; Kim, Eun Hye; Tippett, Donna C.; Wright, Amy; Hillis, Argye E.

    2016-01-01

    The insula has been implicated in many sequelae of stroke. It is the area most commonly infarcted in people with post-stroke arrhythmias, loss of thermal sensation, hospital acquired pneumonia, and apraxia of speech. We hypothesized that some of these results reflect the fact that: (1) ischemic strokes that involve the insula are larger than strokes that exclude the insula (and therefore are associated with more common and persistent deficits); and (2) insular involvement is a marker of middle cerebral artery (MCA) occlusion. We analyzed MRI scans of 861 patients with acute ischemic hemispheric strokes unselected for functional deficits, and compared infarcts involving the insula to infarcts not involving the insula using t-tests for continuous variables and chi square tests for dichotomous variables. Mean infarct volume was larger for infarcts including the insula (n = 232) versus excluding the insula (n = 629): 65.8 ± 78.8 versus 10.2 ± 15.9 cm3 (p < 0.00001). Even when we removed lacunar infarcts, mean volume of non-lacunar infarcts that included insula (n = 775) were larger than non-lacunar infarcts (n = 227) that excluded insula: 67.0 cm3 ± 79.2 versus 11.5 cm3 ± 16.7 (p < 0.00001). Of infarcts in the 90th percentile for volume, 87% included the insula (χ2 = 181.8; p < 0.00001). Furthermore, 79.0% infarcts due to MCA occlusion included the insula; 78.5% of infarcts without MCA occlusion excluded the insula (χ2 = 93.1; p < 0.0001). The association between insular damage and acute or chronic sequelae likely often reflects the fact that insular infarct is a marker of large infarcts caused by occlusion of the MCA more than a specific role of the insula in a range of functions. Particularly in acute stroke, some deficits may also be due to ischemia of the MCA or ICA territory caused by large vessel occlusion. PMID:26909326

  20. Interhemispheric insular and inferior frontal connectivity are associated with substance abuse in a psychiatric population.

    PubMed

    Viswanath, Humsini; Velasquez, Kenia M; Savjani, Ricky; Molfese, David L; Curtis, Kaylah; Molfese, Peter J; Eagleman, David M; Baldwin, Philip R; Frueh, B Christopher; Fowler, J Christopher; Salas, Ramiro

    2015-05-01

    Substance abuse is highly comorbid with major psychiatric disorders. While the neural underpinnings of drug abuse have been studied extensively, most existing studies compare drug users without comorbidities and healthy, non-user controls. Such studies do not generalize well to typical patients with substance abuse disorders. Therefore, we studied a population of psychiatric inpatients (n = 151) with a range of mental illnesses. Psychiatric disorders were diagnosed via structured interviews. Sixty-five percent of patients met criteria for at least one substance use disorder. Patients were recruited for resting state functional connectivity (RSFC) and diffusion tensor imaging (DTI) experiments to examine the interhemispheric connectivity between brain regions hypothesized to be involved in drug addiction, namely: the inferior, medial, and superior frontal gyri; insula; striatum; and anterior cingulate cortex. The World Health Organization Alcohol, Smoking, and Substance Involvement Screening Test (WHOA) questionnaire was used to further assess drug use. An association between use of tobacco, alcohol, cocaine, sedatives, and hallucinogens with increased insular interhemispheric connectivity was observed. In addition, increased inferior frontal gyrus interhemispheric connectivity was associated with amphetamine and inhalant use. Our results suggest that increased inter-hemispheric insula connectivity is associated with the use of several drugs of abuse. Importantly, psychiatric inpatients without a history of drug dependence were used as an ecologically valid control group rather than the more typical comparison between "mentally ill vs. healthy control" populations. We suggest that dysfunction of interhemispheric connectivity of the insula and to a lesser extent of the inferior frontal gyrus, are related to drug abuse in psychiatric populations. PMID:25592214

  1. Structural and functional connectivity mapping of the vestibular circuitry from human brainstem to cortex.

    PubMed

    Kirsch, V; Keeser, D; Hergenroeder, T; Erat, O; Ertl-Wagner, B; Brandt, T; Dieterich, M

    2016-04-01

    Structural and functional interconnections of the bilateral central vestibular network have not yet been completely delineated. This includes both ipsilateral and contralateral pathways and crossing sites on the way from the vestibular nuclei via the thalamic relay stations to multiple "vestibular cortex" areas. This study investigated "vestibular" connectivity in the living human brain in between the vestibular nuclei and the parieto-insular vestibular cortex (PIVC) by combined structural and functional connectivity mapping using diffusion tensor imaging and functional connectivity magnetic resonance imaging in 24 healthy right-handed volunteers. We observed a congruent functional and structural link between the vestibular nuclei and the ipsilateral and contralateral PIVC. Five separate and distinct vestibular pathways were identified: three run ipsilaterally, while the two others cross either in the pons or the midbrain. Two of the ipsilateral projections run through the posterolateral or paramedian thalamic subnuclei, while the third bypasses the thalamus to reach the inferior part of the insular cortex directly. Both contralateral pathways travel through the posterolateral thalamus. At the cortical level, the PIVC regions of both hemispheres with a right hemispherical dominance are interconnected transcallosally through the antero-caudal splenium. The above-described bilateral vestibular circuitry in its entirety takes the form of a structure of a rope ladder extending from the brainstem to the cortex with three crossings in the brainstem (vestibular nuclei, pons, midbrain), none at thalamic level and a fourth cortical crossing through the splenium of the corpus callosum. PMID:25552315

  2. Mesophotic communities of the insular shelf at Tutuila, American Samoa

    NASA Astrophysics Data System (ADS)

    Bare, A. Y.; Grimshaw, K. L.; Rooney, J. J.; Sabater, M. G.; Fenner, D.; Carroll, B.

    2010-06-01

    An investigation into the insular shelf and submerged banks surrounding Tutuila, American Samoa, was conducted using a towed camera system. Surveys confirmed the presence of zooxanthellate scleractinian coral communities at mesophotic depths (30-110 m). Quantification of video data, separated into 10-m-depth intervals, yielded a vertical, landward-to-seaward and horizontal distribution of benthic assemblages. Hard substrata composed a majority of bottom cover in shallow water, whereas unconsolidated sediments dominated the deep insular shelf and outer reef slopes. Scleractinian coral cover was highest atop mid-shelf patch reefs and on the submerged bank tops in depths of 30-50 m. Macroalgal cover was highest near shore and on reef slopes approaching the bank tops at 50-60 m. Percent cover of scleractinian coral colony morphology revealed a number of trends. Encrusting corals belonging to the genus Montipora were most abundant at shallow depths with cover gradually decreasing as depth increased. Massive corals, such as Porites spp., displayed a similar trend. Percent cover values of plate-like corals formed a normal distribution, with the highest cover observed in the 60-70 m depth range. Shallow plate-like corals belonged mostly to the genus Acropora and appeared to be significantly prevalent on the northeastern and eastern banks. Deeper plate-like corals on the reef slopes were dominated by Leptoseris, Pachyseris, or Montipora genera. Branching coral cover was high in the 80-110 m depth range. Columnar and free-living corals were also occasionally observed from 40-70 m.

  3. Opposite effects of mu and delta opioid receptor agonists on excitatory propagation induced in rat somatosensory and insular cortices by dental pulp stimulation.

    PubMed

    Yokota, Eiko; Koyanagi, Yuko; Nakamura, Hiroko; Horinuki, Eri; Oi, Yoshiyuki; Kobayashi, Masayuki

    2016-08-15

    The insular cortex (IC) contributes to nociceptive information processing. IC neurons express opioid receptors, including the mu (MOR), kappa (KOR), and delta (DOR) subtypes. Opioidergic agonists suppress excitatory synaptic transmission in the cerebral cortex. In addition, morphine injection into the IC reduces responses to noxious thermal stimuli. However, the mechanisms of the opioid-dependent modulation of cortical excitation at the macroscopic level, which bridge the cellular and behavioral findings, have remained unknown. The present in vivo optical imaging study aimed to examine the effects of the agonists of each subtype on cortical excitatory propagation in the IC and the neighboring cortices, the primary (S1) and secondary somatosensory (S2) areas. To assess the opioidergic effects on the cortical circuits, we applied electrical stimulation to the maxillary 1st molar pulp, which induced excitation in the ventral part of S1 and the S2/insular oral region (IOR). The initial excitatory response was observed 10-14ms after stimulation, and then excitation propagated concentrically. DAMGO (10-100μM), an MOR agonist, suppressed the amplitude of cortical excitation and shrank the maximum excitation areas in S1 and S2/IOR. In contrast, 10-100μM DPDPE, a DOR agonist, increased the amplitude of excitation and expanded the area of maximum excitation. U50488 (10-100μM), a KOR agonist, had little effect on cortical excitation. These results suggest that MOR-induced suppression of excitatory propagation in the IC is an underlying mechanism of the powerful analgesic effects of MOR agonists. In contrast, DOR may play a minor role in suppressing acute pain. PMID:27246300

  4. Glacial Features on the Northern Insular Margin of Iceland

    NASA Astrophysics Data System (ADS)

    Helgadóttir, G.; Brandsdóttir, B.; Detrick, R. S.; Driscoll, N.

    2003-12-01

    The iceberg scoured insular margin of Iceland is incised by several major fjords which mark the pathways of major outlet glaciers during recent glaciations. New Simrad EM300 multibeam bathymetric and Chirp sonar data from the northern insular margin have revealed glacial and glaciotectonic formations some of which, to our knowledge, have not been previously recognized. The iceberg scoured bank areas are mostly devoid of loose sediments which has accumulated within the fjords. Glacial erosion along the Kolbeinsey Ridge indicates that the Iceland ice cap extended beond 67° N during the last glacial maximum. Multiple marginal moraines exist at 400--500 m depth within a 3--6 km wide, U-shaped valley along the western margin of the ridge (at 66° 55'N). The region east of the ridge is dominated by large volcanic complexes which bear the marks of glacial erosion, however, volcanic deposits from postglacial eruptions have blanketed all glacial features in this region. Scoured bedrock surfaces and eskers reflect the direction of two major outlet glaciers, into Skagafjördur-Skagafjardardjúp and Eyjafjördur-Eyjafjardaráll. The region between 66° 20'N and 66° 35'N in Eyjafjardaráll is dominated by a system of a Λ -shaped highly reflective (till?) ridges, which are characteristically up to 1 km long and 300--500 m wide and open towards the presumed glacial flow. The northernmost ridges strike NNE-SSW, parallel to a 10 km long lateral moraine, which most likely separated the two main outlet glaciers in this region, i.e. from Skagafjördur and Eyjafjördur. Further south, they change direction gradually, along with the fjord curvature. The Λ -shaped ridges most likely represent glaciotectonic features formed during repeated glacier advances. They are not drumlins as drumlins generally increase in volume up-glacier but the ridges down-glacier. Instead they represent some sort of composite ridges intervening depressions conforming to the general shape of the glacier

  5. Allozyme Variation in the Endangered Insular Endemic Castilleja grisea

    PubMed Central

    HELENURM, KAIUS; WEST, RACHEL; BURCKHALTER, STEVEN J.

    2005-01-01

    • Background and Aims Genetic diversity in Castilleja grisea, an endangered, perennial herb endemic to San Clemente Island, California was investigated. Subsequent to the elimination of goats from the island in 1992, many populations of C. grisea have reappeared and have been increasing in size. • Methods Nineteen populations were surveyed for their genotype at 19 allozyme loci. • Key Results At the taxon level, 57·9 % of loci are polymorphic with AP = 3·09 and HE = 0·137. Populations averaged 33·0 % polymorphic loci with AP = 2·43 and HE = 0·099. Most variation is found within rather than among populations (GST = 0·128), although differentiation among populations is significant. Genetic identities range from I = 0·960 to I = 1·000 with mean I = 0·990. There is no significant relationship between genetic and geographic distance. Gene flow among populations is Nm = 2·50 based on private alleles and Nm = 1·70 based on FST. Outcrossing rates based on fixation indices average t = 1·01, indicating a primarily outcrossed mating system. • Conclusions The observed genetic variation is moderately high, unusually so for an insular endemic species, suggesting that C. grisea may not have lost substantial genetic variation during 150 years of overgrazing, and indicating that it is unlikely to be endangered by genetic factors. PMID:15820989

  6. Distribution and biology of Indo-Pacific insular hypogeal shrimps

    USGS Publications Warehouse

    Maciolek, J.A.

    1983-01-01

    Ten species of caridean shrimps, representing nine genera in five families, have been found in exposures of the marine water table at 28 islands from Hawaii to the western Indian Ocean. Synthesis of literature information and personal observations indicate that, as a group, these shrimps are characterized by red body pigment, reduced but pigmented eyes, euryhalinity, a proclivity for interstitial seawater in limestone or lava rock, generalized food requirements, and probable pre-Pleistocene origins. The shrimps have not been found in waters cooler than about 20°C.Species are often solitary, but as many as five are known to coexist. Six of the species have widely scattered populations, some as far apart as Hawaii and the Red Sea. Passive oceanic dispersal is endorsed as a general explanation for such apparently disjunct distributions. On the basis of an assumed primary habitat requirement of interstitial marine water, which could include that in shallow submerged rock as well as that in emergent (insular) rock, I hypothesize a much more cosmopolitan distribution of these shrimps in the Indo-Pacific Tropical Zone.

  7. Insular Area energy vulnerability, Puerto Rico, US Virgin Islands. Technical Appendix 1

    SciTech Connect

    Stern, M.; Willard, E.E.; Efferding, S.

    1994-05-01

    This report was prepared in response to Section 1406 of the Energy Policy Act of 1992 (P.L. 192-486). The Act directed the Department of Energy (DOE) to ``conduct a study of the implications of the unique vulnerabilities of the insular areas to an oil supply disruption,`` and to ``outline how the insular areas shall gain access to vital oil supplies during times of national emergency.`` The Act defines the insular areas to be the US Virgin Islands and Puerto Rico in the Caribbean, and Guam, American Samoa, the Commonwealth of the Northern Mariana Islands (CNMI), and Palau in the Pacific. This report is the analysis of Puerto Rico and the US Virgin Islands. In the study, ``unique vulnerabilities`` were defined as susceptibility to: (1) more frequent or more likely interruptions of oil supplies compared to the mainland, and/or (2) disproportionately larger or more likely economic losses in the event of an oil supply disruption. In order to asses unique vulnerabilities, the study examined in the insular areas` experience during past global disruptions of oil supplies and during local emergencies caused by natural disasters. The effects of several possible future global disruptions and local emergencies were also analyzed. Analyses were based on historical data, simulations using energy and economic models, and interviews with officials in the insular governments and the energy industry.

  8. Tuberculosis Epidemiology in Islands: Insularity, Hosts and Trade

    PubMed Central

    Acevedo, Pelayo; Romero, Beatriz; Vicente, Joaquin; Caracappa, Santo; Galluzzo, Paola; Marineo, Sandra; Vicari, Domenico; Torina, Alessandra; Casal, Carmen; de la Fuente, Jose; Gortazar, Christian

    2013-01-01

    Because of their relative simplicity and the barriers to gene flow, islands are ideal systems to study the distribution of biodiversity. However, the knowledge that can be extracted from this peculiar ecosystem regarding epidemiology of economically relevant diseases has not been widely addressed. We used information available in the scientific literature for 10 old world islands or archipelagos and original data on Sicily to gain new insights into the epidemiology of the Mycobacterium tuberculosis complex (MTC). We explored three nonexclusive working hypotheses on the processes modulating bovine tuberculosis (bTB) herd prevalence in cattle and MTC strain diversity: insularity, hosts and trade. Results suggest that bTB herd prevalence was positively correlated with island size, the presence of wild hosts, and the number of imported cattle, but neither with isolation nor with cattle density. MTC strain diversity was positively related with cattle bTB prevalence, presence of wild hosts and the number of imported cattle, but not with island size, isolation, and cattle density. The three most common spoligotype patterns coincided between Sicily and mainland Italy. However in Sicily, these common patterns showed a clearer dominance than on the Italian mainland, and seven of 19 patterns (37%) found in Sicily had not been reported from continental Italy. Strain patterns were not spatially clustered in Sicily. We were able to infer several aspects of MTC epidemiology and control in islands and thus in fragmented host and pathogen populations. Our results point out the relevance of the intensity of the cattle commercial networks in the epidemiology of MTC, and suggest that eradication will prove more difficult with increasing size of the island and its environmental complexity, mainly in terms of the diversity of suitable domestic and wild MTC hosts. PMID:23923053

  9. Dyscalculia, Dysgraphia, and Left-Right Confusion from a Left Posterior Peri-Insular Infarct

    PubMed Central

    Bhattacharyya, S.; Cai, X.; Klein, J. P.

    2014-01-01

    The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation. PMID:24817791

  10. A giant submarine slope failure on the northern insular slope of Puerto Rico

    USGS Publications Warehouse

    Schwab, W.C.; Danforth, W.W.; Scanlon, K.M.; Masson, D.G.

    1991-01-01

    A large amphitheater-shaped scarp, approximately 55 km across, was imaged on the northern insular slope of Puerto Rico using long-range sidescan sonar and bathymetric data. This scarp results from the removal of more than 1500 km3 of Tertiary strata. A review of seismic-reflection profiles, stratigraphic data, and subsidence models of the northern insular margin of Puerto Rico were used to infer that large-scale slope failure was induced by the tectonic oversteepening of the insular slope and was responsible for the formation of the scarp. The oversteepening probably was caused by the most recent episode of convergence of the Caribbean and North American plates, which began between approximately 4 and 2.5 m.y. ago. The Tertiary strata have been tilted approximately 4.5?? to the north in the last 4 m.y. ?? 1991.

  11. Dyscalculia, dysgraphia, and left-right confusion from a left posterior peri-insular infarct.

    PubMed

    Bhattacharyya, S; Cai, X; Klein, J P

    2014-01-01

    The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation. PMID:24817791

  12. A Case of Semantic Variant Primary Progressive Aphasia with Severe Insular Atrophy

    PubMed Central

    Chow, T. W.; Links, K. A.; Masterman, D. L.; Mendez, M.F.; Vinters, H. V.

    2012-01-01

    Insular degeneration has been linked to symptoms of frontotemporal dementia (FTD). Presented in this case is a patient exhibiting semantic variant primary progressive aphasia, behavioral disturbance. Upon autopsy, he was found to have severe insular atrophy. In addition, selective serotonin reuptake inhibitors (SSRIs) were ineffective in reducing symptoms of obsessive-compulsive behaviours or emotional blunting. This case suggests that Seeley et al.'s hypothesis that VEN and fork cell-rich brain regions, particularly in the insula, are targeted in additional subtypes of FTD beyond the behavioral variant. PMID:22150361

  13. Impaired executive functioning after left anterior insular stroke: a case report.

    PubMed

    Markostamou, Ioanna; Rudolf, Jobst; Tsiptsios, Iakovos; Kosmidis, Mary H

    2015-01-01

    Given the insular's anatomic complexity and functional interconnectivity, acute lesions may result in varied clinical presentations, including autonomic, somatosensory, perceptual, motor, affective, and cognitive deficits. Although functional neuroimaging studies have demonstrated its role in executive functions, no clinical manifestations have been reported to date. We present the case of a woman with an acute left anterior insular infarction leading to executive (i.e., word and design fluency, mental flexibility, sustained attention, inhibitory control), but not language, visuoperceptual, or memory impairment. This case confirms the left anterior insula's involvement in executive functioning and suggests that an infarction may result in executive impairment. PMID:25537237

  14. Competitive (AP7) and non-competitive (MK-801) NMDA receptor antagonists differentially alter glucose utilization in rat cortex

    SciTech Connect

    Clow, D.W.; Lee, S.J.; Hammer, R.P. Jr. )

    1991-04-01

    The effects of D,L-2-amino-7-phosphonoheptanoic acid (AP7), a competitive N-methyl-D-aspartate (NMDA) receptor antagonist, and MK-801, a non-competitive NMDA receptor antagonist, on regional brain metabolism were studied in unanesthetized, freely moving rats by using the quantitative {sup 14}C2-deoxyglucose autoradiographic procedure. AP7 (338 or 901 mg/kg) produced a dose-dependent decrease of metabolic activity throughout most of the regions studied including sensory, motor, and limbic cortices. In contrast, MK-801 (0.1 or 1.0 mg/kg) resulted in a dose-dependent decrease of metabolic activity in sensory cortices, and an increase in limbic regions such as the hippocampal stratum lacunosum moleculare and entorhinal cortex. MK-801 also produced a biphasic response in agranular motor cortex, whereby the low dose increased while the high dose decreased labeling. In addition, MK-801 produced heterogeneous effects on regional cerebral metabolism in sensory cortices. Metabolic activity decreased in layer IV relative to layer Va following MK-801 treatment in primary somatosensory (SI) and visual (VI) cortices, suggesting a shift in activity from afferent fibers innervating layer IV to those innervating layer Va. MK-801 administration also decreased metabolic activity in granular SI relative to dysgranular SI, and in VI relative to secondary visual cortex (VII), thus providing a relative sparing of activity in dysgranular SI and VII. Thus, the non-competitive NMDA receptor antagonist suppressed activity from extrinsic neocortical sources, enhancing relative intracortical activity and stimulating limbic regions, while the competitive NMDA antagonist depressed metabolic activity in all cortical regions.

  15. Simultaneous but Not Independent Anisomycin Infusions in Insular Cortex and Amygdala Hinder Stabilization of Taste Memory when Updated

    ERIC Educational Resources Information Center

    Garcia-DeLaTorre, Paola; Rodriguez-Ortiz, Carlos J.; Arreguin-Martinez, Jose L.; Cruz-Castaneda, Paulina; Bermudez-Rattoni, Federico

    2009-01-01

    Reconsolidation has been described as a process where a consolidated memory returns to a labile state when retrieved. Growing evidence suggests that reconsolidation is, in fact, a destabilization/stabilization process that incorporates updated information to a previously consolidated memory. We used the conditioned taste aversion (CTA) task in…

  16. [Beta]-Adrenergic Receptors in the Insular Cortex are Differentially Involved in Aversive vs. Incidental Context Memory Formation

    ERIC Educational Resources Information Center

    Miranda, Maria Isabel; Sabath, Elizabeth; Nunez-Jaramillo, Luis; Puron-Sierra, Liliana

    2011-01-01

    The goal of this research was to determine the effects of [beta]-adrenergic antagonism in the IC before or after inhibitory avoidance (IA) training or context pre-exposure in a latent inhibition protocol. Pretraining intra-IC infusion of the [beta]-adrenergic antagonist propranolol disrupted subsequent IA retention and impaired latent inhibition…

  17. 47 CFR 54.101 - Supported services for rural, insular and high cost areas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... extent the local government in an eligible carrier's service area has implemented 911 or enhanced 911... cost areas. 54.101 Section 54.101 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... services for rural, insular and high cost areas. (a) Services designated for support. The...

  18. 47 CFR 54.101 - Supported services for rural, insular and high cost areas.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... extent the local government in an eligible carrier's service area has implemented 911 or enhanced 911... cost areas. 54.101 Section 54.101 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... services for rural, insular and high cost areas. (a) Services designated for support. The...

  19. 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.

    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.

  20. 5 CFR 532.259 - Special appropriated fund wage schedules for U.S. insular areas.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.259 Special... the same time and with rates identical to the foreign area appropriated fund wage schedules established under § 532.255 of this subpart. (c) Wage employees recruited from outside the insular area...

  1. 5 CFR 532.259 - Special appropriated fund wage schedules for U.S. insular areas.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Special appropriated fund wage schedules for U.S. insular areas. 532.259 Section 532.259 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.259 Special appropriated fund wage schedules for...

  2. 3 CFR 13537 - Executive Order 13537 of April 14, 2010. Interagency Group on Insular Areas

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 3 The President 1 2011-01-01 2011-01-01 false Executive Order 13537 of April 14, 2010. Interagency Group on Insular Areas 13537 Order 13537 Presidential Documents Executive Orders Executive Order 13537... its own expenses of participating in the IGIA. (b) Nothing in this order shall be construed to...

  3. Negative childhood experiences alter a prefrontal-insular-motor cortical network in healthy adults: A preliminary multimodal rsfMRI-fMRI-MRS-dMRI study

    PubMed Central

    Duncan, Niall W.; Hayes, Dave J.; Wiebking, Christine; Tiret, Brice; Pietruska, Karin; Chen, David Q.; Rainville, Pierre; Marjańska, Malgorzata; Mohammid, Omar; Doyon, Julien; Hodaie, Mojgan; Northoff, Georg

    2016-01-01

    Research in humans and animals has shown that negative childhood experiences (NCE) can have long-term effects on the structure and function of the brain. Alterations have been noted in grey and white matter, in the brain’s resting state, on the glutamatergic system, and on neural and behavioural responses to aversive stimuli. These effects can be linked to psychiatric disorder such as depression and anxiety disorders that are influenced by excessive exposure to early life stressors. The aim of the current study was to investigate the effect of NCEs on these systems. Resting state functional MRI (rsfMRI), aversion task fMRI, glutamate magnetic resonance spectroscopy (MRS), and diffusion magnetic resonance imaging (dMRI) were combined with the Childhood Trauma Questionnaire (CTQ) in healthy subjects to examine the impact of NCEs on the brain. Low CTQ scores, a measure of NCEs, were related to higher resting state glutamate levels and higher resting state entropy in the medial prefrontal cortex (mPFC). CTQ scores, mPFC glutamate and entropy, correlated with neural BOLD responses to the anticipation of aversive stimuli in regions throughout the aversion-related network, with strong correlations between all measures in the motor cortex and left insula. Structural connectivity strength, measured using mean fractional anisotropy, between the mPFC and left insula correlated to aversion-related signal changes in the motor cortex. These findings highlight the impact of NCEs on multiple inter-related brain systems. In particular, they highlight the role of a prefrontal-insular-motor cortical network in the processing and responsivity to aversive stimuli and its potential adaptability by NCEs. PMID:26287448

  4. Negative childhood experiences alter a prefrontal-insular-motor cortical network in healthy adults: A preliminary multimodal rsfMRI-fMRI-MRS-dMRI study.

    PubMed

    Duncan, Niall W; Hayes, Dave J; Wiebking, Christine; Tiret, Brice; Pietruska, Karin; Chen, David Q; Rainville, Pierre; Marjańska, Małgorzata; Ayad, Omar; Doyon, Julien; Hodaie, Mojgan; Northoff, Georg

    2015-11-01

    Research in humans and animals has shown that negative childhood experiences (NCE) can have long-term effects on the structure and function of the brain. Alterations have been noted in grey and white matter, in the brain's resting state, on the glutamatergic system, and on neural and behavioural responses to aversive stimuli. These effects can be linked to psychiatric disorder such as depression and anxiety disorders that are influenced by excessive exposure to early life stressors. The aim of the current study was to investigate the effect of NCEs on these systems. Resting state functional MRI (rsfMRI), aversion task fMRI, glutamate magnetic resonance spectroscopy (MRS), and diffusion magnetic resonance imaging (dMRI) were combined with the Childhood Trauma Questionnaire (CTQ) in healthy subjects to examine the impact of NCEs on the brain. Low CTQ scores, a measure of NCEs, were related to higher resting state glutamate levels and higher resting state entropy in the medial prefrontal cortex (mPFC). CTQ scores, mPFC glutamate and entropy, correlated with neural BOLD responses to the anticipation of aversive stimuli in regions throughout the aversion-related network, with strong correlations between all measures in the motor cortex and left insula. Structural connectivity strength, measured using mean fractional anisotropy, between the mPFC and left insula correlated to aversion-related signal changes in the motor cortex. These findings highlight the impact of NCEs on multiple inter-related brain systems. In particular, they highlight the role of a prefrontal-insular-motor cortical network in the processing and responsivity to aversive stimuli and its potential adaptability by NCEs. PMID:26287448

  5. 75 FR 10463 - Office of Insular Affairs; Allocation of Duty-Exemptions for Calendar Year 2010 for Watch...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-08

    ... Changes in Watch, Watch Movement and Jewelry Program for the U.S. Insular Possessions, 65 FR 8048... producer allocation Belair Quartz, Inc 500,000 The balance of the units allocated to the USVI is...

  6. Behavioural Variant Frontotemporal Dementia with Bilateral Insular Hypometabolism: A Case Report

    PubMed Central

    Sood, Mamta; Bhad, Roshan; Tripathi, Manjari

    2016-01-01

    Fronto-Temporal Dementia (FTD) is a cluster of syndromes, characterized by progressive deterioration of cognition, language and/or behavioural changes associated with degeneration of the frontal and temporal lobes. A 53-year-old man was admitted with a history of gradually progressive behavioural disturbances, disinhibition, unprovoked anger outbursts, apathy, disorganised behaviour and impaired self-care. A clinical diagnosis of Fronto temporal Dementia (behavioural variant) was made. Extensive investigations found no abnormality except in FDG-PET scan of the brain which revealed hypo metabolism in bilateral anterior insular region. Insula is an important brain area implicated in emotional awareness and behaviour control. Hypo metabolism in insular region in the absence of any structural neuroimaging findings, in a case of behavioural variant of Fronto-temporal dementia suggest that, it might be one of the earliest neurobiological changes occurring in this disorder. PMID:27190928

  7. Insular carcinoma: A distinct thyroid carcinoma with associated iodine-131 localization

    SciTech Connect

    Justin, E.P.; Seabold, J.E.; Robinson, R.A.; Walker, W.P.; Gurll, N.J.; Hawes, D.R. )

    1991-07-01

    Insular carcinoma, once considered a poorly-differentiated thyroid cancer, has been reclassified as a distinct thyroid neoplasm. Since this neoplasm is composed of follicular epithelial cells, it may concentrate radioiodide (131I) making postoperative 131I imaging for detection of metastases and radiotherapy possible. A 20-yr review of 35 cases diagnosed as anaplastic or undifferentiated thyroid carcinoma at this medical center revealed five patients with insular carcinoma. Four patients showed postoperative 131I localization and received therapeutic doses of 131I. Three of the four showed extrathyroidal 131I localization in neoplastic lesions. In one patient, the resolution of metastatic lesions by magnetic resonance and 131I imaging suggests that 131I may have an important therapeutic role in this aggressive neoplasm.

  8. Mainland size variation informs predictive models of exceptional insular body size change in rodents

    PubMed Central

    Durst, Paul A. P.; Roth, V. Louise

    2015-01-01

    The tendency for island populations of mammalian taxa to diverge in body size from their mainland counterparts consistently in particular directions is both impressive for its regularity and, especially among rodents, troublesome for its exceptions. However, previous studies have largely ignored mainland body size variation, treating size differences of any magnitude as equally noteworthy. Here, we use distributions of mainland population body sizes to identify island populations as ‘extremely’ big or small, and we compare traits of extreme populations and their islands with those of island populations more typical in body size. We find that although insular rodents vary in the directions of body size change, ‘extreme’ populations tend towards gigantism. With classification tree methods, we develop a predictive model, which points to resource limitations as major drivers in the few cases of insular dwarfism. Highly successful in classifying our dataset, our model also successfully predicts change in untested cases. PMID:26085585

  9. Follicular thyroid carcinoma with insular component: a retrospective case study, immunohistochemical analysis and literature review.

    PubMed

    Htwe, T T; Karim, N; Lam, A K

    2012-03-01

    This is a retrospective case study of a 61-year-old woman diagnosed with follicular thyroid carcinoma. The patient underwent thyroidectomy for the treatment of goitre after being admitted for shortness of breath. Microscopic and immunohistochemical studies were performed, which confirmed follicular carcinoma of the thyroid with an insular component. We also conducted a review of the literature on this uncommon entity. PMID:22434304

  10. The shore fishes of the Trindade-Martin Vaz insular complex: an update.

    PubMed

    Simon, T; Macieira, R M; Joyeux, J-C

    2013-06-01

    A compilation of historical and recent collections and observations of shore fishes yielded 154 recorded species for Trindade and 67 for Martin Vaz. Twelve taxa, mostly small cryptobenthic species with limited dispersal capabilities and low ecological amplitude, are endemic to this insular complex. In several cases, the seamounts of the Vitória-Trindade Chain appear to have acted as stepping stones between the mainland and islands in periods of low sea level. PMID:23731156

  11. Population size and time since island isolation determine genetic diversity loss in insular frog populations.

    PubMed

    Wang, Supen; Zhu, Wei; Gao, Xu; Li, Xianping; Yan, Shaofei; Liu, Xuan; Yang, Ji; Gao, Zengxiang; Li, Yiming

    2014-02-01

    Understanding the factors that contribute to loss of genetic diversity in fragmented populations is crucial for conservation measurements. Land-bridge archipelagoes offer ideal model systems for identifying the long-term effects of these factors on genetic variations in wild populations. In this study, we used nine microsatellite markers to quantify genetic diversity and differentiation of 810 pond frogs (Pelophylax nigromaculatus) from 24 islands of the Zhoushan Archipelago and three sites on nearby mainland China and estimated the effects of the island area, population size, time since island isolation, distance to the mainland and distance to the nearest larger island on reduced genetic diversity of insular populations. The mainland populations displayed higher genetic diversity than insular populations. Genetic differentiations and no obvious gene flow were detected among the frog populations on the islands. Hierarchical partitioning analysis showed that only time since island isolation (square-root-transformed) and population size (log-transformed) significantly contributed to insular genetic diversity. These results suggest that decreased genetic diversity and genetic differentiations among insular populations may have been caused by random genetic drift following isolation by rising sea levels during the Holocene. The results provide strong evidence for a relationship between retained genetic diversity and population size and time since island isolation for pond frogs on the islands, consistent with the prediction of the neutral theory for finite populations. Our study highlights the importance of the size and estimated isolation time of populations in understanding the mechanisms of genetic diversity loss and differentiation in fragmented wild populations. PMID:24351057

  12. The spinothalamic system targets motor and sensory areas in the cerebral cortex of monkeys.

    PubMed

    Dum, Richard P; Levinthal, David J; Strick, Peter L

    2009-11-11

    Classically, the spinothalamic (ST) system has been viewed as the major pathway for transmitting nociceptive and thermoceptive information to the cerebral cortex. There is a long-standing controversy about the cortical targets of this system. We used anterograde transneuronal transport of the H129 strain of herpes simplex virus type 1 in the Cebus monkey to label the cortical areas that receive ST input. We found that the ST system reaches multiple cortical areas located in the contralateral hemisphere. The major targets are granular insular cortex, secondary somatosensory cortex and several cortical areas in the cingulate sulcus. It is noteworthy that comparable cortical regions in humans consistently display activation when subjects are acutely exposed to painful stimuli. We next combined anterograde transneuronal transport of virus with injections of a conventional tracer into the ventral premotor area (PMv). We used the PMv injection to identify the cingulate motor areas on the medial wall of the hemisphere. This combined approach demonstrated that each of the cingulate motor areas receives ST input. Our meta-analysis of imaging studies indicates that the human equivalents of the three cingulate motor areas also correspond to sites of pain-related activation. The cingulate motor areas in the monkey project directly to the primary motor cortex and to the spinal cord. Thus, the substrate exists for the ST system to have an important influence on the cortical control of movement. PMID:19906970

  13. Are there differences in immune function between continental and insular birds?

    PubMed Central

    Matson, Kevin D

    2006-01-01

    Generally, immune system architecture varies with different environments, which presumably reflect different pathogen pressures. Specifically, populations from relatively disease-free, oceanic islands are expected to exhibit reorganized immune systems, which might be characterized by attenuated responses, given the costs of immune function. Some insular animals exhibit an ‘island syndrome,’ including increased susceptibility to disease, and some insular populations have declined when they failed to resist infection by introduced pathogens. I measured eight indices of immune function (haemolysis, haemagglutination, concentration of haptoglobin and concentration of five leukocyte types) in 15 phylogenetically matched pairs of bird populations from North America and from the islands of Hawaii, Bermuda and the Galápagos. Immune responses were not attenuated in insular birds, and several indices, including the concentration of plasma haptoglobin, were elevated. Thus, I find no support for the specific hypothesis that depauperate parasite communities and the costs of immune defences select for reduced immune function. Instead, I suggest that life on islands leads to an apparent reorganization of immune function, which is defined by increases in defences that are innate and inducible. These increases might signal that systems of acquired humoral immunity and immunological memory are less important or dysfunctional in island populations. PMID:16928627

  14. Nestedness of desert bat assemblages: species composition patterns in insular and terrestrial landscapes.

    PubMed

    Frick, Winifred F; Hayes, John P; Heady, Paul A

    2009-01-01

    Nested patterns of community composition exist when species at depauperate sites are subsets of those occurring at sites with more species. Nested subset analysis provides a framework for analyzing species occurrences to determine non-random patterns in community composition and potentially identify mechanisms that may shape faunal assemblages. We examined nested subset structure of desert bat assemblages on 20 islands in the southern Gulf of California and at 27 sites along the Baja California peninsula coast, the presumable source pool for the insular faunas. Nested structure was analyzed using a conservative null model that accounts for expected variation in species richness and species incidence across sites (fixed row and column totals). Associations of nestedness and island traits, such as size and isolation, as well as species traits related to mobility, were assessed to determine the potential role of differential extinction and immigration abilities as mechanisms of nestedness. Bat faunas were significantly nested in both the insular and terrestrial landscape and island size was significantly correlated with nested structure, such that species on smaller islands tended to be subsets of species on larger islands, suggesting that differential extinction vulnerabilities may be important in shaping insular bat faunas. The role of species mobility and immigration abilities is less clearly associated with nestedness in this system. Nestedness in the terrestrial landscape is likely due to stochastic processes related to random placement of individuals and this may also influence nested patterns on islands, but additional data on abundances will be necessary to distinguish among these potential mechanisms. PMID:18941795

  15. Cognition without Cortex.

    PubMed

    Güntürkün, Onur; Bugnyar, Thomas

    2016-04-01

    Assumptions on the neural basis of cognition usually focus on cortical mechanisms. Birds have no cortex, but recent studies in parrots and corvids show that their cognitive skills are on par with primates. These cognitive findings are accompanied by neurobiological discoveries that reveal avian and mammalian forebrains are homologous, and show similarities in connectivity and function down to the cellular level. But because birds have a large pallium, but no cortex, a specific cortical architecture cannot be a requirement for advanced cognitive skills. During the long parallel evolution of mammals and birds, several neural mechanisms for cognition and complex behaviors may have converged despite an overall forebrain organization that is otherwise vastly different. PMID:26944218

  16. Two insular regions are differentially involved in behavioral variant FTD and nonfluent/agrammatic variant PPA.

    PubMed

    Mandelli, Maria Luisa; Vitali, Paolo; Santos, Miguel; Henry, Maya; Gola, Kelly; Rosenberg, Lynne; Dronkers, Nina; Miller, Bruce; Seeley, William W; Gorno-Tempini, Maria Luisa

    2016-01-01

    The non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) and the behavioral variant frontotemporal dementia (bvFTD) are focal neurodegenerative disorders belonging to the FTD-spectrum clinical syndromes. NfvPPA is characterized by effortful speech and/or agrammatism and left frontal atrophy, while bvFTD is characterized by social-emotional dysfunction often accompanied by right-lateralized frontal damage. Despite their contrasting clinical presentations, both disorders show prominent left anterior insula atrophy. We investigated differential patterns of insular sub-region atrophy in nfvPPA and bvFTD. Based on knowledge of insular connectivity and physiology, we hypothesized that the left superior precentral region of the dorsal anterior insula (SPGI) would be more atrophic in nvfPPA due to its critical role in motor speech, whereas the ventral anterior region would be more atrophied in bvFTD reflecting its known role in social-emotional-autonomic functions. Early stage nfvPPA and bvFTD patients matched for disease severity, age, gender and education and healthy controls participated in the study. Detailed clinical history, neurological examination, neuropsychological screening evaluation, and high-resolution T1-weighted brain magnetic resonance imaging (MRI) were collected. Voxel-based morphometry (VBM) was applied to perform group comparisons across the whole brain and in bilateral insula region of interest (ROI). Correlation analyses between insular sub-region atrophy and relevant clinical features were performed. Whole brain group comparisons between nfvPPA and bvFTD showed the expected predominantly left or right anterior insular atrophy pattern. ROI analysis of bilateral insula showed that the left SPGI was significantly more atrophied in nfvPPA compared to bvFTD, while the bilateral ventral anterior and right dorsal anterior insula sub-regions were more atrophied in bvFTD than nfvPPA. Only left SPGI volume correlated with speech production

  17. CX-516 Cortex pharmaceuticals.

    PubMed

    Danysz, Wojciech

    2002-07-01

    CX-516 is one of a series of AMPA modulators under development by Cortex, in collaboration with Shire and Servier, for the potential treatment of Alzheimer's disease (AD), schizophrenia and mild cognitive impairment (MCI) [234221]. By June 2001, CX-516 was in phase II trials for both schizophrenia and attention deficit hyperactivity disorder (ADHD) [412513]. A phase II trial in fragile X syndrome and autism was expected to start in May 2002 [449861]. In October 2001, Cortex was awarded a Phase II SBIR grant of $769,818 from the National Institutes of Mental Health to investigate the therapeutic potential of AMPAkines in schizophrenia. This award was to support a phase IIb study of CX-516 as a combination therapy in schizophrenia patients concomitantly treated with olanzapine. The trial was to enroll 80 patients and employ a randomized, double-blind, placebo-controlled design in which the placebo group was to receive olanzapine plus placebo and the active group was to receive olanzapine plus CX-516 [425982]. In April 2000, Shire and Cortex signed an option agreement in which Shire was to evaluate CX-516for the treatment of ADHD. Under the terms of the agreement, Shire would undertake a double-blind, placebo-controlled evaluation of CX-516 involving ADHD patients. If the study proved effective, Shire would have the right to convert its option into an exclusive worldwide license for the AMPAkines for ADHD under a development and licensing agreement. Should Shire elect to execute this agreement, Shire would bear all future developmental costs [363618]. By February 2002, Cortex and Servier had revealed their intention to begin enrolment for an international study of an AMPAkine compound as a potential treatment for MCI in the near future. Assuming enrollment proceeded as anticipated, results were expected during the second quarter of 2003 [439301]. By May 2002, phase II trials were underway [450134]. In March 2002, Cortex was awarded extended funding under the

  18. Building and Applying "Insularity Theory": Review on Knapp's Prehistoric and Protohistoric Cyprus, 2008.

    NASA Astrophysics Data System (ADS)

    Katsarou-Tzeveleki, Stella

    listing of external factors (colonization, invasions) originating in the Near East and the Aegean as sequential narrative history, and the descriptive, systemic analysis of 'materiality, production, trade, migration and colonization which have for long been the cornerstones of Cypriot archaeology' (p. 11). In contrast, he turns his attention towards the internal processes within the island society of Bronze Age Cyprus, which shape its insularity and give it a distinctive identity at this specific period, processes that lead to contextual history and formative tradition. 'To study how any society changes, at any time, it is crucial first to look at internal rather than external factors' (p. 1). Defining the concept of insularity is his aim; therefore, he begins with a number of very apposite rhetorical questions (p. 13) and identifies several individual parameters (connectivity, islandscape, social identity, ethnicity, migration, acculturation, hybridization) to which he assigns collective and individual meanings. The eight chapters that follow may be assigned, broadly, to three general units: in the first of these (ch. 1-2), Knapp offers a synthesis of these parameters in the form of a 'theory of insularity'. In the second (ch. 3-7) he formulates his revised narrative of the prehistory and social identity of the island, which involves a presentation of social and economic, rather than stylistic categories, on the basis of the parameters laid down in his theoretical scheme. Finally, in the third unit (ch. 8), he records his overall conclusions, the new cognitive experiences and concerns that have emerged from the application of his theory, both to Cyprus and to insular archaeology in the Mediterranean and on a world scale. Knapp's synthesis of the theory of insularity in the first unit is a major contribution to Mediterranean archaeology, and makes this book a seminal work. Continuing and broadening Broodbank's (2000) reasoning about the Cyclades, Knapp, with Cyprus as his

  19. Neurocontrol in sensory cortex

    NASA Astrophysics Data System (ADS)

    Ritt, Jason; Nandi, Anirban; Schroeder, Joseph; Ching, Shinung

    Technology to control neural ensembles is rapidly advancing, but many important challenges remain in applications, such as design of controls (e.g. stimulation patterns) with specificity comparable to natural sensory encoding. We use the rodent whisker tactile system as a model for active touch, in which sensory information is acquired in a closed loop between feedforward encoding of sensory information and feedback guidance of sensing motions. Motivated by this system, we present optimal control strategies that are tailored for underactuation (a large ratio of neurons or degrees of freedom to stimulation channels) and limited observability (absence of direct measurement of the system state), common in available stimulation technologies for freely behaving animals. Using a control framework, we have begun to elucidate the feedback effect of sensory cortex activity on sensing in behaving animals. For example, by optogenetically perturbing primary sensory cortex (SI) activity at varied timing relative to individual whisker motions, we find that SI modulates future sensing behavior within 15 msec, on a whisk by whisk basis, changing the flow of incoming sensory information based on past experience. J.T.R. and S.C. hold Career Awards at the Scientific Interface from the Burroughs Wellcome Fund.

  20. Subacute Pain after Traumatic Brain Injury Is Associated with Lower Insular N-Acetylaspartate Concentrations.

    PubMed

    Widerström-Noga, Eva; Govind, Varan; Adcock, James P; Levin, Bonnie E; Maudsley, Andrew A

    2016-07-15

    Persistent pain is experienced by more than 50% of persons who sustain a traumatic brain injury (TBI), and more than 30% experience significant pain as early as 6 weeks after injury. Although neuropathic pain is a common consequence after CNS injuries, little attention has been given to neuropathic pain symptoms after TBI. Magnetic resonance spectroscopy (MRS) studies in subjects with TBI show decreased brain concentrations of N-acetylaspartate (NAA), a marker of neuronal density and viability. Although decreased brain NAA has been associated with neuropathic pain associated with spinal cord injury (SCI) and diabetes, this relationship has not been examined after TBI. The primary purpose of this study was to test the hypothesis that lower NAA concentrations in brain areas involved in pain perception and modulation would be associated with greater severity of neuropathic pain symptoms. Participants with TBI underwent volumetric MRS, pain and psychosocial interviews. Cluster analysis of the Neuropathic Pain Symptom Inventory subscores resulted in two TBI subgroups: The Moderate Neuropathic Pain (n = 17; 37.8%), with significantly (p = 0.038) lower insular NAA than the Low or no Neuropathic Pain group (n = 28; 62.2%), or age- and sex-matched controls (n = 45; p < 0.001). A hierarchical linear regression analysis controlling for age, sex, and time post-TBI showed that pain severity was significantly (F = 11.0; p < 0.001) predicted by a combination of lower insular NAA/Creatine (p < 0.001), lower right insular gray matter fractional volume (p < 0.001), female sex (p = 0.005), and older age (p = 0.039). These findings suggest that neuronal dysfunction in brain areas involved in pain processing is associated with pain after TBI. PMID:26486760

  1. The effects of feral cats on insular wildlife: the Club-Med syndrome

    USGS Publications Warehouse

    Hess, Steve C.; Danner, Raymond M.

    2012-01-01

    Domestic cats have been introduced to many of the world‘s islands where they have been particularly devastating to insular wildlife which, in most cases, evolved in the absence of terrestrial predatory mammals and feline diseases. We review the effects of predation, feline diseases, and the life history characteristics of feral cats and their prey that have contributed to the extirpation and extinction of many insular vertebrate species. The protozoan Toxoplasma gondii is a persistent land-based zoonotic pathogen hosted by cats that is known to cause mortality in several insular bird species. It also enters marine environments in cat feces where it can cause the mortality of marine mammals. Feral cats remain widespread on islands throughout the world and are frequently subsidized in colonies which caretakers often assert have little negative effect on native wildlife. However, population genetics, home range, and movement studies all suggest that there are no locations on smaller islands where these cats cannot penetrate within two generations. While the details of past vertebrate extinctions were rarely documented during contemporary time, a strong line of evidence is emerging that the removal of feral cats from islands can rapidly facilitate the recolonization of extirpated species, particularly seabirds. Islands offer unique, mostly self-contained ecosystems in which to conduct controlled studies of the effects of feral cats on wildlife, having implications for continental systems. The response of terrestrial wildlife such as passerine birds, small mammals, and herptiles still needs more thorough long-term monitoring and documentation after the removal of feral cats.

  2. Intractable reflex audiogenic epilepsy successfully treated by peri-insular hemispherotomy.

    PubMed

    Martinez-Mañas, Rosa; Daniel, Roy Thomas; Debatisse, Damien; Maeder-Ingvar, Malin; Meagher-Villemure, Kathleen; Villemure, Jean-Guy; Deonna, Thierry

    2004-10-01

    We report a case of an infantile hemiplegia seizure syndrome (IHSS) that presented with intractable reflex audiogenic startle epilepsy which in itself is an uncommon form of seizure disorder. Peri-insular hemispherotomy provided complete seizure control. Also of particular interest was that this syndrome resulted from an iatrogenic brain injury sustained during the course of a caesarian section. We review the different mechanisms of birth injury reported in the literature and, discuss the physiopathogenesis of the hemispheric damage in this patient. We also review the literature on "reflex epilepsy" as it applies to this case. Intractable reflex audiogenic (startle) epilepsy in IHSS submitted to hemispherotomy has not previously been reported. PMID:15324827

  3. [Zinc and insulin level in islet cells under various functional state of insular apparatus].

    PubMed

    Berehova, T V; Hryhorova, N V; Ieshchenko, Iu V; Bovt, V D; Ieshchenko, V A

    2007-01-01

    The work is devoted to the study of zinc role in pancreas incretory function. Golden hamster and human pancreatic beta cells were investigated under varions functional state of insular apparatus. An increase of zinc and insulin content in islet beta cells was observed during inhibition of its' secretory activity and decrease of both components content in the cells occurred after intensifying of its' activity. Under pancreatic diabetes zinc and insulin quantities in beta cells were significantly less the norm. The results of comparative investigations confirm the thesis concerning this metal and hormone connection in beta-insulocytes. PMID:17902378

  4. Susceptibility to Infection and Immune Response in Insular and Continental Populations of Egyptian Vulture: Implications for Conservation

    PubMed Central

    Gangoso, Laura; Grande, Juan M.; Lemus, Jesús A.; Blanco, Guillermo; Grande, Javier; Donázar, José A.

    2009-01-01

    Background A generalized decline in populations of Old World avian scavengers is occurring on a global scale. The main cause of the observed crisis in continental populations of these birds should be looked for in the interaction between two factors - changes in livestock management, including the increased use of pharmaceutical products, and disease. Insular vertebrates seem to be especially susceptible to diseases induced by the arrival of exotic pathogens, a process often favored by human activities, and sedentary and highly dense insular scavengers populations may be thus especially exposed to infection by such pathogens. Here, we compare pathogen prevalence and immune response in insular and continental populations of the globally endangered Egyptian vulture under similar livestock management scenarios, but with different ecological and evolutionary perspectives. Methods/Principal Findings Adult, immature, and fledgling vultures from the Canary Islands and the Iberian Peninsula were sampled to determine a) the prevalence of seven pathogen taxa and b) their immunocompetence, as measured by monitoring techniques (white blood cells counts and immunoglobulins). In the Canarian population, pathogen prevalence was higher and, in addition, an association among pathogens was apparent, contrary to the situation detected in continental populations. Despite that, insular fledglings showed lower leukocyte profiles than continental birds and Canarian fledglings infected by Chlamydophila psittaci showed poorer cellular immune response. Conclusions/Significance A combination of environmental and ecological factors may contribute to explain the high susceptibility to infection found in insular vultures. The scenario described here may be similar in other insular systems where populations of carrion-eaters are in strong decline and are seriously threatened. Higher susceptibility to infection may be a further factor contributing decisively to the extinction of island scavengers

  5. Reward-related activity in the medial prefrontal cortex is driven by consumption

    PubMed Central

    Horst, Nicole K.; Laubach, Mark

    2013-01-01

    An emerging literature suggests that the medial prefrontal cortex (mPFC) is crucial for the ability to track behavioral outcomes over time and has a critical role in successful foraging. Here, we examine this issue by analyzing changes in neuronal spike activity and local field potentials in the rat mPFC in relation to the consumption of rewarding stimuli. Using multi-electrode recording methods, we simultaneously recorded from ensembles of neurons and field potentials in the mPFC during the performance of an operant-delayed alternation task and a variable-interval licking procedure. In both tasks, we found that consummatory behavior (licking) activates many mPFC neurons and is associated with theta-band phase locking by mPFC field potentials. Many neurons that were modulated by the delivery of reward were also modulated when rats emitted bouts of licks during the period of consumption. The majority of these licking-modulated neurons were found in the rostral part of the prelimbic cortex, a region that is heavily interconnected with the gustatory insular cortex and projects to subcortical feeding-related centers. Based on the tight coupling between spike activity, theta-band phase locking, and licking behavior, we suggest that reward-related activity in the mPFC is driven by consummatory behavior. PMID:23596384

  6. Word Recognition in Auditory Cortex

    ERIC Educational Resources Information Center

    DeWitt, Iain D. J.

    2013-01-01

    Although spoken word recognition is more fundamental to human communication than text recognition, knowledge of word-processing in auditory cortex is comparatively impoverished. This dissertation synthesizes current models of auditory cortex, models of cortical pattern recognition, models of single-word reading, results in phonetics and results in…

  7. Island colonization and evolution of the insular woody habit in Echium L. (Boraginaceae).

    PubMed

    Böhle, U R; Hilger, H H; Martin, W F

    1996-10-15

    Numerous island-inhabiting species of predominantly herbaceous angiosperm genera are woody shrubs or trees. Such "insular woodiness" is strongly manifested in the genus Echium, in which the continental species of circummediterranean distribution are herbaceous, whereas endemic species of islands along the Atlantic coast of north Africa are woody perennial shrubs. The history of 37 Echium species was traced with 70 kb of noncoding DNA determined from both chloroplast and nuclear genomes. In all, 239 polymorphic positions with 137 informative sites, in addition to 27 informative indels, were found. Island-dwelling Echium species are shown to descend from herbaceous continental ancestors via a single island colonization event that occurred < 20 million years ago. Founding colonization appears to have taken place on the Canary Islands, from which the Madeira and Cape Verde archipelagos were invaded. Colonization of island habitats correlates with a recent origin of perennial woodiness from herbaceous habit and was furthermore accompanied by intense speciation, which brought forth remarkable diversity of forms among contemporary island endemics. We argue that the origin of insular woodiness involved response to counter-selection of inbreeding depression in founding island colonies. PMID:8876207

  8. Intraoperative diffusion tensor imaging predicts the recovery of motor dysfunction after insular lesions☆

    PubMed Central

    Li, Jinjiang; Chen, Xiaolei; Zhang, Jiashu; Zheng, Gang; Lv, Xueming; Li, Fangye; Hu, Shen; Zhang, Ting; Xu, Bainan

    2013-01-01

    Insular lesions remain surgically challenging because of the need to balance aggressive resection and functional protection. Motor function deficits due to corticospinal tract injury are a common complication of surgery for lesions adjacent to the internal capsule and it is therefore essential to evaluate the corticospinal tract adjacent to the lesion. We used diffusion tensor imaging to evaluate the corticospinal tract in 89 patients with insular lobe lesions who underwent surgery in Chinese PLA General Hospital from February 2009 to May 2011. Postoperative motor function evaluation revealed that 57 patients had no changes in motor function, and 32 patients suffered motor dysfunction or aggravated motor dysfunction. Of the affected patients, 20 recovered motor function during the 6–12-month follow-up, and an additional 12 patients did not recover over more than 12 months of follow-up. Following reconstruction of the corticospinal tract, fractional anisotropy comparison demonstrated that preoperative, intraoperative and follow-up normalized fractional anisotropy in the stable group was higher than in the transient deficits group or the long-term deficits group. Compared with the transient deficits group, intraoperative normalized fractional anisotropy significantly decreased in the long-term deficits group. We conclude that intraoperative fractional anisotropy values of the corticospinal tracts can be used as a prognostic indicator of motor function outcome. PMID:25206435

  9. High antipredatory efficiency of insular lizards: a warning signal of excessive specimen collection?

    PubMed

    Delibes, Miguel; Blázquez, María del Carmen; Soriano, Laura; Revilla, Eloy; Godoy, José Antonio

    2011-01-01

    We live-captured lizards on islands in the Gulf of California and the Baja California peninsula mainland, and compared their ability to escape predation. Contrary to expectations, endemic lizard species from uninhabited islands fled from humans earlier and more efficiently than those from peninsular mainland areas. In fact, 58.2% (n=146) of the lizards we tried to capture on the various islands escaped successfully, while this percentage was only 14.4% (n=160) on the peninsular mainland. Separate evidence (e.g., proportion of regenerated tails, low human population at the collection areas, etc.) challenges several potential explanations for the higher antipredatory efficiency of insular lizards (e.g., more predation pressure on islands, habituation to humans on the peninsula, etc.). Instead, we suggest that the ability of insular lizards to avoid predators may be related to harvesting by humans, perhaps due to the value of endemic species as rare taxonomic entities. If this hypothesis is correct, predation-related behavioral changes in rare species could provide early warning signals of their over-exploitation, thus encouraging the adoption of conservation measures. PMID:22216244

  10. Correlations of neuronal and microvascular densities in murine cortex revealed by direct counting and colocalization of nuclei and vessels

    PubMed Central

    Tsai, Philbert S.; Kaufhold, John P.; Blinder, Pablo; Friedman, Beth; Drew, Patrick J.; Karten, Harvey J.; Lyden, Patrick D.; Kleinfeld, David

    2016-01-01

    It is well known that the density of neurons varies within the adult brain. In neocortex, this includes variations in neuronal density between different lamina as well as between different regions. Yet the concomitant variation of the microvessels is largely uncharted. Here we present automated histological, imaging, and analysis tools to simultaneously map the locations of all neuronal and non-neuronal nuclei and the centerlines and diameters of all blood vessels within thick slabs of neocortex from mice. Based on total inventory measurements of different cortical regions (~ 107 cells vectorized across brains), these methods revealed: (1) In three dimensions, the mean distance of the center of neuronal somata to the closest microvessel was 14 μm. (2) Volume samples within lamina of a given region show that the density of microvessels does not match the strong laminar variation in neuronal density. This holds for both agranular and granular cortex. (3) Volume samples in successive radii from the midline to the ventral-lateral edge, where each volume summed the number of cells and microvessels from the pia to the white matter, show a significant correlation between neuronal and microvessel densities. These data show that while neuronal and vascular densities do not track each other on the 100 μm scale of cortical lamina, they do track each other on the 1 – 10 mm scale of the cortical mantle. The absence of a disproportionate density of blood vessels in granular lamina is argued to be consistent with the initial locus of functional brain imaging signals. PMID:19923289

  11. "There Are No Housewives on 'Star Trek'": A Reexamination of Exit Rights for the Children of Insular Fundamentalist Parents

    ERIC Educational Resources Information Center

    McAvoy, Paula

    2012-01-01

    In this essay, Paula McAvoy addresses the problem caused by the liberal state's necessary tolerance of insular fundamentalist groups and the concern that children raised in such groups do not have a fair opportunity to evaluate their inherited beliefs. This tension comes to the fore around disagreements over schooling and requests for religious…

  12. Insular Ecosystems of the Southeastern United States- A Regional Synthesis to Support Biodiversity Conservation in a Changing Climate

    USGS Publications Warehouse

    Cartwright, Jennifer M.; Wolfe, William J.

    2016-01-01

    In the southeastern United States, insular ecosystems—such as rock outcrops, depression wetlands, high-elevation balds, flood-scoured riparian corridors, and insular prairies and barrens—occupy a small fraction of land area but constitute an important source of regional and global biodiversity, including concentrations of rare and endemic plant taxa. Maintenance of this biodiversity depends upon regimes of abiotic stress and disturbance, incorporating factors such as soil surface temperature, widely fluctuating hydrologic conditions, fires, flood scouring, and episodic droughts that may be subject to alteration by climate change. Over several decades, numerous localized, site-level investigations have yielded important information about the floristics, physical environments, and ecological dynamics of these insular ecosystems; however, the literature from these investigations has generally remained fragmented. This report consists of literature syntheses for eight categories of insular ecosystems of the southeastern United States, concerning (1) physical geography, (2) ecological determinants of community structures including vegetation dynamics and regimes of abiotic stress and disturbance, (3) contributions to regional and global biodiversity, (4) historical and current anthropogenic threats and conservation approaches, and (5) key knowledge gaps relevant to conservation, particularly in terms of climate-change effects on biodiversity. This regional synthesis was undertaken to discern patterns across ecosystems, identify knowledge gaps, and lay the groundwork for future analyses of climate-change vulnerability. Findings from this synthesis indicate that, despite their importance to regional and global biodiversity, insular ecosystems of the southeastern United States have been subjected to a variety of direct and indirect human alterations. In many cases, important questions remain concerning key determinants of ecosystem function. In particular, few

  13. Late Miocene insular mice from the Tusco-Sardinian palaeobioprovince provide new insights on the palaeoecology of the Oreopithecus faunas.

    PubMed

    Casanovas-Vilar, Isaac; van Dam, Jan A; Moyà-Solà, Salvador; Rook, Lorenzo

    2011-07-01

    Oreopithecus bambolii is one of the few hominoids that evolved under insular conditions, resulting in the development of unique adaptations that have fueled an intensive debate. The palaeoenvironment associated with this great ape has been the subject of great controversy as well. On the one hand, palaeobotanical data indicate that Oreopithecus likely inhabited mixed mesophytic forests interrupted by swamps; on the other hand, an abundance of hypsodont bovids points towards the existence of dry and open environments. Here, we provide a new approach based on the ecomorphology of the extinct endemic Muridae (rats and mice) of the so-called Oreopithecus faunas. Our results show that the successive species of endemic insular murids (Huerzelerimys and Anthracomys) evolved a number of adaptations observed only in extant family members that include significant proportions of grass in their diet. While this fits the pattern exhibited by large mammals, it contrasts with the available palaeobotanical information, which indicates that grasses were minor components of the vegetation. This contradiction may be explained because these endemic murids may have been adapted to the consumption of particular food items such as hard parts of aquatic plants (as shown by some extant murid species). However, because it is unlikely that the remaining herbivore mammals were adapted to this diet as well, we favour an alternative hypothesis that takes into account the peculiar ecological conditions of insular ecosystems leading to a density-dependent selective regime with strong competition. Such a regime would promote the selection of dental adaptations to increase feeding efficiency and durability of the dentition (such as hypsodonty) as seen in some fossil insular ruminants. This hypothesis requires further testing, but may partly account for parallel evolution of dental traits in phylogenetically unrelated insular mammals. PMID:21371736

  14. Maps of the Auditory Cortex.

    PubMed

    Brewer, Alyssa A; Barton, Brian

    2016-07-01

    One of the fundamental properties of the mammalian brain is that sensory regions of cortex are formed of multiple, functionally specialized cortical field maps (CFMs). Each CFM comprises two orthogonal topographical representations, reflecting two essential aspects of sensory space. In auditory cortex, auditory field maps (AFMs) are defined by the combination of tonotopic gradients, representing the spectral aspects of sound (i.e., tones), with orthogonal periodotopic gradients, representing the temporal aspects of sound (i.e., period or temporal envelope). Converging evidence from cytoarchitectural and neuroimaging measurements underlies the definition of 11 AFMs across core and belt regions of human auditory cortex, with likely homology to those of macaque. On a macrostructural level, AFMs are grouped into cloverleaf clusters, an organizational structure also seen in visual cortex. Future research can now use these AFMs to investigate specific stages of auditory processing, key for understanding behaviors such as speech perception and multimodal sensory integration. PMID:27145914

  15. MRI volumetry of prefrontal cortex

    NASA Astrophysics Data System (ADS)

    Sheline, Yvette I.; Black, Kevin J.; Lin, Daniel Y.; Pimmel, Joseph; Wang, Po; Haller, John W.; Csernansky, John G.; Gado, Mokhtar; Walkup, Ronald K.; Brunsden, Barry S.; Vannier, Michael W.

    1995-05-01

    Prefrontal cortex volumetry by brain magnetic resonance (MR) is required to estimate changes postulated to occur in certain psychiatric and neurologic disorders. A semiautomated method with quantitative characterization of its performance is sought to reliably distinguish small prefrontal cortex volume changes within individuals and between groups. Stereological methods were tested by a blinded comparison of measurements applied to 3D MR scans obtained using an MPRAGE protocol. Fixed grid stereologic methods were used to estimate prefrontal cortex volumes on a graphic workstation, after the images are scaled from 16 to 8 bits using a histogram method. In addition images were resliced into coronal sections perpendicular to the bicommissural plane. Prefrontal cortex volumes were defined as all sections of the frontal lobe anterior to the anterior commissure. Ventricular volumes were excluded. Stereological measurement yielded high repeatability and precision, and was time efficient for the raters. The coefficient of error was cortex boundaries on 3D images was critical to obtaining accurate measurements. MR prefrontal cortex volumetry by stereology can yield accurate and repeatable measurements. Small frontal lobe volume reductions in patients with brain disorders such as depression and schizophrenia can be efficiently assessed using this method.

  16. Household waste compositional analysis variation from insular communities in the framework of waste prevention strategy plans.

    PubMed

    Zorpas, Antonis A; Lasaridi, Katia; Voukkali, Irene; Loizia, Pantelitsa; Chroni, Christina

    2015-04-01

    Waste management planning requires reliable data regarding waste generation, affecting factors on waste generation and forecasts of waste quantities based on facts. In order to decrease the environmental impacts of waste management the choice of prevention plan as well as the treatment method must be based on the features of the waste that are produced in a specific area. Factors such as culture, economic development, climate, and energy sources have an impact on waste composition; composition influences the need of collecting waste more or less frequently of waste collection and disposition. The research question was to discover the main barriers concerning the compositional analysis in Insular Communities under warm climate conditions and the findings from this study enabled the main contents of a waste management plan to be established. These included advice to residents on waste minimisation, liaison with stakeholders and the expansion of kerbside recycling schemes. PMID:25690412

  17. Reduction of brain and sense organs in the fossil insular bovid Myotragus.

    PubMed

    Köhler, Meike; Moyà-Solà, Salvador

    2004-01-01

    Our study of the fossil rupicaprine bovid Myotragus [Bate, 1909] from the Mediterranean island Majorca (Spain) provides evidence that this animal underwent significant changes (reduction) in the relative size of brain and sense organs after geographic isolation at the end of the Messinian Salinity Crisis (Miocene-Pliocene boundary, 5.2 Mya). The changes in the central nervous system of Myotragus parallel the pattern reported for domesticated animals, in which decrease in relative brain size is accompanied by a decrease in the relative size of their sense organs. We interpret the important size reduction of brain and sense organs in Myotragus as an adaptive strategy for more efficient energy use under the special environmental conditions of the insular ecosystem, characterized by absence of predation and limitation of trophic resources. PMID:14726622

  18. Introductions do not compensate for functional and phylogenetic losses following extinctions in insular bird assemblages.

    PubMed

    Sobral, Fernando L; Lees, Alexander C; Cianciaruso, Marcus V

    2016-09-01

    The ratio of species extinctions to introductions has been comparable for many insular assemblages, suggesting that introductions could have 'compensated' for extinctions. However, the capacity for introduced species to replace ecological roles and evolutionary history lost following extinction is unclear. We investigated changes in bird functional and phylogenetic diversity in the wake of extinctions and introductions across a sample of 32 islands worldwide. We found that extinct and introduced species have comparable functional and phylogenetic alpha diversity. However, this was distributed at different positions in functional space and in the phylogeny, indicating a 'false compensation'. Introduced and extinct species did not have equivalent functional roles nor belong to similar lineages. This makes it unlikely that novel island biotas composed of introduced taxa will be able to maintain ecological roles and represent the evolutionary histories of pre-disturbance assemblages and highlights the importance of evaluating changes in alpha and beta diversity concurrently. PMID:27353518

  19. Laser Ablation as Treatment Strategy for Medically Refractory Dominant Insular Epilepsy – Therapeutic and Functional Considerations

    PubMed Central

    Hawasli, Ammar H.; Bandt, S. Kathleen; Hogan, R. Edward; Werner, Nicole; Leuthardt, Eric C.

    2014-01-01

    Since its introduction to neurosurgery in 2008, laser ablative techniques have been largely confined to the management of unresectable tumors. Application of this technology for the management of focal epilepsy in the adult population has not been fully explored. Given that nearly 1,000,000 Americans live with medically refractory epilepsy and current surgical techniques only address a fraction of epileptic pathologies, additional therapeutic options are needed. We report the successful treatment of dominant insular epilepsy in a 53 year-old male with minimally-invasive laser ablation complicated by mild verbal and memory deficits. We also report neuropsychological test data on this patient before surgery and at 8-months after the ablation procedure. This account represents the first reported successful patient outcome of laser ablation as an effective treatment option for medically refractory post-stroke epilepsy in an adult. PMID:25359500

  20. Outbreaks of photosensitisation and deaths in cattle due to Myoporum aff. Insulare R. Br. toxicity.

    PubMed

    Jerrett, I V; Chinnock, R J

    1983-06-01

    Outbreaks of photosensitisation and deaths in cattle on 5 farms in Victoria occurred following access to Myoporum affinity insulare. Signs were observed 2 to 6 days after access to myoporum trees or pruned branches and included depression, anorexia, photosensitisation, constipation, agalactia, jaundice, and mucosal petechiation. Serum gamma glutamyl transferase and aspartate amino transferase levels were elevated in all cases. Gross findings in fatally intoxicated cows consisted of widespread haemorrhages and pale yellow mottling of the liver. Distinctive histological lesions of periportal hepatic necrosis and bile duct proliferation were seen in all cases. An 8-month-old heifer given 30 g/kg fresh minced leaves by stomach tube died approximately 70 h after initial dosing. Post-mortem findings of widespread haemorrhage and hepatic periportal necrosis and bile duct proliferation were identical to those of field cases. PMID:6626066

  1. Designing an Information System for the Preservation of the Insular Tropical Environment of Reunion Island

    NASA Astrophysics Data System (ADS)

    Conruyt, Noël; Sébastien, Didier; Courdier, Rémy; David, Daniel; Sébastien, Nicolas; Ralambondrainy, Tiana

    Decision-makers who wish to manage Insular Tropical Environments more efficiently need to narrow the gap between the production of scientific knowledge in universities, or other labs, and its pragmatic use by the general public and administrations. Today, one of the main challenges concerning the environment is the preservation of the biodiversity of ecosystems that suffer from urban and agricultural pressure. As we can only protect what we know, it is all the more important to share expert knowledge about habitats and species by using Internet in order to educate the public about their wealth and beauty. Based on Reunion Island, and taking into consideration an expected population growth of over 30% in the next twenty years, we are working to predict the human impact on this closed territory. To help tackle these two questions about biodiversity and land consumption, we have designed an Information System (IS) in the framework of the ETIC program. Our aim is to enhance insular tropical environment research in order to help the Reunion National Park to manage its protected territory. On the one hand, biodiversity research is handled statically, using knowledge bases and databases, to enhance Systematics and ecological university research. On the other hand, spatial planning concerns are treated dynamically, using multi-agent systems to simulate population densification movements. These software technologies have been implemented and integrated through a common architectural system in the ETIC program. They were conceived using Web Services that allow each module to communicate its functionalities and information with one another, as well as with external systems.

  2. Subjective Somatosensory Experiences Disclosed by Focused Attention: Cortical-Hippocampal-Insular and Amygdala Contributions

    PubMed Central

    Bauer, Clemens C. C.; Barrios, Fernando A.; Díaz, José-Luis

    2014-01-01

    In order to explore the neurobiological foundations of qualitative subjective experiences, the present study was designed to correlate objective third-person brain fMRI measures with subjective first-person identification and scaling of local, subtle, and specific somatosensory sensations, obtained directly after the imaging procedure. Thus, thirty-four volunteers were instructed to focus and sustain their attention to either provoked or spontaneous sensations of each thumb during the fMRI procedure. By means of a Likert scale applied immediately afterwards, the participants recalled and evaluated the intensity of their attention and identified specific somatosensory sensations (e.g. pulsation, vibration, heat). Using the subject's subjective scores as covariates to model both attention intensity and general somatosensory experiences regressors, the whole-brain random effect analyses revealed activations in the frontopolar prefrontal cortex (BA10), primary somatosensory cortex (BA1), premotor cortex (BA 6), precuneus (BA 7), temporopolar cortex (BA 38), inferior parietal lobe (BA 39), hippocampus, insula and amygdala. Furthermore, BA10 showed differential activity, with ventral BA10 correlating exclusively with attention (r(32) = 0.54, p = 0.0013) and dorsal BA10 correlating exclusively with somatosensory sensation (r(32) = 0.46, p = 0.007). All other reported brain areas showed significant positive correlations solely with subjective somatosensory experiences reports. These results provide evidence that the frontopolar prefrontal cortex has dissociable functions depending on specific cognitive demands; i.e. the dorsal portion of the frontopolar prefrontal cortex in conjunction with primary somatosensory cortex, temporopolar cortex, inferior parietal lobe, hippocampus, insula and amygdala are involved in the processing of spontaneous general subjective somatosensory experiences disclosed by focused and sustained attention. PMID:25166875

  3. Environmental drivers of megafaunal assemblage composition and biomass distribution over mainland and insular slopes of the Balearic Basin (Western Mediterranean)

    NASA Astrophysics Data System (ADS)

    Fanelli, E.; Cartes, J. E.; Papiol, V.; López-Pérez, C.

    2013-08-01

    The influence of mesoscale physical and trophic variables on deep-sea megafauna, a scale of variation often neglected in deep-sea studies, is crucial for understanding their role in the ecosystem. Drivers of megafaunal assemblage composition and biomass distribution have been investigated in two contrasting areas of the Balearic basin in the NW Mediterranean: on the mainland slope (Catalonian coasts) and on the insular slope (North of Mallorca, Balearic Islands). An experimental bottom trawl survey was carried out during summer 2010, at stations in both sub-areas located between 450 and 2200 m water depth. Environmental data were collected simultaneously: near-bottom physical parameters, and the elemental and isotopic composition of sediments. Initially, data were analysed along the whole depth gradient, and then assemblages from the two areas were compared. Analysis of the trawls showed the existence of one group associated with the upper slope (US=450-690 m), another with the middle slope (MS=1000-1300 m) and a third with the lower slope (LS=1400-2200 m). Also, significant differences in the assemblage composition were found between mainland and insular slopes at MS. Dominance by different species was evident when the two areas were compared by SIMPER analysis. The greatest fish biomass was recorded in both areas at 1000-1300 m, a zone linked to minimum temperature and maximum O2 concentration on the bottom. Near the mainland, fish assemblages were best explained (43% of total variance, DISTLM analysis) by prey availability (gelatinous zooplankton biomass). On the insular slope, trophic webs seemed less complex and were based on vertical input of surface primary production. Decapods, which reached their highest biomass values on the upper slope, were correlated with salinity and temperature in both the areas. However, while hydrographic conditions (temperature and salinity) seemed to be the most important variables over the insular slope, resource availability

  4. Delayed-alternation performance after selective lesions within the prefrontal cortex of the cat.

    PubMed

    Markowitsch, H J; Pritzel, M; Kessler, J; Guldin, W; Freeman, R B

    1980-02-01

    On the basis of new neuroanatomical findings on relationships between subregions of the mediodorsal thalamic nucleus and the prefrontal cortex of the cat, it was attempted to investigate the relative importance of prefrontal subfields with the aim of obtaining evidence in favor of a functional inequality of different prefrontal subfields. Four areas, named presylvian (PRS), proreal (PR), dorsomedial (DM), and orbito-insular (OI) sectors, were ablated successfully in 30 adult animals. Performance of a 10-sec delayed-alternation task was compared pre- and postoperatively. Furthermore, most of the cats had to learn an extension of this task postoperatively, using a 20-sec delay period, and lastly, these animals were subjected to an extinction test. Significant performance differences were obtained between cats of different groups in all three tasks. Lesions of subregion PR, and even more of subregion PRS, led to severe behavioral deterioration, whereas lesions of subregion OI were without effect, when compared with the behavior of a sham-operated control group. PRS-cats, furthermore, showed motor disturbances during the first postoperative week. The results obtained suggest that it is possible to subdivide the cat's prefrontal cortex functionally. In addition, it is hypothesized that behavioral changes in cats of groups PRS and PR are due to an inability to use kinesthetic information properly. PMID:7284081

  5. NMDAR-dependent proteasome activity in the gustatory cortex is necessary for conditioned taste aversion.

    PubMed

    Rosenberg, Tali; Elkobi, Alina; Dieterich, Daniela C; Rosenblum, Kobi

    2016-04-01

    Taste information is processed in different brain structures in the mammalian brain, including the gustatory cortex (GC), which resides within the insular cortex. N-methyl-d-aspartate receptor (NMDAR) activity in the GC is necessary for the acquisition of conditioned taste aversion (CTA) but not positive novel taste learning. Previous studies have shown that taste memory consolidation requires intact protein synthesis in the GC. In addition, the direct involvement of translation initiation and elongation factors was documented in the GC during taste learning. However, protein expression is defined by protein synthesis, degradation, and localization. Protein degradation is critical for the consolidation and reconsolidation of other forms of learning, such as fear learning and addiction behavior, but its role in cortical-dependent learning is not clear. Here, we show for the first time that proteasome activity is specifically increased in the GC 4h following experiencing of a novel taste. This increase in proteasome activity was abolished by local administration to the GC of the NMDA antagonist, APV, as well as a CaMKII inhibitor, at the time of acquisition. In addition, local application of lactacystin, a proteasome inhibitor, resulted in impaired CTA, but not novel taste learning. These results suggest that NMDAR-dependent proteasome activity in the GC participates in the association process between novel taste experience and negative visceral sensation. PMID:26785229

  6. Effects of insularity on digestion: living on islands induces shifts in physiological and morphological traits in island reptiles

    NASA Astrophysics Data System (ADS)

    Sagonas, Kostas; Pafilis, Panayiotis; Valakos, Efstratios D.

    2015-10-01

    Living on islands entails numerous challenges for animals, among which resource scarcity stands out. In order to survive, animals have to optimize energy acquisition. We examined the impact of insularity on digestion comparing a series of physiological and morphological traits of adult males between insular and mainland populations of the Balkan green lizard. Island lizards had longer gastrointestinal tracts and gut passage times and higher digestive efficiencies. The dissection of the hindgut revealed an unexpected finding, the presence of cecal valves that were more frequent in island lizards. Thanks to all above islanders retain food for longer periods and thus maximize energy income and increase the amount of the extracted nutrients. That way, they secure energy income from the limited, in time and quantity, food resources of the islands.

  7. Building and Applying "Insularity Theory": Review on Knapp's Prehistoric and Protohistoric Cyprus, 2008.

    NASA Astrophysics Data System (ADS)

    Katsarou-Tzeveleki, Stella

    listing of external factors (colonization, invasions) originating in the Near East and the Aegean as sequential narrative history, and the descriptive, systemic analysis of 'materiality, production, trade, migration and colonization which have for long been the cornerstones of Cypriot archaeology' (p. 11). In contrast, he turns his attention towards the internal processes within the island society of Bronze Age Cyprus, which shape its insularity and give it a distinctive identity at this specific period, processes that lead to contextual history and formative tradition. 'To study how any society changes, at any time, it is crucial first to look at internal rather than external factors' (p. 1). Defining the concept of insularity is his aim; therefore, he begins with a number of very apposite rhetorical questions (p. 13) and identifies several individual parameters (connectivity, islandscape, social identity, ethnicity, migration, acculturation, hybridization) to which he assigns collective and individual meanings. The eight chapters that follow may be assigned, broadly, to three general units: in the first of these (ch. 1-2), Knapp offers a synthesis of these parameters in the form of a 'theory of insularity'. In the second (ch. 3-7) he formulates his revised narrative of the prehistory and social identity of the island, which involves a presentation of social and economic, rather than stylistic categories, on the basis of the parameters laid down in his theoretical scheme. Finally, in the third unit (ch. 8), he records his overall conclusions, the new cognitive experiences and concerns that have emerged from the application of his theory, both to Cyprus and to insular archaeology in the Mediterranean and on a world scale. Knapp's synthesis of the theory of insularity in the first unit is a major contribution to Mediterranean archaeology, and makes this book a seminal work. Continuing and broadening Broodbank's (2000) reasoning about the Cyclades, Knapp, with Cyprus as his

  8. An Ovarian Carcinoid Tumor With Peptide YY-Positive Insular Component: A Case Report and Review of the Literature.

    PubMed

    Erdenebaatar, Chimeddulam; Yamaguchi, Munekage; Saito, Fumitaka; Motooka, Chisato; Tashiro, Hironori; Katabuchi, Hidetaka

    2016-07-01

    Ovarian carcinoid tumors are uncommon and account for 1% of all carcinoid tumors. The insular type of ovarian carcinoid tumor is common in western countries; in contrast, the strumal and trabecular types seem to be common in Asian countries. Strumal and trabecular types are associated with peptide YY (PYY) production, which may cause constipation. Here, we report the case of a 70-yr-old Japanese woman with chronic constipation who was referred to Kumamoto University Hospital because of a right adnexal mass. Imaging tests suggested that the solid mass might be malignant; therefore, abdominal total hysterectomy, bilateral salpingo-oophorectomy, and omentectomy were performed. A subsequent histopathologic examination confirmed an insular carcinoid tumor with a trabecular component in the right ovary. Both components were positive for PYY but not for serotonin. The patient complained of diarrhea instead of constipation soon after the surgery. Because PYY-positive insular carcinoid tumor in the ovary has not been previously reported, we reviewed 19 reported cases of patients with PYY-positive ovarian carcinoid tumors. The origins, common histologic types and symptoms caused by specific peptides secreted in ovarian carcinoid tumors differ between western and Asian countries. PMID:26630222

  9. Increased Low- and High-Frequency Oscillatory Activity in the Prefrontal Cortex of Fibromyalgia Patients

    PubMed Central

    Lim, Manyoel; Kim, June Sic; Kim, Dajung J.; Chung, Chun Kee

    2016-01-01

    Recent human neuroimaging studies have suggested that fibromyalgia (FM), a chronic widespread pain disorder, exhibits altered thalamic structure and function. Since the thalamus has extensive reciprocal connection with the cortex, structural and functional thalamic alterations in FM might be linked to aberrant thalamocortical oscillation. This study investigated the presence of abnormal brain rhythmicity in low- and high-frequency bands during resting state in patients with FM and their relationship to clinical pain symptom. Spontaneous magnetoencephalography (MEG) activity was recorded in 18 females with FM and 18 age- and sex-matched healthy control (HC) subjects. The most remarkable finding was that FM patients had general increases in theta, beta and gamma power along with a slowing of the dominant alpha peak. Increased spectral powers in the theta-band were primarily localized to the left dorsolateral prefrontal (DLPFC) and orbitofrontal cortex (OFC). Beta and gamma over-activation were localized to insular, primary motor and primary and secondary somatosensory (S2) cortices, as well as the DLPFC and OFC. Furthermore, enhanced high-frequency oscillatory activities in the DLPFC and OFC were associated with higher affective pain scores in patients with FM. Our results demonstrate that FM patients feature enhanced low- and high-frequency oscillatory activity in the brain areas related to cognitive and emotional modulation of pain. Increased low- and high-frequency activity of the prefrontal cortex may contribute to persistent perception of pain in FM. Therapeutic intervention based on manipulating neural oscillation to restore normal thalamocortical rhythmicity may be beneficial to pain relief in FM. PMID:27014041

  10. Manganese-enhanced MR imaging of brain activation evoked by noxious peripheral electrical stimulation.

    PubMed

    Cha, Myeounghoon; Lee, Kyuhong; Lee, Chulhyun; Cho, Jee-Hyun; Cheong, Chaejoon; Sohn, Jin-Hun; Lee, Bae Hwan

    2016-02-01

    As imaging technology develops, magnetic resonance imaging (MRI) has furthered our understanding of brain function by clarifying the anatomical structure and generating functional imaging data related to information processing in pain conditions. Recent studies have reported that manganese (Mn(2+))-enhanced MRI (MEMRI) provides valuable information about the functions of the central nervous system. The aim of this study was to identify specific brain regions activated during noxious electric stimulation using high-resolution MEMRI. Male Sprague Dawley rats were divided into three groups: naïve, sham electrical stimulation, and noxious electric stimulation. Under urethane with α-chloralose mixture anesthesia, a catheter was placed in the external carotid artery to administrate 20% mannitol and manganese chloride (25mM MnCl2). Noxious electric stimulation (2Hz, 10V) was applied to the hind paw with a needle electrode. Stimulation-induced neuronal activation was detected using 4.7-T MRI. In response to noxious electrical stimulation, remarkable Mn(2+)-enhanced signals were observed in the agranular insular cortex, auditory cortex, primary somatosensory cortex of the hind limb, and granular and dysgranular insular cortex, which correspond to sensory tactile electric stimulus to the hindpaws. These results indicate that the combination of MEMRI with activity-induced Mn(2+)-dependent contrast can delineate functional areas in the rat brain. PMID:26733299

  11. The Functions of the Orbitofrontal Cortex

    ERIC Educational Resources Information Center

    Rolls, Edmund T.

    2004-01-01

    The orbitofrontal cortex contains the secondary taste cortex, in which the reward value of taste is represented. It also contains the secondary and tertiary olfactory cortical areas, in which information about the identity and also about the reward value of odours is represented. The orbitofrontal cortex also receives information about the sight…

  12. Genetic drift and rapid evolution of viviparity in insular fire salamanders (Salamandra salamandra).

    PubMed

    Velo-Antón, G; Zamudio, K R; Cordero-Rivera, A

    2012-04-01

    Continental islands offer an excellent opportunity to investigate adaptive processes and to time microevolutionary changes that precede macroevolutionary events. We performed a population genetic study of the fire salamander (Salamandra salamandra), a species that displays unique intraspecific diversity of reproductive strategies, to address the microevolutionary processes leading to phenotypic and genetic differentiation of island, coastal and interior populations. We used eight microsatellite markers to estimate genetic diversity, population structure and demographic parameters in viviparous insular populations and ovoviviparous coastal and interior populations. Our results show considerable genetic differentiation (F(ST) range: 0.06-0.27), and no clear signs of gene flow among populations, except between the large and admixed interior populations. We find no support for island colonization by rafting or intentional/accidental anthropogenic introductions, indicating that rising sea levels were responsible for isolation of the island populations approximately 9000 years ago. Our study provides evidence of rapid genetic differentiation between island and coastal populations, and rapid evolution of viviparity driven by climatic selective pressures on island populations, geographic isolation with genetic drift, or a combination of these factors. Studies of these viviparous island populations in early stages of divergence help us better understand the microevolutionary processes involved in rapid phenotypic shifts. PMID:22086081

  13. Sediment distribution on a storm-dominated insular shelf, Luquillo, Puerto Rico, U.S.A.

    USGS Publications Warehouse

    Schwab, W.C.; Rodriguez, R.W.; Danforthf, W.W.; Gowen, M.H.

    1996-01-01

    A sea-floor mapping investigation designed to assess the sediment distribution, the movement of the nearshore sand supply, and the fate of sediment eroded from the shoreline was conducted using high-resolution sidescan-sonar, seismic reflection, and sediment sampling techniques on the northern insular shelf of Puerto Rico, off the town of Luquillo. Sea-floor structures and the distribution of sediment texture and composition suggest that regional oceanographic processes result in a net offshore direction for cross-shelf sediment transport on the middle and outer shelf during storms. If these same processes are active on the inner shelf, mapping results indicate that this sediment is not transported seaward of a series of east-west trending Pleistocene-age eolianite ridges that outcrop on the middle shelf. The eolianite ridges may act as natural dams, preventing the removal of sediment from the nearshore area. Sand deposits behind the "dams" are up to 20 m thick on the shoreward flank of the ridges.

  14. Genetic structure in insular and mainland populations of house sparrows (Passer domesticus) and their hemosporidian parasites

    PubMed Central

    Bichet, Coraline; Moodley, Yoshan; Penn, Dustin J; Sorci, Gabriele; Garnier, Stéphane

    2015-01-01

    Small and isolated populations usually exhibit low levels of genetic variability, and thus, they are expected to have a lower capacity to adapt to changes in environmental conditions, such as exposure to pathogens and parasites. Comparing the genetic variability of selectively neutral versus functional loci allows one to assess the evolutionary history of populations and their future evolutionary potential. The genes of the major histocompatibility complex (MHC) control immune recognition of parasites, and their unusually high diversity is genes which is likely driven by parasite-mediated balancing selection. Here, we examined diversity and differentiation of neutral microsatellite loci and functional MHC class I genes in house sparrows (Passer domesticus), living in six insular and six mainland populations, and we aimed to determine whether their diversity or differentiation correlates with the diversity and the prevalence of infection of hemosporidian parasites. We found that island bird populations tended to have lower neutral genetic variability, whereas MHC variability gene was similar between island and mainland populations. Similarly, island populations tended to show greater genetic differentiation than mainland populations, especially at microsatellite markers. The maintenance of MHC genetic diversity and its less marked structure in the island populations could be attributed to balancing-selection. The greater MHC differentiation among populations was negatively correlated with similarity in blood parasites (prevalence and diversity of parasite strains) between populations. Even at low prevalence and small geographical scale, haemosporidian parasites might contribute to structure the variability of immune genes among populations of hosts. PMID:25937907

  15. A novel application of the ESR method: dating of insular phosphorites and reef limestone

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Brumby, S.; Jacobson, G.; Beckwith, A. L. J.; Polach, H. A.

    Samples composed of cemented coral conglomerate, reef limestone, and phosphorite have been obtained from outcrops and two drillholes on Nauru Island, central Pacific Ocean. They have been used to test the ESR dating method as applied to insular phosphorite and reef limestone, up to several million years in age. The following time framework for the diagenesis and recrystallisation of the deposits was obtained: 0.08-0.10 Ma for superficial phosphatic crust; 0.18-0.22 Ma for massive phosphorite with nodules and replaced coral; 0.50-0.60 Ma for uppermost reef limestone; 1.00-2.00 Ma for reef limestone at a depth of about 15 m; 3.00-5.00 Ma for reef limestone under the modern reef flat, perhaps extending to the interior upland at a depth of about 70-80 m. These ages are consistent with the stratigraphic positions and geological estimations, thus demonstrating that both phosphatic deposits and reef limestone are suitable for ESR dating. The age limination for reef limestone specimens may be more than 3-4 million years.

  16. Ontogeny of Neuro-Insular Complexes and Islets Innervation in the Human Pancreas

    PubMed Central

    Proshchina, Alexandra E.; Krivova, Yulia S.; Barabanov, Valeriy M.; Saveliev, Sergey V.

    2014-01-01

    The ontogeny of the neuro-insular complexes (NIC) and the islets innervation in human pancreas has not been studied in detail. Our aim was to describe the developmental dynamics and distribution of the nervous system structures in the endocrine part of human pancreas. We used double-staining with antibodies specific to pan-neural markers [neuron-specific enolase (NSE) and S100 protein] and to hormones of pancreatic endocrine cells. NSE and S100-positive nerves and ganglia were identified in the human fetal pancreas from gestation week (gw) 10 onward. Later the density of S100 and NSE-positive fibers increased. In adults, this network was sparse. The islets innervation started to form from gw 14. NSE-containing endocrine cells were identified from gw 12 onward. Additionally, S100-positive cells were detected both in the periphery and within some of the islets starting at gw 14. The analysis of islets innervation has shown that the fetal pancreas contained NIC and the number of these complexes was reduced in adults. The highest density of NIC is detected during middle and late fetal periods, when the mosaic islets, typical for adults, form. The close integration between the developing pancreatic islets and the nervous system structures may play an important role not only in the hormone secretion, but also in the islets morphogenesis. PMID:24795697

  17. Household waste compositional analysis variation from insular communities in the framework of waste prevention strategy plans

    SciTech Connect

    Zorpas, Antonis A.; Lasaridi, Katia; Voukkali, Irene; Loizia, Pantelitsa; Chroni, Christina

    2015-04-15

    Highlights: • Waste framework directive has set clear waste prevention procedures. • Household Compositional analysis. • Waste management plans. • Zero waste approach. • Waste generation. - Abstract: Waste management planning requires reliable data regarding waste generation, affecting factors on waste generation and forecasts of waste quantities based on facts. In order to decrease the environmental impacts of waste management the choice of prevention plan as well as the treatment method must be based on the features of the waste that are produced in a specific area. Factors such as culture, economic development, climate, and energy sources have an impact on waste composition; composition influences the need of collecting waste more or less frequently of waste collection and disposition. The research question was to discover the main barriers concerning the compositional analysis in Insular Communities under warm climate conditions and the findings from this study enabled the main contents of a waste management plan to be established. These included advice to residents on waste minimisation, liaison with stakeholders and the expansion of kerbside recycling schemes.

  18. Reduced functional connectivity in the thalamo-insular subnetwork in patients with acute anorexia nervosa.

    PubMed

    Ehrlich, Stefan; Lord, Anton R; Geisler, Daniel; Borchardt, Viola; Boehm, Ilka; Seidel, Maria; Ritschel, Franziska; Schulze, Anne; King, Joseph A; Weidner, Kerstin; Roessner, Veit; Walter, Martin

    2015-05-01

    The neural underpinnings of anorexia nervosa (AN) are poorly understood. Results from existing functional brain imaging studies using disorder-relevant food- or body-stimuli have been heterogeneous and may be biased due to varying compliance or strategies of the participants. In this study, resting state functional connectivity imaging was used. To explore the distributed nature and complexity of brain function we characterized network patterns in patients with acute AN. Thirty-five unmedicated female acute AN patients and 35 closely matched healthy female participants underwent resting state functional magnetic resonance imaging. We used a network-based statistic (NBS) approach [Zalesky et al., 2010a] to identify differences between groups by isolating a network of interconnected nodes with a deviant connectivity pattern. Group comparison revealed a subnetwork of connections with decreased connectivity including the amygdala, thalamus, fusiform gyrus, putamen and the posterior insula as the central hub in the patient group. Results were not driven by changes in intranodal or global connectivity. No network could be identified where AN patients had increased coupling. Given the known involvement of the identified thalamo-insular subnetwork in interoception, decreased connectivity in AN patients in these nodes might reflect changes in the propagation of sensations that alert the organism to urgent homeostatic imbalances and pain-processes that are known to be severely disturbed in AN and might explain the striking discrepancy between patient's actual and perceived internal body state. PMID:25611053

  19. Genetic drift and rapid evolution of viviparity in insular fire salamanders (Salamandra salamandra)

    PubMed Central

    Velo-Antón, G; Zamudio, K R; Cordero-Rivera, A

    2012-01-01

    Continental islands offer an excellent opportunity to investigate adaptive processes and to time microevolutionary changes that precede macroevolutionary events. We performed a population genetic study of the fire salamander (Salamandra salamandra), a species that displays unique intraspecific diversity of reproductive strategies, to address the microevolutionary processes leading to phenotypic and genetic differentiation of island, coastal and interior populations. We used eight microsatellite markers to estimate genetic diversity, population structure and demographic parameters in viviparous insular populations and ovoviviparous coastal and interior populations. Our results show considerable genetic differentiation (FST range: 0.06–0.27), and no clear signs of gene flow among populations, except between the large and admixed interior populations. We find no support for island colonization by rafting or intentional/accidental anthropogenic introductions, indicating that rising sea levels were responsible for isolation of the island populations approximately 9000 years ago. Our study provides evidence of rapid genetic differentiation between island and coastal populations, and rapid evolution of viviparity driven by climatic selective pressures on island populations, geographic isolation with genetic drift, or a combination of these factors. Studies of these viviparous island populations in early stages of divergence help us better understand the microevolutionary processes involved in rapid phenotypic shifts. PMID:22086081

  20. The avian fossil record in Insular Southeast Asia and its implications for avian biogeography and palaeoecology

    PubMed Central

    2014-01-01

    Excavations and studies of existing collections during the last decades have significantly increased the abundance as well as the diversity of the avian fossil record for Insular Southeast Asia. The avian fossil record covers the Eocene through the Holocene, with the majority of bird fossils Pleistocene in age. Fossil bird skeletal remains represent at least 63 species in 54 genera and 27 families, and two ichnospecies are represented by fossil footprints. Birds of prey, owls and swiftlets are common elements. Extinctions seem to have been few, suggesting continuity of avian lineages since at least the Late Pleistocene, although some shifts in species ranges have occurred in response to climatic change. Similarities between the Late Pleistocene avifaunas of Flores and Java suggest a dispersal route across southern Sundaland. Late Pleistocene assemblages of Niah Cave (Borneo) and Liang Bua (Flores) support the rainforest refugium hypothesis in Southeast Asia as they indicate the persistence of forest cover, at least locally, throughout the Late Pleistocene and Holocene. PMID:24688871

  1. Variations in Phase and Amplitude of Rhythmic Clock Gene Expression across Prefrontal Cortex, Hippocampus, Amygdala, and Hypothalamic Paraventricular and Suprachiasmatic Nuclei of Male and Female Rats.

    PubMed

    Chun, Lauren E; Woodruff, Elizabeth R; Morton, Sarah; Hinds, Laura R; Spencer, Robert L

    2015-10-01

    The molecular circadian clock is a self-regulating transcription/translation cycle of positive (Bmal1, Clock/Npas2) and negative (Per1,2,3, Cry1,2) regulatory components. While the molecular clock has been well characterized in the body's master circadian pacemaker, the hypothalamic suprachiasmatic nucleus (SCN), only a few studies have examined both the positive and negative clock components in extra-SCN brain tissue. Furthermore, there has yet to be a direct comparison of male and female clock gene expression in the brain. This comparison is warranted, as there are sex differences in circadian functioning and disorders associated with disrupted clock gene expression. This study examined basal clock gene expression (Per1, Per2, Bmal1 mRNA) in the SCN, prefrontal cortex (PFC), rostral agranular insula, hypothalamic paraventricular nucleus (PVN), amygdala, and hippocampus of male and female rats at 4-h intervals throughout a 12:12 h light:dark cycle. There was a significant rhythm of Per1, Per2, and Bmal1 in the SCN, PFC, insula, PVN, subregions of the hippocampus, and amygdala with a 24-h period, suggesting the importance of an oscillating molecular clock in extra-SCN brain regions. There were 3 distinct clock gene expression profiles across the brain regions, indicative of diversity among brain clocks. Although, generally, the clock gene expression profiles were similar between male and female rats, there were some sex differences in the robustness of clock gene expression (e.g., females had fewer robust rhythms in the medial PFC, more robust rhythms in the hippocampus, and a greater mesor in the medial amygdala). Furthermore, females with a regular estrous cycle had attenuated aggregate rhythms in clock gene expression in the PFC compared with noncycling females. This suggests that gonadal hormones may modulate the expression of the molecular clock. PMID:26271538

  2. Cognitive and affective theory of mind share the same local patterns of activity in posterior temporal but not medial prefrontal cortex.

    PubMed

    Corradi-Dell'Acqua, Corrado; Hofstetter, Christoph; Vuilleumier, Patrik

    2014-08-01

    Understanding emotions in others engages specific brain regions in temporal and medial prefrontal cortices. These activations are often attributed to more general cognitive 'mentalizing' functions, associated with theory of mind and also necessary to represent people's non-emotional mental states, such as beliefs or intentions. Here, we directly investigated whether understanding emotional feelings recruit similar or specific brain systems, relative to other non-emotional mental states. We used functional magnetic resonance imaging with multivoxel pattern analysis in 46 volunteers to compare activation patterns in theory-of-mind tasks for emotions, relative to beliefs or somatic states accompanied with pain. We found a striking dissociation between the temporoparietal cortex, that exhibited a remarkable voxel-by-voxel pattern overlap between emotions and beliefs (but not pain), and the dorsomedial prefrontal cortex, that exhibited distinct (and yet nearby) patterns of activity during the judgment of beliefs and emotions in others. Pain judgment was instead associated with activity in the supramarginal gyrus, middle cingulate cortex and middle insular cortex. Our data reveal for the first time a functional dissociation within brain networks sub-serving theory of mind for different mental contents, with a common recruitment for cognitive and affective states in temporal regions, and distinct recruitment in prefrontal areas. PMID:23770622

  3. Cognitive and affective theory of mind share the same local patterns of activity in posterior temporal but not medial prefrontal cortex

    PubMed Central

    Hofstetter, Christoph; Vuilleumier, Patrik

    2014-01-01

    Understanding emotions in others engages specific brain regions in temporal and medial prefrontal cortices. These activations are often attributed to more general cognitive ‘mentalizing’ functions, associated with theory of mind and also necessary to represent people’s non-emotional mental states, such as beliefs or intentions. Here, we directly investigated whether understanding emotional feelings recruit similar or specific brain systems, relative to other non-emotional mental states. We used functional magnetic resonance imaging with multivoxel pattern analysis in 46 volunteers to compare activation patterns in theory-of-mind tasks for emotions, relative to beliefs or somatic states accompanied with pain. We found a striking dissociation between the temporoparietal cortex, that exhibited a remarkable voxel-by-voxel pattern overlap between emotions and beliefs (but not pain), and the dorsomedial prefrontal cortex, that exhibited distinct (and yet nearby) patterns of activity during the judgment of beliefs and emotions in others. Pain judgment was instead associated with activity in the supramarginal gyrus, middle cingulate cortex and middle insular cortex. Our data reveal for the first time a functional dissociation within brain networks sub-serving theory of mind for different mental contents, with a common recruitment for cognitive and affective states in temporal regions, and distinct recruitment in prefrontal areas. PMID:23770622

  4. Restoration of quinine-stimulated Fos-immunoreactive neurons in the central nucleus of the amygdala and gustatory cortex following reinnervation or cross-reinnervation of the lingual taste nerves in rats

    PubMed Central

    King, Camille Tessitore; Garcea, Mircea; Spector, Alan C.

    2014-01-01

    Remarkably, when lingual gustatory nerves are surgically re-routed to inappropriate taste fields in the tongue, some taste functions recover. We previously demonstrated that quinine-stimulated oromotor rejection reflexes and neural activity (assessed by Fos-immunoreactivity) in subregions of hindbrain gustatory nuclei were restored if the posterior tongue, which contains receptor cells that respond strongly to bitter compounds, was cross-reinnervated by the chorda tympani nerve. Such functional recovery was not seen if instead, the anterior tongue, where receptor cells are less responsive to bitter compounds, was cross-reinnervated by the glossopharyngeal nerve, despite that this nerve typically responds robustly to bitter substances. Thus, recovery depended more on the taste field being reinnervated than on the nerve itself. Here, the distribution of quinine-stimulated Fos-immunoreactive neurons in two taste-associated forebrain areas was examined in these same rats. In the central nucleus of the amygdala (CeA), a rostrocaudal gradient characterized the normal quinine-stimulated Fos response, with the greatest number of labeled cells rostrally situated. Quinine-stimulated neurons were found throughout the gustatory cortex but a ‘hot spot’ was observed in its anterior-posterior center in subregions approximating the dysgranular/agranular layers. Fos neurons here and in the rostral CeA were highly correlated with quinine-elicited gapes. Denervation of the posterior tongue eliminated, and its reinnervation by either nerve restored, numbers of quinine-stimulated labeled cells in the rostral-most CeA and in the subregion approximating dysgranular gustatory cortex. These results underscore the remarkable plasticity of the gustatory system and also help clarify the functional anatomy of neural circuits activated by bitter taste stimulation. PMID:24477770

  5. Behavioral Interference and C/EBP[Beta] Expression in the Insular-Cortex Reveal a Prolonged Time Period for Taste Memory Consolidation

    ERIC Educational Resources Information Center

    Elkobi, Alina; Jacobson-Pick, Shlomit; Karni, Avi; Rosenblum, Kobi; Merhav, Maayan; Kuulmann-Vander, Shelly

    2006-01-01

    Memory consolidation is defined as the time window during which the memory trace is susceptible to behavioral, electrical, or pharmacological interventions. Here, the authors presented rats with two novel tastes at consecutive time intervals. Clear interference was evident when a novel taste formed the second taste input whereby, surprisingly, the…

  6. Familiar Taste Induces Higher Dendritic Levels of Activity-Regulated Cytoskeleton-Associated Protein in the Insular Cortex than a Novel One

    ERIC Educational Resources Information Center

    Morin, Jean-Pascal; Quiroz, Cesar; Mendoza-Viveros, Lucia; Ramirez-Amaya, Victor; Bermudez-Rattoni, Federico

    2011-01-01

    The immediate early gene (IEG) "Arc" is known to play an important role in synaptic plasticity; its protein is locally translated in the dendrites where it has been involved in several types of plasticity mechanisms. Because of its tight coupling with neuronal activity, "Arc" has been widely used as a tool to tag behaviorally activated networks.…

  7. Touch activates human auditory cortex.

    PubMed

    Schürmann, Martin; Caetano, Gina; Hlushchuk, Yevhen; Jousmäki, Veikko; Hari, Riitta

    2006-05-01

    Vibrotactile stimuli can facilitate hearing, both in hearing-impaired and in normally hearing people. Accordingly, the sounds of hands exploring a surface contribute to the explorer's haptic percepts. As a possible brain basis of such phenomena, functional brain imaging has identified activations specific to audiotactile interaction in secondary somatosensory cortex, auditory belt area, and posterior parietal cortex, depending on the quality and relative salience of the stimuli. We studied 13 subjects with non-invasive functional magnetic resonance imaging (fMRI) to search for auditory brain areas that would be activated by touch. Vibration bursts of 200 Hz were delivered to the subjects' fingers and palm and tactile pressure pulses to their fingertips. Noise bursts served to identify auditory cortex. Vibrotactile-auditory co-activation, addressed with minimal smoothing to obtain a conservative estimate, was found in an 85-mm3 region in the posterior auditory belt area. This co-activation could be related to facilitated hearing at the behavioral level, reflecting the analysis of sound-like temporal patterns in vibration. However, even tactile pulses (without any vibration) activated parts of the posterior auditory belt area, which therefore might subserve processing of audiotactile events that arise during dynamic contact between hands and environment. PMID:16488157

  8. Maps Showing Composition of Surficial Sediments on the Insular Shelf of Southwestern Puerto Rico

    USGS Publications Warehouse

    Shideler, Gerald L.

    1980-01-01

    The limited availability of onshore sand deposits for use in construction appears to be a future major problem in Puerto Rico (U.S. Bureau of Mines, 1972; Committee on Puerto Rico and the Sea, 1974). Consequently, the mining of offshore sand deposits as supplemental sources of construction aggregate may becom e necessary. For this reason, the U.S. Geological Survey and the Department of Natural Resources of the Commonwealth of Puerto Rico have conducted investigations of potential offshore sand deposits on the Puerto Rico insular shelf. This report provides information on the composition of surficial sediments on the southwestern Puerto Rico shelf (fig. 1), an area that may be one of the more favorable potential sites for offshore sand resources. Water depths over most of the study area are less than 22 meters (m). The sea floor is composed of live and dead patch and fringing reefs, areas of rock exposures, and sedim ent-covered areas. The adjacent coastline includes prominent embaym ents and a conspicuous rock promontory (Cabo Rojo) connected by a tombolo to the mainland of Puerto Rico. The study area is in the belt of northeast trade winds. Waves approach the coast predominantly from the southeast, resulting in a predominantly westward littoral drift along the south coast (Grove and Trumbull, 1978). Local sand movement on the southern shelf is shown by an active sand wave field south of Bah1a Sucia in which the sand wave crests have migrated toward the southwest (Grove and Trumbull, 1978). The presence of the sand wave field suggests that large volumes of sand having potential for mining are locally present in the study area.

  9. A Selective Insular Perfusion Deficit Contributes to Compromised Salience Network Connectivity in Recovering Alcoholic Men

    PubMed Central

    Sullivan, Edith V.; Müller-Oehring, Eva; Pitel, Anne-Lise; Chanraud, Sandra; Shankaranarayanan, Ajit; Alsop, David C.; Rohlfing, Torsten; Pfefferbaum, Adolf

    2013-01-01

    Background Alcoholism can disrupt neural synchrony between nodes of intrinsic functional networks that are maximally active when resting relative to engaging in a task, the default mode network (DMN) pattern. Untested, however, are whether the DMN in alcoholics can rebound normally from the relatively depressed task-state to the active resting-state and whether local perfusion deficits could disrupt network synchrony when switching from conditions of rest to task to rest, thereby indicating a physiological mechanism of neural network adaptation capability. Methods Whole-brain, 3D pulsed-continuous arterial spin labeling (PCASL) provided measurements of regional cerebral blood flow (rCBF) in 12 alcoholics and 12 controls under three conditions: pre-task rest, spatial working-memory task, post-task rest. Results With practice, alcoholics and controls achieved similar task accuracy and reaction times. Both groups exhibited a high-low-high pattern of perfusion levels in DMN regions during the rest-task-rest runs and the opposite pattern in posterior and cerebellar regions known to be associated with spatial working memory. Alcoholics showed selective differences from controls in the rest-task-rest CBF pattern in the anterior precuneus and CBF level in the insula, a hub of the salience network. Connectivity analysis identified activation synchrony from an insula seed to salience nodes (parietal, medial frontal, anterior cingulate cortices) in controls only. Conclusions We propose that attenuated insular CBF is a mechanism underlying compromised connectivity among salience network nodes. This local perfusion deficit in alcoholics has the potential to impair ability to switch from cognitive states of interoceptive cravings to cognitive control for curbing internal urges. PMID:23587427

  10. Cocaine reduces cytochrome oxidase activity in the prefrontal cortex and modifies its functional connectivity with brainstem nuclei

    PubMed Central

    Vélez-Hernández, M.E.; Padilla, E.; Gonzalez-Lima, F.; Jiménez-Rivera, C.A.

    2014-01-01

    Cocaine-induced psychomotor stimulation may be mediated by metabolic hypofrontality and modification of brain functional connectivity. Functional connectivity refers to the pattern of relationships among brain regions, and one way to evaluate this pattern is using interactivity correlations of the metabolic marker cytochrome oxidase among different regions. This is the first study of how repeated cocaine modifies: (1) mean cytochrome oxidase activity in neural areas using quantitative enzyme histochemistry, and (2) functional connectivity among brain regions using inter-correlations of cytochrome oxidase activity. Rats were injected with 15 mg/kg i.p. cocaine or saline for 5 days, which lead to cocaine-enhanced total locomotion. Mean cytochrome oxidase activity was significantly decreased in cocaine-treated animals in the superficial dorsal and lateral frontal cortical association areas Fr2 and Fr3 when compared to saline-treated animals. Functional connectivity showed that the cytochrome oxidase activity of the noradrenergic locus coeruleus and the infralimbic cortex were positively inter-correlated in cocaine but not in control rats. Positive cytochrome oxidase activity inter-correlations were also observed between the dopaminergic substantia nigra compacta and Fr2 and Fr3 areas and the lateral orbital cortex in cocaine-treated animals. In contrast, cytochrome oxidase activity in the interpeduncular nucleus was negatively correlated with that of Fr2, anterior insular cortex, and lateral orbital cortex in saline but not in cocaine groups. After repeated cocaine specific prefrontal areas became hypometabolic and their functional connectivity changed in networks involving noradrenergic and dopaminergic brainstem nuclei. We suggest that this pattern of hypofrontality and altered functional connectivity may contribute to cocaine-induced psychomotor stimulation. PMID:24505625

  11. New threshold temperatures for the development of a North American diamondback moth (Lepidoptera: Plutellidae) population and its larval parasitoid, Diadegma insulare (Hymenoptera: Ichneumonidae).

    PubMed

    Bahar, M H; Soroka, J J; Grenkow, L; Dosdall, L M

    2014-10-01

    The currently accepted lower threshold temperature for the development of diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), the world's most destructive insect pest of cruciferous crops, is around 6.0°C, and there is no known upper threshold temperature. Neither are there established threshold temperatures for diamondback moth's major natural enemy, Diadegma insulare (Hymenoptera: Ichneumonidae). Laboratory studies were undertaken to determine the survival and development of a North American diamondback moth population and its parasitoid D. insulare at 20 constant temperatures ranging from 2.0 to 38.0°C. Diamondback moth completed development from second instar to adult within a temperature range of 4.0-37°C, and D. insulare completed its life cycle from egg to adult within a temperature range of 4.0-33°C. The developmental data were fitted into one linear and four nonlinear models. Using goodness-of-fit and the ability to estimate parameters of biological significance as selection criteria, the Wang model was the most acceptable among the nonlinear models to describe the relationship between temperature and development of both species. According to this model, the lower and upper threshold temperatures for diamondback moth were 2.1 and 38.0°C, respectively, and for D. insulare they were 2.1 and 34.0°C, respectively. Based on the Degree Day model, diamondback moth required 143 d above the lower threshold of 4.23°C to complete the life cycle, while D. insulare required 286 d above the lower threshold of 2.57°C. This study suggests that temperatures during the crop-growing seasons in North America are not limiting factors for development of either diamondback moth or D. insulare. PMID:25259698

  12. Multimap formation in visual cortex

    PubMed Central

    Jain, Rishabh; Millin, Rachel; Mel, Bartlett W.

    2015-01-01

    An extrastriate visual area such as V2 or V4 contains neurons selective for a multitude of complex shapes, all sharing a common topographic organization. Simultaneously developing multiple interdigitated maps—hereafter a “multimap”—is challenging in that neurons must compete to generate a diversity of response types locally, while cooperating with their dispersed same-type neighbors to achieve uniform visual field coverage for their response type at all orientations, scales, etc. Previously proposed map development schemes have relied on smooth spatial interaction functions to establish both topography and columnar organization, but by locally homogenizing cells' response properties, local smoothing mechanisms effectively rule out multimap formation. We found in computer simulations that the key requirements for multimap development are that neurons are enabled for plasticity only within highly active regions of cortex designated “learning eligibility regions” (LERs), but within an LER, each cell's learning rate is determined only by its activity level with no dependence on location. We show that a hybrid developmental rule that combines spatial and activity-dependent learning criteria in this way successfully produces multimaps when the input stream contains multiple distinct feature types, or in the degenerate case of a single feature type, produces a V1-like map with “salt-and-pepper” structure. Our results support the hypothesis that cortical maps containing a fine mixture of different response types, whether in monkey extrastriate cortex, mouse V1 or elsewhere in the cortex, rather than signaling a breakdown of map formation mechanisms at the fine scale, are a product of a generic cortical developmental scheme designed to map cells with a diversity of response properties across a shared topographic space. PMID:26641946

  13. Finding prefrontal cortex in the rat.

    PubMed

    Leonard, Christiana M

    2016-08-15

    The prefrontal cortex of the rat. I. Cortical projection of the mediodorsal nucleus. II. Efferent connections The cortical projection field of the mediodorsal nucleus of the thalamus (MD) was identified in the rat using the Fink-Heimer silver technique for tracing degenerating fibers. Small stereotaxic lesions confined to MD were followed by terminal degeneration in the dorsal bank of the rhinal sulcus (sulcal cortex) and the medial wall of the hemisphere anterior and dorsal to the genu of the corpus callosum (medial cortex). No degenerating fibers were traced to the convexity of the hemisphere. The cortical formation receiving a projection from MD is of a relatively undifferentiated type which had been previously classified as juxtallocortex. A study of the efferent fiber connections of the rat׳s MD-projection cortex demonstrated some similarities to those of monkey prefrontal cortex. A substantial projection to the pretectal area and deep layers of the superior colliculus originates in medial cortex, a connection previously reported for caudal prefrontal (area 8) cortex in the monkey. Sulcal cortex projects to basal olfactory structures and lateral hypothalamus, as does orbital frontal cortex in the monkey. The rat׳s MD-projection cortex differs from that in the monkey in that it lacks a granular layer and appears to have no prominent direct associations with temporal and juxtahippocampal areas. Furthermore, retrograde degeneration does not appear in the rat thalamus after damage to MD-projection areas, suggesting that the striatum or thalamus receives a proportionally larger share of the MD-projection in this animal than it does in the monkey. Comparative behavioral investigations are in progress to investigate functional differences between granular prefrontal cortex in the primate and the relatively primitive MD-projection cortex in the rat. © 1969. This article is part of a Special Issue entitled SI:50th Anniversary Issue. PMID:26867704

  14. Altered Value Coding in the Ventromedial Prefrontal Cortex in Healthy Older Adults

    PubMed Central

    Yu, Jing; Mamerow, Loreen; Lei, Xu; Fang, Lei; Mata, Rui

    2016-01-01

    Previous work suggests that aging is associated with changes in risk taking but less is known about their underlying neural basis, such as the potential age differences in the neural processing of value and risk. The goal of the present study was to investigate adult age differences in functional neural responses in a naturalistic risk-taking task. Twenty-six young adults and 27 healthy older adults completed the Balloon Analogue Risk Task while undergoing functional magnetic resonance imaging. Young and older adults showed similar overt risk-taking behavior. Group comparison of neural activity in response to risky vs. control stimuli revealed similar patterns of activation in the bilateral striatum, anterior insula (AI) and ventromedial prefrontal cortex (vmPFC). Group comparison of parametrically modulated activity in response to continued pumping similarly revealed comparable results for both age groups in the AI and, potentially, the striatum, yet differences emerged for regional activity in the vmPFC. At whole brain level, insular, striatal and vmPFC activation was predictive of behavioral risk taking for young but not older adults. The current results are interpreted and discussed as preserved neural tracking of risk and reward in the AI and striatum, respectively, but altered value coding in the vmPFC in the two age groups. The latter finding points toward older adults exhibiting differential vmPFC-related integration and value coding. Furthermore, neural activation holds differential predictive validity for behavioral risk taking in young and older adults.

  15. The Role of Protein Phosphorylation in the Gustatory Cortex and Amygdala During Taste Learning

    PubMed Central

    Adaikkan, Chinnakkaruppan

    2012-01-01

    Protein phosphorylation and dephosphorylation form a major post-translation mechanism that enables a given cell to respond to ever-changing internal and external environments. Neurons, similarly to any other cells, use protein phosphorylation/dephosphorylation to maintain an internal homeostasis, but they also use it for updating the state of synaptic and intrinsic properties, following activation by neurotransmitters and growth factors. In the present review we focus on the roles of several families of kinases, phosphatases, and other synaptic-plasticity-related proteins, which activate membrane receptors and various intracellular signals to promote transcription, translation and protein degradation, and to regulate the appropriate cellular proteomes required for taste memory acquisition, consolidation and maintenance. Attention is especially focused on the protein phosphorylation state in two forebrain areas that are necessary for taste-memory learning and retrieval: the insular cortex and the amygdala. The various temporal phases of taste learning require the activation of appropriate waves of biochemical signals. These include: extracellular signal regulated kinase I and II (ERKI/II) signal transduction pathways; Ca2+-dependent pathways; tyrosine kinase/phosphatase-dependent pathways; brain-derived neurotrophicfactor (BDNF)-dependent pathways; cAMP-responsive element bindingprotein (CREB); and translation-regulation factors, such as initiation and elongation factors, and the mammalian target of rapamycin (mTOR). Interestingly, coding of hedonic and aversive taste information in the forebrain requires activation of different signal transduction pathways. PMID:22792024

  16. Effects of clonality on the genetic variability of rare, insular species: the case of Ruta microcarpa from the Canary Islands

    PubMed Central

    Meloni, M; Reid, A; Caujapé-Castells, J; Marrero, Á; Fernández-Palacios, J M; Mesa-Coelo, R A; Conti, E

    2013-01-01

    Many plant species combine sexual and clonal reproduction. Clonal propagation has ecological costs mainly related to inbreeding depression and pollen discounting; at the same time, species able to reproduce clonally have ecological and evolutionary advantages being able to persist when conditions are not favorable for sexual reproduction. The presence of clonality has profound consequences on the genetic structure of populations, especially when it represents the predominant reproductive strategy in a population. Theoretical studies suggest that high rate of clonal propagation should increase the effective number of alleles and heterozygosity in a population, while an opposite effect is expected on genetic differentiation among populations and on genotypic diversity. In this study, we ask how clonal propagation affects the genetic diversity of rare insular species, which are often characterized by low levels of genetic diversity, hence at risk of extinction. We used eight polymorphic microsatellite markers to study the genetic structure of the critically endangered insular endemic Ruta microcarpa. We found that clonality appears to positively affect the genetic diversity of R. microcarpa by increasing allelic diversity, polymorphism, and heterozygosity. Moreover, clonal propagation seems to be a more successful reproductive strategy in small, isolated population subjected to environmental stress. Our results suggest that clonal propagation may benefit rare species. However, the advantage of clonal growth may be only short-lived for prolonged clonal growth could ultimately lead to monoclonal populations. Some degree of sexual reproduction may be needed in a predominantly clonal species to ensure long-term viability. PMID:23789068

  17. Evolutionary appearance of von Economo's neurons in the mammalian cerebral cortex.

    PubMed

    Cauda, Franco; Geminiani, Giuliano Carlo; Vercelli, Alessandro

    2014-01-01

    von Economo's neurons (VENs) are large, spindle-shaped projection neurons in layer V of the frontoinsular (FI) cortex, and the anterior cingulate cortex. During human ontogenesis, the VENs can first be differentiated at late stages of gestation, and increase in number during the first eight postnatal months. VENs have been identified in humans, chimpanzee, bonobos, gorillas, orangutan and, more recently, in the macaque. Their distribution in great apes seems to correlate with human-like social cognitive abilities and self-awareness. VENs are also found in whales, in a number of different cetaceans, and in the elephant. This phylogenetic distribution may suggest a correlation among the VENs, brain size and the "social brain." VENs may be involved in the pathogenesis of specific neurological and psychiatric diseases, such as autism, callosal agenesis and schizophrenia. VENs are selectively affected in a behavioral variant of frontotemporal dementia in which empathy, social awareness and self-control are seriously compromised, thus associating VENs with the social brain. However, the presence of VENs has also been related to special functions such as mirror self-recognition. Areas containing VENs have been related to motor awareness or sense-of-knowing, discrimination between self and other, and between self and the external environment. Along this line, VENs have been related to the "global Workspace" architecture: in accordance the VENs have been correlated to emotional and interoceptive signals by providing fast connections (large axons = fast communication) between salience-related insular and cingulate and other widely separated brain areas. Nevertheless, the lack of a characterization of their physiology and anatomical connectivity allowed only to infer their functional role based on their location and on the functional magnetic resonance imaging data. The recent finding of VENs in the anterior insula of the macaque opens the way to new insights and experimental

  18. Rich Club Organization of Macaque Cerebral Cortex and Its Role in Network Communication

    PubMed Central

    Harriger, Logan; van den Heuvel, Martijn P.; Sporns, Olaf

    2012-01-01

    Graph-theoretical analysis of brain connectivity data has revealed significant features of brain network organization across a range of species. Consistently, large-scale anatomical networks exhibit highly nonrandom attributes including an efficient small world modular architecture, with distinct network communities that are interlinked by hub regions. The functional importance of hubs motivates a closer examination of their mutual interconnections, specifically to examine the hypothesis that hub regions are more densely linked than expected based on their degree alone, i.e. forming a central rich club. Extending recent findings of rich club topology in the cat and human brain, this report presents evidence for the existence of rich club organization in the cerebral cortex of a non-human primate, the macaque monkey, based on a connectivity data set representing a collation of numerous tract tracing studies. Rich club regions comprise portions of prefrontal, parietal, temporal and insular cortex and are widely distributed across network communities. An analysis of network motifs reveals that rich club regions tend to form star-like configurations, indicative of their central embedding within sets of nodes. In addition, rich club nodes and edges participate in a large number of short paths across the network, and thus contribute disproportionately to global communication. As rich club regions tend to attract and disperse communication paths, many of the paths follow a characteristic pattern of first increasing and then decreasing node degree. Finally, the existence of non-reciprocal projections imposes a net directional flow of paths into and out of the rich club, with some regions preferentially attracting and others dispersing signals. Overall, the demonstration of rich club organization in a non-human primate contributes to our understanding of the network principles underlying neural connectivity in the mammalian brain, and further supports the hypothesis that

  19. Evolutionary appearance of von Economo’s neurons in the mammalian cerebral cortex

    PubMed Central

    Cauda, Franco; Geminiani, Giuliano Carlo; Vercelli, Alessandro

    2014-01-01

    von Economo’s neurons (VENs) are large, spindle-shaped projection neurons in layer V of the frontoinsular (FI) cortex, and the anterior cingulate cortex. During human ontogenesis, the VENs can first be differentiated at late stages of gestation, and increase in number during the first eight postnatal months. VENs have been identified in humans, chimpanzee, bonobos, gorillas, orangutan and, more recently, in the macaque. Their distribution in great apes seems to correlate with human-like social cognitive abilities and self-awareness. VENs are also found in whales, in a number of different cetaceans, and in the elephant. This phylogenetic distribution may suggest a correlation among the VENs, brain size and the “social brain.” VENs may be involved in the pathogenesis of specific neurological and psychiatric diseases, such as autism, callosal agenesis and schizophrenia. VENs are selectively affected in a behavioral variant of frontotemporal dementia in which empathy, social awareness and self-control are seriously compromised, thus associating VENs with the social brain. However, the presence of VENs has also been related to special functions such as mirror self-recognition. Areas containing VENs have been related to motor awareness or sense-of-knowing, discrimination between self and other, and between self and the external environment. Along this line, VENs have been related to the “global Workspace” architecture: in accordance the VENs have been correlated to emotional and interoceptive signals by providing fast connections (large axons = fast communication) between salience-related insular and cingulate and other widely separated brain areas. Nevertheless, the lack of a characterization of their physiology and anatomical connectivity allowed only to infer their functional role based on their location and on the functional magnetic resonance imaging data. The recent finding of VENs in the anterior insula of the macaque opens the way to new insights and

  20. Combined adverse effects of cascading events on systems' functionality: an insular case study, French West Indies

    NASA Astrophysics Data System (ADS)

    Desramaut, Nicolas; Wang, Justin; Gehl, Pierre; Marti, Jose; Baills, Audrey; Reveillere, Arnaud

    2013-04-01

    In our modern societies, lifelines play a vital role, even in normal conditions. Therefore, during crises, the dependency to critical infrastructures is likely to be exacerbated. Indeed, in order to provide quick emergency services to the population, systems have to be functional. However, even if not directly damaged, in order to be functional, elements of the different systems have to receive enough resources but also to be able to supply their own services. In a multi-risk approach, this necessity to take into account systemic vulnerability to assess the real impact of natural hazards on society is even made more obvious. For example, impacts of one hazard, taken separately, might not significantly affect societies, but might reduce redundancy, and therefore could increase functional vulnerability to other hazards. The present study aims at analyzing the effects of cascading events on the behaviour of interdependent systems and on the capacities of the health care system to treat the victims. In order to work on a close system, an insular context (Guadeloupe, French West Indies) has been selected. The hazard cascading scenario consists of a M6.3 earthquake striking Basse-Terre, and triggering landslides in the mountainous areas where antecedent precipitations have made the area prone to slide. Damages due to earthquakes have been estimated for the 5 considered systems (buildings, healthcare system, electrical network, water supply network and transportation). Due to their localization in mountainous areas, landslides would affect only transportation networks, with closure of roads. The inter- and intra-dependencies of systems have been modeled thanks to the I2Sim platform developed at UBC. The functionality of each element is therefore the consequence of the physical (direct damage) but also functional (indirect) damage. Analyses are performed for different strategies of resources allocations, and one of the final results is the impact of the induced landslides

  1. Processing of Hedonic and Chemosensory Features of Taste in Medial Prefrontal and Insular Networks

    PubMed Central

    Jezzini, Ahmad; Mazzucato, Luca; La Camera, Giancarlo

    2013-01-01

    Most of the research on cortical processing of taste has focused on either the primary gustatory cortex (GC) or the orbitofrontal cortex (OFC). However, these are not the only areas involved in taste processing. Gustatory information can also reach another frontal region, the medial prefrontal cortex (mPFC), via direct projections from GC. mPFC has been studied extensively in relation to its role in controlling goal-directed action and reward-guided behaviors, yet very little is known about its involvement in taste coding. The experiments presented here address this important point and test whether neurons in mPFC can significantly process the physiochemical and hedonic dimensions of taste. Spiking responses to intraorally delivered tastants were recorded from rats implanted with bundles of electrodes in mPFC and GC. Analysis of single-neuron and ensemble activity revealed similarities and differences between the two areas. Neurons in mPFC can encode the chemosensory identity of gustatory stimuli. However, responses in mPFC are sparser, more narrowly tuned, and have a later onset than in GC. Although taste quality is more robustly represented in GC, taste palatability is coded equally well in the two areas. Additional analysis of responses in neurons processing the hedonic value of taste revealed differences between the two areas in temporal dynamics and sensitivities to palatability. These results add mPFC to the network of areas involved in processing gustatory stimuli and demonstrate significant differences in taste-coding between GC and mPFC. PMID:24285901

  2. Processing of hedonic and chemosensory features of taste in medial prefrontal and insular networks.

    PubMed

    Jezzini, Ahmad; Mazzucato, Luca; La Camera, Giancarlo; Fontanini, Alfredo

    2013-11-27

    Most of the research on cortical processing of taste has focused on either the primary gustatory cortex (GC) or the orbitofrontal cortex (OFC). However, these are not the only areas involved in taste processing. Gustatory information can also reach another frontal region, the medial prefrontal cortex (mPFC), via direct projections from GC. mPFC has been studied extensively in relation to its role in controlling goal-directed action and reward-guided behaviors, yet very little is known about its involvement in taste coding. The experiments presented here address this important point and test whether neurons in mPFC can significantly process the physiochemical and hedonic dimensions of taste. Spiking responses to intraorally delivered tastants were recorded from rats implanted with bundles of electrodes in mPFC and GC. Analysis of single-neuron and ensemble activity revealed similarities and differences between the two areas. Neurons in mPFC can encode the chemosensory identity of gustatory stimuli. However, responses in mPFC are sparser, more narrowly tuned, and have a later onset than in GC. Although taste quality is more robustly represented in GC, taste palatability is coded equally well in the two areas. Additional analysis of responses in neurons processing the hedonic value of taste revealed differences between the two areas in temporal dynamics and sensitivities to palatability. These results add mPFC to the network of areas involved in processing gustatory stimuli and demonstrate significant differences in taste-coding between GC and mPFC. PMID:24285901

  3. Subspecialization in the human posterior medial cortex

    PubMed Central

    Bzdok, Danilo; Heeger, Adrian; Langner, Robert; Laird, Angela R.; Fox, Peter T.; Palomero-Gallagher, Nicola; Vogt, Brent A.; Zilles, Karl; Eickhoff, Simon B.

    2014-01-01

    The posterior medial cortex (PMC) is particularly poorly understood. Its neural activity changes have been related to highly disparate mental processes. We therefore investigated PMC properties with a data-driven exploratory approach. First, we subdivided the PMC by whole-brain coactivation profiles. Second, functional connectivity of the ensuing PMC regions was compared by task-constrained meta-analytic coactivation mapping (MACM) and task-unconstrained resting-state correlations (RSFC). Third, PMC regions were functionally described by forward/reverse functional inference. A precuneal cluster was mostly connected to the intraparietal sulcus, frontal eye fields, and right temporo-parietal junction; associated with attention and motor tasks. A ventral posterior cingulate cortex (PCC) cluster was mostly connected to the ventromedial prefrontal cortex and middle left inferior parietal cortex (IPC); associated with facial appraisal and language tasks. A dorsal PCC cluster was mostly connected to the dorsomedial prefrontal cortex, anterior/posterior IPC, posterior midcingulate cortex, and left dorsolateral prefrontal cortex; associated with delay discounting. A cluster in the retrosplenial cortex was mostly connected to the anterior thalamus and hippocampus. Furthermore, all PMC clusters were congruently coupled with the default mode network according to task-constrained but not task-unconstrained connectivity. We thus identified distinct regions in the PMC and characterized their neural networks and functional implications. PMID:25462801

  4. Mapping Prefrontal Cortex Functions in Human Infancy

    ERIC Educational Resources Information Center

    Grossmann, Tobias

    2013-01-01

    It has long been thought that the prefrontal cortex, as the seat of most higher brain functions, is functionally silent during most of infancy. This review highlights recent work concerned with the precise mapping (localization) of brain activation in human infants, providing evidence that prefrontal cortex exhibits functional activation much…

  5. 19 CFR 7.3 - Duty-free treatment of goods imported from insular possessions of the United States other than...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... INSULAR POSSESSIONS AND GUANTANAMO BAY NAVAL STATION § 7.3 Duty-free treatment of goods imported from... foreign materials valued at either more than 70 percent of the total value of the goods or, in the case of... than 50 percent of the total value of the goods; and (ii) Come to the customs territory of the...

  6. 19 CFR 7.3 - Duty-free treatment of goods imported from insular possessions of the United States other than...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... INSULAR POSSESSIONS AND GUANTANAMO BAY NAVAL STATION § 7.3 Duty-free treatment of goods imported from... foreign materials valued at either more than 70 percent of the total value of the goods or, in the case of... than 50 percent of the total value of the goods; and (ii) Come to the customs territory of the...

  7. 19 CFR 7.3 - Duty-free treatment of goods imported from insular possessions of the United States other than...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... INSULAR POSSESSIONS AND GUANTANAMO BAY NAVAL STATION § 7.3 Duty-free treatment of goods imported from... foreign materials valued at either more than 70 percent of the total value of the goods or, in the case of... than 50 percent of the total value of the goods; and (ii) Come to the customs territory of the...

  8. 19 CFR 7.3 - Duty-free treatment of goods imported from insular possessions of the United States other than...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... INSULAR POSSESSIONS AND GUANTANAMO BAY NAVAL STATION § 7.3 Duty-free treatment of goods imported from... foreign materials valued at either more than 70 percent of the total value of the goods or, in the case of... than 50 percent of the total value of the goods; and (ii) Come to the customs territory of the...

  9. 19 CFR 7.3 - Duty-free treatment of goods imported from insular possessions of the United States other than...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... section 423 of the Tax Reform Act of 1986, as amended (19 U.S.C. 2703 note), goods which are the growth or... possession from materials that were the growth, product or manufacture of any such insular possession or of... goods described in section 213(b) of the Caribbean Basin Economic Recovery Act (19 U.S.C. 2703(b)),...

  10. Still No Progress in Implementing Controls over Contracts and Grants with Indians. Report to the Chairman, Committee on Interior and Insular Affairs, House of Representatives.

    ERIC Educational Resources Information Center

    Comptroller General of the U.S., Washington, DC.

    As a result of the Bureau of Indian Affairs' (BIA) laxness in improving management of programs and services for Indians, the Chairman of the House Committee on Interior and Insular Affairs requested the General Accounting Office (GAO) to review the accountability of federal funds and property involving contracts and grants totaling about $726…

  11. Medicaid and CHIP: Opportunities Exist to Improve U.S. Insular Area Demographic Data That Could Be Used to Help Determine Federal Funding. GAO-09-558R

    ERIC Educational Resources Information Center

    Kohn, Linda T.

    2009-01-01

    The five largest insular areas of the United States--American Samoa, the Commonwealth of the Northern Mariana Islands (CNMI), Guam, Puerto Rico, and the U.S. Virgin Islands--receive federal funding through Medicaid and the State Children's Health Insurance Program (CHIP), joint federal-state programs that finance health care for certain low-income…

  12. Useful signals from motor cortex

    PubMed Central

    Schwartz, Andrew B

    2007-01-01

    Historically, the motor cortical function has been explained as a funnel to muscle activation. This invokes the idea that motor cortical neurons, or ‘upper motoneurons’, directly cause muscle contraction just like spinal motoneurons. Thus, the motor cortex and muscle activity are inextricably entwined like a puppet master and his marionette. Recently, this concept has been challenged by current experimentation showing that many behavioural aspects of action are represented in motor cortical activity. Although this activity may still be related to muscle activation, the relation between the two is likely to be indirect and complex, whereas the relation between cortical activity and kinematic parameters is simple and robust. These findings show how to extract useful signals that help explain the underlying process that generates behaviour and to harness these signals for potentially therapeutic applications. PMID:17255162

  13. Molecular detection of Rickettsia, Borrelia, and Babesia species in Ixodes ricinus sampled in northeastern, central, and insular areas of Italy.

    PubMed

    Castro, Lyda R; Gabrielli, Simona; Iori, Albertina; Cancrini, Gabriella

    2015-07-01

    The aim of the present study was to provide insight into the diversity of tick-borne pathogens circulating in Italy, carried/transmitted by Ixodes ricinus, one of the most abundant tick species in the country. A total of 447 specimens sampled in five areas of northeastern, central and insular Italy were analysed by polymerase chain reaction and sequencing for the presence of rickettsiae, borreliae and babesiae. Several rickettsial species of the spotted fever group of zoonotic concern and other zoonotic pathogens were found, such as Borrelia burgdorferi s.s., Borrelia afzelii, Borrelia garinii, and Babesia venatorum. These findings confirm a wide distribution of tick-borne bacterial and protozoan species in Italy, and highlight the sanitary importance of I. ricinus, often recorded as feeding on humans. PMID:25784072

  14. The Oldest Gibbon Fossil (Hylobatidae) from Insular Southeast Asia: Evidence from Trinil, (East Java, Indonesia), Lower/Middle Pleistocene

    PubMed Central

    Ingicco, Thomas; de Vos, John; Huffman, O. Frank

    2014-01-01

    A fossil femur excavated by Eugène Dubois between 1891–1900 in the Lower/Middle Pleistocene bonebed of the Trinil site (Java, Indonesia) was recognised by us as that of a Hylobatidae. The specimen, Trinil 5703 of the Dubois Collection (Leiden, The Netherlands), has the same distinctive form of fossilization that is seen in many of the bonebed fossils from Trinil in the collection. Anatomical comparison of Trinil 5703 to a sample of carnivore and primate femora, supported by morphometric analyses, lead to the attribution of the fossil to gibbon. Trinil 5703 therefore provides the oldest insular record of this clade, one of the oldest known Hylobatidae fossils from Southeast Asia. Because living Hylobatidae only inhabit evergreen rain forests, the paleoenvironment within the river drainage in the greater Trinil area evidently included forests of this kind during the Lower/Middle Pleistocene as revealed here. PMID:24914951

  15. The oldest gibbon fossil (Hylobatidae) from insular Southeast Asia: evidence from Trinil, (East Java, Indonesia), Lower/Middle Pleistocene.

    PubMed

    Ingicco, Thomas; de Vos, John; Huffman, O Frank

    2014-01-01

    A fossil femur excavated by Eugène Dubois between 1891-1900 in the Lower/Middle Pleistocene bonebed of the Trinil site (Java, Indonesia) was recognised by us as that of a Hylobatidae. The specimen, Trinil 5703 of the Dubois Collection (Leiden, The Netherlands), has the same distinctive form of fossilization that is seen in many of the bonebed fossils from Trinil in the collection. Anatomical comparison of Trinil 5703 to a sample of carnivore and primate femora, supported by morphometric analyses, lead to the attribution of the fossil to gibbon. Trinil 5703 therefore provides the oldest insular record of this clade, one of the oldest known Hylobatidae fossils from Southeast Asia. Because living Hylobatidae only inhabit evergreen rain forests, the paleoenvironment within the river drainage in the greater Trinil area evidently included forests of this kind during the Lower/Middle Pleistocene as revealed here. PMID:24914951

  16. Vocalization Induced CFos Expression in Marmoset Cortex

    PubMed Central

    Miller, Cory T.; DiMauro, Audrey; Pistorio, Ashley; Hendry, Stewart; Wang, Xiaoqin

    2010-01-01

    All non-human primates communicate with conspecifics using vocalizations, a system involving both the production and perception of species-specific vocal signals. Much of the work on the neural basis of primate vocal communication in cortex has focused on the sensory processing of vocalizations, while relatively little data are available for vocal production. Earlier physiological studies in squirrel monkeys had shed doubts on the involvement of primate cortex in vocal behaviors. The aim of the present study was to identify areas of common marmoset (Callithrix jacchus) cortex that are potentially involved in vocal communication. In this study, we quantified cFos expression in three areas of marmoset cortex – frontal, temporal (auditory), and medial temporal – under various vocal conditions. Specifically, we examined cFos expression in these cortical areas during the sensory, motor (vocal production), and sensory–motor components of vocal communication. Our results showed an increase in cFos expression in ventrolateral prefrontal cortex as well as the medial and lateral belt areas of auditory cortex in the vocal perception condition. In contrast, subjects in the vocal production condition resulted in increased cFos expression only in dorsal premotor cortex. During the sensory–motor condition (antiphonal calling), subjects exhibited cFos expression in each of the above areas, as well as increased expression in perirhinal cortex. Overall, these results suggest that various cortical areas outside primary auditory cortex are involved in primate vocal communication. These findings pave the way for further physiological studies of the neural basis of primate vocal communication. PMID:21179582

  17. Connections of the corticomedial amygdala in the golden hamster. II. Efferents of the ''olfactory amygdala''

    SciTech Connect

    Kevetter, G.A.; Winans, S.S.

    1981-03-20

    The anterior cortical (C1) and posterolateral cortical (C2) nuclei of the amygdala are designated the ''olfactory amygdala'' because they each receive direct projections from the main olfactory bulb. The efferents of these nuclei were traced after stereotaxic placement of 1-5 muCi tritiated proline in the corticomedial amygdala of the male golden hamsters. Following survival times of 12, 24, or 48 hours, 20 micron frozen sections of the brains were processed for light microscopic autoradiography. Efferents from C2 terminate in layers II and III of the olfactory tubercle and in layer Ib of pars ventralis and pars medialis of the anterior olfactory nucleus. Fibers from this nucleus also project to layers I and II of the infralimbic cortex and to the molecular layer of the agranular insular cortex. More posteriorly, fibers from C2 terminate in layer I of the dorsolateral entorhinal cortex, and in the endopiriform nucleus. From C1, efferent fibers travel in the stria terminalis and terminate in the precommissural bed nucleus of the stria terminalis and in the mediobasal hypothalamus. Efferents from C1 also innervate the molecular layer of C2, the amygdalo-hippocampal area, and the adjacent piriform cortex. Neurons in both C1 and C2 project to the molecular layer of the medial amygdaloid nucleus and the posteromedial cortical nucleus of the amygdala, the plexiform layer of the ventral subiculum, and the molecular layer of the lateral entorhinal cortex.

  18. The human entorhinal cortex: a cytoarchitectonic analysis.

    PubMed

    Insausti, R; Tuñón, T; Sobreviela, T; Insausti, A M; Gonzalo, L M

    1995-05-01

    The entorhinal cortex of man is in the medial aspect of the temporal lobe. As in other mammalian species, it constitutes an essential component of the hippocampal formation and the route through which the neocortex interacts with the hippocampus. The importance of knowing its architecture in detail arises from the possibility of extrapolating it to experimental findings, notably in the nonhuman primate. We have investigated the cytoarchitectonic features of the human entorhinal cortex by using as a base our previous study (D.G. Amaral, R. Insausti, and W.M. Cowan [1987] J. Comp. Neurol. 264:326-355) of the nonhuman primate entorhinal cortex. We prepared serial sections of the temporal lobe from 35 normal brains. Thionin- and myelin-stained series were made of all cases. Sections spaced 500 microns apart through the full rostrocaudal extent of the entorhinal cortex were analyzed. The human entorhinal cortex is made up of six layers, of which layer IV does not appear throughout all subfields of the entorhinal cortex. The overall appearance resembles that of the adjacent neocortex in lateral and caudal portions. In harmony with general structural principles in the nonhuman primate entorhinal cortex, our analysis supports the partitioning of the human entorhinal cortex into eight different subfields. (1) The olfactory subfield (EO), the rostralmost field, is little laminated. (2) The lateral rostral subfield (ELr), laterally located, merges with the laterally adjacent perirhinal cortex. (3) The rostral subfield (ER) is between EO and ELr, with better differentiation of layers II and III than EO. (4) The medial intermediate subfield (EMI) is located at the medial border. (5) The intermediate field (EI) is a lateral continuation of EMI; lamina dissecans (layer IV) can be best appreciated in this field. (6) The lateral caudal subfield (ELc) laterally borders on EI as a continuation of ELr. (7) The caudal subfield (EC) lies caudal to the beginning of the hippocampal

  19. Medial perirhinal cortex disambiguates confusable objects

    PubMed Central

    Tyler, Lorraine K.; Monsch, Andreas U.; Taylor, Kirsten I.

    2012-01-01

    Our brain disambiguates the objects in our cluttered visual world seemingly effortlessly, enabling us to understand their significance and to act appropriately. The role of anteromedial temporal structures in this process, particularly the perirhinal cortex, is highly controversial. In some accounts, the perirhinal cortex is necessary for differentiating between perceptually and semantically confusable objects. Other models claim that the perirhinal cortex neither disambiguates perceptually confusable objects nor plays a unique role in semantic processing. One major hurdle to resolving this central debate is the fact that brain damage in human patients typically encompasses large portions of the anteromedial temporal lobe, such that the identification of individual substructures and precise neuroanatomical locus of the functional impairments has been difficult. We tested these competing accounts in patients with Alzheimer’s disease with varying degrees of atrophy in anteromedial structures, including the perirhinal cortex. To assess the functional contribution of each anteromedial temporal region separately, we used a detailed region of interest approach. From each participant, we obtained magnetic resonance imaging scans and behavioural data from a picture naming task that contrasted naming performance with living and non-living things as a way of manipulating perceptual and semantic confusability; living things are more similar to one another than non-living things, which have more distinctive features. We manually traced neuroanatomical regions of interest on native-space cortical surface reconstructions to obtain mean thickness estimates for the lateral and medial perirhinal cortex and entorhinal cortex. Mean cortical thickness in each region of interest, and hippocampal volume, were submitted to regression analyses predicting naming performance. Importantly, atrophy of the medial perirhinal cortex, but not lateral perirhinal cortex, entorhinal cortex or

  20. A layered network model of sensory cortex

    SciTech Connect

    Travis, B.J.

    1986-01-01

    An integrated computational approach to modeling sensory systems which couples realistic layered neural models of sensory cortex and midbrain nuclei to detailed models of the sense organs (e.g., retina or cochlea) is described. The approach is applied to the auditory system. Through an exercise of the model, it is shown that spatial location of sounds may be a natural consequence of the way cochlear response is mapped onto the cortex. 31 refs., 23 figs., 3 tabs.

  1. The Role of Human Parietal Cortex in Attention Networks

    ERIC Educational Resources Information Center

    Han, Shihui; Jiang, Yi; Gu, Hua; Rao, Hengyi; Mao, Lihua; Cui, Yong; Zhai, Renyou

    2004-01-01

    The parietal cortex has been proposed as part of the neural network for guiding spatial attention. However, it is unclear to what degree the parietal cortex contributes to the attentional modulations of activities of the visual cortex and the engagement of the frontal cortex in the attention network. We recorded behavioural performance and…

  2. The posterior medial cortex in urologic chronic pelvic pain syndrome: detachment from default mode network-a resting-state study from the MAPP Research Network.

    PubMed

    Martucci, Katherine T; Shirer, William R; Bagarinao, Epifanio; Johnson, Kevin A; Farmer, Melissa A; Labus, Jennifer S; Apkarian, A Vania; Deutsch, Georg; Harris, Richard E; Mayer, Emeran A; Clauw, Daniel J; Greicius, Michael D; Mackey, Sean C

    2015-09-01

    Altered resting-state (RS) brain activity, as a measure of functional connectivity (FC), is commonly observed in chronic pain. Identifying a reliable signature pattern of altered RS activity for chronic pain could provide strong mechanistic insights and serve as a highly beneficial neuroimaging-based diagnostic tool. We collected and analyzed RS functional magnetic resonance imaging data from female patients with urologic chronic pelvic pain syndrome (N = 45) and matched healthy participants (N = 45) as part of an NIDDK-funded multicenter project (www.mappnetwork.org). Using dual regression and seed-based analyses, we observed significantly decreased FC of the default mode network to 2 regions in the posterior medial cortex (PMC): the posterior cingulate cortex (PCC) and the left precuneus (threshold-free cluster enhancement, family-wise error corrected P < 0.05). Further investigation revealed that patients demonstrated increased FC between the PCC and several brain regions implicated in pain, sensory, motor, and emotion regulation processes (eg, insular cortex, dorsolateral prefrontal cortex, thalamus, globus pallidus, putamen, amygdala, hippocampus). The left precuneus demonstrated decreased FC to several regions of pain processing, reward, and higher executive functioning within the prefrontal (orbitofrontal, anterior cingulate, ventromedial prefrontal) and parietal cortices (angular gyrus, superior and inferior parietal lobules). The altered PMC connectivity was associated with several phenotype measures, including pain and urologic symptom intensity, depression, anxiety, quality of relationships, and self-esteem levels in patients. Collectively, these findings indicate that in patients with urologic chronic pelvic pain syndrome, regions of the PMC are detached from the default mode network, whereas neurological processes of self-referential thought and introspection may be joined to pain and emotion regulatory processes. PMID:26010458

  3. Repeated treatment with electroconvulsive seizures induces HDAC2 expression and down-regulation of NMDA receptor-related genes through histone deacetylation in the rat frontal cortex.

    PubMed

    Park, Hong Geun; Yu, Hyun Sook; Park, Soyoung; Ahn, Yong Min; Kim, Yong Sik; Kim, Se Hyun

    2014-09-01

    The enzymatic activity of histone deacetylases (HDACs) leads to a histone deacetylation-mediated condensed chromatic structure, resulting in transcriptional repression, which has been implicated in the modifications of neural circuits and behaviors. Repeated treatment with electroconvulsive seizure (ECS) induces changes in histone acetylation, expression of various genes, and intrabrain cellular changes, including neurogenesis. In this study, we examined the effects of repeated ECS on the expression of class I HDACs and related changes in histone modifications and gene expression in the rat frontal cortex. Ten days of repeated ECS treatments (E10X) up-regulated HDAC2 expression at the mRNA and protein levels in the rat frontal cortex compared with sham-treated controls; this was evident in the nuclei of neuronal cells in the prefrontal, cingulate, orbital, and insular cortices. Among the known HDAC2 target genes, mRNA expression of N-methyl-d-aspartate (NMDA) receptor signaling-related genes, including early growth response-1 (Egr1), c-Fos, glutamate receptor, ionotropic, N-methyl d-aspartate 2A (Nr2a), Nr2b, neuritin1 (Nrn1), and calcium/calmodulin-dependent protein kinase II alpha (Camk2α), were decreased, and the histone acetylation of H3 and/or H4 proteins was also reduced by E10X. Chromatin immunoprecipitation analysis revealed that HDAC2 occupancy in the promoters of down-regulated genes was increased significantly. Moreover, administration of sodium butyrate, a HDAC inhibitor, during the course of E10X ameliorated the ECS-induced down-regulation of genes in the rat frontal cortex. These findings suggest that induction of HDAC2 by repeated ECS treatment could play an important role in the down-regulation of NMDA receptor signaling-related genes in the rat frontal cortex through histone modification. PMID:24606669

  4. Auditory connections and functions of prefrontal cortex

    PubMed Central

    Plakke, Bethany; Romanski, Lizabeth M.

    2014-01-01

    The functional auditory system extends from the ears to the frontal lobes with successively more complex functions occurring as one ascends the hierarchy of the nervous system. Several areas of the frontal lobe receive afferents from both early and late auditory processing regions within the temporal lobe. Afferents from the early part of the cortical auditory system, the auditory belt cortex, which are presumed to carry information regarding auditory features of sounds, project to only a few prefrontal regions and are most dense in the ventrolateral prefrontal cortex (VLPFC). In contrast, projections from the parabelt and the rostral superior temporal gyrus (STG) most likely convey more complex information and target a larger, widespread region of the prefrontal cortex. Neuronal responses reflect these anatomical projections as some prefrontal neurons exhibit responses to features in acoustic stimuli, while other neurons display task-related responses. For example, recording studies in non-human primates indicate that VLPFC is responsive to complex sounds including vocalizations and that VLPFC neurons in area 12/47 respond to sounds with similar acoustic morphology. In contrast, neuronal responses during auditory working memory involve a wider region of the prefrontal cortex. In humans, the frontal lobe is involved in auditory detection, discrimination, and working memory. Past research suggests that dorsal and ventral subregions of the prefrontal cortex process different types of information with dorsal cortex processing spatial/visual information and ventral cortex processing non-spatial/auditory information. While this is apparent in the non-human primate and in some neuroimaging studies, most research in humans indicates that specific task conditions, stimuli or previous experience may bias the recruitment of specific prefrontal regions, suggesting a more flexible role for the frontal lobe during auditory cognition. PMID:25100931

  5. Mepraia spinolai in the Southeastern Pacific Ocean coast (Chile) - first insular record and feeding pattern on the Pan de Azúcar island.

    PubMed

    Sagua Franco, H; Araya Rojas, J; González Cortes, J; Neira Cortes, I

    2000-01-01

    In a field collection performed at Pan de Azúcar Island in Northern Chile, 95 specimens representing all instars of Mepraia spinolai were collected. The intestinal contents of 55 specimens were examined for Trypanosoma cruzi infection and were found to be negative. This is the first record of an insular habitat for M. spinolai, where the insects had fed mainly on seabirds (78%), some on marine mammals (5%), and some on reptiles (7%). PMID:10733734

  6. Propagating waves in visual cortex: a large-scale model of turtle visual cortex.

    PubMed

    Nenadic, Zoran; Ghosh, Bijoy K; Ulinski, Philip

    2003-01-01

    This article describes a large-scale model of turtle visual cortex that simulates the propagating waves of activity seen in real turtle cortex. The cortex model contains 744 multicompartment models of pyramidal cells, stellate cells, and horizontal cells. Input is provided by an array of 201 geniculate neurons modeled as single compartments with spike-generating mechanisms and axons modeled as delay lines. Diffuse retinal flashes or presentation of spots of light to the retina are simulated by activating groups of geniculate neurons. The model is limited in that it does not have a retina to provide realistic input to the geniculate, and the cortex and does not incorporate all of the biophysical details of real cortical neurons. However, the model does reproduce the fundamental features of planar propagating waves. Activation of geniculate neurons produces a wave of activity that originates at the rostrolateral pole of the cortex at the point where a high density of geniculate afferents enter the cortex. Waves propagate across the cortex with velocities of 4 microm/ms to 70 microm/ms and occasionally reflect from the caudolateral border of the cortex. PMID:12567015

  7. Autistic Traits in Neurotypical Adults are Related to Cingulo-Insular Functional Connectivity

    PubMed Central

    Di Martino, Adriana; Shehzad, Zarrar; Kelly, Clare A.M.; Roy, Amy Krain; Gee, Dylan G.; Uddin, Lucina Q.; Gotimer, Kristin; Klein, Donald F.; Castellanos, F. Xavier; Milham, Michael P.

    2010-01-01

    Objective Based on the increased recognition of the dimensional nature of autistic traits, we examined their neural correlates in neurotypical individuals using the Social Responsiveness Scale-Adult version (SRS-A). The SRS-A measures autistic traits that are continuously distributed in the general population. Here, we establish a novel approach to examining the neural basis of autistic traits, attempting to directly relate SRS-A scores to patterns of functional connectivity observed for the pregenual anterior cingulate cortex (pgACC), a region commonly implicated in social cognition. Methods Resting state fMRI scans were collected in 25 neurotypical individuals (26.4 ± 5.6 y) who provided SRS-A completed by an informant who knew the participant in natural social settings. Whole brain corrected connectivity analyses were then conducted using the SRS-A as a covariate of interest. Results We found a significant negative relationship between SRS-A and pgACC functional connectivity with the anterior portion of mid-insula (Z > 2.3; p < .05, corrected). Specifically, low levels of autistic traits were observed when a substantial portion of the anterior mid-insula showed positive connectivity with pgACC. In contrast, elevated levels of autistic traits were associated with negative connectivity between the pgACC and the anterior mid-insula. Conclusions Resting state functional connectivity of the pgACC-insula social network was related to autistic traits in neurotypical adults. Application of this approach in samples with autism spectrum disorders is needed to confirm whether the pgACC- anterior mid insula circuit is dimensionally related to the severity of autistic traits in clinical populations. PMID:19605539

  8. Insular and Hippocampal Gray Matter Volume Reductions in Patients with Major Depressive Disorder

    PubMed Central

    Kugel, Harald; Krug, Axel; Schöning, Sonja; Ohrmann, Patricia; Uhlmann, Christina; Postert, Christian; Suslow, Thomas; Heindel, Walter; Arolt, Volker; Kircher, Tilo; Dannlowski, Udo

    2014-01-01

    Background Major depressive disorder is a serious psychiatric illness with a highly variable and heterogeneous clinical course. Due to the lack of consistent data from previous studies, the study of morphometric changes in major depressive disorder is still a major point of research requiring additional studies. The aim of the study presented here was to characterize and quantify regional gray matter abnormalities in a large sample of clinically well-characterized patients with major depressive disorder. Methods For this study one-hundred thirty two patients with major depressive disorder and 132 age- and gender-matched healthy control participants were included, 35 with their first episode and 97 with recurrent depression. To analyse gray matter abnormalities, voxel-based morphometry (VBM8) was employed on T1 weighted MRI data. We performed whole-brain analyses as well as a region-of-interest approach on the hippocampal formation, anterior cingulate cortex and amygdala, correlating the number of depressive episodes. Results Compared to healthy control persons, patients showed a strong gray-matter reduction in the right anterior insula. In addition, region-of-interest analyses revealed significant gray-matter reductions in the hippocampal formation. The observed alterations were more severe in patients with recurrent depressive episodes than in patients with a first episode. The number of depressive episodes was negatively correlated with gray-matter volume in the right hippocampus and right amygdala. Conclusions The anterior insula gray matter structure appears to be strongly affected in major depressive disorder and might play an important role in the neurobiology of depression. The hippocampal and amygdala volume loss cumulating with the number of episodes might be explained either by repeated neurotoxic stress or alternatively by higher relapse rates in patients showing hippocampal atrophy. PMID:25051163

  9. [Numerical taxonomy of corlor in Phellodendron Cortex].

    PubMed

    Jin, Yan; Huang, Lu-qi; Yuan, Yuan; Zhang, Shan-shan; Jin, Shi-yuan

    2015-10-01

    Through the investigation of Phellodendron Cortex on the market, and 28 batches of samples were collected. By using spectrophotometer the color values of outer surface, inner surface and cross - section of these samples were measured. These measured color data was translated into 3D structure diagram by using the Lab color space tool. The level difference value, the mean value and the threshold value were calculated based the measured color data of these different batches of samples. All 28 groups measured data was analyzed using the methods of Ward linkage and average Euclidean distance. At the same time, we invited Professor Jin Shiyuan, the "Chinese medicine master", to identify, quality-evaluate and grade these 28 batches of Phellodendron Cortex samples base on the traditional experience, then compared the traditional empirical results with the spectrophotometer measurement results. The result showed that, the Phellodendron Cortex could be divided into Phellodendri Amurensis Cortex and Phellodendri Chinensis Cortex by color numerical clustering, and classified according to quality. The classification result has a high degree of consistency with the traditional experience. PMID:26975099

  10. Frontal association cortex is engaged in stimulus integration during associative learning.

    PubMed

    Nakayama, Daisuke; Baraki, Zohal; Onoue, Kousuke; Ikegaya, Yuji; Matsuki, Norio; Nomura, Hiroshi

    2015-01-01

    The frontal association cortex (FrA) is implicated in higher brain function. Aberrant FrA activity is likely to be involved in dementia pathology. However, the functional circuits both within the FrA and with other regions are unclear. A recent study showed that inactivation of the FrA impairs memory consolidation of an auditory fear conditioning in young mice. In addition, dendritic spine remodeling of FrA neurons is sensitive to paired sensory stimuli that produce associative memory. These findings suggest that the FrA is engaged in neural processes critical to associative learning. Here we characterize stimulus integration in the mouse FrA during associative learning. We experimentally separated contextual fear conditioning into context exposure and shock, and found that memory formation requires protein synthesis associated with both context exposure and shock in the FrA. Both context exposure and shock trigger Arc, an activity-dependent immediate-early gene, expression in the FrA, and a subset of FrA neurons was dually activated by both stimuli. In addition, we found that the FrA receives projections from the perirhinal (PRh) and insular (IC) cortices and basolateral amygdala (BLA), which are implicated in context and shock encoding. PRh and IC neurons projecting to the FrA were activated by context exposure and shock, respectively. Arc expression in the FrA associated with context exposure and shock depended on PRh activity and both IC and BLA activities, respectively. These findings indicate that the FrA is engaged in stimulus integration and contributes to memory formation in associative learning. PMID:25496961

  11. Sexual differentiation of mammalian frontal cortex

    SciTech Connect

    Maggi, A.; Zucchi, I.

    1987-03-23

    The pattern of distribution of the progesterone binding sites was examined in selected nuclei of the brain of male and female rat. In female rats the frontal cortex resulted to be the region with the highest concentration of /sup 3/H R5020 biding sites. However, in male rats the same region showed very little progestin binding activity. When female rats were androgenized via neonatal exposure to testosterone, the progestin binding activity of the frontal cortex became similar to that observed in male rats. The present investigation indicates that sexual differentiation of the rat brain may include also brain regions not clearly involved in sex related functions like the frontal cortex. 30 references, 2 figures, 1 table.

  12. The Age of Human Cerebral Cortex Neurons

    SciTech Connect

    Bhardwaj, R D; Curtis, M A; Spalding, K L; Buchholz, B A; Fink, D; Bjork-Eriksson, T; Nordborg, C; Gage, F H; Druid, H; Eriksson, P S; Frisen, J

    2006-04-06

    The traditional static view of the adult mammalian brain has been challenged by the realization of continuous generation of neurons from stem cells. Based mainly on studies in experimental animals, adult neurogenesis may contribute to recovery after brain insults and decreased neurogenesis has been implicated in the pathogenesis of neurological and psychiatric diseases in man. The extent of neurogenesis in the adult human brain has, however, been difficult to establish. We have taken advantage of the integration of {sup 14}C, generated by nuclear bomb tests during the Cold War, in DNA to establish the age of neurons in the major areas of the human cerebral cortex. Together with the analysis of the cortex from patients who received BrdU, which integrates in the DNA of dividing cells, our results demonstrate that whereas non-neuronal cells turn over, neurons in the human cerebral cortex are not generated postnatally at detectable levels, but are as old as the individual.

  13. Cortex commands the performance of skilled movement.

    PubMed

    Guo, Jian-Zhong; Graves, Austin R; Guo, Wendy W; Zheng, Jihong; Lee, Allen; Rodríguez-González, Juan; Li, Nuo; Macklin, John J; Phillips, James W; Mensh, Brett D; Branson, Kristin; Hantman, Adam W

    2015-01-01

    Mammalian cerebral cortex is accepted as being critical for voluntary motor control, but what functions depend on cortex is still unclear. Here we used rapid, reversible optogenetic inhibition to test the role of cortex during a head-fixed task in which mice reach, grab, and eat a food pellet. Sudden cortical inhibition blocked initiation or froze execution of this skilled prehension behavior, but left untrained forelimb movements unaffected. Unexpectedly, kinematically normal prehension occurred immediately after cortical inhibition, even during rest periods lacking cue and pellet. This 'rebound' prehension was only evoked in trained and food-deprived animals, suggesting that a motivation-gated motor engram sufficient to evoke prehension is activated at inhibition's end. These results demonstrate the necessity and sufficiency of cortical activity for enacting a learned skill. PMID:26633811

  14. How might the motor cortex individuate movements?

    PubMed

    Schieber, M H

    1990-11-01

    The ability to individuate movements--that is, the ability to move one or more body parts independently of the movement or posture of other contiguous body parts--imparts an increasing flexibility to the motor repertoire of higher mammals. The movements used in walking, grasping, or eating contrast greatly with the phylogenetically more recent movements of the same body parts used, respectively, in dancing, playing a musical instrument, or talking. The movements used in the latter functions depend critically on the primary motor cortex (area 4). With advances in our understanding of the output organization of the motor cortex (reviewed recently by Roger Lemon), which have been based largely on studies of the hand area in primates, we can now consider more fully certain problems inherent in moving body parts individually, and some ways in which the motor cortex might accomplish this feat. PMID:1701575

  15. Cortex commands the performance of skilled movement

    PubMed Central

    Guo, Jian-Zhong; Graves, Austin R; Guo, Wendy W; Zheng, Jihong; Lee, Allen; Rodríguez-González, Juan; Li, Nuo; Macklin, John J; Phillips, James W; Mensh, Brett D; Branson, Kristin; Hantman, Adam W

    2015-01-01

    Mammalian cerebral cortex is accepted as being critical for voluntary motor control, but what functions depend on cortex is still unclear. Here we used rapid, reversible optogenetic inhibition to test the role of cortex during a head-fixed task in which mice reach, grab, and eat a food pellet. Sudden cortical inhibition blocked initiation or froze execution of this skilled prehension behavior, but left untrained forelimb movements unaffected. Unexpectedly, kinematically normal prehension occurred immediately after cortical inhibition, even during rest periods lacking cue and pellet. This ‘rebound’ prehension was only evoked in trained and food-deprived animals, suggesting that a motivation-gated motor engram sufficient to evoke prehension is activated at inhibition’s end. These results demonstrate the necessity and sufficiency of cortical activity for enacting a learned skill. DOI: http://dx.doi.org/10.7554/eLife.10774.001 PMID:26633811

  16. Spatial updating in human parietal cortex

    NASA Technical Reports Server (NTRS)

    Merriam, Elisha P.; Genovese, Christopher R.; Colby, Carol L.

    2003-01-01

    Single neurons in monkey parietal cortex update visual information in conjunction with eye movements. This remapping of stimulus representations is thought to contribute to spatial constancy. We hypothesized that a similar process occurs in human parietal cortex and that we could visualize it with functional MRI. We scanned subjects during a task that involved remapping of visual signals across hemifields. We observed an initial response in the hemisphere contralateral to the visual stimulus, followed by a remapped response in the hemisphere ipsilateral to the stimulus. We ruled out the possibility that this remapped response resulted from either eye movements or visual stimuli alone. Our results demonstrate that updating of visual information occurs in human parietal cortex.

  17. Progenitor genealogy in the developing cerebral cortex.

    PubMed

    Laguesse, Sophie; Peyre, Elise; Nguyen, Laurent

    2015-01-01

    The mammalian cerebral cortex is characterized by a complex histological organization that reflects the spatio-temporal stratifications of related stem and neural progenitor cells, which are responsible for the generation of distinct glial and neuronal subtypes during development. Some work has been done to shed light on the existing filiations between these progenitors as well as their respective contribution to cortical neurogenesis. The aim of the present review is to summarize the current views of progenitor hierarchy and relationship in the developing cortex and to further discuss future research directions that would help us to understand the molecular and cellular regulating mechanisms involved in cerebral corticogenesis. PMID:25141969

  18. Geology of the insular shelf south of St. Thomas and St. John, U.S. Virgin Islands

    USGS Publications Warehouse

    Garrison, L. E.; Holmes, Charles Ward; Trumbull, James V.

    1971-01-01

    A reconnaissance study has been made of the geology of the insular shelf south of St. Thomas and St. John, Virgin Islands. High-resolution seismic-reflection profiling reveals that a buried northeast-southwest striking bedrock ridge controls the shallow structure of the eastern portion of the shelf. This ridge is thought to be related to the Virgin Islands pluton farther north. Bedrock in the western shelf portion is more deeply buried and is thought to be a flatter terrain, probably lithologically similar to rocks exposed on St. Thomas. The sediment cover appears to consist principally of carbonate grains in the sand-size range. This sand is covered to various degrees by carbonate nodules at depths below about 34 m, but at shallower depths the nodules are not present. Three large areas of sandy bottom were mapped 1) west of Brewers Bay, 2) near Buck Island, and 3) off south-central St. John. Variations in the amounts of land-derived particles, organic matter, and silt/clay sized material were mapped in these bodies.

  19. Reproducibility of Neurochemical Profile Quantification in Pregenual Cingulate, Anterior Midcingulate, and Bilateral Posterior Insular Subdivisions Measured at 3 Tesla.

    PubMed

    de Matos, Nuno M P; Meier, Lukas; Wyss, Michael; Meier, Dieter; Gutzeit, Andreas; Ettlin, Dominik A; Brügger, Mike

    2016-01-01

    The current report assessed measurement reproducibility of proton magnetic resonance spectroscopy at 3 Tesla in the left and right posterior insular, pregenual anterior cingulate, and anterior midcingulate cortices. Ten healthy male volunteers aged 21-30 years were tested at four different days, of which nine were included in the data analysis. Intra- and inter-subject variability of myo-inositol, creatine, glutamate, total-choline, total-N-acetylaspartate, and combined glutamine-glutamate were calculated considering the influence of movement parameters, age, daytime of measurements, and tissue composition. Overall mean intra-/inter-subject variability for all neurochemicals combined revealed small mean coefficients of variation across the four regions: 5.3/9.05% in anterior midcingulate, 6.6/8.84% in pregenual anterior cingulate, 7.3/10.00% in left posterior and 8.2/10.55% in right posterior insula. Head movement, tissue composition and day time revealed no significant explanatory variance contribution suggesting a negligible influence on the data. A strong correlation between Cramer-Rao Lower Bounds (a measure of fitting errors) and the mean intra-subject coefficients of variation (r = 0.799, p < 0.001) outlined the importance of low fitting errors in order to obtain robust and finally meaningful measurements. The present findings confirm proton magnetic resonance spectroscopy as a reliable tool to measure brain neurochemistry in small subregions of the human brain. PMID:27445745

  20. Reproducibility of Neurochemical Profile Quantification in Pregenual Cingulate, Anterior Midcingulate, and Bilateral Posterior Insular Subdivisions Measured at 3 Tesla

    PubMed Central

    de Matos, Nuno M. P.; Meier, Lukas; Wyss, Michael; Meier, Dieter; Gutzeit, Andreas; Ettlin, Dominik A.; Brügger, Mike

    2016-01-01

    The current report assessed measurement reproducibility of proton magnetic resonance spectroscopy at 3 Tesla in the left and right posterior insular, pregenual anterior cingulate, and anterior midcingulate cortices. Ten healthy male volunteers aged 21–30 years were tested at four different days, of which nine were included in the data analysis. Intra- and inter-subject variability of myo-inositol, creatine, glutamate, total-choline, total-N-acetylaspartate, and combined glutamine–glutamate were calculated considering the influence of movement parameters, age, daytime of measurements, and tissue composition. Overall mean intra-/inter-subject variability for all neurochemicals combined revealed small mean coefficients of variation across the four regions: 5.3/9.05% in anterior midcingulate, 6.6/8.84% in pregenual anterior cingulate, 7.3/10.00% in left posterior and 8.2/10.55% in right posterior insula. Head movement, tissue composition and day time revealed no significant explanatory variance contribution suggesting a negligible influence on the data. A strong correlation between Cramer–Rao Lower Bounds (a measure of fitting errors) and the mean intra-subject coefficients of variation (r = 0.799, p < 0.001) outlined the importance of low fitting errors in order to obtain robust and finally meaningful measurements. The present findings confirm proton magnetic resonance spectroscopy as a reliable tool to measure brain neurochemistry in small subregions of the human brain. PMID:27445745

  1. Signatures of volcanism and aridity in the evolution of an insular pine (Pinus canariensis Chr. Sm. Ex DC in Buch)

    PubMed Central

    López de Heredia, U; López, R; Collada, C; Emerson, B C; Gil, L

    2014-01-01

    Oceanic islands of volcanic origin provide useful templates for the study of evolution because they are subjected to recurrent perturbations that generate steep environmental gradients that may promote adaptation. Here we combine population genetic data from nuclear genes with the analysis of environmental variation and phenotypic data from common gardens to disentangle the confounding effects of demography and selection to identify the factors of importance for the evolution of the insular pine P. canariensis. Eight nuclear genes were partially sequenced in a survey covering the entire species range, and phenotypic traits were measured in four common gardens from contrasting environments. The explanatory power of population substrate age and environmental indices were assessed against molecular and phenotypic diversity estimates. In addition, neutral genetic variability (FST) and the genetic differentiation of phenotypic variation (QST) were compared in order to identify the evolutionary forces acting on these traits. Two key factors in the evolution of the species were identified: (1) recurrent volcanic activity has left an imprint in the genetic diversity of the nuclear genes; (2) aridity in southern slopes promotes local adaptation in the driest localities of P. canariensis, despite high levels of gene flow among populations. PMID:24619181

  2. Genetic structure of introduced populations: 120-year-old DNA footprint of historic introduction in an insular small mammal population

    PubMed Central

    Simpson, Siobhan; Blampied, Nick; Peniche, Gabriela; Dozières, Anne; Blackett, Tiffany; Coleman, Stephen; Cornish, Nina; Groombridge, Jim J

    2013-01-01

    Wildlife populations have been introduced to new areas by people for centuries, but this human-mediated movement can disrupt natural patterns of genetic structure by altering patterns of gene flow. Insular populations are particularly prone to these influences due to limited opportunities for natural dispersal onto islands. Consequently, understanding how genetic patterns develop in island populations is important, particularly given that islands are frequently havens for protected wildlife. We examined the evolutionary origins and extent of genetic structure within the introduced island population of red squirrels (Sciurus vulgaris) on the Channel Island of Jersey using mitochondrial DNA (mtDNA) control region sequence and nuclear microsatellite genotypes. Our findings reveal two different genetic origins and a genetic architecture reflective of the introductions 120 years ago. Genetic structure is marked within the maternally inherited mtDNA, indicating slow dispersal of female squirrels. However, nuclear markers detected only weak genetic structure, indicating substantially greater male dispersal. Data from both mitochondrial and nuclear markers support historic records that squirrels from England were introduced to the west of the island and those from mainland Europe to the east. Although some level of dispersal and introgression across the island between the two introductions is evident, there has not yet been sufficient gene flow to erase this historic genetic “footprint.” We also investigated if inbreeding has contributed to high observed levels of disease, but found no association. Genetic footprints of introductions can persist for considerable periods of time and beyond traditional timeframes of wildlife management. PMID:23532702

  3. In favor of general probability distributions: lateral prefrontal and insular cortices respond to stimulus inherent, but irrelevant differences.

    PubMed

    Mestres-Missé, Anna; Trampel, Robert; Turner, Robert; Kotz, Sonja A

    2016-04-01

    A key aspect of optimal behavior is the ability to predict what will come next. To achieve this, we must have a fairly good idea of the probability of occurrence of possible outcomes. This is based both on prior knowledge about a particular or similar situation and on immediately relevant new information. One question that arises is: when considering converging prior probability and external evidence, is the most probable outcome selected or does the brain represent degrees of uncertainty, even highly improbable ones? Using functional magnetic resonance imaging, the current study explored these possibilities by contrasting words that differ in their probability of occurrence, namely, unbalanced ambiguous words and unambiguous words. Unbalanced ambiguous words have a strong frequency-based bias towards one meaning, while unambiguous words have only one meaning. The current results reveal larger activation in lateral prefrontal and insular cortices in response to dominant ambiguous compared to unambiguous words even when prior and contextual information biases one interpretation only. These results suggest a probability distribution, whereby all outcomes and their associated probabilities of occurrence-even if very low-are represented and maintained. PMID:25523107

  4. Elastic instabilities in a layered cerebral cortex: A revised axonal tension model for cortex folding

    NASA Astrophysics Data System (ADS)

    Schwarz, J. M.

    Despite decades of research, there is still no consensus regarding the mechanism(s) driving cerebral cortex folding. Two different mechanisms--axonal tension based on efficient wiring of the neurons and differential growth-induced buckling--are the prevailing hypotheses, though quantitative comparison with data raises issues with both of them. I will present a model for the elasticity of the cerebral cortex as a layered material with bending energy along the layers and elastic energy between them. The cortex is also subjected to axons pulling from the underlying white matter. Above a critical threshold force, a 'flat' cortex configuration becomes unstable and periodic undulations emerge, i.e. a buckling instability occurs, to presumably initiate folds in the cortex. This model builds on the original axonal tension model for cortex folding based on the efficient wiring of neurons but with no buckling mechanism and allows one to understand why small mice brains exhibit no folds, while larger human brains do. Finally, an estimate of the bending rigidity constant for the cortex can be made based on the critical wavelength to quantitatively test this revised axonal tensional model. This work was done in collaboration with Oksana Manyuhina and David Mayett.

  5. Developmental Outcomes after Early Prefrontal Cortex Damage

    ERIC Educational Resources Information Center

    Eslinger, Paul J.; Flaherty-Craig, Claire V.; Benton, Arthur L.

    2004-01-01

    The neuropsychological bases of cognitive, social, and moral development are minimally understood, with a seemingly wide chasm between developmental theories and brain maturation models. As one approach to bridging ideas in these areas, we review 10 cases of early prefrontal cortex damage from the clinical literature, highlighting overall clinical…

  6. Motor Cortex Reorganization across the Lifespan

    ERIC Educational Resources Information Center

    Plowman, Emily K.; Kleim, Jeffrey A.

    2010-01-01

    The brain is a highly dynamic structure with the capacity for profound structural and functional change. Such neural plasticity has been well characterized within motor cortex and is believed to represent one of the neural mechanisms for acquiring and modifying motor behaviors. A number of behavioral and neural signals have been identified that…

  7. The Piriform Cortex and Human Focal Epilepsy

    PubMed Central

    Vaughan, David N.; Jackson, Graeme D.

    2014-01-01

    It is surprising that the piriform cortex, when compared to the hippocampus, has been given relatively little significance in human epilepsy. Like the hippocampus, it has a phylogenetically preserved three-layered cortex that is vulnerable to excitotoxic injury, has broad connections to both limbic and cortical areas, and is highly epileptogenic – being critical to the kindling process. The well-known phenomenon of early olfactory auras in temporal lobe epilepsy highlights its clinical relevance in human beings. Perhaps because it is anatomically indistinct and difficult to approach surgically, as it clasps the middle cerebral artery, it has, until now, been understandably neglected. In this review, we emphasize how its unique anatomical and functional properties, as primary olfactory cortex, predispose it to involvement in focal epilepsy. From recent convergent findings in human neuroimaging, clinical epileptology, and experimental animal models, we make the case that the piriform cortex is likely to play a facilitating and amplifying role in human focal epileptogenesis, and may influence progression to epileptic intractability. PMID:25538678

  8. Excitatory neuronal connectivity in the barrel cortex

    PubMed Central

    Feldmeyer, Dirk

    2012-01-01

    Neocortical areas are believed to be organized into vertical modules, the cortical columns, and the horizontal layers 1–6. In the somatosensory barrel cortex these columns are defined by the readily discernible barrel structure in layer 4. Information processing in the neocortex occurs along vertical and horizontal axes, thereby linking individual barrel-related columns via axons running through the different cortical layers of the barrel cortex. Long-range signaling occurs within the neocortical layers but also through axons projecting through the white matter to other neocortical areas and subcortical brain regions. Because of the ease of identification of barrel-related columns, the rodent barrel cortex has become a prototypical system to study the interactions between different neuronal connections within a sensory cortical area and between this area and other cortical as well subcortical regions. Such interactions will be discussed specifically for the feed-forward and feedback loops between the somatosensory and the somatomotor cortices as well as the different thalamic nuclei. In addition, recent advances concerning the morphological characteristics of excitatory neurons and their impact on the synaptic connectivity patterns and signaling properties of neuronal microcircuits in the whisker-related somatosensory cortex will be reviewed. In this context, their relationship between the structural properties of barrel-related columns and their function as a module in vertical synaptic signaling in the whisker-related cortical areas will be discussed. PMID:22798946

  9. Cerebral cortex structure in prodromal Huntington disease.

    PubMed

    Nopoulos, Peggy C; Aylward, Elizabeth H; Ross, Christopher A; Johnson, Hans J; Magnotta, Vincent A; Juhl, Andrew R; Pierson, Ronald K; Mills, James; Langbehn, Douglas R; Paulsen, Jane S

    2010-12-01

    Neuroimaging studies of subjects who are gene-expanded for Huntington Disease, but not yet diagnosed (termed prodromal HD), report that the cortex is "spared," despite the decrement in striatal and cerebral white-matter volume. Measurement of whole-cortex volume can mask more subtle, but potentially clinically relevant regional changes in volume, thinning, or surface area. The current study addressed this limitation by evaluating cortical morphology of 523 prodromal HD subjects. Participants included 693 individuals enrolled in the PREDICT-HD protocol. Of these participants, 523 carried the HD gene mutation (prodromal HD group); the remaining 170 were non gene-expanded and served as the comparison group. Based on age and CAG repeat length, gene-expanded subjects were categorized as "Far from onset," "Midway to onset," "Near onset," and "already diagnosed." MRI scans were processed using FreeSurfer. Cortical volume, thickness, and surface area were not significantly different between the Far from onset group and controls. However, beginning in the Midway to onset group, the cortex showed significant volume decrement, affecting most the posterior and superior cerebral regions. This pattern progressed when evaluating the groups further into the disease process. Areas that remained mostly unaffected included ventral and medial regions of the frontal and temporal cortex. Morphologic changes were mostly in thinning as surface area did not substantially change in most regions. Early in the course of HD, the cortex shows changes that are manifest as cortical thinning and are most robust in the posterior and superior regions of the cerebrum. PMID:20688164

  10. Cerebral Cortex Structure in Prodromal Huntington Disease

    PubMed Central

    Nopoulos, Peggy C.; Aylward, Elizabeth H.; Ross, Christopher A.; Johnson, Hans J.; Magnotta, Vincent A.; Juhl, Andrew R.; Pierson, Ronald K.; Mills, James; Langbehn, Douglas R.; Paulsen, Jane S.

    2010-01-01

    Neuroimaging studies of subjects who are gene-expanded for Huntington Disease, but not yet diagnosed (termed prodromal HD), report that the cortex is “spared,” despite the decrement in striatal and cerebral white-matter volume. Measurement of whole-cortex volume can mask more subtle, but potentially clinically relevant regional changes in volume, thinning, or surface area. The current study addressed this limitation by evaluating cortical morphology of 523 prodromal HD subjects. Participants included 693 individuals enrolled in the PREDICT-HD protocol. Of these participants, 523 carried the HD gene mutation (prodromal HD group); the remaining 170 were non gene-expanded and served as the comparison group. Based on age and CAG repeat length, gene-expanded subjects were categorized as “Far from onset,” “Midway to onset,” “Near onset,” and “already diagnosed.” MRI scans were processed using FreeSurfer. Cortical volume, thickness, and surface area were not significantly different between the Far from onset group and controls. However, beginning in the Midway to onset group, the cortex showed significant volume decrement, affecting most the posterior and superior cerebral regions. This pattern progressed when evaluating the groups further into the disease process. Areas that remained mostly unaffected included ventral and medial regions of the frontal and temporal cortex. Morphologic changes were mostly in thinning as surface area did not substantially change in most regions. Early in the course of HD, the cortex shows changes that are manifest as cortical thinning and are most robust in the posterior and superior regions of the cerebrum. PMID:20688164

  11. Cholecystokinin from the entorhinal cortex enables neural plasticity in the auditory cortex

    PubMed Central

    Li, Xiao; Yu, Kai; Zhang, Zicong; Sun, Wenjian; Yang, Zhou; Feng, Jingyu; Chen, Xi; Liu, Chun-Hua; Wang, Haitao; Guo, Yi Ping; He, Jufang

    2014-01-01

    Patients with damage to the medial temporal lobe show deficits in forming new declarative memories but can still recall older memories, suggesting that the medial temporal lobe is necessary for encoding memories in the neocortex. Here, we found that cortical projection neurons in the perirhinal and entorhinal cortices were mostly immunopositive for cholecystokinin (CCK). Local infusion of CCK in the auditory cortex of anesthetized rats induced plastic changes that enabled cortical neurons to potentiate their responses or to start responding to an auditory stimulus that was paired with a tone that robustly triggered action potentials. CCK infusion also enabled auditory neurons to start responding to a light stimulus that was paired with a noise burst. In vivo intracellular recordings in the auditory cortex showed that synaptic strength was potentiated after two pairings of presynaptic and postsynaptic activity in the presence of CCK. Infusion of a CCKB antagonist in the auditory cortex prevented the formation of a visuo-auditory association in awake rats. Finally, activation of the entorhinal cortex potentiated neuronal responses in the auditory cortex, which was suppressed by infusion of a CCKB antagonist. Together, these findings suggest that the medial temporal lobe influences neocortical plasticity via CCK-positive cortical projection neurons in the entorhinal cortex. PMID:24343575

  12. Cell Counts in Cerebral Cortex of an Autistic Patient.

    ERIC Educational Resources Information Center

    Coleman, Paul D.; And Others

    1985-01-01

    Numbers of neurons and glia were counted in the cerebral cortex of one case of autism and two age- and sex-matched controls. Cell counts were made in primary auditory cortex, Broca's speech area, and auditory association cortex. No consistent differences in cell density were found between brains of autistic and control patients. (Author/CL)

  13. Necessary, yet dissociable contributions of the insular and ventromedial prefrontal cortices to norm adaptation: computational and lesion evidence in humans.

    PubMed

    Gu, Xiaosi; Wang, Xingchao; Hula, Andreas; Wang, Shiwei; Xu, Shuai; Lohrenz, Terry M; Knight, Robert T; Gao, Zhixian; Dayan, Peter; Montague, P Read

    2015-01-14

    Social norms and their enforcement are fundamental to human societies. The ability to detect deviations from norms and to adapt to norms in a changing environment is therefore important to individuals' normal social functioning. Previous neuroimaging studies have highlighted the involvement of the insular and ventromedial prefrontal (vmPFC) cortices in representing norms. However, the necessity and dissociability of their involvement remain unclear. Using model-based computational modeling and neuropsychological lesion approaches, we examined the contributions of the insula and vmPFC to norm adaptation in seven human patients with focal insula lesions and six patients with focal vmPFC lesions, in comparison with forty neurologically intact controls and six brain-damaged controls. There were three computational signals of interest as participants played a fairness game (ultimatum game): sensitivity to the fairness of offers, sensitivity to deviations from expected norms, and the speed at which people adapt to norms. Significant group differences were assessed using bootstrapping methods. Patients with insula lesions displayed abnormally low adaptation speed to norms, yet detected norm violations with greater sensitivity than controls. Patients with vmPFC lesions did not have such abnormalities, but displayed reduced sensitivity to fairness and were more likely to accept the most unfair offers. These findings provide compelling computational and lesion evidence supporting the necessary, yet dissociable roles of the insula and vmPFC in norm adaptation in humans: the insula is critical for learning to adapt when reality deviates from norm expectations, and that the vmPFC is important for valuation of fairness during social exchange. PMID:25589742

  14. Successful Aging among Elders Living in the Mani Continental Region vs. Insular Areas of the Mediterranean: the MEDIS Study

    PubMed Central

    Mariolis, Anargiros; Foscolou, Alexandra; Tyrovolas, Stefanos; Piscopo, Suzanne; Valacchi, Giuseppe; Tsakountakis, Nikos; Zeimbekis, Akis; Bountziouka, Vassiliki; Gotsis, Efthimios; Metallinos, George; Tyrovola, Dimitra; Tur, Josep-Antoni; Matalas, Antonia-Leda; Lionis, Christos; Polychronopoulos, Evangelos; Panagiotakos, Demosthenes

    2016-01-01

    To evaluate the role of geography i.e., continental vs. insular Mediterranean, on successful aging among older inhabitants. During 2005-2014, 2693 elderly (aged 65 to 100 years) individuals from 21 Mediterranean islands in Greece, Italy and Spain as well as Cyprus, Malta, and the rural region of Mani (southeast continental region of Greece keeping old-time traditions), were voluntarily recruited. Successful aging was evaluated using a validated index composed of 10 health-related socio-lifestyle and clinical characteristics. After accounting for age, sex, body mass index (BMI), physical activity, smoking habits, MedDietScore and access to health care services, the older inhabitants of islands were found to have a higher level of the successful aging index when compared to their counterparts in Mani (Beta=0.174, p<0.001); moreover, islanders exhibited slightly more years of “good” health (68.7 vs 68.4 years for Mani residents (p=0.99)). However, compared to the residents of Mani, islanders had 1.64 times higher odds (95%CI, 1.08-2.48) for having hypertension, 2.4-times higher odds (95%CI, 1.34-4.21) for having diabetes and 1.52 times higher odds (95%CI, 0.97-2.38) for having hypercholesterolemia. Engaging in physical activities and healthy dietary habits were the major determinants of healthy aging, among islanders as compared to their counterparts of continental Mani region. Elder residents of the continental Mani area enjoyed a better health status, whereas elder islanders had a higher level of successful aging; a finding which could be attributed to differences in lifestyle among elders. PMID:27330843

  15. Necessary, Yet Dissociable Contributions of the Insular and Ventromedial Prefrontal Cortices to Norm Adaptation: Computational and Lesion Evidence in Humans

    PubMed Central

    Gu, Xiaosi; Wang, Xingchao; Hula, Andreas; Wang, Shiwei; Xu, Shuai; Lohrenz, Terry M.; Knight, Robert T.; Gao, Zhixian; Dayan, Peter

    2015-01-01

    Social norms and their enforcement are fundamental to human societies. The ability to detect deviations from norms and to adapt to norms in a changing environment is therefore important to individuals' normal social functioning. Previous neuroimaging studies have highlighted the involvement of the insular and ventromedial prefrontal (vmPFC) cortices in representing norms. However, the necessity and dissociability of their involvement remain unclear. Using model-based computational modeling and neuropsychological lesion approaches, we examined the contributions of the insula and vmPFC to norm adaptation in seven human patients with focal insula lesions and six patients with focal vmPFC lesions, in comparison with forty neurologically intact controls and six brain-damaged controls. There were three computational signals of interest as participants played a fairness game (ultimatum game): sensitivity to the fairness of offers, sensitivity to deviations from expected norms, and the speed at which people adapt to norms. Significant group differences were assessed using bootstrapping methods. Patients with insula lesions displayed abnormally low adaptation speed to norms, yet detected norm violations with greater sensitivity than controls. Patients with vmPFC lesions did not have such abnormalities, but displayed reduced sensitivity to fairness and were more likely to accept the most unfair offers. These findings provide compelling computational and lesion evidence supporting the necessary, yet dissociable roles of the insula and vmPFC in norm adaptation in humans: the insula is critical for learning to adapt when reality deviates from norm expectations, and that the vmPFC is important for valuation of fairness during social exchange. PMID:25589742

  16. The insular shelves of the Faial-Pico Ridge (Azores archipelago): A morphological record of its evolution

    NASA Astrophysics Data System (ADS)

    Quartau, R.; Madeira, J.; Mitchell, N. C.; Tempera, F.; Silva, P. F.; Brandão, F.

    2015-05-01

    Shelves surrounding reefless volcanic ocean islands are formed by surf erosion of their slopes during changing sea levels. Posterosional lava flows, if abundant, can cross the coastal cliffs and fill partially or completely the accommodation space left by erosion. In this study, multibeam bathymetry, high-resolution seismic reflection profiles, and sediment samples are used to characterize the morphology of the insular shelves adjacent to Pico Island. The data show offshore fresh lava flow morphologies, as well as an irregular basement beneath shelf sedimentary bodies and reduced shelf width adjacent to older volcanic edifices in Pico. These observations suggest that these shelves have been significantly filled by volcanic progradation and can thus be classified as "rejuvenated." Despite the general volcanic infilling of the shelves around Pico, most of their edges are below the depth of the Last Glacial Maximum, revealing that at least parts of the island have subsided after the shelves formed by surf erosion. Prograding lava deltas reached the shelf edge in some areas triggering small slope failures, locally decreasing the shelf width and depth of their edges. These areas can represent a significant risk for the local population; hence, their identification can be useful for hazard assessment and contribute to wiser land use planning. Shelf and subaerial geomorphology, magnetic anomalies and crustal structure data of the two islands were also interpreted to reconstruct the long-term combined onshore and offshore evolution of the Faial-Pico ridge. The subaerial emergence of this ridge is apparently older than previously thought, i.e., before ˜850 ka.

  17. Successful Aging among Elders Living in the Mani Continental Region vs. Insular Areas of the Mediterranean: the MEDIS Study.

    PubMed

    Mariolis, Anargiros; Foscolou, Alexandra; Tyrovolas, Stefanos; Piscopo, Suzanne; Valacchi, Giuseppe; Tsakountakis, Nikos; Zeimbekis, Akis; Bountziouka, Vassiliki; Gotsis, Efthimios; Metallinos, George; Tyrovola, Dimitra; Tur, Josep-Antoni; Matalas, Antonia-Leda; Lionis, Christos; Polychronopoulos, Evangelos; Panagiotakos, Demosthenes

    2016-05-01

    To evaluate the role of geography i.e., continental vs. insular Mediterranean, on successful aging among older inhabitants. During 2005-2014, 2693 elderly (aged 65 to 100 years) individuals from 21 Mediterranean islands in Greece, Italy and Spain as well as Cyprus, Malta, and the rural region of Mani (southeast continental region of Greece keeping old-time traditions), were voluntarily recruited. Successful aging was evaluated using a validated index composed of 10 health-related socio-lifestyle and clinical characteristics. After accounting for age, sex, body mass index (BMI), physical activity, smoking habits, MedDietScore and access to health care services, the older inhabitants of islands were found to have a higher level of the successful aging index when compared to their counterparts in Mani (Beta=0.174, p<0.001); moreover, islanders exhibited slightly more years of "good" health (68.7 vs 68.4 years for Mani residents (p=0.99)). However, compared to the residents of Mani, islanders had 1.64 times higher odds (95%CI, 1.08-2.48) for having hypertension, 2.4-times higher odds (95%CI, 1.34-4.21) for having diabetes and 1.52 times higher odds (95%CI, 0.97-2.38) for having hypercholesterolemia. Engaging in physical activities and healthy dietary habits were the major determinants of healthy aging, among islanders as compared to their counterparts of continental Mani region. Elder residents of the continental Mani area enjoyed a better health status, whereas elder islanders had a higher level of successful aging; a finding which could be attributed to differences in lifestyle among elders. PMID:27330843

  18. Climate as a driver of tropical insular diversity: comparative phylogeography of two ecologically distinctive frogs in Puerto Rico

    PubMed Central

    Barker, Brittany S.; Rodríguez-Robles, Javier A.; Cook, Joseph A.

    2014-01-01

    The effects of late Quaternary climate on distributions and evolutionary dynamics of insular species are poorly understood in most tropical archipelagoes. We used ecological niche models under past and current climate to derive hypotheses regarding how stable climatic conditions shaped genetic diversity in two ecologically distinctive frogs in Puerto Rico. Whereas the Mountain Coquí, Eleutherodactylus portoricensis, is restricted to montane forest in the Cayey and Luquillo Mountains, the Red-eyed Coquí, E. antillensis, is a habitat generalist distributed across the entire Puerto Rican Bank (Puerto Rico and the Virgin Islands, excluding St. Croix). To test our hypotheses, we conducted phylogeographic and population genetic analyses based on mitochondrial and nuclear loci of each species across their range in Puerto Rico. Patterns of population differentiation in E. portoricensis, but not in E. antillensis, supported our hypotheses. For E. portoricensis, these patterns include: individuals isolated by long-term unsuitable climate in the Río Grande de Loíza Basin in eastern Puerto Rico belong to different genetic clusters; past and current climate strongly predicted genetic differentiation; and Cayey and Luquillo Mountains populations split prior to the last interglacial. For E. antillensis, these patterns include: genetic clusters did not fully correspond to predicted long-term unsuitable climate; and past and current climate weakly predicted patterns of genetic differentiation. Genetic signatures in E. antillensis are consistent with a recent range expansion into western Puerto Rico, possibly resulting from climate change and anthropogenic influences. As predicted, regions with a large area of long-term suitable climate were associated with higher genetic diversity in both species, suggesting larger and more stable populations. Finally, we discussed the implications of our findings for developing evidence-based management decisions for E. portoricensis, a taxon

  19. Uptake of trimethoprim by renal cortex.

    PubMed

    Cacini, W; Myre, S A

    1985-10-01

    The purpose of this study was to examine the mechanisms involved in the uptake of the urinary antibacterial drug trimethoprim by incubated slices of rat renal cortex. Concentration-dependent studies of the uptake process demonstrated that a saturable component was involved. The results of inhibitor studies as well as the time-course pattern support the conclusion that at least two processes are involved in the uptake of trimethoprim. These include active transport via the organic cation system, accounting for about 40% of the total uptake, and a second component that continues to operate under conditions of inhibited cellular metabolism. Chromatographic examination of post-incubation bathing medium and slice extracts failed to demonstrate renal cortex metabolism of trimethoprim. PMID:4052093

  20. Mitochondrial structure in the rat adrenal cortex.

    PubMed Central

    Merry, B J

    1975-01-01

    Two distinct classes of mitochondria are described in the normal adrenal cortex of the Sprague Dawley CFY rat. Polyaminar mitochondria were frequently observed in the zona fasciculata and zona reticularis, particularly after ACTH stimulation of the cortex resulting from cold-stress exposure. It is uncertain whether such organelles are degenerating forms, or whether they have a specific functional role related to steroidogenesis in the normal cortical cell. In both normal and stressed adrenal cortices, protrusions of the outer membrane of mitochondria were evident, and were often seen penetrating lipid droplets. It is suggested that these protrusions may have some significance in the transport of cholesterol from the lipid droplet to the inner mitochondrial memrane 'desmolase complex', thus facilitating side-chain cleavage of cholesterol to pregnenolone. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 PMID:166969

  1. Reconstructing speech from human auditory cortex.

    PubMed

    Pasley, Brian N; David, Stephen V; Mesgarani, Nima; Flinker, Adeen; Shamma, Shihab A; Crone, Nathan E; Knight, Robert T; Chang, Edward F

    2012-01-01

    How the human auditory system extracts perceptually relevant acoustic features of speech is unknown. To address this question, we used intracranial recordings from nonprimary auditory cortex in the human superior temporal gyrus to determine what acoustic information in speech sounds can be reconstructed from population neural activity. We found that slow and intermediate temporal fluctuations, such as those corresponding to syllable rate, were accurately reconstructed using a linear model based on the auditory spectrogram. However, reconstruction of fast temporal fluctuations, such as syllable onsets and offsets, required a nonlinear sound representation based on temporal modulation energy. Reconstruction accuracy was highest within the range of spectro-temporal fluctuations that have been found to be critical for speech intelligibility. The decoded speech representations allowed readout and identification of individual words directly from brain activity during single trial sound presentations. These findings reveal neural encoding mechanisms of speech acoustic parameters in higher order human auditory cortex. PMID:22303281

  2. Reconstructing Speech from Human Auditory Cortex

    PubMed Central

    Pasley, Brian N.; David, Stephen V.; Mesgarani, Nima; Flinker, Adeen; Shamma, Shihab A.; Crone, Nathan E.; Knight, Robert T.; Chang, Edward F.

    2012-01-01

    How the human auditory system extracts perceptually relevant acoustic features of speech is unknown. To address this question, we used intracranial recordings from nonprimary auditory cortex in the human superior temporal gyrus to determine what acoustic information in speech sounds can be reconstructed from population neural activity. We found that slow and intermediate temporal fluctuations, such as those corresponding to syllable rate, were accurately reconstructed using a linear model based on the auditory spectrogram. However, reconstruction of fast temporal fluctuations, such as syllable onsets and offsets, required a nonlinear sound representation based on temporal modulation energy. Reconstruction accuracy was highest within the range of spectro-temporal fluctuations that have been found to be critical for speech intelligibility. The decoded speech representations allowed readout and identification of individual words directly from brain activity during single trial sound presentations. These findings reveal neural encoding mechanisms of speech acoustic parameters in higher order human auditory cortex. PMID:22303281

  3. Speed cells in the medial entorhinal cortex.

    PubMed

    Kropff, Emilio; Carmichael, James E; Moser, May-Britt; Moser, Edvard I

    2015-07-23

    Grid cells in the medial entorhinal cortex have spatial firing fields that repeat periodically in a hexagonal pattern. When animals move, activity is translated between grid cells in accordance with the animal's displacement in the environment. For this translation to occur, grid cells must have continuous access to information about instantaneous running speed. However, a powerful entorhinal speed signal has not been identified. Here we show that running speed is represented in the firing rate of a ubiquitous but functionally dedicated population of entorhinal neurons distinct from other cell populations of the local circuit, such as grid, head-direction and border cells. These 'speed cells' are characterized by a context-invariant positive, linear response to running speed, and share with grid cells a prospective bias of ∼50-80 ms. Our observations point to speed cells as a key component of the dynamic representation of self-location in the medial entorhinal cortex. PMID:26176924

  4. The role of prefrontal cortex in psychopathy

    PubMed Central

    Koenigs, Michael

    2014-01-01

    Psychopathy is a personality disorder characterized by remorseless and impulsive antisocial behavior. Given the significant societal costs of the recidivistic criminal activity associated with the disorder, there is a pressing need for more effective treatment strategies, and hence, a better understanding of the psychobiological mechanisms underlying the disorder. The prefrontal cortex (PFC) is likely to play an important role in psychopathy. In particular, the ventromedial and anterior cingulate sectors of PFC are theorized to mediate a number of social and affective decision-making functions that appear to be disrupted in psychopathy. This article provides a critical summary of human neuroimaging data implicating prefrontal dysfunction in psychopathy. A growing body of evidence associates psychopathy with structural and functional abnormalities in ventromedial PFC and anterior cingulate cortex. Although this burgeoning field still faces a number of methodological challenges and outstanding questions that will need to be resolved by future studies, the research to date has established a link between psychopathy and PFC. PMID:22752782

  5. Specificity and randomness in the visual cortex

    PubMed Central

    Ohki, Kenichi; Reid, R. Clay

    2009-01-01

    Summary Research on the functional anatomy of visual cortical circuit has recently zoomed in from the macroscopic level to the microscopic. High-resolution functional imaging has revealed that the functional architecture of orientation maps in higher mammals is built with single-cell precision. In contrast, orientation selectivity in rodents is dispersed on visual cortex in a salt-and-pepper fashion, despite highly tuned visual responses. Recent studies of synaptic physiology indicate that there are disjoint subnetworks of interconnected cells in the rodent visual cortex. These intermingled subnetworks, described in vitro, may relate to the intermingled ensembles of cells tuned to different orientations, described in vivo. This hypothesis may soon be tested with new anatomic techniques that promise to reveal detailed wiring diagrams in cortical circuits. PMID:17720489

  6. Glycine metabolism in rat kidney cortex slices.

    PubMed

    Rowsell, E V; Al-Naama, M M; Rowsell, K V

    1982-04-15

    When rat kidney cortex slices were incubated with glycine or [1-14C]glycine, after correcting for metabolite changes with control slices, product formation and glycine utilization fitted the requirements of the equation: 2 Glycine leads to ammonia + CO2 + serine. Evidence is presented that degradation via glyoxylate, by oxidation or transamination, is unlikely to have any significant role in kidney glycine catabolism. It is concluded that glycine metabolism in rat kidney is largely via glycine cleavage closely coupled with serine formation. 1-C decarboxylation and urea formation with glycine in rat hepatocyte suspensions were somewhat greater than decarboxylation or ammonia formation in kidney slices, showing that in the rat, potentially, the liver is quantitatively the more important organ in glycine catabolism. There was no evidence of ammonia formation from glycine with rat brain cortex, heart, spleen or diaphragm and 1-C decarboxylation was very weak. PMID:6810880

  7. Social Distance Evaluation in Human Parietal Cortex

    PubMed Central

    Yamakawa, Yoshinori; Kanai, Ryota; Matsumura, Michikazu; Naito, Eiichi

    2009-01-01

    Across cultures, social relationships are often thought of, described, and acted out in terms of physical space (e.g. “close friends” “high lord”). Does this cognitive mapping of social concepts arise from shared brain resources for processing social and physical relationships? Using fMRI, we found that the tasks of evaluating social compatibility and of evaluating physical distances engage a common brain substrate in the parietal cortex. The present study shows the possibility of an analytic brain mechanism to process and represent complex networks of social relationships. Given parietal cortex's known role in constructing egocentric maps of physical space, our present findings may help to explain the linguistic, psychological and behavioural links between social and physical space. PMID:19204791

  8. The left parietal cortex and motor attention.

    PubMed

    Rushworth, M F; Nixon, P D; Renowden, S; Wade, D T; Passingham, R E

    1997-09-01

    The posterior parietal cortex, particularly in the right hemisphere, is crucially important for covert orienting; lesions impair the ability to disengage the focus of covert orienting attention from one potential saccade target to another (Posner, M. I. et al., Journal of Neuroscience, 1984, 4, 1863-1874). We have developed a task where precues allow subjects to covertly prepare subsequent cued hand movements, as opposed to an orienting or eye movement. We refer to this process as motor attention to distinguish it from orienting attention. Nine subjects with lesions that included the left parietal cortex and nine subjects with lesions including the right parietal cortex were compared with control subjects on the task. The left hemisphere subjects showed the same ability as controls to engage attention to a movement when they were forewarned by a valid precue. The left hemisphere subjects, however, were impaired in their ability to disengage the focus of motor attention from one movement to another when the precue was incorrect. The results support the existence of two distinct attentional systems allied to the orienting and limb motor systems. Damage to either system causes analogous problems in disengaging from one orienting/movement target to another. The left parietal cortex, particularly the supramarginal gyrus, is associated with motor attention. All the left hemisphere subjects had ideomotor apraxia and had particular problems performing sequences of movements. We suggest that the well documented left hemisphere and apraxic impairment in movement sequencing is the consequence of a difficulty in shifting the focus of motor attention from one movement in a sequence to the next. PMID:9364496

  9. Cone inputs to murine striate cortex

    PubMed Central

    Ekesten, Björn; Gouras, Peter

    2008-01-01

    Background We have recorded responses from single neurons in murine visual cortex to determine the effectiveness of the input from the two murine cone photoreceptor mechanisms and whether there is any unique selectivity for cone inputs at this higher region of the visual system that would support the possibility of colour vision in mice. Each eye was stimulated by diffuse light, either 370 (strong stimulus for the ultra-violet (UV) cone opsin) or 505 nm (exclusively stimulating the middle wavelength sensitive (M) cone opsin), obtained from light emitting diodes (LEDs) in the presence of a strong adapting light that suppressed the responses of rods. Results Single cells responded to these diffuse stimuli in all areas of striate cortex. Two types of responsive cells were encountered. One type (135/323 – 42%) had little to no spontaneous activity and responded at either the on and/or the off phase of the light stimulus with a few impulses often of relatively large amplitude. A second type (166/323 – 51%) had spontaneous activity and responded tonically to light stimuli with impulses often of small amplitude. Most of the cells responded similarly to both spectral stimuli. A few (18/323 – 6%) responded strongly or exclusively to one or the other spectral stimulus and rarely in a spectrally opponent manner. Conclusion Most cells in murine striate cortex receive excitatory inputs from both UV- and M-cones. A small fraction shows either strong selectivity for one or the other cone mechanism and occasionally cone opponent responses. Cells that could underlie chromatic contrast detection are present but extremely rare in murine striate cortex. PMID:19014590

  10. Determination of pyrethroid pesticides in cinnamomi cortex.

    PubMed

    Tagami, Takaomi; Kajimura, Keiji; Nomura, Chie; Taguchi, Shuzo; Iwagami, Syozo

    2009-01-01

    In Japan, maximum residue levels (MRL) have been set for eight pesticides (alpha-BHC, beta-BHC, gamma-BHC, delta-BHC (BHCs), p,p'-DDE, o,p'-DDT, p,p'-DDD, p,p'-DDT (DDTs)) in 14 crude drugs (below 0.2 ppm as total of BHCs, below 0.2 ppm as total of DDTs). There are fears that pesticides present in crude drugs for which MRL are set will be changed from BHCs and DDTs to other pesticides with MRL setting as the turning point. There are few surveys of pyrethroid pesticide in crude drugs distributed in Japan. The actual situation of pyrethroid pesticides in crude drugs distributed in Japan after setting MRL is not unclear and should be clarified. Although a method to analyze permethrin, cypermethrin and fenvalerate in 11 crude drugs was reported, it is not adequate because the recovery rates of permethrin, cypermethrin and fenvalerate from Cinnamomi cortex were very low and the method, including liquid-liquid partition is difficult. In this study, we developed a method using solid-phase extraction to analyze permethrin, cypermethrin and fenvalerate in Cinnamomi cortex with acceptable recovery rates. The sample solution was determined by gas chromatography/mass spectrometry with negative chemical ionization. The recovery rates of permethrin, cypermethrin and fenvalerate from Cinnamomi cortex were between 87.9 and 90.7%. Five samples of Cinnamomi cortex were analyzed according to the proposed method. No samples contained permethrin, cypermethrin and fenvalerate over detection limits. The proposed method could analyze permethrin, cypermethrin and fenvalerate in all crude drugs for which MRL are set. PMID:19122445

  11. Disparity processing in primary visual cortex.

    PubMed

    Henriksen, Sid; Tanabe, Seiji; Cumming, Bruce

    2016-06-19

    The first step in binocular stereopsis is to match features on the left retina with the correct features on the right retina, discarding 'false' matches. The physiological processing of these signals starts in the primary visual cortex, where the binocular energy model has been a powerful framework for understanding the underlying computation. For this reason, it is often used when thinking about how binocular matching might be performed beyond striate cortex. But this step depends critically on the accuracy of the model, and real V1 neurons show several properties that suggest they may be less sensitive to false matches than the energy model predicts. Several recent studies provide empirical support for an extended version of the energy model, in which the same principles are used, but the responses of single neurons are described as the sum of several subunits, each of which follows the principles of the energy model. These studies have significantly improved our understanding of the role played by striate cortex in the stereo correspondence problem.This article is part of the themed issue 'Vision in our three-dimensional world'. PMID:27269598

  12. Tonotopic mapping of human auditory cortex.

    PubMed

    Saenz, Melissa; Langers, Dave R M

    2014-01-01

    Since the early days of functional magnetic resonance imaging (fMRI), retinotopic mapping emerged as a powerful and widely-accepted tool, allowing the identification of individual visual cortical fields and furthering the study of visual processing. In contrast, tonotopic mapping in auditory cortex proved more challenging primarily because of the smaller size of auditory cortical fields. The spatial resolution capabilities of fMRI have since advanced, and recent reports from our labs and several others demonstrate the reliability of tonotopic mapping in human auditory cortex. Here we review the wide range of stimulus procedures and analysis methods that have been used to successfully map tonotopy in human auditory cortex. We point out that recent studies provide a remarkably consistent view of human tonotopic organisation, although the interpretation of the maps continues to vary. In particular, there remains controversy over the exact orientation of the primary gradients with respect to Heschl's gyrus, which leads to different predictions about the location of human A1, R, and surrounding fields. We discuss the development of this debate and argue that literature is converging towards an interpretation that core fields A1 and R fold across the rostral and caudal banks of Heschl's gyrus, with tonotopic gradients laid out in a distinctive V-shaped manner. This suggests an organisation that is largely homologous with non-human primates. This article is part of a Special Issue entitled Human Auditory Neuroimaging. PMID:23916753

  13. The human cerebral cortex flattens during adolescence.

    PubMed

    Alemán-Gómez, Yasser; Janssen, Joost; Schnack, Hugo; Balaban, Evan; Pina-Camacho, Laura; Alfaro-Almagro, Fidel; Castro-Fornieles, Josefina; Otero, Soraya; Baeza, Immaculada; Moreno, Dolores; Bargalló, Nuria; Parellada, Mara; Arango, Celso; Desco, Manuel

    2013-09-18

    The human cerebral cortex appears to shrink during adolescence. To delineate the dynamic morphological changes involved in this process, 52 healthy male and female adolescents (11-17 years old) were neuroimaged twice using magnetic resonance imaging, approximately 2 years apart. Using a novel morphometric analysis procedure combining the FreeSurfer and BrainVisa image software suites, we quantified global and lobar change in cortical thickness, outer surface area, the gyrification index, the average Euclidean distance between opposing sides of the white matter surface (gyral white matter thickness), the convex ("exposed") part of the outer cortical surface (hull surface area), sulcal length, depth, and width. We found that the cortical surface flattens during adolescence. Flattening was strongest in the frontal and occipital cortices, in which significant sulcal widening and decreased sulcal depth co-occurred. Globally, sulcal widening was associated with cortical thinning and, for the frontal cortex, with loss of surface area. For the other cortical lobes, thinning was related to gyral white matter expansion. The overall flattening of the macrostructural three-dimensional architecture of the human cortex during adolescence thus involves changes in gray matter and effects of the maturation of white matter. PMID:24048830

  14. Functional subregions of the human entorhinal cortex

    PubMed Central

    Maass, Anne; Berron, David; Libby, Laura A; Ranganath, Charan; Düzel, Emrah

    2015-01-01

    The entorhinal cortex (EC) is the primary site of interactions between the neocortex and hippocampus. Studies in rodents and nonhuman primates suggest that EC can be divided into subregions that connect differentially with perirhinal cortex (PRC) vs parahippocampal cortex (PHC) and with hippocampal subfields along the proximo-distal axis. Here, we used high-resolution functional magnetic resonance imaging at 7 Tesla to identify functional subdivisions of the human EC. In two independent datasets, PRC showed preferential intrinsic functional connectivity with anterior-lateral EC and PHC with posterior-medial EC. These EC subregions, in turn, exhibited differential connectivity with proximal and distal subiculum. In contrast, connectivity of PRC and PHC with subiculum followed not only a proximal-distal but also an anterior-posterior gradient. Our data provide the first evidence that the human EC can be divided into functional subdivisions whose functional connectivity closely parallels the known anatomical connectivity patterns of the rodent and nonhuman primate EC. DOI: http://dx.doi.org/10.7554/eLife.06426.001 PMID:26052749

  15. Occipital cortex of blind individuals is functionally coupled with executive control areas of frontal cortex.

    PubMed

    Deen, Ben; Saxe, Rebecca; Bedny, Marina

    2015-08-01

    In congenital blindness, the occipital cortex responds to a range of nonvisual inputs, including tactile, auditory, and linguistic stimuli. Are these changes in functional responses to stimuli accompanied by altered interactions with nonvisual functional networks? To answer this question, we introduce a data-driven method that searches across cortex for functional connectivity differences across groups. Replicating prior work, we find increased fronto-occipital functional connectivity in congenitally blind relative to blindfolded sighted participants. We demonstrate that this heightened connectivity extends over most of occipital cortex but is specific to a subset of regions in the inferior, dorsal, and medial frontal lobe. To assess the functional profile of these frontal areas, we used an n-back working memory task and a sentence comprehension task. We find that, among prefrontal areas with overconnectivity to occipital cortex, one left inferior frontal region responds to language over music. By contrast, the majority of these regions responded to working memory load but not language. These results suggest that in blindness occipital cortex interacts more with working memory systems and raise new questions about the function and mechanism of occipital plasticity. PMID:25803598

  16. A giant submarine slope failure on the insular slope north of Puerto Rico: A response of Arecibo basin strata to tectonic stress

    SciTech Connect

    Schwab, W.C.; Danforth, W.W.; Scanlon, K.M. )

    1990-06-01

    An amphitheater-shaped scarp, approximately 55 km across in water depths from about 3,000 m to 6,700 m was imaged on the northern insular slope of Puerto Rico (southern slope of the Puerto Rico Trench) using the GLORIA side-scan sonar system. This scarp represents the removal of more than 1,500 m{sup 3} of Tertiary Arecibo basin strata. The head of the scarp coincides with the location of a fault zone observed on nearby seismic-reflection profiles. Interpretation of the GLORIA imagery, and a review of available bathymetric, geophysical, and stratigraphic data and tectonic-framework models suggest that the scarp formed as a consequence of slope failure induced by tectonic oversteepening of the insular slope. The oversteepening may be a result of the most recent episode of convergence of the Caribbean and North American plates, which began approximately 4 million years ago. The Arecibo basin strata have been tilted approximately 4{degree} to the north and are apparently gravitationally unstable under the present seismic regime. The volume of material involved in this slope failure is comparable to the material displaced in tsunamogenic submarine landslides along the Peru Trench and Hawaiian Ridge. Therefore, if the slope failure north of Puerto Rico was catastrophic, it was large enough to have generated a tsunami that would have flooded the low ground of northern Puerto Rico.

  17. Checkerboard Patterns, Interspecific Competition, and Extinction: Lessons from Distribution Patterns of Tarsiers (Tarsius) and Slow Lorises (Nycticebus) in Insular Southeast Asia

    PubMed Central

    Nekaris, K. A. I.

    2010-01-01

    Tarsiers (Tarsius) and slow lorises (Nycticebus) are the only extant nocturnal primates occurring in Southeast Asia. Harcourt (1999) hypothesized that in insular Southeast Asia, slow lorises and tarsiers showed a checkerboard distribution on 12 small (<12,000 km2) islands, i.e., only one or the other occurs, and attributed this to extreme levels of competition between these 2 largely faunivorous primates. Further, he predicted slow lorises were able to persist on smaller islands than tarsiers. We re-evaluated these findings using an expanded dataset including 49 islands where tarsiers or slow lorises occur. Tarsiers and slow lorises live on islands of similar size (median size of ca. 300–900 km2), and both taxa inhabit an equal proportion of small, medium, and large islands. On small islands within their area of sympatry tarsiers occur on 1 island, slow lorises on 8, both genera on 3, and we can assume they have become extinct from 11 small islands since the Last Glacial Maximum. Sizes of islands where tarsiers or slow lorises have become extinct do not differ from islands where they are still extant. We show that slow lorises occur on more islands in insular Southeast Asia than perhaps previously assumed, but these islands are not smaller on average than islands where tarsiers occur. A checkerboard distribution between these taxa is not evident. More studies are needed at the macroecological level to assess the importance of biogeographic history in explaining their present-day distribution patterns. PMID:21212813

  18. The relationship between physical and biological habitat conditions and hermatypic coral recruits abundance within insular reefs (Colombian Caribbean).

    PubMed

    Bernal-Sotelo, Katherine; Acosta, Alberto

    2012-09-01

    Little evidence exists on the dependence between the presence and abundance of juvenile hermatypic corals and the conditions of their habitats, despite that juveniles contribute with the understanding of the community structure and its reproductive success. To assess this, the abundance of nine species of juvenile corals was correlated with eight macro-habitat (location of the reef on shelf, depth) and micro-habitat (type and inclination of the substrate, exposure to light, texture and amount of sediment accumulated on bottom, potential growth area for juveniles) conditions. Sampling was conducted in four insular coral reefs in the Colombian Caribbean: two oceanic and two continental reefs (influenced by large rivers), covering a total of 600m2 and the distribution of corals on a vertical gradient. Contingency tables and coefficients (magnitude) and multiple correspondence analyses were used to evaluate the dependency ratios for each species. The results showed that Agaricia tenuifolia displayed the most robust pattern of dependence (two high and two moderate), significant for juveniles present at a high frequency in continental reefs, devoid of potential area for juvenile growth (surrounded by macroalgae), and covering horizontal substrates exposed to light. The juveniles were associated with a habitat of moderate to high bottom accumulation of extremely fine sediment. Porites astreoides presented four moderate dependencies; ocean reefs between 2-16m depths, a high frequency of juveniles on horizontal substrates, exposed to light, non-sedimented and occupied by competitors. Siderastrea siderea displayed three moderate dependences for juveniles in cryptic zones, inclined substrate and devoid of competitors. A. lamarcki, Leptoseris cucullata and A. agaricites presented two moderate dependences; these species share high abundance of juveniles in habitats with no sediment, exposed to light and occupied by competitors (except A. agaricites). The P. porites, Favia

  19. Apraxia, pantomime and the parietal cortex

    PubMed Central

    Niessen, E.; Fink, G.R.; Weiss, P.H.

    2014-01-01

    Apraxia, a disorder of higher motor cognition, is a frequent and outcome-relevant sequel of left hemispheric stroke. Deficient pantomiming of object use constitutes a key symptom of apraxia and is assessed when testing for apraxia. To date the neural basis of pantomime remains controversial. We here review the literature and perform a meta-analysis of the relevant structural and functional imaging (fMRI/PET) studies. Based on a systematic literature search, 10 structural and 12 functional imaging studies were selected. Structural lesion studies associated pantomiming deficits with left frontal, parietal and temporal lesions. In contrast, functional imaging studies associate pantomimes with left parietal activations, with or without concurrent frontal or temporal activations. Functional imaging studies that selectively activated parietal cortex adopted the most stringent controls. In contrast to previous suggestions, current analyses show that both lesion and functional studies support the notion of a left-hemispheric fronto-(temporal)-parietal network underlying pantomiming object use. Furthermore, our review demonstrates that the left parietal cortex plays a key role in pantomime-related processes. More specifically, stringently controlled fMRI-studies suggest that in addition to storing motor schemas, left parietal cortex is also involved in activating these motor schemas in the context of pantomiming object use. In addition to inherent differences between structural and functional imaging studies and consistent with the dedifferentiation hypothesis, the age difference between young healthy subjects (typically included in functional imaging studies) and elderly neurological patients (typically included in structural lesion studies) may well contribute to the finding of a more distributed representation of pantomiming within the motor-dominant left hemisphere in the elderly. PMID:24967158

  20. Retinotopic Organization of Human Ventral Visual Cortex

    PubMed Central

    Arcaro, Michael J.; McMains, Stephanie A.; Singer, Benjamin D.; Kastner, Sabine

    2009-01-01

    Functional magnetic resonance imaging (fMRI) studies have shown that human ventral visual cortex anterior to area hV4 contains two visual field maps, VO-1 and VO-2, that together form the VO-cluster (Brewer et al., 2005). This cluster is characterized by common functional response properties and responds preferentially to color and object stimuli. Here, we confirm the topographic and functional characteristics of the VO-cluster and describe two new visual field maps that are located anterior to VO-2 extending across the collateral sulcus into the posterior parahippocampal cortex (PHC). We refer to these visual field maps as parahippocampal areas PHC-1 and PHC-2. Each PHC map contains a topographic representation of contralateral visual space. The polar angle representation in PHC-1 extends from regions near the lower vertical meridian (that is the shared border with VO-2) to those close to the upper vertical meridian (that is the shared border with PHC-2). The polar angle representation in PHC-2 is a mirror-reversal of the PHC-1 representation. PHC-1 and PHC-2 share a foveal representation and show a strong bias towards representations of peripheral eccentricities. Both the foveal and peripheral representations of PHC-1 and PHC-2 respond more strongly to scenes than to objects or faces, with greater scene preference in PHC-2 than PHC-1. Importantly, both areas heavily overlap with the functionally defined parahippocampal place area (PPA). Our results suggest that ventral visual cortex can be subdivided on the basis of topographic criteria into a greater number of discrete maps than previously thought. PMID:19710316

  1. Inhibition by Somatostatin Interneurons in Olfactory Cortex

    PubMed Central

    Large, Adam M.; Kunz, Nicholas A.; Mielo, Samantha L.; Oswald, Anne-Marie M.

    2016-01-01

    Inhibitory circuitry plays an integral role in cortical network activity. The development of transgenic mouse lines targeting unique interneuron classes has significantly advanced our understanding of the functional roles of specific inhibitory circuits in neocortical sensory processing. In contrast, considerably less is known about the circuitry and function of interneuron classes in piriform cortex, a paleocortex responsible for olfactory processing. In this study, we sought to utilize transgenic technology to investigate inhibition mediated by somatostatin (SST) interneurons onto pyramidal cells (PCs), parvalbumin (PV) interneurons, and other interneuron classes. As a first step, we characterized the anatomical distributions and intrinsic properties of SST and PV interneurons in four transgenic lines (SST-cre, GIN, PV-cre, and G42) that are commonly interbred to investigate inhibitory connectivity. Surprisingly, the distributions SST and PV cell subtypes targeted in the GIN and G42 lines were sparse in piriform cortex compared to neocortex. Moreover, two-thirds of interneurons recorded in the SST-cre line had electrophysiological properties similar to fast spiking (FS) interneurons rather than regular (RS) or low threshold spiking (LTS) phenotypes. Nonetheless, like neocortex, we find that SST-cells broadly inhibit a number of unidentified interneuron classes including putatively identified PV cells and surprisingly, other SST cells. We also confirm that SST-cells inhibit pyramidal cell dendrites and thus, influence dendritic integration of afferent and recurrent inputs to the piriform cortex. Altogether, our findings suggest that SST interneurons play an important role in regulating both excitation and the global inhibitory network during olfactory processing. PMID:27582691

  2. Neostriatal modulation of motor cortex excitability.

    PubMed

    Ryan, L J; Sanders, D J

    1994-07-18

    The influence of the basal ganglia motor loop on motor cortex function was examined by pharmacologically altering neostriatal activity while monitoring the electrical stimulation thresholds for eliciting movements of the ipsilateral and contralateral motor cortex in ketamine anesthetized rats. Repeated unilateral intraneostriatal infusions (1-3) of the glutamate agonist, kainic acid (0.1 microliter, 75 ng), or glutamate (0.3 microliter, 1.65 micrograms) reliably increased ipsilateral but not contralateral cortical thresholds. Single infusions of kainic acid (0.3 microliter, 150 or 225 ng) elevated ipsilateral cortical thresholds for 30-45 min; with glutamate (0.3 microliter, 1.65 micrograms), the change lasted less than 10 min. Antidromically identified striatonigral projection neurons (n = 8) located approximately 500 microM from the infusion cannula, showed either increased firing (n = 4) for less than 10 min following glutamate infusion or no change from their non-firing state (n = 4). Non-antidromically activated neurons (n = 3) were all excited by the infusion, although an interval of inhibition preceded or followed the excitation in two cases. Infusions (0.3 microliter) of inhibitory agents (GABA, 31 and 310 ng; muscimol 34.2 ng; and DNQX 34.2 ng) did not alter cortical threshold, nor did saline vehicle. Lesion of the ventrolateral but not ventromedial thalamic nucleus prevented the modulation of cortical thresholds following intraneostriatal infusion of 225 ng kainic acid. Thus the neostriatal alteration of cortical thresholds indicates a modulation of cortical excitability via thalamic projections and not the outcome of competing descending cortical and neonstriatal influences converging on motorneurons. These results suggest that tonic feedforward modulation of the motor cortex and the pyramidal tract by the basal ganglia can be inhibitory. PMID:7922571

  3. Inhibition by Somatostatin Interneurons in Olfactory Cortex.

    PubMed

    Large, Adam M; Kunz, Nicholas A; Mielo, Samantha L; Oswald, Anne-Marie M

    2016-01-01

    Inhibitory circuitry plays an integral role in cortical network activity. The development of transgenic mouse lines targeting unique interneuron classes has significantly advanced our understanding of the functional roles of specific inhibitory circuits in neocortical sensory processing. In contrast, considerably less is known about the circuitry and function of interneuron classes in piriform cortex, a paleocortex responsible for olfactory processing. In this study, we sought to utilize transgenic technology to investigate inhibition mediated by somatostatin (SST) interneurons onto pyramidal cells (PCs), parvalbumin (PV) interneurons, and other interneuron classes. As a first step, we characterized the anatomical distributions and intrinsic properties of SST and PV interneurons in four transgenic lines (SST-cre, GIN, PV-cre, and G42) that are commonly interbred to investigate inhibitory connectivity. Surprisingly, the distributions SST and PV cell subtypes targeted in the GIN and G42 lines were sparse in piriform cortex compared to neocortex. Moreover, two-thirds of interneurons recorded in the SST-cre line had electrophysiological properties similar to fast spiking (FS) interneurons rather than regular (RS) or low threshold spiking (LTS) phenotypes. Nonetheless, like neocortex, we find that SST-cells broadly inhibit a number of unidentified interneuron classes including putatively identified PV cells and surprisingly, other SST cells. We also confirm that SST-cells inhibit pyramidal cell dendrites and thus, influence dendritic integration of afferent and recurrent inputs to the piriform cortex. Altogether, our findings suggest that SST interneurons play an important role in regulating both excitation and the global inhibitory network during olfactory processing. PMID:27582691

  4. Visual Working Memory in Human Cortex

    PubMed Central

    Barton, Brian; Brewer, Alyssa A.

    2016-01-01

    Visual working memory (VWM) is the ability to maintain visual information in a readily available and easily updated state. Converging evidence has revealed that VWM capacity is limited by the number of maintained objects, which is about 3 - 4 for the average human. Recent work suggests that VWM capacity is also limited by the resolution required to maintain objects, which is tied to the objects' inherent complexity. Electroencephalogram (EEG) studies using the Contralateral Delay Activity (CDA) paradigm have revealed that cortical representations of VWM are at a minimum loosely organized like the primary visual system, such that the left side of space is represented in the right hemisphere, and vice versa. Recent functional magnetic resonance imaging (fMRI) work shows that the number of objects is maintained by representations in the inferior intraparietal sulcus (IPS) along dorsal parietal cortex, whereas the resolution of these maintained objects is subserved by the superior IPS and the lateral occipital complex (LOC). These areas overlap with recently-discovered, retinotopically-organized visual field maps (VFMs) spanning the IPS (IPS-0/1/2/3/4/5), and potentially maps in lateral occipital cortex, such as LO-1/2, and/or TO-1/2 (hMT+). Other fMRI studies have implicated early VFMs in posterior occipital cortex, suggesting that visual areas V1-hV4 are recruited to represent information in VWM. Insight into whether and how these VFMs subserve VWM may illuminate the nature of VWM. In addition, understanding the nature of these maps may allow a greater investigation into individual differences among subjects and even between hemispheres within subjects. PMID:26881188

  5. Premotor and parietal cortex: corticocortical connectivity and combinatorial computations.

    PubMed

    Wise, S P; Boussaoud, D; Johnson, P B; Caminiti, R

    1997-01-01

    The dorsal premotor cortex is a functionally distinct cortical field or group of fields in the primate frontal cortex. Anatomical studies have confirmed that most parietal input to the dorsal premotor cortex originates from the superior parietal lobule. However, these projections arise not only from the dorsal aspect of area 5, as has long been known, but also from newly defined areas of posterior parietal cortex, which are directly connected with the extrastriate visual cortex. Thus, the dorsal premotor cortex receives much more direct visual input than previously accepted. It appears that this fronto-parietal network functions as a visuomotor controller-one that makes computations based on proprioceptive, visual, gaze, attentional, and other information to produce an output that reflects the selection, preparation, and execution of movements. PMID:9056706

  6. Decreased Left Posterior Insular Activity During Auditory Language in Autism American Journal of Neuroradiology – January 2010

    PubMed Central

    Anderson, Jeffrey S.; Lange, Nicholas; Froehlich, Alyson; DuBray, Molly B.; Druzgal, T. Jason; Froimowitz, Michael P.; Alexander, Andrew L.; Bigler, Erin D.; Lainhart, Janet E.

    2009-01-01

    Background and Purpose Individuals with autism spectrum disorders often exhibit atypical language patterns including delay of speech onset, literal speech interpretation, and poor recognition of social and emotional cues in speech. We acquired fMRI images during an auditory language task to evaluate for systematic differences in language network activation between control and high-functioning autistic populations. Materials and Methods 41 right-handed male subjects (26 high-functioning autistic, 15 control) were studied using an auditory phrase recognition task, and areas of differential activation between groups were identified. Hand preference, verbal IQ, age, and language function testing were included as covariables in the analysis. Results Control and autistic subjects showed similar language activation networks, with two notable differences. Control subjects showed significantly increased activation in the left posterior insula compared to autistic subjects (p<0.05, FDR), and autistic subjects showed increased bilaterality of receptive language compared to control subjects. Higher receptive language score on standardized testing was associated with greater activation of the posterior aspect of left Wernicke’s area. Higher verbal IQ was associated with greater activation of bilateral Broca’s area and involvement of prefrontal cortex and lateral premotor cortex. Conclusion Control subjects showed greater activation of the posterior insula during receptive language, which may correlate with impaired emotive processing of language in autism. Autism subjects showed greater bilateral activation of receptive language areas that was out of proportion to differences in hand preference in autism and control populations. PMID:19749222

  7. To Expand and Make Permanent the Youth Conservation Corps. Hearing Before the Committee on Interior and Insular Affairs (U.S. Senate, 93rd Congress, 1st Session on S. 1871, July 25, 1973).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Interior and Insular Affairs.

    This document contains statements and correspondence addressed to a Senate hearing on the Committee on Interior and Insular Affairs chaired by Senator Henry M. Jackson. This hearing concerned a bill to amend the Youth Conservation Corps Act of 1972 (Public Law 92-597, 86 Stat. 1319) to expand and make permanent the Youth Conservation Corps. The…

  8. Aberrant functional connectivity differentiates retrosplenial cortex from posterior cingulate cortex in prodromal Alzheimer's disease.

    PubMed

    Dillen, Kim N H; Jacobs, Heidi I L; Kukolja, Juraj; von Reutern, Boris; Richter, Nils; Onur, Özgür A; Dronse, Julian; Langen, Karl-Josef; Fink, Gereon R

    2016-08-01

    The posterior cingulate cortex (PCC) is a key hub of the default mode network, a resting-state network involved in episodic memory, showing functional connectivity (FC) changes in Alzheimer's disease (AD). However, PCC is a cytoarchitectonically heterogeneous region. Specifically, the retrosplenial cortex (RSC), often subsumed under the PCC, is an area functionally and microanatomically distinct from PCC. To investigate FC patterns of RSC and PCC separately, we used resting-state functional magnetic resonance imaging in healthy aging participants, patients with subjective cognitive impairment, and prodromal AD. Compared to the other 2 groups, we found higher FC from RSC to frontal cortex in subjective cognitive impairment but higher FC to occipital cortex in prodromal AD. Conversely, FC from PCC to the lingual gyrus was higher in prodromal AD. Furthermore, data indicate that RSC and PCC are characterized by differential FC patterns represented by hub-specific interactions with memory and attentions scores in prodromal AD compared to cognitively normal individuals, possibly reflecting compensatory mechanisms for RSC and neurodegenerative processes for PCC. Data thus confirm and extend previous studies suggesting that the RSC is functionally distinct from PCC. PMID:27318139

  9. Gateways of ventral and dorsal streams in mouse visual cortex

    PubMed Central

    Wang, Quanxin; Gao, Enquan; Burkhalter, Andreas

    2011-01-01

    It is widely held that the spatial processing functions underlying rodent navigation are similar to those encoding human episodic memory (Doeller et al, 2010). Spatial and nonspatial information are provided by all senses including vision. It has been suggested that visual inputs are fed to the navigational network in cortex and hippocampus through dorsal and ventral intracortical streams (Whitlock et al, 2008), but this has not been shown directly in rodents. We have used cyto- and chemoarchitectonic markers, topographic mapping of receptive fields and pathway tracing to determine in mouse visual cortex whether the lateromedial (LM) and the anterolateral fields (AL), which are the principal targets of primary visual cortex (V1) (Wang and Burkhalter, 2007) specialized for processing nonspatial and spatial visual information (Gao et al, 2006), are distinct areas with diverse connections. We have found that the LM/AL border coincides with a change in type 2 muscarinic acetylcholine receptor (m2AChR) expression in layer 4 and with the representation of the lower visual field periphery. Our quantitative analyses further show that LM strongly projects to temporal cortex as well as the lateral entorhinal cortex, which has weak spatial selectivity (Hargreaves et al, 2005). In contrast, AL has stronger connections with posterior parietal cortex, motor cortex and the spatially selective medial entorhinal cortex (Haftig et al, 2005). These results support the notion that LM and AL are architecturally, topographically and connectionally distinct areas of extrastriate visual cortex and that they are gateways for ventral and dorsal streams. PMID:21289200

  10. Dynamic cortex stripping for vertebra evaluation

    NASA Astrophysics Data System (ADS)

    Stieger, James; Burns, Joseph E.; Yao, Jianhua; Summers, Ronald M.

    2015-03-01

    Vertebral cortex removal through cancellous bone reconstruction (CBR) algorithms on CT has been shown to enhance the detection rate of bone metastases by radiologists and reduce average reading time per case. Removal of the cortical bone provides an unobstructed view of the inside of vertebrae without any anomalous distractions. However, these algorithms rely on the assumption that the cortical bone of vertebrae can be removed without the identification of the endosteal cortical margin. We present a method for the identification of the endosteal cortical margin based on vertebral models and CT intensity information. First, triangular mesh models are created using the marching cubes algorithm. A search region is established along the normal of the surface and the image gradient is calculated at every point along the search region. The location with the greatest image gradient is selected as the corresponding point on the endosteal cortical margin. In order to analyze the strength of this method, ground truth and control models were also created. Our method was shown to have a significantly reduce the average error from 0.80 mm +/- 0.14 mm to 0.65 mm +/- 0.17 mm (p <0.0001) when compared to erosion. This method can potentially improve CBR algorithms, which improve visualization of cancellous bone lesions such as metastases, by more accurately identifying the inner wall of the vertebral cortex.

  11. Mapping tonotopy in human auditory cortex.

    PubMed

    van Dijk, Pim; Langers, Dave R M

    2013-01-01

    Tonotopy is arguably the most prominent organizational principle in the auditory pathway. Nevertheless, the layout of tonotopic maps in humans is still debated. We present neuroimaging data that robustly identify multiple tonotopic maps in the bilateral auditory cortex. In contrast with some earlier publications, tonotopic gradients were not found to be collinearly aligned along Heschl's gyrus; instead, two tonotopic maps ran diagonally across the anterior and posterior banks of Heschl's gyrus, set at a pronounced angle. On the basis of the direction of the tonotopic gradient, distinct subdivisions of the auditory cortex could be clearly demarcated that suggest homologies with the tonotopic organization in other primates. Finally, we applied our method to tinnitus patients to show that - contradictory to some pathophysiological models - tinnitus does not necessarily involve large-scale tonotopic reorganization. Overall, we expect that tonotopic mapping techniques will significantly enhance our ability to study the hierarchical functional organization of distinct auditory processing centers in the healthy and diseased human brain. PMID:23716248

  12. Retrosplenial Cortex Codes for Permanent Landmarks

    PubMed Central

    Auger, Stephen D.; Mullally, Sinéad L.; Maguire, Eleanor A.

    2012-01-01

    Landmarks are critical components of our internal representation of the environment, yet their specific properties are rarely studied, and little is known about how they are processed in the brain. Here we characterised a large set of landmarks along a range of features that included size, visual salience, navigational utility, and permanence. When human participants viewed images of these single landmarks during functional magnetic resonance imaging (fMRI), parahippocampal cortex (PHC) and retrosplenial cortex (RSC) were both engaged by landmark features, but in different ways. PHC responded to a range of landmark attributes, while RSC was engaged by only the most permanent landmarks. Furthermore, when participants were divided into good and poor navigators, the latter were significantly less reliable at identifying the most permanent landmarks, and had reduced responses in RSC and anterodorsal thalamus when viewing such landmarks. The RSC has been widely implicated in navigation but its precise role remains uncertain. Our findings suggest that a primary function of the RSC may be to process the most stable features in an environment, and this could be a prerequisite for successful navigation. PMID:22912894

  13. Probabilistic functional tractography of the human cortex.

    PubMed

    David, Olivier; Job, Anne-Sophie; De Palma, Luca; Hoffmann, Dominique; Minotti, Lorella; Kahane, Philippe

    2013-10-15

    Single-pulse direct electrical stimulation of cortical regions in patients suffering from focal drug-resistant epilepsy who are explored using intracranial electrodes induces cortico-cortical potentials that can be used to infer functional and anatomical connectivity. Here, we describe a neuroimaging framework that allows development of a new probabilistic atlas of functional tractography of the human cortex from those responses. This atlas is unique because it allows inference in vivo of the directionality and latency of cortico-cortical connectivity, which are still largely unknown at the human brain level. In this technical note, we include 1535 stimulation runs performed in 35 adult patients. We use a case of frontal lobe epilepsy to illustrate the asymmetrical connectivity between the posterior hippocampal gyrus and the orbitofrontal cortex. In addition, as a proof of concept for group studies, we study the probabilistic functional tractography between the posterior superior temporal gyrus and the inferior frontal gyrus. In the near future, the atlas database will be continuously increased, and the methods will be improved in parallel, for more accurate estimation of features of interest. Generated probabilistic maps will be freely distributed to the community because they provide critical information for further understanding and modelling of large-scale brain networks. PMID:23707583

  14. Conceptual size representation in ventral visual cortex.

    PubMed

    Gabay, Shai; Kalanthroff, Eyal; Henik, Avishai; Gronau, Nurit

    2016-01-29

    Recent findings suggest that visual objects may be mapped along the ventral occipitotemporal cortex according to their real-world size (Konkle and Oliva, 2012). It has been argued that such mapping does not reflect an abstract, conceptual size representation, but rather the visual or functional properties associated with small versus big real-world objects. To determine whether a more abstract conceptual size representation may affect visual cortical activation we used meaningless geometrical shapes, devoid of semantic or functional associations, which were associated with specific size representations by virtue of extensive training. Following training, participants underwent functional magnetic resonance imaging (fMRI) scanning while performing a conceptual size comparison task on the geometrical shapes. In addition, a size comparison task was conducted for numeral digits denoting small and big numbers. A region-of-interest analysis revealed larger blood oxygenation level dependent (BOLD) responses for conceptually 'big' than for conceptually 'small' shapes, as well as for big versus small numbers, within medial (parahippocampal place area, PPA) and lateral (occipital place area, OPA) place-selective regions. Processing of the 'big' visual shapes further elicited enhanced activation in early visual cortex, possibly reflecting top-down projections from PPA. By using arbitrary shapes and numbers we minimized visual, categorical, or functional influences on fMRI measurement, providing evidence for a possible neural mechanism underlying the representation of abstract conceptual size within the ventral visual stream. PMID:26731198

  15. Divergent Plasticity of Prefrontal Cortex Networks

    PubMed Central

    Moghaddam, Bita; Homayoun, Houman

    2010-01-01

    The ‘executive’ regions of the prefrontal cortex (PFC) such as the dorsolateral PFC (dlPFC) and its rodent equivalent medial PFC (mPFC) are thought to respond in concert with the ‘limbic’ regions of the PFC such as the orbitofrontal (OFC) cortex to orchestrate behavior that is consistent with context and expected outcome. Both groups of regions have been implicated in behavioral abnormalities associated with addiction and psychiatric disorders, in particular, schizophrenia and mood disorders. Theories about the pathophysiology of these disorders, however, incorporate abnormalities in discrete PFC regions independently of each other or assume they are one and the same and, thus, bunch them under umbrella of ‘PFC dysfunction.’ Emerging data from animal studies suggest that mPFC and OFC neurons display opposing patterns of plasticity during associative learning and in response to repeated exposure to psychostimulants. These data corroborate clinical studies reporting different patterns of activation in OFC versus dlPFC in individuals with schizophrenia or addictive disorders. These suggest that concomitant but divergent engagement of discrete PFC regions is critical for learning stimulus-outcome associations, and the execution of goal-directed behavior that is based on these associations. An atypical interplay between these regions may lead to abnormally high or low salience assigned to stimuli, resulting in symptoms that are fundamental to many psychiatric and addictive disorders, including attentional deficits, improper affective response to stimuli, and inflexible or impulsive behavior. PMID:17912252

  16. Temperament trait Harm Avoidance associates with μ-opioid receptor availability in frontal cortex: a PET study using [(11)C]carfentanil.

    PubMed

    Tuominen, Lauri; Salo, Johanna; Hirvonen, Jussi; Någren, Kjell; Laine, Pauliina; Melartin, Tarja; Isometsä, Erkki; Viikari, Jorma; Raitakari, Olli; Keltikangas-Järvinen, Liisa; Hietala, Jarmo

    2012-07-01

    Harm Avoidance is a temperament trait that associates with sensitivity to aversive and non-rewarding stimuli, higher anticipated threat and negative emotions during stress as well as a higher risk for affective disorders. The neurobiological correlates of interindividual differences in Harm Avoidance are largely unknown. We hypothesized that variability in Harm Avoidance trait would be explained by differences in the activity of μ-opioid system as the opioid system is known to regulate affective states and stress sensitivity. Brain μ-opioid receptor availability was measured in 22 healthy subjects using positron emission tomography and [(11)C]carfentanil, a selective μ-opioid receptor agonist. The subjects were selected from a large Finish population-based cohort (N=2075) on the basis of their pre-existing Temperament and Character Scores. Subjects scoring consistently in the upper (10) and lower (12) quartiles for the Harm Avoidance trait were studied. High Harm Avoidance score associated with high μ-opioid receptor availability (i.e. lower endogenous μ-opioid drive) in anterior cingulate cortex, ventromedial and dorsolateral prefrontal cortices and anterior insular cortex. These associations were driven by two subscales of Harm Avoidance; Shyness with Strangers and Fatigability and Asthenia. In conclusion, higher Harm Avoidance score in healthy subjects is associated with higher μ-opioid availability in regions involved in the regulation of anxiety as well as in the control of emotions, affective component of pain and interoceptive awareness. The results have relevance in the research of vulnerability factors for affective disorders. PMID:22484309

  17. Medial Prefrontal and Anterior Insular Connectivity in Early Schizophrenia and Major Depressive Disorder: A Resting Functional MRI Evaluation of Large-Scale Brain Network Models.

    PubMed

    Penner, Jacob; Ford, Kristen A; Taylor, Reggie; Schaefer, Betsy; Théberge, Jean; Neufeld, Richard W J; Osuch, Elizabeth A; Menon, Ravi S; Rajakumar, Nagalingam; Allman, John M; Williamson, Peter C

    2016-01-01

    Anomalies in the medial prefrontal cortex, anterior insulae, and large-scale brain networks associated with them have been proposed to underlie the pathophysiology of schizophrenia and major depressive disorder (MDD). In this study, we examined the connectivity of the medial prefrontal cortices and anterior insulae in 24 healthy controls, 24 patients with schizophrenia, and 24 patients with MDD early in illness with seed-based resting state functional magnetic resonance imaging analysis using Statistical Probability Mapping. As hypothesized, reduced connectivity was found between the medial prefrontal cortex and the dorsal anterior cingulate cortex and other nodes associated with directed effort in patients with schizophrenia compared to controls while patients with MDD had reduced connectivity between the medial prefrontal cortex and ventral prefrontal emotional encoding regions compared to controls. Reduced connectivity was found between the anterior insulae and the medial prefrontal cortex in schizophrenia compared to controls, but contrary to some models emotion processing regions failed to demonstrate increased connectivity with the medial prefrontal cortex in MDD compared to controls. Although, not statistically significant after correction for multiple comparisons, patients with schizophrenia tended to demonstrate decreased connectivity between basal ganglia-thalamocortical regions and the medial prefrontal cortex compared to patients with MDD, which might be expected as these regions effect action. Results were interpreted to support anomalies in nodes associated with directed effort in schizophrenia and nodes associated with emotional encoding network in MDD compared to healthy controls. PMID:27064387

  18. Medial Prefrontal and Anterior Insular Connectivity in Early Schizophrenia and Major Depressive Disorder: A Resting Functional MRI Evaluation of Large-Scale Brain Network Models

    PubMed Central

    Penner, Jacob; Ford, Kristen A.; Taylor, Reggie; Schaefer, Betsy; Théberge, Jean; Neufeld, Richard W. J.; Osuch, Elizabeth A.; Menon, Ravi S.; Rajakumar, Nagalingam; Allman, John M.; Williamson, Peter C.

    2016-01-01

    Anomalies in the medial prefrontal cortex, anterior insulae, and large-scale brain networks associated with them have been proposed to underlie the pathophysiology of schizophrenia and major depressive disorder (MDD). In this study, we examined the connectivity of the medial prefrontal cortices and anterior insulae in 24 healthy controls, 24 patients with schizophrenia, and 24 patients with MDD early in illness with seed-based resting state functional magnetic resonance imaging analysis using Statistical Probability Mapping. As hypothesized, reduced connectivity was found between the medial prefrontal cortex and the dorsal anterior cingulate cortex and other nodes associated with directed effort in patients with schizophrenia compared to controls while patients with MDD had reduced connectivity between the medial prefrontal cortex and ventral prefrontal emotional encoding regions compared to controls. Reduced connectivity was found between the anterior insulae and the medial prefrontal cortex in schizophrenia compared to controls, but contrary to some models emotion processing regions failed to demonstrate increased connectivity with the medial prefrontal cortex in MDD compared to controls. Although, not statistically significant after correction for multiple comparisons, patients with schizophrenia tended to demonstrate decreased connectivity between basal ganglia-thalamocortical regions and the medial prefrontal cortex compared to patients with MDD, which might be expected as these regions effect action. Results were interpreted to support anomalies in nodes associated with directed effort in schizophrenia and nodes associated with emotional encoding network in MDD compared to healthy controls. PMID:27064387

  19. Representation of Reward Feedback in Primate Auditory Cortex

    PubMed Central

    Brosch, Michael; Selezneva, Elena; Scheich, Henning

    2011-01-01

    It is well established that auditory cortex is plastic on different time scales and that this plasticity is driven by the reinforcement that is used to motivate subjects to learn or to perform an auditory task. Motivated by these findings, we study in detail properties of neuronal firing in auditory cortex that is related to reward feedback. We recorded from the auditory cortex of two monkeys while they were performing an auditory categorization task. Monkeys listened to a sequence of tones and had to signal when the frequency of adjacent tones stepped in downward direction, irrespective of the tone frequency and step size. Correct identifications were rewarded with either a large or a small amount of water. The size of reward depended on the monkeys’ performance in the previous trial: it was large after a correct trial and small after an incorrect trial. The rewards served to maintain task performance. During task performance we found three successive periods of neuronal firing in auditory cortex that reflected (1) the reward expectancy for each trial, (2) the reward-size received, and (3) the mismatch between the expected and delivered reward. These results, together with control experiments suggest that auditory cortex receives reward feedback that could be used to adapt auditory cortex to task requirements. Additionally, the results presented here extend previous observations of non-auditory roles of auditory cortex and shows that auditory cortex is even more cognitively influenced than lately recognized. PMID:21369350

  20. Metaphorically Feeling: Comprehending Textural Metaphors Activates Somatosensory Cortex

    ERIC Educational Resources Information Center

    Lacey, Simon; Stilla, Randall; Sathian, K.

    2012-01-01

    Conceptual metaphor theory suggests that knowledge is structured around metaphorical mappings derived from physical experience. Segregated processing of object properties in sensory cortex allows testing of the hypothesis that metaphor processing recruits activity in domain-specific sensory cortex. Using functional magnetic resonance imaging…

  1. Activity in Prelimbic Cortex Subserves Fear Memory Reconsolidation over Time

    ERIC Educational Resources Information Center

    Stern, Cristina A. J.; Gazarini, Lucas; Vanvossen, Ana C.; Hames, Mayara S.; Bertoglio, Leandro J.

    2014-01-01

    The prelimbic cortex has been implicated in the consolidation of previously learned fear. Herein, we report that temporarily inactivating this medial prefrontal cortex subregion with the GABA [subscript A] agonist muscimol (4.0 nmol in 0.2 µL per hemisphere) was able to equally disrupt 1-, 7-, and 21-d-old contextual fear memories after their…

  2. Discourse Production Following Injury to the Dorsolateral Prefrontal Cortex

    ERIC Educational Resources Information Center

    Coelho, Carl; Le, Karen; Mozeiko, Jennifer; Krueger, Frank; Grafman, Jordan

    2012-01-01

    Individuals with damage to the prefrontal cortex, and the dorsolateral prefrontal cortex (DLPFC) in particular, often demonstrate difficulties with the formulation of complex language not attributable to aphasia. The present study employed a discourse analysis procedure to characterize the language of individuals with left (L) or right (R) DLPFC…

  3. Reduced Anterior Cingulate Cortex Glutamatergic Concentrations in Childhood Major Depression

    ERIC Educational Resources Information Center

    Mirza, Yousha; Tang, Jennifer; Russell, Aileen; Banerjee, S. Preeya; Bhandari, Rashmi; Ivey, Jennifer; Rose, Michelle; Moore, Gregory J.; Rosenberg, David R.

    2004-01-01

    Objective: To examine in vivo glutamatergic neurochemical alterations in the anterior cingulate cortex of children with major depressive disorder (MDD). Method: Single-voxel proton magnetic resonance spectroscopic ([.sup.1]H-MRS) examinations of the anterior cingulate cortex were conducted in 13 psychotropic-naive children and adolescents with MDD…

  4. Medial Prefrontal Cortex Lesions Abolish Contextual Control of Competing Responses

    ERIC Educational Resources Information Center

    Haddon, J. E.; Killcross, A. S.

    2005-01-01

    There is much debate as to the extent and nature of functional specialization within the different subregions of the prefrontal cortex. The current study was undertaken to investigate the effect of damage to medial prefrontal cortex subregions in the rat. Rats were trained on two biconditional discrimination tasks, one auditory and one visual, in…

  5. Olfactocentric Paralimbic Cortex Morphology in Adolescents with Bipolar Disorder

    ERIC Educational Resources Information Center

    Wang, Fei; Kalmar, Jessica H.; Womer, Fay Y.; Edmiston, Erin E.; Chepenik, Lara G.; Chen, Rachel; Spencer, Linda; Blumberg, Hilary P.

    2011-01-01

    The olfactocentric paralimbic cortex plays a critical role in the regulation of emotional and neurovegetative functions that are disrupted in core features of bipolar disorder. Adolescence is thought to be a critical period in both the maturation of the olfactocentric paralimbic cortex and in the emergence of bipolar disorder pathology. Together,…

  6. Contributions of cat posterior parietal cortex to visuospatial discrimination.

    PubMed

    Lomber, S G; Payne, B R

    2000-01-01

    The purpose of the present study was to examine the contributions made by cat posterior parietal cortex to the analyses of the relative position of objects in visual space. Two cats were trained on a landmark task in which they learned to report the position of a landmark object relative to a right or left food-reward chamber. Subsequently, three pairs of cooling loops were implanted bilaterally in contact with visuoparietal cortices forming the crown of the middle suprasylvian gyrus (MSg; architectonic area 7) and the banks of the posterior-middle suprasylvian sulcus (pMS sulcal cortex) and in contact with the ventral-posterior suprasylvian (vPS) region of visuotemporal cortex. Bilateral deactivation of pMS sulcal cortex resulted in a profound impairment for all six tested positions of the landmark, yet bilateral deactivation of neither area 7 nor vPS cortex yielded any deficits. In control tasks (visual orienting and object discrimination), there was no evidence for any degree of attentional blindness or impairment of form discrimination during bilateral deactivation of pMS cortex. Therefore, we conclude that bilateral cooling of pMS cortex, but neither area 7 nor vPS cortex, induces a specific deficit in spatial localization as examined with the landmark task. These observations have significant bearing on our understanding of visuospatial processing in cat, monkey, and human cortices. PMID:11153650

  7. Pre-Surgical Integration of fMRI and DTI of the Sensorimotor System in Transcortical Resection of a High-Grade Insular Astrocytoma

    PubMed Central

    Ekstrand, Chelsea L.; Mickleborough, Marla J. S.; Fourney, Daryl R.; Gould, Layla A.; Lorentz, Eric J.; Ellchuk, Tasha; Borowsky, Ron W.

    2016-01-01

    Herein we report on a patient with a WHO Grade III astrocytoma in the right insular region in close proximity to the internal capsule who underwent a right frontotemporal craniotomy. Total gross resection of insular gliomas remains surgically challenging based on the possibility of damage to the corticospinal tracts. However, maximizing the extent of resection has been shown to decrease future adverse outcomes. Thus, the goal of such surgeries should focus on maximizing extent of resection while minimizing possible adverse outcomes. In this case, pre-surgical planning included integration of functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), to localize motor and sensory pathways. Novel fMRI tasks were individually developed for the patient to maximize both somatosensory and motor activation simultaneously in areas in close proximity to the tumor. Information obtained was used to optimize resection trajectory and extent, facilitating gross total resection of the astrocytoma. Across all three motor-sensory tasks administered, fMRI revealed an area of interest just superior and lateral to the astrocytoma. Further, DTI analyses showed displacement of the corona radiata around the superior dorsal surface of the astrocytoma, extending in the direction of the activation found using fMRI. Taking into account these results, a transcortical superior temporal gyrus surgical approach was chosen in order to avoid the area of interest identified by fMRI and DTI. Total gross resection was achieved and minor post-surgical motor and sensory deficits were temporary. This case highlights the utility of comprehensive pre-surgical planning, including fMRI and DTI, to maximize surgical outcomes on a case-by-case basis. PMID:27013996

  8. Effects of Prolonged Exposure to Hypobaric Hypoxia on Oxidative Stress, Inflammation and Gluco-Insular Regulation: The Not-So-Sweet Price for Good Regulation

    PubMed Central

    Siervo, Mario; Riley, Heather L.; Fernandez, Bernadette O.; Leckstrom, Carl A.; Martin, Daniel S.; Mitchell, Kay; Levett, Denny Z. H.; Montgomery, Hugh E.; Mythen, Monty G.

    2014-01-01

    Objectives The mechanisms by which low oxygen availability are associated with the development of insulin resistance remain obscure. We thus investigated the relationship between such gluco-insular derangements in response to sustained (hypobaric) hypoxemia, and changes in biomarkers of oxidative stress, inflammation and counter-regulatory hormone responses. Methods After baseline testing in London (75 m), 24 subjects ascended from Kathmandu (1,300 m) to Everest Base Camp (EBC;5,300 m) over 13 days. Of these, 14 ascended higher, with 8 reaching the summit (8,848 m). Assessments were conducted at baseline, during ascent to EBC, and 1, 6 and 8 week(s) thereafter. Changes in body weight and indices of gluco-insular control were measured (glucose, insulin, C-Peptide, homeostasis model assessment of insulin resistance [HOMA-IR]) along with biomarkers of oxidative stress (4-hydroxy-2-nonenal-HNE), inflammation (Interleukin-6 [IL-6]) and counter-regulatory hormones (glucagon, adrenalin, noradrenalin). In addition, peripheral oxygen saturation (SpO2) and venous blood lactate concentrations were determined. Results SpO2 fell significantly from 98.0% at sea level to 82.0% on arrival at 5,300 m. Whilst glucose levels remained stable, insulin and C-Peptide concentrations increased by >200% during the last 2 weeks. Increases in fasting insulin, HOMA-IR and glucagon correlated with increases in markers of oxidative stress (4-HNE) and inflammation (IL-6). Lactate levels progressively increased during ascent and remained significantly elevated until week 8. Subjects lost on average 7.3 kg in body weight. Conclusions Sustained hypoxemia is associated with insulin resistance, whose magnitude correlates with the degree of oxidative stress and inflammation. The role of 4-HNE and IL-6 as key players in modifying the association between sustained hypoxia and insulin resistance merits further investigation. PMID:24733551

  9. Functional topography of the human entorhinal cortex

    PubMed Central

    Zaragoza Jimenez, Nestor I

    2015-01-01

    Despite extensive research on the role of the rodent medial and lateral entorhinal cortex (MEC/LEC) in spatial navigation, memory and related disease, their human homologues remain elusive. Here, we combine high-field functional magnetic resonance imaging at 7 T with novel data-driven and model-based analyses to identify corresponding subregions in humans based on the well-known global connectivity fingerprints in rodents and sensitivity to spatial and non-spatial information. We provide evidence for a functional division primarily along the anteroposterior axis. Localising the human homologue of the rodent MEC and LEC has important implications for translating studies on the hippocampo-entorhinal memory system from rodents to humans. DOI: http://dx.doi.org/10.7554/eLife.06738.001 PMID:26052748

  10. Spindle Bursts in Neonatal Rat Cerebral Cortex

    PubMed Central

    Yang, Jenq-Wei; Reyes-Puerta, Vicente; Kilb, Werner; Luhmann, Heiko J.

    2016-01-01

    Spontaneous and sensory evoked spindle bursts represent a functional hallmark of the developing cerebral cortex in vitro and in vivo. They have been observed in various neocortical areas of numerous species, including newborn rodents and preterm human infants. Spindle bursts are generated in complex neocortical-subcortical circuits involving in many cases the participation of motor brain regions. Together with early gamma oscillations, spindle bursts synchronize the activity of a local neuronal network organized in a cortical column. Disturbances in spindle burst activity during corticogenesis may contribute to disorders in cortical architecture and in the activity-dependent control of programmed cell death. In this review we discuss (i) the functional properties of spindle bursts, (ii) the mechanisms underlying their generation, (iii) the synchronous patterns and cortical networks associated with spindle bursts, and (iv) the physiological and pathophysiological role of spindle bursts during early cortical development. PMID:27034844

  11. Population codes in the visual cortex

    PubMed Central

    Tanabe, Seiji

    2013-01-01

    Every sensory event elicits activity in a broad population of cells that is distributed within and across cortical areas. How these neurons function together to represent the sensory environment is a major question in systems neuroscience. A number of proposals have been made, and recent advances in multi-neuronal recording have begun to allow researchers to test the predictions of these population-coding theories. In this review, I provide an introduction to some of the key concepts in population coding and describe several studies in the recent literature. The focus of this review is on sensory representation in the visual cortex and related perceptual decisions. The frameworks used to study population coding include population vectors, linear decoders, and Bayesian inference. Simple examples are provided to illustrate these concepts. Testing theories of population coding is an emerging subject in systems neuroscience, but advances in multi-neuronal recording and analysis suggest that an understanding is within reach. PMID:23542219

  12. Multiple signals in anterior cingulate cortex

    PubMed Central

    Kolling, N; Behrens, TEJ; Wittmann, MK; Rushworth, MFS

    2016-01-01

    Activity in anterior cingulate cortex (ACC) has been linked both to commitment to a course of action, even when it is associated with costs, and to exploring or searching for alternative courses of action. Here we review evidence that this is due to the presence of multiple signals in ACC reflecting the updating of beliefs and internal models of the environment and encoding aspects of choice value, including the average value of choices afforded by the environment (‘search value’). We contrast this evidence with the influential view that ACC activity is better described as reflecting task difficulty. A consideration of cortical neural network properties explains why ACC may carry such signals and also exhibit sensitivity to task difficulty. PMID:26774693

  13. Decoding subjective decisions from orbitofrontal cortex.

    PubMed

    Rich, Erin L; Wallis, Jonathan D

    2016-07-01

    When making a subjective choice, the brain must compute a value for each option and compare those values to make a decision. The orbitofrontal cortex (OFC) is critically involved in this process, but the neural mechanisms remain obscure, in part due to limitations in our ability to measure and control the internal deliberations that can alter the dynamics of the decision process. Here we tracked these dynamics by recovering temporally precise neural states from multidimensional data in OFC. During individual choices, OFC alternated between states associated with the value of two available options, with dynamics that predicted whether a subject would decide quickly or vacillate between the two alternatives. Ensembles of value-encoding neurons contributed to these states, with individual neurons shifting activity patterns as the network evaluated each option. Thus, the mechanism of subjective decision-making involves the dynamic activation of OFC states associated with each choice alternative. PMID:27273768

  14. Spindle Bursts in Neonatal Rat Cerebral Cortex.

    PubMed

    Yang, Jenq-Wei; Reyes-Puerta, Vicente; Kilb, Werner; Luhmann, Heiko J

    2016-01-01

    Spontaneous and sensory evoked spindle bursts represent a functional hallmark of the developing cerebral cortex in vitro and in vivo. They have been observed in various neocortical areas of numerous species, including newborn rodents and preterm human infants. Spindle bursts are generated in complex neocortical-subcortical circuits involving in many cases the participation of motor brain regions. Together with early gamma oscillations, spindle bursts synchronize the activity of a local neuronal network organized in a cortical column. Disturbances in spindle burst activity during corticogenesis may contribute to disorders in cortical architecture and in the activity-dependent control of programmed cell death. In this review we discuss (i) the functional properties of spindle bursts, (ii) the mechanisms underlying their generation, (iii) the synchronous patterns and cortical networks associated with spindle bursts, and (iv) the physiological and pathophysiological role of spindle bursts during early cortical development. PMID:27034844

  15. Early GABAergic circuitry in the cerebral cortex.

    PubMed

    Luhmann, Heiko J; Kirischuk, Sergei; Sinning, Anne; Kilb, Werner

    2014-06-01

    In the cerebral cortex GABAergic signaling plays an important role in regulating early developmental processes, for example, neurogenesis, migration and differentiation. Transient cell populations, namely Cajal-Retzius in the marginal zone and thalamic input receiving subplate neurons, are integrated as active elements in transitory GABAergic circuits. Although immature pyramidal neurons receive GABAergic synaptic inputs already at fetal stages, they are integrated into functional GABAergic circuits only several days later. In consequence, GABAergic synaptic transmission has only a minor influence on spontaneous network activity during early corticogenesis. Concurrent with the gradual developmental shift of GABA action from excitatory to inhibitory and the maturation of cortical synaptic connections, GABA becomes more important in synchronizing neuronal network activity. PMID:24434608

  16. Patterning the cerebral cortex: traveling with morphogens.

    PubMed

    Borello, Ugo; Pierani, Alessandra

    2010-08-01

    The neocortex represents the brain structure that has been subjected to a major expansion in its relative size during the course of mammalian evolution. An exquisite coordination of appropriate growth of competent territories along multiple axes and their spatial patterning is required for regionalization of the cortical primordium and the formation of functional areas. The achievement of such a highly complex architecture relies on a precise orchestration of the proliferation of progenitors, onset of neurogenesis, spatio-temporal generation of distinct cell types and control of their migration. We will review recent work on alternative molecular mechanisms that, via the migration of signaling cells/structures, participate in coordinating growth and spatial patterning in the developing cerebral cortex. By integrating temporal and spatial parameters as well as absolute levels of signaling this novel strategy might represent a general mechanism for long-range patterning in large structures, in addition to the passive diffusion of morphogens. PMID:20542680

  17. Beyond auditory cortex: working with musical thoughts.

    PubMed

    Zatorre, Robert J

    2012-04-01

    Musical imagery is associated with neural activity in auditory cortex, but prior studies have not examined musical imagery tasks requiring mental transformations. This paper describes functional magnetic resonance imaging (fMRI) studies requiring manipulation of musical information. In one set of experiments, listeners were asked to mentally reverse a familiar tune when presented backwards. This manipulation consistently elicits neural activity in the intraparietal sulcus (IPS). Separate experiments requiring judgments about melodies that have been transposed from one musical key to another also elicit IPS activation. Conjunction analyses indicate that the same portions of the IPS are recruited in both tasks. The findings suggest that the dorsal pathway of auditory processing is involved in the manipulation and transformation of auditory information, as has also been shown for visuomotor and visuospatial tasks. As such, it provides a substrate for the creation of new mental representations that are based on manipulation of previously experienced sensory events. PMID:22524363

  18. The scaling of frontal cortex in primates and carnivores

    PubMed Central

    Bush, Eliot C.; Allman, John M.

    2004-01-01

    Size has a profound effect on the structure of the brain. Many brain structures scale allometrically, that is, their relative size changes systematically as a function of brain size. Here we use independent contrasts analysis to examine the scaling of frontal cortex in 43 species of mammals including 25 primates and 15 carnivores. We find evidence for significant differences in scaling between primates and carnivores. Primate frontal cortex hyperscales relative to the rest of neocortex and the rest of the brain. The slope of frontal cortex contrasts on rest of cortex contrasts is 1.18 (95% confidence interval, 1.06-1.30) for primates, which is significantly greater than isometric. It is also significantly greater than the carnivore value of 0.94 (95% confidence interval, 0.82-1.07). This finding supports the idea that there are substantial differences in frontal cortex structure and development between the two groups. PMID:15007170

  19. Ventromedial prefrontal cortex mediates visual attention during facial emotion recognition.

    PubMed

    Wolf, Richard C; Philippi, Carissa L; Motzkin, Julian C; Baskaya, Mustafa K; Koenigs, Michael

    2014-06-01

    The ventromedial prefrontal cortex is known to play a crucial role in regulating human social and emotional behaviour, yet the precise mechanisms by which it subserves this broad function remain unclear. Whereas previous neuropsychological studies have largely focused on the role of the ventromedial prefrontal cortex in higher-order deliberative processes related to valuation and decision-making, here we test whether ventromedial prefrontal cortex may also be critical for more basic aspects of orienting attention to socially and emotionally meaningful stimuli. Using eye tracking during a test of facial emotion recognition in a sample of lesion patients, we show that bilateral ventromedial prefrontal cortex damage impairs visual attention to the eye regions of faces, particularly for fearful faces. This finding demonstrates a heretofore unrecognized function of the ventromedial prefrontal cortex-the basic attentional process of controlling eye movements to faces expressing emotion. PMID:24691392

  20. Motor cortex stimulation for neuropathic pain.

    PubMed

    Lazorthes, Y; Sol, J C; Fowo, S; Roux, F E; Verdié, J C

    2007-01-01

    Since the initial publication of Tsubokawa in 1991, epidural motor cortex stimulation (MCS) is increasingly reported as an effective surgical option for the treatment of refractory neuropathic pain although its mechanism of action remains poorly understood. The authors review the extensive literature published over the last 15 years on central and neuropathic pain. Optimal patient selection remains difficult and the value of pharmacological tests or transcranial magnetic stimulation in predicting the efficacy of MCS has not been established. Pre-operative functional magnetic resonance imaging (fMRI), 3-dimensional volume MRI, neuronavigation and intra-operative neurophysiological monitoring have contributed to improvements in the technique for identifying the precise location of the targeted motor cortical area and the correct placement of the electrode array. MCS should be considered as the treatment of choice in post-stroke pain, thalamic pain or facial anesthesia dolorosa. In brachial plexus avulsion pain, it is preferable to propose initially dorsal root entry zone (DREZ)-tomy; MCS may be offered after DREZotomy has failed to control the pain. In our experience, the results of MCS on phantom limb pain are promising. In general, the efficacy of MCS depends on: a) the accurate placement of the stimulation electrode over the appropriate area of the motor cortex, and b) on sophisticated programming of the stimulation parameters. A better understanding of the MCS mechanism of action will probably make it possible to adjust better the stimulation parameters. The conclusions of multicentered randomised studies, now in progress, will be very useful and are likely to promote further research and clinical applications in this field. PMID:17691287

  1. Determining Physical Properties of the Cell Cortex.

    PubMed

    Saha, Arnab; Nishikawa, Masatoshi; Behrndt, Martin; Heisenberg, Carl-Philipp; Jülicher, Frank; Grill, Stephan W

    2016-03-29

    Actin and myosin assemble into a thin layer of a highly dynamic network underneath the membrane of eukaryotic cells. This network generates the forces that drive cell- and tissue-scale morphogenetic processes. The effective material properties of this active network determine large-scale deformations and other morphogenetic events. For example, the characteristic time of stress relaxation (the Maxwell time τM) in the actomyosin sets the timescale of large-scale deformation of the cortex. Similarly, the characteristic length of stress propagation (the hydrodynamic length λ) sets the length scale of slow deformations, and a large hydrodynamic length is a prerequisite for long-ranged cortical flows. Here we introduce a method to determine physical parameters of the actomyosin cortical layer in vivo directly from laser ablation experiments. For this we investigate the cortical response to laser ablation in the one-cell-stage Caenorhabditis elegans embryo and in the gastrulating zebrafish embryo. These responses can be interpreted using a coarse-grained physical description of the cortex in terms of a two-dimensional thin film of an active viscoelastic gel. To determine the Maxwell time τM, the hydrodynamic length λ, the ratio of active stress ζΔμ, and per-area friction γ, we evaluated the response to laser ablation in two different ways: by quantifying flow and density fields as a function of space and time, and by determining the time evolution of the shape of the ablated region. Importantly, both methods provide best-fit physical parameters that are in close agreement with each other and that are similar to previous estimates in the two systems. Our method provides an accurate and robust means for measuring physical parameters of the actomyosin cortical layer. It can be useful for investigations of actomyosin mechanics at the cellular-scale, but also for providing insights into the active mechanics processes that govern tissue-scale morphogenesis. PMID

  2. Chemical Discrimination of Cortex Phellodendri amurensis and Cortex Phellodendri chinensis by Multivariate Analysis Approach

    PubMed Central

    Sun, Hui; Wang, Huiyu; Zhang, Aihua; Yan, Guangli; Han, Ying; Li, Yuan; Wu, Xiuhong; Meng, Xiangcai; Wang, Xijun

    2016-01-01

    Background: As herbal medicines have an important position in health care systems worldwide, their current assessment, and quality control are a major bottleneck. Cortex Phellodendri chinensis (CPC) and Cortex Phellodendri amurensis (CPA) are widely used in China, however, how to identify species of CPA and CPC has become urgent. Materials and Methods: In this study, multivariate analysis approach was performed to the investigation of chemical discrimination of CPA and CPC. Results: Principal component analysis showed that two herbs could be separated clearly. The chemical markers such as berberine, palmatine, phellodendrine, magnoflorine, obacunone, and obaculactone were identified through the orthogonal partial least squared discriminant analysis, and were identified tentatively by the accurate mass of quadruple-time-of-flight mass spectrometry. A total of 29 components can be used as the chemical markers for discrimination of CPA and CPC. Of them, phellodenrine is significantly higher in CPC than that of CPA, whereas obacunone and obaculactone are significantly higher in CPA than that of CPC. Conclusion: The present study proves that multivariate analysis approach based chemical analysis greatly contributes to the investigation of CPA and CPC, and showed that the identified chemical markers as a whole should be used to discriminate the two herbal medicines, and simultaneously the results also provided chemical information for their quality assessment. SUMMARY Multivariate analysis approach was performed to the investigate the herbal medicineThe chemical markers were identified through multivariate analysis approachA total of 29 components can be used as the chemical markers. UPLC-Q/TOF-MS-based multivariate analysis method for the herbal medicine samples Abbreviations used: CPC: Cortex Phellodendri chinensis, CPA: Cortex Phellodendri amurensis, PCA: Principal component analysis, OPLS-DA: Orthogonal partial least squares discriminant analysis, BPI: Base peaks ion

  3. TMS-induced neural noise in sensory cortex interferes with short-term memory storage in prefrontal cortex

    PubMed Central

    Bancroft, Tyler D.; Hogeveen, Jeremy; Hockley, William E.; Servos, Philip

    2014-01-01

    In a previous study, Harris et al. (2002) found disruption of vibrotactile short-term memory after applying single-pulse transcranial magnetic stimulation (TMS) to primary somatosensory cortex (SI) early in the maintenance period, and suggested that this demonstrated a role for SI in vibrotactile memory storage. While such a role is compatible with recent suggestions that sensory cortex is the storage substrate for working memory, it stands in contrast to a relatively large body of evidence from human EEG and single-cell recording in primates that instead points to prefrontal cortex as the storage substrate for vibrotactile memory. In the present study, we use computational methods to demonstrate how Harris et al.'s results can be reproduced by TMS-induced activity in sensory cortex and subsequent feedforward interference with memory traces stored in prefrontal cortex, thereby reconciling discordant findings in the tactile memory literature. PMID:24634653

  4. Neurons in the medial cortex give rise to Timm-positive boutons in the cerebral cortex of lizards.

    PubMed

    Lopez-Garcia, C; Martinez-Guijarro, F J

    1988-11-01

    The origin of Timm-positive presynaptic boutons in the cerebral cortex of the lizard, Podarcis hispanica, was investigated by injections of horseradish peroxidase (HRP)-saponine in Timm-positive areas, i.e. the dorsal and dorsomedial cortices. A broad retrograde labelling of cell somata in the medial cortex was found. Injections of HRP-saponine in the medial cortex resulted in broad anterograde labelling of boutons located in the Timm-positive zones. A double-labelling of the HRP labelled boutons was obtained by using the Neo-Timm or the sulphide-osmium methods. The present results suggest that neurons of the medial cortex send axons that terminate in Timm-positive boutons in the cerebral cortex of lizards. PMID:2461786

  5. Afferent connections of the parabrachial nucleus in C57BL/6J mice

    PubMed Central

    Tokita, Kenichi; Inoue, Tomio; Boughter, John D.

    2009-01-01

    Although the mouse is an experimental model with an increasing importance in various fields of Neuroscience, the characteristics of its central gustatory pathways have not yet been well documented. Recent electrophysiological studies using the rat and hamster have revealed that taste processing in the brainstem gustatory relays is under the strong influence of inputs from forebrain gustatory structures. In the present study, we investigated the organization of afferent projections to the mouse parabrachial nucleus (PbN), which is located at a key site between the brainstem and gustatory, viscerosensory and autonomic centers in the forebrain. We made injections of the retrograde tracer Fluorogold centered around the “waist” area of the PbN, whose neurons are known to be highly responsive to taste stimuli. Retrogradely labeled neurons were found in the infralimbic, dysgranular and agranular insular cortex as well as the claustrum; the bed nucleus of the stria terminalis and the substantia innominata; the central nucleus of the amygdala; the lateral and medial preoptic areas, the paraventricular, the dorsomedial, the ventromedial, the arcuate, and the lateral hypothalamic areas; the periaqueductal gray, the substantia nigra pars compacta, and the ventral tegmental area; the supratrigeminal nucleus, rostral and caudal nucleus of the solitary tract; the parvicellular intermediate and gigantocellular reticular nucleus; the caudal and interpolar divisions of the spinal trigeminal nucleus, dorsomedial spinal trigeminal nucleus, and the area postrema. Numbers of labeled neurons in the main components of the gustatory system including the insular cortex, bed nucleus of the stria terminalis, central nucleus of the amygdala, lateral hypothalamus, and rostral nucleus of the solitary tract were quantified. These results are basically consistent with those of the previous rat and hamster studies, but some species differences were found. Functional implications of these

  6. Forelimb training drives transient map reorganization in ipsilateral motor cortex.

    PubMed

    Pruitt, David T; Schmid, Ariel N; Danaphongse, Tanya T; Flanagan, Kate E; Morrison, Robert A; Kilgard, Michael P; Rennaker, Robert L; Hays, Seth A

    2016-10-15

    Skilled motor training results in reorganization of contralateral motor cortex movement representations. The ipsilateral motor cortex is believed to play a role in skilled motor control, but little is known about how training influences reorganization of ipsilateral motor representations of the trained limb. To determine whether training results in reorganization of ipsilateral motor cortex maps, rats were trained to perform the isometric pull task, an automated motor task that requires skilled forelimb use. After either 3 or 6 months of training, intracortical microstimulation (ICMS) mapping was performed to document motor representations of the trained forelimb in the hemisphere ipsilateral to that limb. Motor training for 3 months resulted in a robust expansion of right forelimb representation in the right motor cortex, demonstrating that skilled motor training drives map plasticity ipsilateral to the trained limb. After 6 months of training, the right forelimb representation in the right motor cortex was significantly smaller than the representation observed in rats trained for 3 months and similar to untrained controls, consistent with a normalization of motor cortex maps. Forelimb map area was not correlated with performance on the trained task, suggesting that task performance is maintained despite normalization of cortical maps. This study provides new insights into how the ipsilateral cortex changes in response to skilled learning and may inform rehabilitative strategies to enhance cortical plasticity to support recovery after brain injury. PMID:27392641

  7. The auditory representation of speech sounds in human motor cortex

    PubMed Central

    Cheung, Connie; Hamilton, Liberty S; Johnson, Keith; Chang, Edward F

    2016-01-01

    In humans, listening to speech evokes neural responses in the motor cortex. This has been controversially interpreted as evidence that speech sounds are processed as articulatory gestures. However, it is unclear what information is actually encoded by such neural activity. We used high-density direct human cortical recordings while participants spoke and listened to speech sounds. Motor cortex neural patterns during listening were substantially different than during articulation of the same sounds. During listening, we observed neural activity in the superior and inferior regions of ventral motor cortex. During speaking, responses were distributed throughout somatotopic representations of speech articulators in motor cortex. The structure of responses in motor cortex during listening was organized along acoustic features similar to auditory cortex, rather than along articulatory features as during speaking. Motor cortex does not contain articulatory representations of perceived actions in speech, but rather, represents auditory vocal information. DOI: http://dx.doi.org/10.7554/eLife.12577.001 PMID:26943778

  8. Evidence for inhibitory deficits in the prefrontal cortex in schizophrenia

    PubMed Central

    Radhu, Natasha; Garcia Dominguez, Luis; Farzan, Faranak; Richter, Margaret A.; Semeralul, Mawahib O.; Chen, Robert; Fitzgerald, Paul B.

    2015-01-01

    Abnormal gamma-aminobutyric acid inhibitory neurotransmission is a key pathophysiological mechanism underlying schizophrenia. Transcranial magnetic stimulation can be combined with electroencephalography to index long-interval cortical inhibition, a measure of GABAergic receptor-mediated inhibitory neurotransmission from the frontal and motor cortex. In previous studies we have reported that schizophrenia is associated with inhibitory deficits in the dorsolateral prefrontal cortex compared to healthy subjects and patients with bipolar disorder. The main objective of the current study was to replicate and extend these initial findings by evaluating long-interval cortical inhibition from the dorsolateral prefrontal cortex in patients with schizophrenia compared to patients with obsessive-compulsive disorder. A total of 111 participants were assessed: 38 patients with schizophrenia (average age: 35.71 years, 25 males, 13 females), 27 patients with obsessive-compulsive disorder (average age: 36.15 years, 11 males, 16 females) and 46 healthy subjects (average age: 33.63 years, 23 females, 23 males). Long-interval cortical inhibition was measured from the dorsolateral prefrontal cortex and motor cortex through combined transcranial magnetic stimulation and electroencephalography. In the dorsolateral prefrontal cortex, long-interval cortical inhibition was significantly reduced in patients with schizophrenia compared to healthy subjects (P = 0.004) and not significantly different between patients with obsessive-compulsive disorder and healthy subjects (P = 0.5445). Long-interval cortical inhibition deficits in the dorsolateral prefrontal cortex were also significantly greater in patients with schizophrenia compared to patients with obsessive-compulsive disorder (P = 0.0465). There were no significant differences in long-interval cortical inhibition across all three groups in the motor cortex. These results demonstrate that long-interval cortical inhibition deficits in the

  9. Orbitofrontal Cortex Volume and Brain Reward Response in Obesity

    PubMed Central

    Shott, Megan E.; Cornier, Marc-Andre; Mittal, Vijay A.; Pryor, Tamara L.; Orr, Joseph M.; Brown, Mark S.; Frank, Guido K.W.

    2014-01-01

    Background/Objectives What drives overconsumption of food is poorly understood. Alterations in brain structure and function could contribute to increased food seeking. Recently brain orbitofrontal cortex volume has been implicated in dysregulated eating but little is know how brain structure relates to function. Subjects/Methods We examined obese (n=18, age=28.7.4±8.3 years) and healthy control women (n=24, age=27.4±6.3 years) using a multimodal brain imaging approach. We applied magnetic resonance and diffusion tensor imaging to study brain gray and white matter volume as well as white matter integrity, and tested whether orbitofrontal cortex volume predicts brain reward circuitry activation in a taste reinforcement-learning paradigm that has been associated with dopamine function. Results Obese individuals displayed lower gray and associated white matter volumes (p<.05 family wise error (FWE)-small volume corrected) compared to controls in the orbitofrontal cortex, striatum, and insula. White matter integrity was reduced in obese individuals in fiber tracts including the external capsule, corona radiata, sagittal stratum, and the uncinate, inferior fronto-occipital, and inferior longitudinal fasciculi. Gray matter volume of the gyrus rectus at the medial edge of the orbitofrontal cortex predicted functional taste reward-learning response in frontal cortex, insula, basal ganglia, amygdala, hypothalamus and anterior cingulate cortex in control but not obese individuals. Conclusions This study indicates a strong association between medial orbitofrontal cortex volume and taste reinforcement-learning activation in the brain in control but not in obese women. Lower brain volumes in the orbitofrontal cortex and other brain regions associated with taste reward function as well as lower integrity of connecting pathways in obesity may support a more widespread disruption of reward pathways. The medial orbitofrontal cortex is an important structure in the termination of

  10. Stream segregation in the anesthetized auditory cortex.

    PubMed

    Scholes, Chris; Palmer, Alan R; Sumner, Christian J

    2015-10-01

    Auditory stream segregation describes the way that sounds are perceptually segregated into groups or streams on the basis of perceptual attributes such as pitch or spectral content. For sequences of pure tones, segregation depends on the tones' proximity in frequency and time. In the auditory cortex (and elsewhere) responses to sequences of tones are dependent on stimulus conditions in a similar way to the perception of these stimuli. However, although highly dependent on stimulus conditions, perception is also clearly influenced by factors unrelated to the stimulus, such as attention. Exactly how 'bottom-up' sensory processes and non-sensory 'top-down' influences interact is still not clear. Here, we recorded responses to alternating tones (ABAB …) of varying frequency difference (FD) and rate of presentation (PR) in the auditory cortex of anesthetized guinea-pigs. These data complement previous studies, in that top-down processing resulting from conscious perception should be absent or at least considerably attenuated. Under anesthesia, the responses of cortical neurons to the tone sequences adapted rapidly, in a manner sensitive to both the FD and PR of the sequences. While the responses to tones at frequencies more distant from neuron best frequencies (BFs) decreased as the FD increased, the responses to tones near to BF increased, consistent with a release from adaptation, or forward suppression. Increases in PR resulted in reductions in responses to all tones, but the reduction was greater for tones further from BF. Although asymptotically adapted responses to tones showed behavior that was qualitatively consistent with perceptual stream segregation, responses reached asymptote within 2 s, and responses to all tones were very weak at high PRs (>12 tones per second). A signal-detection model, driven by the cortical population response, made decisions that were dependent on both FD and PR in ways consistent with perceptual stream segregation. This

  11. The spatiotopic 'visual' cortex of the blind

    NASA Astrophysics Data System (ADS)

    Likova, Lora

    2012-03-01

    Visual cortex activity in the blind has been shown in sensory tasks. Can it be activated in memory tasks? If so, are inherent features of its organization meaningfully employed? Our recent results in short-term blindfolded subjects imply that human primary visual cortex (V1) may operate as a modality-independent 'sketchpad' for working memory (Likova, 2010a). Interestingly, the spread of the V1 activation approximately corresponded to the spatial extent of the images in terms of their angle of projection to the subject. We now raise the questions of whether under long-term visual deprivation V1 is also employed in non-visual memory task, in particular in congenitally blind individuals, who have never had visual stimulation to guide the development of the visual area organization, and whether such spatial organization is still valid for the same paradigm that was used in blindfolded individuals. The outcome has implications for an emerging reconceptualization of the principles of brain architecture and its reorganization under sensory deprivation. Methods: We used a novel fMRI drawing paradigm in congenitally and late-onset blind, compared with sighted and blindfolded subjects in three conditions of 20s duration, separated by 20s rest-intervals, (i) Tactile Exploration: raised-line images explored and memorized; (ii) Tactile Memory Drawing: drawing the explored image from memory; (iii) Scribble: mindless drawing movements with no memory component. Results and Conclusions: V1 was strongly activated for Tactile Memory Drawing and Tactile Exploration in these totally blind subjects. Remarkably, after training, even in the memory task, the mapping of V1 activation largely corresponded to the angular projection of the tactile stimuli relative to the ego-center (i.e., the effective visual angle at the head); beyond this projective boundary, peripheral V1 signals were dramatically reduced or even suppressed. The matching extent of the activation in the congenitally blind

  12. Stream segregation in the anesthetized auditory cortex

    PubMed Central

    Scholes, Chris; Palmer, Alan R.; Sumner, Christian J.

    2015-01-01

    Auditory stream segregation describes the way that sounds are perceptually segregated into groups or streams on the basis of perceptual attributes such as pitch or spectral content. For sequences of pure tones, segregation depends on the tones' proximity in frequency and time. In the auditory cortex (and elsewhere) responses to sequences of tones are dependent on stimulus conditions in a similar way to the perception of these stimuli. However, although highly dependent on stimulus conditions, perception is also clearly influenced by factors unrelated to the stimulus, such as attention. Exactly how ‘bottom-up’ sensory processes and non-sensory ‘top-down’ influences interact is still not clear. Here, we recorded responses to alternating tones (ABAB …) of varying frequency difference (FD) and rate of presentation (PR) in the auditory cortex of anesthetized guinea-pigs. These data complement previous studies, in that top-down processing resulting from conscious perception should be absent or at least considerably attenuated. Under anesthesia, the responses of cortical neurons to the tone sequences adapted rapidly, in a manner sensitive to both the FD and PR of the sequences. While the responses to tones at frequencies more distant from neuron best frequencies (BFs) decreased as the FD increased, the responses to tones near to BF increased, consistent with a release from adaptation, or forward suppression. Increases in PR resulted in reductions in responses to all tones, but the reduction was greater for tones further from BF. Although asymptotically adapted responses to tones showed behavior that was qualitatively consistent with perceptual stream segregation, responses reached asymptote within 2 s, and responses to all tones were very weak at high PRs (>12 tones per second). A signal-detection model, driven by the cortical population response, made decisions that were dependent on both FD and PR in ways consistent with perceptual stream segregation. This

  13. A functional microcircuit for cat visual cortex.

    PubMed Central

    Douglas, R J; Martin, K A

    1991-01-01

    1. We have studied in vivo the intracellular responses of neurones in cat visual cortex to electrical pulse stimulation of the cortical afferents and have developed a microcircuit that simulates much of the experimental data. 2. Inhibition and excitation are not separable events, because individual neurones are embedded in microcircuits that contribute strong population effects. Synchronous electrical activation of the cortex inevitably set in motion a sequence of excitation and inhibition in every neurone we recorded. The temporal form of this response depends on the cortical layer in which the neurone is located. Superficial layer (layers 2+3) pyramidal neurones show a more marked polysynaptic excitatory phase than the pyramids of the deep layers (layers 5+6). 3. Excitatory effects on pyramidal neurones, particularly the superficial layer pyramids, are in general not due to monosynaptic input from thalamus, but polysynaptic input from cortical pyramids. Since the thalamic input is transient it does not provide the major, sustained excitation arriving at any cortical neurone. Instead the intracortical excitatory connections provide the major component of the excitation. 4. The polysynaptic excitatory response would be sustained well after the stimulus, were it not for the suppressive effect of intracortical inhibition induced by the pulse stimulation. 5. Intracellular recording combined with ionophoresis of gamma-aminobutyric acid (GABA) agonists and antagonists showed that intracortical inhibition is mediated by GABAA and GABAB receptors. The GABAA component occurs in the early phase of the impulse response. It is reflected in the strong hyperpolarization that follows the excitatory response and lasts about 50 ms. The GABAB component occurs in the late phase of the response, and is reflected in a sustained hyperpolarization that lasts some 200-300 ms. Both components are seen in all cortical pyramidal neurones. However, the GABAA component appears more powerful

  14. METAPHORICALLY FEELING: COMPREHENDING TEXTURAL METAPHORS ACTIVATES SOMATOSENSORY CORTEX

    PubMed Central

    Lacey, Simon; Stilla, Randall; Sathian, K.

    2012-01-01

    Conceptual metaphor theory suggests that knowledge is structured around metaphorical mappings derived from physical experience. Segregated processing of object properties in sensory cortex allows testing of the hypothesis that metaphor processing recruits activity in domain-specific sensory cortex. Using functional magnetic resonance imaging (fMRI) we show that texture-selective somatosensory cortex in the parietal operculum is activated when processing sentences containing textural metaphors, compared to literal sentences matched for meaning. This finding supports the idea that comprehension of metaphors is perceptually grounded. PMID:22305051

  15. Local production of astrocytes in the cerebral cortex.

    PubMed

    Ge, W-P; Jia, J-M

    2016-05-26

    Astrocytes are the largest glial population in the mammalian brain. Astrocytes in the cerebral cortex are reportedly generated from four sources, namely radial glia, progenitors in the subventricular zone (SVZ progenitors), locally proliferating glia, and NG2 glia; it remains an open question, however, as to what extent these four cell types contribute to the substantial increase in astrocytes that occurs postnatally in the cerebral cortex. Here we summarize all possible sources of astrocytes and discuss their roles in this postnatal increase. In particular, we focus on astrocytes derived from local proliferation within the cortex. PMID:26343293

  16. Optogenetic dissection of medial prefrontal cortex circuitry

    PubMed Central

    Riga, Danai; Matos, Mariana R.; Glas, Annet; Smit, August B.; Spijker, Sabine; Van den Oever, Michel C.

    2014-01-01

    The medial prefrontal cortex (mPFC) is critically involved in numerous cognitive functions, including attention, inhibitory control, habit formation, working memory and long-term memory. Moreover, through its dense interconnectivity with subcortical regions (e.g., thalamus, striatum, amygdala and hippocampus), the mPFC is thought to exert top-down executive control over the processing of aversive and appetitive stimuli. Because the mPFC has been implicated in the processing of a wide range of cognitive and emotional stimuli, it is thought to function as a central hub in the brain circuitry mediating symptoms of psychiatric disorders. New optogenetics technology enables anatomical and functional dissection of mPFC circuitry with unprecedented spatial and temporal resolution. This provides important novel insights in the contribution of specific neuronal subpopulations and their connectivity to mPFC function in health and disease states. In this review, we present the current knowledge obtained with optogenetic methods concerning mPFC function and dysfunction and integrate this with findings from traditional intervention approaches used to investigate the mPFC circuitry in animal models of cognitive processing and psychiatric disorders. PMID:25538574

  17. Cortex phellodendri Extract Relaxes Airway Smooth Muscle

    PubMed Central

    Jiang, Qiu-Ju; Chen, Weiwei; Dan, Hong; Tan, Li; Zhu, He; Yang, Guangzhong; Shen, Jinhua; Peng, Yong-Bo; Zhao, Ping; Xue, Lu; Yu, Meng-Fei; Ma, Liqun; Si, Xiao-Tang; Wang, Zhuo; Dai, Jiapei; Qin, Gangjian; Zou, Chunbin; Liu, Qing-Hua

    2016-01-01

    Cortex phellodendri is used to reduce fever and remove dampness and toxin. Berberine is an active ingredient of C. phellodendri. Berberine from Argemone ochroleuca can relax airway smooth muscle (ASM); however, whether the nonberberine component of C. phellodendri has similar relaxant action was unclear. An n-butyl alcohol extract of C. phellodendri (NBAECP, nonberberine component) was prepared, which completely inhibits high K+- and acetylcholine- (ACH-) induced precontraction of airway smooth muscle in tracheal rings and lung slices from control and asthmatic mice, respectively. The contraction induced by high K+ was also blocked by nifedipine, a selective blocker of L-type Ca2+ channels. The ACH-induced contraction was partially inhibited by nifedipine and pyrazole 3, an inhibitor of TRPC3 and STIM/Orai channels. Taken together, our data demonstrate that NBAECP can relax ASM by inhibiting L-type Ca2+ channels and TRPC3 and/or STIM/Orai channels, suggesting that NBAECP could be developed to a new drug for relieving bronchospasm. PMID:27239213

  18. Decoding Trajectories from Posterior Parietal Cortex Ensembles

    PubMed Central

    Mulliken, Grant H.; Musallam, Sam; Andersen, Richard A.

    2009-01-01

    High-level cognitive signals in the posterior parietal cortex (PPC) have previously been used to decode the intended endpoint of a reach, providing the first evidence that PPC can be used for direct control of a neural prosthesis (Musallam et al., 2004). Here we expand on this work by showing that PPC neural activity can be harnessed to estimate not only the endpoint but also to continuously control the trajectory of an end effector. Specifically, we trained two monkeys to use a joystick to guide a cursor on a computer screen to peripheral target locations while maintaining central ocular fixation. We found that we could accurately reconstruct the trajectory of the cursor using a relatively small ensemble of simultaneously recorded PPC neurons. Using a goal-based Kalman filter that incorporates target information into the state-space, we showed that the decoded estimate of cursor position could be significantly improved. Finally, we tested whether we could decode trajectories during closed-loop brain control sessions, in which the real-time position of the cursor was determined solely by a monkey’s neural activity in PPC. The monkey learned to perform brain control trajectories at 80% success rate(for 8 targets) after just 4–5 sessions. This improvement in behavioral performance was accompanied by a corresponding enhancement in neural tuning properties (i.e., increased tuning depth and coverage of encoding parameter space) as well as an increase in off-line decoding performance of the PPC ensemble. PMID:19036985

  19. The medial prefrontal cortex exhibits money illusion

    PubMed Central

    Weber, Bernd; Rangel, Antonio; Wibral, Matthias; Falk, Armin

    2009-01-01

    Behavioral economists have proposed that money illusion, which is a deviation from rationality in which individuals engage in nominal evaluation, can explain a wide range of important economic and social phenomena. This proposition stands in sharp contrast to the standard economic assumption of rationality that requires individuals to judge the value of money only on the basis of the bundle of goods that it can buy—its real value—and not on the basis of the actual amount of currency—its nominal value. We used fMRI to investigate whether the brain's reward circuitry exhibits money illusion. Subjects received prizes in 2 different experimental conditions that were identical in real economic terms, but differed in nominal terms. Thus, in the absence of money illusion there should be no differences in activation in reward-related brain areas. In contrast, we found that areas of the ventromedial prefrontal cortex (vmPFC), which have been previously associated with the processing of anticipatory and experienced rewards, and the valuation of goods, exhibited money illusion. We also found that the amount of money illusion exhibited by the vmPFC was correlated with the amount of money illusion exhibited in the evaluation of economic transactions. PMID:19307555

  20. Lateralization of auditory-cortex functions.

    PubMed

    Tervaniemi, Mari; Hugdahl, Kenneth

    2003-12-01

    In the present review, we summarize the most recent findings and current views about the structural and functional basis of human brain lateralization in the auditory modality. Main emphasis is given to hemodynamic and electromagnetic data of healthy adult participants with regard to music- vs. speech-sound encoding. Moreover, a selective set of behavioral dichotic-listening (DL) results and clinical findings (e.g., schizophrenia, dyslexia) are included. It is shown that human brain has a strong predisposition to process speech sounds in the left and music sounds in the right auditory cortex in the temporal lobe. Up to great extent, an auditory area located at the posterior end of the temporal lobe (called planum temporale [PT]) underlies this functional asymmetry. However, the predisposition is not bound to informational sound content but to rapid temporal information more common in speech than in music sounds. Finally, we obtain evidence for the vulnerability of the functional specialization of sound processing. These altered forms of lateralization may be caused by top-down and bottom-up effects inter- and intraindividually In other words, relatively small changes in acoustic sound features or in their familiarity may modify the degree in which the left vs. right auditory areas contribute to sound encoding. PMID:14629926

  1. Sensitivity to syntax in visual cortex

    PubMed Central

    Dikker, Suzanne; Rabagliati, Hugh; Pylkkänen, Liina

    2009-01-01

    One of the most intriguing findings on language comprehension is that violations of syntactic predictions can affect event-related potentials as early as 120 ms, in the same time-window as early sensory processing. This effect, the so-called early left-anterior negativity (ELAN), has been argued to reflect word category access and initial syntactic structure building (Friederici, 2002). In two experiments, we used magnetoencephalography to investigate whether (a) rapid word category identification relies on overt category-marking closed-class morphemes and (b) whether violations of word category predictions affect modality-specific sensory responses. Participants read sentences containing violations of word category predictions. Unexpected items varied in whether or not their word category was marked by an overt function morpheme. In Experiment 1, the amplitude of the visual evoked M100 component was increased for unexpected items, but only when word category was overtly marked by a function morpheme. Dipole modeling localized the generator of this effect to the occipital cortex. Experiment 2 replicated the main results of Experiment 1 and eliminated two non-morphology-related explanations of the M100 contrast we observed between targets containing overt category-marking and targets that lacked such morphology. Our results show that during reading, syntactically relevant cues in the input can affect activity in occipital regions at around 125 ms, a finding that may shed new light on the remarkable rapidity of language processing. PMID:19121826

  2. Inhibition in the Human Auditory Cortex

    PubMed Central

    Inui, Koji; Nakagawa, Kei; Nishihara, Makoto; Motomura, Eishi; Kakigi, Ryusuke

    2016-01-01

    Despite their indispensable roles in sensory processing, little is known about inhibitory interneurons in humans. Inhibitory postsynaptic potentials cannot be recorded non-invasively, at least in a pure form, in humans. We herein sought to clarify whether prepulse inhibition (PPI) in the auditory cortex reflected inhibition via interneurons using magnetoencephalography. An abrupt increase in sound pressure by 10 dB in a continuous sound was used to evoke the test response, and PPI was observed by inserting a weak (5 dB increase for 1 ms) prepulse. The time course of the inhibition evaluated by prepulses presented at 10–800 ms before the test stimulus showed at least two temporally distinct inhibitions peaking at approximately 20–60 and 600 ms that presumably reflected IPSPs by fast spiking, parvalbumin-positive cells and somatostatin-positive, Martinotti cells, respectively. In another experiment, we confirmed that the degree of the inhibition depended on the strength of the prepulse, but not on the amplitude of the prepulse-evoked cortical response, indicating that the prepulse-evoked excitatory response and prepulse-evoked inhibition reflected activation in two different pathways. Although many diseases such as schizophrenia may involve deficits in the inhibitory system, we do not have appropriate methods to evaluate them; therefore, the easy and non-invasive method described herein may be clinically useful. PMID:27219470

  3. Does the orbitofrontal cortex signal value?

    PubMed Central

    Schoenbaum, Geoffrey; Takahashi, Yuji; Liu, Tzu-Lan; McDannald, Michael A.

    2012-01-01

    The orbitofrontal cortex (OFC) has long been implicated in associative learning. Early work by Mishkin and Rolls showed that the OFC was critical for rapid changes in learned behavior, a role that was reflected in the encoding of associative information by orbitofrontal neurons. Over the years, new data—particularly neurophysiological data—have increasingly emphasized the OFC in signaling actual value. These signals have been reported to vary according to internal preferences and judgments and to even be completely independent of the sensory qualities of predictive cues, the actual rewards, and the responses required to obtain them. At the same time, increasingly sophisticated behavioral studies have shown that the OFC is often unnecessary for simple value-based behavior and instead seems critical when information about specific outcomes must be used to guide behavior and learning. Here, we review these data and suggest a theory that potentially reconciles these two ideas, value versus specific outcomes, and bodies of work on the OFC. PMID:22145878

  4. The perirhinal cortex and recognition memory interference

    PubMed Central

    Watson, H.C.; Lee, A. C. H.

    2013-01-01

    There has recently been an increase in interest in the effects of visual interference on memory processing, with the aim of eluciating the role of the perirhinal cortex (PRC) in recognition memory. One view argues that the PRC processes highly complex conjunctions of object features, and recent evidence from rodents suggests that these representations may be vital for buffering against the effects of pre-retrieval interference on object recognition memory. To investigate whether PRC-dependent object representations play a similar role in humans, we used functional magnetic resonance imaging to scan neurologically healthy participants while they carried out a novel interference-match-to-sample task. This paradigm was specifically designed to concurrently assess the impact of object vs. spatial interference, on recognition memory for objects or scenes, while keeping constant the amount of object and scene information presented across all trials. Activity at retrieval was examined, within an anatomically defined PRC region of interest, according to the demand for object or scene memory, following a period of object compared to spatial interference. Critically, we found greater PRC activity for object memory following object interference, compared to object memory following scene interference, and no difference between object and scene interference for scene recognition. These data demonstrate a role for the human PRC following a period of object, but not scene, interference, during object recognition memory, and emphasize the importance of representational content to mnemonic processing. PMID:23447626

  5. Concentric scheme of monkey auditory cortex

    NASA Astrophysics Data System (ADS)

    Kosaki, Hiroko; Saunders, Richard C.; Mishkin, Mortimer

    2003-04-01

    The cytoarchitecture of the rhesus monkey's auditory cortex was examined using immunocytochemical staining with parvalbumin, calbindin-D28K, and SMI32, as well as staining for cytochrome oxidase (CO). The results suggest that Kaas and Hackett's scheme of the auditory cortices can be extended to include five concentric rings surrounding an inner core. The inner core, containing areas A1 and R, is the most densely stained with parvalbumin and CO and can be separated on the basis of laminar patterns of SMI32 staining into lateral and medial subdivisions. From the inner core to the fifth (outermost) ring, parvalbumin staining gradually decreases and calbindin staining gradually increases. The first ring corresponds to Kaas and Hackett's auditory belt, and the second, to their parabelt. SMI32 staining revealed a clear border between these two. Rings 2 through 5 extend laterally into the dorsal bank of the superior temporal sulcus. The results also suggest that the rostral tip of the outermost ring adjoins the rostroventral part of the insula (area Pro) and the temporal pole, while the caudal tip adjoins the ventral part of area 7a.

  6. Perceptual Learning In The Developing Auditory Cortex

    PubMed Central

    Bao, Shaowen

    2015-01-01

    A hallmark of the developing auditory cortex is the heightened plasticity in the critical period, during which acoustic inputs can indelibly alter cortical function. However, not all sounds in the natural acoustic environment are ethologically relevant. How does the auditory system resolve relevant sounds from the acoustic environment in such an early developmental stage when most associative learning mechanisms are not yet fully functional? What can the auditory system learn from one of the most important classes of sounds—animal vocalizations? How does naturalistic acoustic experience shape cortical sound representation and perception? To answer these questions, we need to consider an unusual strategy—statistical learning—where what the system needs to learn is embedded in the sensory input. Here, I will review recent findings on how certain statistical structure of natural animal vocalizations shapes auditory cortical acoustic representations, and how cortical plasticity may underlie learned categorical sound perception. These results will be discussed in the context of human speech perception. PMID:25728188

  7. Retinal Oscillations Carry Visual Information to Cortex

    PubMed Central

    Koepsell, Kilian; Wang, Xin; Vaingankar, Vishal; Wei, Yichun; Wang, Qingbo; Rathbun, Daniel L.; Usrey, W. Martin; Hirsch, Judith A.; Sommer, Friedrich T.

    2009-01-01

    Thalamic relay cells fire action potentials that transmit information from retina to cortex. The amount of information that spike trains encode is usually estimated from the precision of spike timing with respect to the stimulus. Sensory input, however, is only one factor that influences neural activity. For example, intrinsic dynamics, such as oscillations of networks of neurons, also modulate firing pattern. Here, we asked if retinal oscillations might help to convey information to neurons downstream. Specifically, we made whole-cell recordings from relay cells to reveal retinal inputs (EPSPs) and thalamic outputs (spikes) and then analyzed these events with information theory. Our results show that thalamic spike trains operate as two multiplexed channels. One channel, which occupies a low frequency band (<30 Hz), is encoded by average firing rate with respect to the stimulus and carries information about local changes in the visual field over time. The other operates in the gamma frequency band (40–80 Hz) and is encoded by spike timing relative to retinal oscillations. At times, the second channel conveyed even more information than the first. Because retinal oscillations involve extensive networks of ganglion cells, it is likely that the second channel transmits information about global features of the visual scene. PMID:19404487

  8. Beta Oscillation Dynamics in Extrastriate Cortex after Removal of Primary Visual Cortex

    PubMed Central

    Schmiedt, Joscha T.; Maier, Alexander; Fries, Pascal; Saunders, Richard C.; Leopold, David A.

    2014-01-01

    The local field potential (LFP) in visual cortex is typically characterized by the following spectral pattern: before the onset of a visual stimulus, low-frequency oscillations (beta, 12–20 Hz) dominate, whereas during the presentation of a stimulus these oscillations diminish and are replaced by fluctuations at higher frequencies (gamma, >30 Hz). The origin of beta oscillations in vivo remains unclear, as is the basis of their suppression during visual stimulation. Here we investigate the contribution of ascending input from primary visual cortex (V1) to beta oscillation dynamics in extrastriate visual area V4 of behaving monkeys. We recorded LFP activity in V4 before and after resecting a portion of V1. After the surgery, the visually induced gamma LFP activity in the lesion projection zone of V4 was markedly reduced, consistent with previously reported spiking responses (Schmid et al., 2013). In the beta LFP range, the lesion had minimal effect on the normal pattern of spontaneous oscillations. However, the lesion led to a surprising and permanent reversal of the normal beta suppression during visual stimulation, with visual stimuli eliciting beta magnitude increases up to 50%, particularly in response to moving stimuli. This reversed beta activity pattern was specific to stimulus locations affected by the V1 lesion. Our results shed light on the mechanisms of beta activity in extrastriate visual cortex: The preserved spontaneous oscillations point to a generation mechanism independent of the geniculostriate pathway, whereas the positive beta responses support the contribution of visual information to V4 via direct thalamo-extrastriate projections. PMID:25164679

  9. From the Cover: Odor maps in the olfactory cortex

    NASA Astrophysics Data System (ADS)

    Zou, Zhihua; Li, Fusheng; Buck, Linda B.

    2005-05-01

    In the olfactory system, environmental chemicals are deconstructed into neural signals and then reconstructed to form odor perceptions. Much has been learned about odor coding in the olfactory epithelium and bulb, but little is known about how odors are subsequently encoded in the cortex to yield diverse perceptions. Here, we report that the representation of odors by fixed glomeruli in the olfactory bulb is transformed in the cortex into highly distributed and multiplexed odor maps. In the mouse olfactory cortex, individual odorants are represented by subsets of sparsely distributed neurons. Different odorants elicit distinct, but partially overlapping, patterns that are strikingly similar among individuals. With increases in odorant concentration, the representations expand spatially and include additional cortical neurons. Structurally related odorants have highly related representations, suggesting an underlying logic to the mapping of odor identities in the cortex. odorant receptor | smell

  10. Cortex Matures Faster in Youths With Highest IQ

    MedlinePlus

    ... Research News From NIH Cortex Matures Faster in Youths With Highest IQ Past Issues / Summer 2006 Table ... please turn Javascript on. Photo: Getty image (StockDisc) Youths with superior IQ are distinguished by how fast ...

  11. Ventromedial prefrontal cortex mediates visual attention during facial emotion recognition

    PubMed Central

    Wolf, Richard C.; Philippi, Carissa L.; Motzkin, Julian C.; Baskaya, Mustafa K.

    2014-01-01

    The ventromedial prefrontal cortex is known to play a crucial role in regulating human social and emotional behaviour, yet the precise mechanisms by which it subserves this broad function remain unclear. Whereas previous neuropsychological studies have largely focused on the role of the ventromedial prefrontal cortex in higher-order deliberative processes related to valuation and decision-making, here we test whether ventromedial prefrontal cortex may also be critical for more basic aspects of orienting attention to socially and emotionally meaningful stimuli. Using eye tracking during a test of facial emotion recognition in a sample of lesion patients, we show that bilateral ventromedial prefrontal cortex damage impairs visual attention to the eye regions of faces, particularly for fearful faces. This finding demonstrates a heretofore unrecognized function of the ventromedial prefrontal cortex—the basic attentional process of controlling eye movements to faces expressing emotion. PMID:24691392

  12. The Laryngeal Motor Cortex: Its Organization and Connectivity

    PubMed Central

    Simonyan, Kristina

    2014-01-01

    Our ability to learn and control the motor aspects of complex laryngeal behaviors, such as speech and song, is modulated by the laryngeal motor cortex (LMC), which is situated in the area 4 of the primary motor cortex and establishes both direct and indirect connections with laryngeal motoneurons. In contrast, the LMC in monkeys is located in the area 6 of the premotor cortex, projects only indirectly to laryngeal motoneurons and its destruction has essentially no effect on production of species-specific calls. These differences in cytoarchitectonic location and connectivity may be a result of hominid evolution that led to the LMC shift from the phylogenetically “old” to “new” motor cortex in order to fulfill its paramount function, i.e., voluntary motor control of human speech and song production. PMID:24929930

  13. Robust neuronal dynamics in premotor cortex during motor planning.

    PubMed

    Li, Nuo; Daie, Kayvon; Svoboda, Karel; Druckmann, Shaul

    2016-04-28

    Neural activity maintains representations that bridge past and future events, often over many seconds. Network models can produce persistent and ramping activity, but the positive feedback that is critical for these slow dynamics can cause sensitivity to perturbations. Here we use electrophysiology and optogenetic perturbations in the mouse premotor cortex to probe the robustness of persistent neural representations during motor planning. We show that preparatory activity is remarkably robust to large-scale unilateral silencing: detailed neural dynamics that drive specific future movements were quickly and selectively restored by the network. Selectivity did not recover after bilateral silencing of the premotor cortex. Perturbations to one hemisphere are thus corrected by information from the other hemisphere. Corpus callosum bisections demonstrated that premotor cortex hemispheres can maintain preparatory activity independently. Redundancy across selectively coupled modules, as we observed in the premotor cortex, is a hallmark of robust control systems. Network models incorporating these principles show robustness that is consistent with data. PMID:27074502

  14. The onset of visual experience gates auditory cortex critical periods

    PubMed Central

    Mowery, Todd M.; Kotak, Vibhakar C.; Sanes, Dan H.

    2016-01-01

    Sensory systems influence one another during development and deprivation can lead to cross-modal plasticity. As auditory function begins before vision, we investigate the effect of manipulating visual experience during auditory cortex critical periods (CPs) by assessing the influence of early, normal and delayed eyelid opening on hearing loss-induced changes to membrane and inhibitory synaptic properties. Early eyelid opening closes the auditory cortex CPs precociously and dark rearing prevents this effect. In contrast, delayed eyelid opening extends the auditory cortex CPs by several additional days. The CP for recovery from hearing loss is also closed prematurely by early eyelid opening and extended by delayed eyelid opening. Furthermore, when coupled with transient hearing loss that animals normally fully recover from, very early visual experience leads to inhibitory deficits that persist into adulthood. Finally, we demonstrate a functional projection from the visual to auditory cortex that could mediate these effects. PMID:26786281

  15. Cortex Matures Faster in Youths With Highest IQ

    MedlinePlus

    ... NIH Cortex Matures Faster in Youths With Highest IQ Past Issues / Summer 2006 Table of Contents For ... on. Photo: Getty image (StockDisc) Youths with superior IQ are distinguished by how fast the thinking part ...

  16. Left auditory cortex specialization for vertical harmonic structure of chords.

    PubMed

    Passynkova, Natalia; Sander, Kerstin; Scheich, Henning

    2005-12-01

    The representation of consonant and dissonant chords in the auditory cortex was investigated using low-noise functional magnetic resonance imaging and different experimental paradigms to separate the effects of vertical harmony from those of other musical features. The results revealed higher activation by consonant compared with dissonant chords in the left posterior auditory cortex, suggesting contributions of mechanisms of encoding the acoustical chord structure rather than mechanisms based on sequential integration of chords. PMID:16597802

  17. Specialized cortical subnetworks differentially connect frontal cortex to parahippocampal areas.

    PubMed

    Hirai, Yasuharu; Morishima, Mieko; Karube, Fuyuki; Kawaguchi, Yasuo

    2012-02-01

    How information is manipulated and segregated within local circuits in the frontal cortex remains mysterious, in part because of inadequate knowledge regarding the connectivity of diverse pyramidal cell subtypes. The frontal cortex participates in the formation and retrieval of declarative memories through projections to the perirhinal cortex, and in procedural learning through projections to the striatum/pontine nuclei. In rat frontal cortex, we identified two pyramidal cell subtypes selectively projecting to distinct subregions of perirhinal cortex (PRC). PRC-projecting cells in upper layer 2/3 (L2/3) of the frontal cortex projected to perirhinal area 35, while neurons in L5 innervated perirhinal area 36. L2/3 PRC-projecting cells partially overlapped with those projecting to the basolateral amygdala. L5 PRC-projecting cells partially overlapped with crossed corticostriatal cells, but were distinct from neighboring corticothalamic (CTh)/corticopontine cells. L5 PRC-projecting and CTh cells were different in their electrophysiological properties and dendritic/axonal morphologies. Within the frontal cortex, L2/3 PRC-projecting cells innervated L5 PRC-projecting and CTh cells with similar probabilities, but received feedback excitation only from PRC-projecting cells. These data suggest that specific neuron subtypes in different cortical layers are reciprocally excited via interlaminar loops. Thus, two interacting output channels send information from the frontal cortex to different hierarchical stages of the parahippocampal network, areas 35 and 36, with additional collaterals selectively targeting the amygdala or basal ganglia, respectively. Combined with the hierarchical connectivity of PRC-projecting and CTh cells, these observations demonstrate an exquisite diversification of frontal projection neurons selectively connected according to their participation in distinct memory subsystems. PMID:22302828

  18. Auditory Cortex Basal Activity Modulates Cochlear Responses in Chinchillas

    PubMed Central

    León, Alex; Elgueda, Diego; Silva, María A.; Hamamé, Carlos M.; Delano, Paul H.

    2012-01-01

    Background The auditory efferent system has unique neuroanatomical pathways that connect the cerebral cortex with sensory receptor cells. Pyramidal neurons located in layers V and VI of the primary auditory cortex constitute descending projections to the thalamus, inferior colliculus, and even directly to the superior olivary complex and to the cochlear nucleus. Efferent pathways are connected to the cochlear receptor by the olivocochlear system, which innervates outer hair cells and auditory nerve fibers. The functional role of the cortico-olivocochlear efferent system remains debated. We hypothesized that auditory cortex basal activity modulates cochlear and auditory-nerve afferent responses through the efferent system. Methodology/Principal Findings Cochlear microphonics (CM), auditory-nerve compound action potentials (CAP) and auditory cortex evoked potentials (ACEP) were recorded in twenty anesthetized chinchillas, before, during and after auditory cortex deactivation by two methods: lidocaine microinjections or cortical cooling with cryoloops. Auditory cortex deactivation induced a transient reduction in ACEP amplitudes in fifteen animals (deactivation experiments) and a permanent reduction in five chinchillas (lesion experiments). We found significant changes in the amplitude of CM in both types of experiments, being the most common effect a CM decrease found in fifteen animals. Concomitantly to CM amplitude changes, we found CAP increases in seven chinchillas and CAP reductions in thirteen animals. Although ACEP amplitudes were completely recovered after ninety minutes in deactivation experiments, only partial recovery was observed in the magnitudes of cochlear responses. Conclusions/Significance These results show that blocking ongoing auditory cortex activity modulates CM and CAP responses, demonstrating that cortico-olivocochlear circuits regulate auditory nerve and cochlear responses through a basal efferent tone. The diversity of the obtained effects

  19. Reduced structural connectivity in ventral visual cortex in congenital prosopagnosia.

    PubMed

    Thomas, Cibu; Avidan, Galia; Humphreys, Kate; Jung, Kwan-jin; Gao, Fuqiang; Behrmann, Marlene

    2009-01-01

    Using diffusion tensor imaging and tractography, we found that a disruption in structural connectivity in ventral occipito-temporal cortex may be the neurobiological basis for the lifelong impairment in face recognition that is experienced by individuals who suffer from congenital prosopagnosia. Our findings suggest that white-matter fibers in ventral occipito-temporal cortex support the integrated function of a distributed cortical network that subserves normal face processing. PMID:19029889

  20. Auditory Cortex Is Required for Fear Potentiation of Gap Detection

    PubMed Central

    Weible, Aldis P.; Liu, Christine; Niell, Cristopher M.

    2014-01-01

    Auditory cortex is necessary for the perceptual detection of brief gaps in noise, but is not necessary for many other auditory tasks such as frequency discrimination, prepulse inhibition of startle responses, or fear conditioning with pure tones. It remains unclear why auditory cortex should be necessary for some auditory tasks but not others. One possibility is that auditory cortex is causally involved in gap detection and other forms of temporal processing in order to associate meaning with temporally structured sounds. This predicts that auditory cortex should be necessary for associating meaning with gaps. To test this prediction, we developed a fear conditioning paradigm for mice based on gap detection. We found that pairing a 10 or 100 ms gap with an aversive stimulus caused a robust enhancement of gap detection measured 6 h later, which we refer to as fear potentiation of gap detection. Optogenetic suppression of auditory cortex during pairing abolished this fear potentiation, indicating that auditory cortex is critically involved in associating temporally structured sounds with emotionally salient events. PMID:25392510

  1. Neurodynamics of the prefrontal cortex during conditional visuomotor associations.

    PubMed

    Loh, Marco; Pasupathy, Anitha; Miller, Earl K; Deco, Gustavo

    2008-03-01

    The prefrontal cortex is believed to be important for cognitive control, working memory, and learning. It is known to play an important role in the learning and execution of conditional visuomotor associations, a cognitive task in which stimuli have to be associated with actions by trial-and-error learning. In our modeling study, we sought to integrate several hypotheses on the function of the prefrontal cortex using a computational model, and compare the results to experimental data. We constructed a module of prefrontal cortex neurons exposed to two different inputs, which we envision to originate from the inferotemporal cortex and the basal ganglia. We found that working memory properties do not describe the dominant dynamics in the prefrontal cortex, but the activation seems to be transient, probably progressing along a pathway from sensory to motor areas. During the presentation of the cue, the dynamics of the prefrontal cortex is bistable, yielding a distinct activation for correct and error trails. We find that a linear change in network parameters relates to the changes in neural activity in consecutive correct trials during learning, which is important evidence for the underlying learning mechanisms. PMID:18004947

  2. Dissociation in prefrontal cortex of affective and attentional shifts.

    PubMed

    Dias, R; Robbins, T W; Roberts, A C

    1996-03-01

    The prefrontal cortex is implicated in such human characteristics as volition, planning, abstract reasoning and affect. Frontal-lobe damage can cause disinhibition such that the behaviour of a subject is guided by previously acquired responses that are inappropriate to the current situation. Here we demonstrate that disinhibition, or a loss of inhibitory control, can be selective for particular cognitive functions and that different regions of the prefrontal cortex provide inhibitory control in different aspects of cognitive processing. Thus, whereas damage to the lateral prefrontal cortex (Brodmann's area 9) in monkeys causes a loss of inhibitory control in attentional selection, damage to the orbito-frontal cortex in monkeys causes a loss of inhibitory control in 'affective' processing, thereby impairing the ability to alter behaviour in response to fluctuations in the emotional significance of stimuli. These findings not only support the view that the prefrontal cortex has multiple functions, but also provide evidence for the distribution of different cognitive functions within specific regions of prefrontal cortex. PMID:8598908

  3. The Role of Cingulate Cortex in Vicarious Pain

    PubMed Central

    Yesudas, Esther H.; Lee, Tatia M. C.

    2015-01-01

    Vicarious pain is defined as the observation of individuals in pain. There is growing neuroimaging evidence suggesting that the cingulate cortex plays a significant role in self-experienced pain processing. Yet, very few studies have directly tested the distinct functions of the cingulate cortex for vicarious pain. In this review, one EEG and eighteen neuroimaging studies reporting cingulate cortex activity during pain observation were discussed. The data indicate that there is overlapping neural activity in the cingulate cortex during self- and vicarious pain. Such activity may contribute to shared neural pain representations that permit inference of the affective state of individuals in pain, facilitating empathy. However, the exact location of neuronal populations in which activity overlaps or differs for self- and observed pain processing requires further confirmation. This review also discusses evidence suggesting differential functions of the cingulate cortex in cognitive, affective, and motor processing during empathy induction. While affective processing in the cingulate cortex during pain observation has been explored relatively more often, its attention and motor roles remain underresearched. Shedding light on the neural correlates of vicarious pain and corresponding empathy in healthy populations can provide neurobiological markers and intervention targets for empathic deficits found in various clinical disorders. PMID:25815331

  4. Mechanisms of spatial attention control in frontal and parietal cortex.

    PubMed

    Szczepanski, Sara M; Konen, Christina S; Kastner, Sabine

    2010-01-01

    Theories of spatial attentional control have been largely based upon studies of patients suffering from visuospatial neglect, resulting from circumscribed lesions of frontal and posterior parietal cortex. In the intact brain, the control of spatial attention has been related to a distributed frontoparietal attention network. Little is known about the nature of the control mechanisms exerted by this network. Here, we used a novel region-of-interest approach to relate activations of the attention network to recently described topographic areas in frontal cortex [frontal eye field (FEF), PreCC/IFS (precentral cortex/inferior frontal sulcus)] and parietal cortex [intraparietal sulcus areas (IPS1-IPS5) and an area in the superior parietal lobule (SPL1)] to examine their spatial attention signals. We found that attention signals in most topographic areas were spatially specific, with stronger responses when attention was directed to the contralateral than to the ipsilateral visual field. Importantly, two hemispheric asymmetries were found. First, a region in only right, but not left SPL1 carried spatial attention signals. Second, left FEF and left posterior parietal cortex (IPS1/2) generated stronger contralateral biasing signals than their counterparts in the right hemisphere. These findings are the first to characterize spatial attention signals in topographic frontal and parietal cortex and provide a neural basis in support of an interhemispheric competition account of spatial attentional control. PMID:20053897

  5. Spatial processing in the auditory cortex of the macaque monkey

    NASA Astrophysics Data System (ADS)

    Recanzone, Gregg H.

    2000-10-01

    The patterns of cortico-cortical and cortico-thalamic connections of auditory cortical areas in the rhesus monkey have led to the hypothesis that acoustic information is processed in series and in parallel in the primate auditory cortex. Recent physiological experiments in the behaving monkey indicate that the response properties of neurons in different cortical areas are both functionally distinct from each other, which is indicative of parallel processing, and functionally similar to each other, which is indicative of serial processing. Thus, auditory cortical processing may be similar to the serial and parallel "what" and "where" processing by the primate visual cortex. If "where" information is serially processed in the primate auditory cortex, neurons in cortical areas along this pathway should have progressively better spatial tuning properties. This prediction is supported by recent experiments that have shown that neurons in the caudomedial field have better spatial tuning properties than neurons in the primary auditory cortex. Neurons in the caudomedial field are also better than primary auditory cortex neurons at predicting the sound localization ability across different stimulus frequencies and bandwidths in both azimuth and elevation. These data support the hypothesis that the primate auditory cortex processes acoustic information in a serial and parallel manner and suggest that this may be a general cortical mechanism for sensory perception.

  6. The role of cingulate cortex in vicarious pain.

    PubMed

    Yesudas, Esther H; Lee, Tatia M C

    2015-01-01

    Vicarious pain is defined as the observation of individuals in pain. There is growing neuroimaging evidence suggesting that the cingulate cortex plays a significant role in self-experienced pain processing. Yet, very few studies have directly tested the distinct functions of the cingulate cortex for vicarious pain. In this review, one EEG and eighteen neuroimaging studies reporting cingulate cortex activity during pain observation were discussed. The data indicate that there is overlapping neural activity in the cingulate cortex during self- and vicarious pain. Such activity may contribute to shared neural pain representations that permit inference of the affective state of individuals in pain, facilitating empathy. However, the exact location of neuronal populations in which activity overlaps or differs for self- and observed pain processing requires further confirmation. This review also discusses evidence suggesting differential functions of the cingulate cortex in cognitive, affective, and motor processing during empathy induction. While affective processing in the cingulate cortex during pain observation has been explored relatively more often, its attention and motor roles remain underresearched. Shedding light on the neural correlates of vicarious pain and corresponding empathy in healthy populations can provide neurobiological markers and intervention targets for empathic deficits found in various clinical disorders. PMID:25815331

  7. The multisensory function of the human primary visual cortex.

    PubMed

    Murray, Micah M; Thelen, Antonia; Thut, Gregor; Romei, Vincenzo; Martuzzi, Roberto; Matusz, Pawel J

    2016-03-01

    It has been nearly 10 years since Ghazanfar and Schroeder (2006) proposed that the neocortex is essentially multisensory in nature. However, it is only recently that sufficient and hard evidence that supports this proposal has accrued. We review evidence that activity within the human primary visual cortex plays an active role in multisensory processes and directly impacts behavioural outcome. This evidence emerges from a full pallet of human brain imaging and brain mapping methods with which multisensory processes are quantitatively assessed by taking advantage of particular strengths of each technique as well as advances in signal analyses. Several general conclusions about multisensory processes in primary visual cortex of humans are supported relatively solidly. First, haemodynamic methods (fMRI/PET) show that there is both convergence and integration occurring within primary visual cortex. Second, primary visual cortex is involved in multisensory processes during early post-stimulus stages (as revealed by EEG/ERP/ERFs as well as TMS). Third, multisensory effects in primary visual cortex directly impact behaviour and perception, as revealed by correlational (EEG/ERPs/ERFs) as well as more causal measures (TMS/tACS). While the provocative claim of Ghazanfar and Schroeder (2006) that the whole of neocortex is multisensory in function has yet to be demonstrated, this can now be considered established in the case of the human primary visual cortex. PMID:26275965

  8. What does spatial alternation tell us about retrosplenial cortex function?

    PubMed Central

    Nelson, Andrew J. D.; Powell, Anna L.; Holmes, Joshua D.; Vann, Seralynne D.; Aggleton, John P.

    2015-01-01

    The retrosplenial cortex supports navigation, but there are good reasons to suppose that the retrosplenial cortex has a very different role in spatial memory from that of the hippocampus and anterior thalamic nuclei. For example, retrosplenial lesions appear to have little or no effect on standard tests of spatial alternation. To examine these differences, the current study sought to determine whether the retrosplenial cortex is important for just one spatial cue type (e.g., allocentric, directional or intra-maze cues) or whether the retrosplenial cortex helps the animal switch between competing spatial strategies or competing cue types. Using T-maze alternation, retrosplenial lesion rats were challenged with situations in which the available spatial information between the sample and test phases was changed, so taxing the interaction between different cue types. Clear lesion deficits emerged when intra- and extra-maze cues were placed in conflict (by rotating the maze between the sample and choice phases), or when the animals were tested in the dark in a double-maze. Finally, temporary inactivation of the retrosplenial cortex by muscimol infusions resulted in a striking deficit on standard T-maze alternation, indicating that, over time, other sites may be able to compensate for the loss of the retrosplenial cortex. This pattern of results is consistent with the impoverished use of both allocentric and directional information, exacerbated by an impaired ability to switch between different cue types. PMID:26042009

  9. [Study on quantitative methods of cleistocalycis operculati cortex].

    PubMed

    Chen, Li-Si; Ou, Jia-Ju; Li, Shu-Yuan; Lu, Song-Gui

    2014-08-01

    Cleistocalycis Operculati Cortex is the dry bark of Cleistocalyx operculatus. It is the raw material of Compound Hibiscuse which is external sterilization antipruritic drugs. The quality standard of Cleistocalycis Operculati Cortex in Guangdong Province "standard for the traditional Chinese medicine" (second volumes) only contains TLC identification. It is unable to effectively monitor and control the quality of Cleistocalycis Operculati Cortex. A reversed-phase HPLC method was established for the determination of 3, 3'-O-dimethylellagic acid from Cleistocalycis Operculati Cortex and the content was calculated by external standard method for the first time. Under the selected chromatographic conditions, the target components between peaks to achieve effective separation. 3,3'-O- dimethylellagic acid standard solution at the concentration of 1.00 - 25.0 mg x L(-1) showed a good linear relationship. The standard curve was Y = 77.33X + 7.904, r = 0.999 5. The average recovery was 101.0%, RSD was 1.3%. The HPLC method for the determination of 3,3'-O-dimethylellagic acid in Cleistocalycis Operculati Cortex is accurate and reliable. It can provide a strong technical support for monitoring the quality of Cleistocalycis Operculati Cortex. PMID:25509300

  10. Behavior Modulates Effective Connectivity between Cortex and Striatum

    PubMed Central

    Nakhnikian, Alexander; Rebec, George V.; Grasse, Leslie M.; Dwiel, Lucas L.; Shimono, Masanori; Beggs, John M.

    2014-01-01

    It has been notoriously difficult to understand interactions in the basal ganglia because of multiple recurrent loops. Another complication is that activity there is strongly dependent on behavior, suggesting that directional interactions, or effective connections, can dynamically change. A simplifying approach would be to examine just the direct, monosynaptic projections from cortex to striatum and contrast this with the polysynaptic feedback connections from striatum to cortex. Previous work by others on effective connectivity in this pathway indicated that activity in cortex could be used to predict activity in striatum, but that striatal activity could not predict cortical activity. However, this work was conducted in anesthetized or seizing animals, making it impossible to know how free behavior might influence effective connectivity. To address this issue, we applied Granger causality to local field potential signals from cortex and striatum in freely behaving rats. Consistent with previous results, we found that effective connectivity was largely unidirectional, from cortex to striatum, during anesthetized and resting states. Interestingly, we found that effective connectivity became bidirectional during free behaviors. These results are the first to our knowledge to show that striatal influence on cortex can be as strong as cortical influence on striatum. In addition, these findings highlight how behavioral states can affect basal ganglia interactions. Finally, we suggest that this approach may be useful for studies of Parkinson's or Huntington's diseases, in which effective connectivity may change during movement. PMID:24618981

  11. Preferential encoding of visual categories in parietal cortex compared with prefrontal cortex.

    PubMed

    Swaminathan, Sruthi K; Freedman, David J

    2012-02-01

    The ability to recognize the behavioral relevance, or category membership, of sensory stimuli is critical for interpreting the meaning of events in our environment. Neurophysiological studies of visual categorization have found categorical representations of stimuli in prefrontal cortex (PFC), an area that is closely associated with cognitive and executive functions. Recent studies have also identified neuronal category signals in parietal areas that are typically associated with visual-spatial processing. It has been proposed that category-related signals in parietal cortex and other visual areas may result from 'top-down' feedback from PFC. We directly compared neuronal activity in the lateral intraparietal (LIP) area and PFC in monkeys performing a visual motion categorization task. We found that LIP showed stronger, more reliable and shorter latency category signals than PFC. These findings suggest that LIP is strongly involved in visual categorization and argue against the idea that parietal category signals arise as a result of feedback from PFC during this task. PMID:22246435

  12. Epileptiform synchronization in the cingulate cortex

    PubMed Central

    Panuccio, Gabriella; Curia, Giulia; Colosimo, Alfredo; Cruccu, Giorgio; Avoli, Massimo

    2016-01-01

    Summary Purpose The anterior cingulate cortex (ACC)— which plays a role in pain, emotions and behavior— can generate epileptic seizures. To date, little is known on the neuronal mechanisms leading to epileptiform synchronization in this structure. Therefore, we investigated the role of excitatory and inhibitory synaptic transmission in epileptiform activity in this cortical area. In addition, since the ACC presents with a high density of opioid receptors, we studied the effect of opioid agonism on epileptiform synchronization in this brain region. Methods We used field and intracellular recordings in conjunction with pharmacological manipulations to characterize the epileptiform activity generated by the rat ACC in a brain slice preparation. Results Bath-application of the convulsant 4- aminopyridine (4AP, 50 μM) induced both brief and prolonged periods of epileptiform synchronization resembling interictal- and ictal-like discharges, respectively. Interictal events could occur more frequently before the onset of ictal activity that was contributed by N-methyl-D-aspartate (NMDA) receptors. Mu-opioid receptor activation abolished 4AP-induced ictal events and markedly reduced the occurrence of the pharmacologically isolated GABAergic synchronous potentials. Ictal discharges were replaced by interictal events during GABAergic antagonism; this GABA-independent activity was influenced by subsequent mu-opioid agonist application. Conclusions Our results indicate that both glutamatergic and GABAergic signaling contribute to epileptiform synchronization leading to the generation of electrographic ictal events in the ACC. In addition, mu-opioid receptors appear to modulate both excitatory and inhibitory mechanisms, thus influencing epileptiform synchronization in the ACC. PMID:19178556

  13. Frontal cortex mediates unconsciously triggered inhibitory control.

    PubMed

    van Gaal, Simon; Ridderinkhof, K Richard; Fahrenfort, Johannes J; Scholte, H Steven; Lamme, Victor A F

    2008-08-01

    To further our understanding of the function of conscious experience we need to know which cognitive processes require awareness and which do not. Here, we show that an unconscious stimulus can trigger inhibitory control processes, commonly ascribed to conscious control mechanisms. We combined the metacontrast masking paradigm and the Go/No-Go paradigm to study whether unconscious No-Go signals can actively trigger high-level inhibitory control processes, strongly associated with the prefrontal cortex (PFC). Behaviorally, unconscious No-Go signals sometimes triggered response inhibition to the level of complete response termination and yielded a slow down in the speed of responses that were not inhibited. Electroencephalographic recordings showed that unconscious No-Go signals elicit two neural events: (1) an early occipital event and (2) a frontocentral event somewhat later in time. The first neural event represents the visual encoding of the unconscious No-Go stimulus, and is also present in a control experiment where the masked stimulus has no behavioral relevance. The second event is unique to the Go/No-Go experiment, and shows the subsequent implementation of inhibitory control in the PFC. The size of the frontal activity pattern correlated highly with the impact of unconscious No-Go signals on subsequent behavior. We conclude that unconscious stimuli can influence whether a task will be performed or interrupted, and thus exert a form of cognitive control. These findings challenge traditional views concerning the proposed relationship between awareness and cognitive control and stretch the alleged limits and depth of unconscious information processing. PMID:18685030

  14. Encoding frequency contrast in primate auditory cortex

    PubMed Central

    Scott, Brian H.; Semple, Malcolm N.

    2014-01-01

    Changes in amplitude and frequency jointly determine much of the communicative significance of complex acoustic signals, including human speech. We have previously described responses of neurons in the core auditory cortex of awake rhesus macaques to sinusoidal amplitude modulation (SAM) signals. Here we report a complementary study of sinusoidal frequency modulation (SFM) in the same neurons. Responses to SFM were analogous to SAM responses in that changes in multiple parameters defining SFM stimuli (e.g., modulation frequency, modulation depth, carrier frequency) were robustly encoded in the temporal dynamics of the spike trains. For example, changes in the carrier frequency produced highly reproducible changes in shapes of the modulation period histogram, consistent with the notion that the instantaneous probability of discharge mirrors the moment-by-moment spectrum at low modulation rates. The upper limit for phase locking was similar across SAM and SFM within neurons, suggesting shared biophysical constraints on temporal processing. Using spike train classification methods, we found that neural thresholds for modulation depth discrimination are typically far lower than would be predicted from frequency tuning to static tones. This “dynamic hyperacuity” suggests a substantial central enhancement of the neural representation of frequency changes relative to the auditory periphery. Spike timing information was superior to average rate information when discriminating among SFM signals, and even when discriminating among static tones varying in frequency. This finding held even when differences in total spike count across stimuli were normalized, indicating both the primacy and generality of temporal response dynamics in cortical auditory processing. PMID:24598525

  15. Signaling Interactions in the Adrenal Cortex

    PubMed Central

    Spät, András; Hunyady, László; Szanda, Gergő

    2016-01-01

    The major physiological stimuli of aldosterone secretion are angiotensin II (AII) and extracellular K+, whereas cortisol production is primarily regulated by corticotropin (ACTH) in fasciculata cells. AII triggers Ca2+ release from internal stores that is followed by store-operated and voltage-dependent Ca2+ entry, whereas K+-evoked depolarization activates voltage-dependent Ca2+ channels. ACTH acts primarily through the formation of cAMP and subsequent protein phosphorylation by protein kinase A. Both Ca2+ and cAMP facilitate the transfer of cholesterol to mitochondrial inner membrane. The cytosolic Ca2+ signal is transferred into the mitochondrial matrix and enhances pyridine nucleotide reduction. Increased formation of NADH results in increased ATP production, whereas that of NADPH supports steroid production. In reality, the control of adrenocortical function is a lot more sophisticated with second messengers crosstalking and mutually modifying each other’s pathways. Cytosolic Ca2+ and cGMP are both capable of modifying cAMP metabolism, while cAMP may enhance Ca2+ release and voltage-activated Ca2+ channel activity. Besides, mitochondrial Ca2+ signal brings about cAMP formation within the organelle and this further enhances aldosterone production. Maintained aldosterone and cortisol secretion are optimized by the concurrent actions of Ca2+ and cAMP, as exemplified by the apparent synergism of Ca2+ influx (inducing cAMP formation) and Ca2+ release during response to AII. Thus, cross-actions of parallel signal transducing pathways are not mere intracellular curiosities but rather substantial phenomena, which fine-tune the biological response. Our review focuses on these functionally relevant interactions between the Ca2+ and the cyclic nucleotide signal transducing pathways hitherto described in the adrenal cortex. PMID:26973596

  16. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

    PubMed Central

    Ioannides, Andreas A.; Liu, Lichan; Poghosyan, Vahe; Saridis, George A.; Gjedde, Albert; Ptito, Maurice; Kupers, Ron

    2013-01-01

    Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45–70 Hz activity at latencies of 20–50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex. PMID:23935576

  17. Population structure and the evolution of sexual size dimorphism and sex ratios in an insular population of Florida box turtles (Terrapene carolina bauri)

    USGS Publications Warehouse

    Dodd, C.K., Jr.

    1997-01-01

    Hypotheses in the chelonian literature suggest that in species with sexual size dimorphism, the smaller sex will mature at a smaller size and a younger age than the larger sex, sex ratios should be biased in favor of the earlier maturing sex, and deviations from a 1:1 sex ratio result from maturation of the smaller sex at a younger age. I tested these hypotheses using data collected from 1991 to 1995 on an insular (Egmont Key) population of Florida box turtles, Terrapene carolina bauri. Contrary to predictions, the earlier maturing sex (males) grew to larger sizes than the late maturing sex. Males were significantly larger than females in mean carapace length but not mean body mass. Sex ratios were not balanced, favoring the earlier maturing sex (1.6 males:1 female), but the sex-ratio imbalance did not result from faster maturation of the smaller sex. The imbalance in the sex ratio in Egmont Key's box turtles is not the result of sampling biases; it may result from nest placement. Size-class structure and sex ratios can provide valuable insights into the status and trends of populations of long-lived turtles.

  18. The morphology of insular shelves as a key for understanding the geological evolution of volcanic islands: Insights from Terceira Island (Azores)

    NASA Astrophysics Data System (ADS)

    Quartau, R.; Hipólito, A.; Romagnoli, C.; Casalbore, D.; Madeira, J.; Tempera, F.; Roque, C.; Chiocci, F. L.

    2014-05-01

    from volcanic ocean islands result from the competition between two main processes, wave erosion that forms and enlarges them and volcanic progradation that reduces their dimension. In places where erosion dominates over volcanism, shelf width can be used as a proxy for the relative age of the subaerial volcanic edifices and reconstruction of their extents prior to erosion can be achieved. In this study, new multibeam bathymetry and high-resolution seismic reflection profiles are exploited to characterize the morphology of the insular shelves adjacent to each volcanic edifice of Terceira Island in order to improve the understanding of its evolution. Subaerial morphological and geological/stratigraphic data were also used to establish the connection between the onshore and offshore evolution. Shelf width contiguous to each main volcanic edifice is consistent with the known subaerial geological history of the island; most of the older edifices have wider shelves than younger ones. The shelf edge proved to be a very useful indicator in revealing the original extent of each volcanic edifice in plan view. Its depth was also used to reconstruct vertical movements, showing that older edifices like Serra do Cume-Ribeirinha, Guilherme Moniz, and Pico Alto have subsided while more recent ones have not. The morphology of the shelf (namely the absence/presence of fresh lava flow morphologies and several types of erosional, depositional, and tectonic features) integrated with the analysis of the coastline morphology allowed us to better constrain previous geological interpretations of the island evolution.

  19. Wet- and dry-season steroid hormone profiles and stress reactivity of an insular dwarf snake, the Hog Island boa (Boa constrictor imperator).

    PubMed

    Holding, Matthew L; Frazier, Julius A; Dorr, Scott W; Pollock, Nicholas B; Muelleman, P J; Branske, Amber; Henningsen, Sloane N; Eikenaar, Cas; Escallón, Camilo; Montgomery, Chad E; Moore, Ignacio T; Taylor, Emily N

    2014-01-01

    Field endocrine studies providing new comparisons for inference into the evolutionary and ecological factors shaping organismal physiology are important, often yielding novel physiological insights. Here, we explored factors associated with the sex steroid hormone concentrations and adrenocortical response to capture stress in Hog Island boas (Boa constrictor imperator) in the Cayos Cochinos archipelago of Honduras to generate comparative field hormone data from a tropical reptile and test the island tameness hypothesis. Baseline concentrations of testosterone, corticosterone, estradiol, and progesterone were measured during the wet and dry seasons, and an acute stressor of 1 h in a cloth bag was used to assess the stress response. Plasma steroid concentrations in these snakes were generally low in comparison to other taxa. Higher testosterone concentrations in males and higher estradiol and corticosterone concentrations in females were observed during the wet season compared to the dry season, which may be indicative of mating activities and vitellogenesis during this period. Snakes displayed a 15-fold increase in corticosterone concentrations in response to capture stress, a rise that was not impacted by whether a snake had been captured during previous years. The adrenocortical stress response was greater in males and positively related to body temperature. We suggest that this system merits future inquiries into the physiology and behavior of B. c. imperator, particularly as a model for studying insular impacts on diverse life history characters. PMID:24769701

  20. Magnetic source imaging in posterior cortex epilepsies.

    PubMed

    Badier, Jean-Michel; Bartolomei, Fabrice; Chauvel, Patrick; Bénar, Christian-George; Gavaret, Martine

    2015-01-01

    Posterior cortex epilepsies (PCE) are characterized by less satisfying postoperative results than temporal lobe epilepsies and are thus challenging for non-invasive presurgical investigations. The objective of this study was to evaluate the performance of magnetic source imaging (MSI) in PCE, validating the results by the SEEG (stereoelectroencephalography) definition of irritative and epileptogenic zones (IZ and EZ). Fourteen PCE surgery candidates were investigated using MSI and SEEG. LCMV (Linearly Constrained Minimum Variance) and MUSIC algorithms were used. IZ was quantified using a semi-automatic detection of interictal spikes. EZ was quantified using the epileptogenicity index (EI) method that accounts for both the propensity of a brain area to generate rapid discharges and the time for this area to get involved in the seizure. EI values range from 0 (no epileptogenicity) to 1 (maximal epileptogenicity). Levels of concordance between MSI and IZ, MSI and EZ were determined as follows: A = localized on MSI and SEEG for the site of value 1 (IZ and EZ quantification), B = localized on MSI and SEEG for a part of the IZ or a structure involved in the EZ (without the maximal value 1), C = localized on MSI and not SEEG, D = localized on SEEG and not MSI, E = localized on MSI and SEEG, discordant for site. Five PCE cases were characterized by focal IZ, nine by distributed IZ between several distant brain areas. MSI allowed to determinate IZ in 4/5 focal IZ cases. In case of distributed IZ, levels of concordance were A (2 cases), B (4 cases) and D (3 cases). In most distributed cases, MSI allowed to localize only a part of the IZ. Medial temporal involvement in the IZ was frequent (9/12 cases) and not evidenced by MSI. The brain area that demonstrated the maximal value of EI was shown by MSI in four out of five (80 %) focal IZ cases, in two out of nine (22 %) distributed cases. MSI results depend on IZ characteristics. A distributed IZ organization

  1. Microstimulation of visual cortex to restore vision.

    PubMed

    Tehovnik, Edward J; Slocum, Warren M; Smirnakis, Stelios M; Tolias, Andreas S

    2009-01-01

    This review argues that one reason why a functional visuo-cortical prosthetic device has not been developed to restore even minimal vision to blind individuals is because there is no animal model to guide the design and development of such a device. Over the past 8 years we have been conducting electrical microstimulation experiments on alert behaving monkeys with the aim of better understanding how electrical stimulation of the striate cortex (area V1) affects oculo- and skeleto-motor behaviors. Based on this work and upon review of the literature, we arrive at several conclusions: (1) As with the development of the cochlear implant, the development of a visuo-cortical prosthesis can be accelerated by using animals to test the perceptual effects of microstimulating V1 in intact and blind monkeys. (2) Although a saccade-based paradigm is very convenient for studying the effectiveness of delivering stimulation to V1 to elicit saccadic eye movements, it is less ideal for probing the volitional state of monkeys, as they perceive electrically induced phosphenes. (3) Electrical stimulation of V1 can delay visually guided saccades generated to a punctate target positioned in the receptive field of the stimulated neurons. We call the region of visual space affected by the stimulation a delay field. The study of delay fields has proven to be an efficient way to study the size and shape of phosphenes generated by stimulation of macaque V1. (4) An alternative approach to ascertain what monkeys see during electrical stimulation of V1 is to have them signal the detection of current with a lever press. Monkeys can readily detect currents of 1-2 microA delivered to V1. In order to evoke featured phosphenes currents of under 5 microA will be necessary. (5) Partially lesioning the retinae of monkeys is superior to completely lesioning the retinae when determining how blindness affects phosphene induction. We finish by proposing a future experimental paradigm designed to determine

  2. Cultivating the cortex in German neuroanatomy.

    PubMed

    Hagner, M

    2001-12-01

    The cerebral localization of mental functions is one of the centerpieces of modern brain research. Though the localization paradigm in its cultural and social interwovenness has been characterized as successful in the last third of the nineteenth century by a variety of historians of the neurosciences, there is also general agreement that localization came under threat around 1900. Besides the so-called holistic protest against the localization of mental functions, the neuroanatomical approach itself was challenged by experimental psychology, psychiatric nosology, and psychoanalysis. This story underestimates the fact that anatomically-based localization remained powerful in response to these multiple challenges. This meant a neuroanatomical revision of tools, concepts, and practices. But this meant also a shift in the cultivation of the cortex from a more philosophical agenda to rather concrete political claims. More specifically, the idea of the cortext as the noblest part of man was supplemented by suggestions concerning its "Höherzüchtung." I will analyze this re-orientation and radicalization in two steps. First, I briefly discuss the anatomical and philosophical account of Theodor Meynert and then turn to Paul Flechsig who in the late nineteenth century inscribed the ability to create culture and civilization into the cortext. Second, I focus on the neuroanatomists Oskar and Cécile Vogt, who began their careers around 1900 and expanded the cultivation of the cortext. Even before World War I, they proclaimed a "cerebral hygiene." Consequently, the Vogts linked their innovative neuroanatomical researches with the rising field of genetics, racial hygiene, and eugenics. In the early Weimar Republic, the Vogts openly supported socialist ideas and were engaged in establishing an Institute for Brain Research in Soviet Moscow, where Lenin's brain was analyzed. By the end of the Weimar Republic, the rhetoric of the Vogts was bluntly authoritarian. Based on a few

  3. Dental Occlusal Changes Induce Motor Cortex Neuroplasticity.

    PubMed

    Avivi-Arber, L; Lee, J-C; Sessle, B J

    2015-12-01

    Modification to the dental occlusion may alter oral sensorimotor functions. Restorative treatments aim to restore sensorimotor functions; however, it is unclear why some patients fail to adapt to the restoration and remain with sensorimotor complaints. The face primary motor cortex (face-M1) is involved in the generation and control of orofacial movements. Altered sensory inputs or motor function can induce face-M1 neuroplasticity. We took advantage of the continuous eruption of the incisors in Sprague-Dawley rats and used intracortical microstimulation (ICMS) to map the jaw and tongue motor representations in face-M1. Specifically, we tested the hypothesis that multiple trimming of the right mandibular incisor, to keep it out of occlusal contacts for 7 d, and subsequent incisor eruption and restoration of occlusal contacts, can alter the ICMS-defined features of jaw and tongue motor representations (i.e., neuroplasticity). On days 1, 3, 5, and 7, the trim and trim-recovered groups had 1 to 2 mm of incisal trimming of the incisor; a sham trim group had buccal surface trimming with no occlusal changes; and a naive group had no treatment. Systematic mapping was performed on day 8 in the naive, trim, and sham trim groups and on day 14 in the trim-recovered group. In the trim group, the tongue onset latency was shorter in the left face-M1 than in the right face-M1 (P < .001). In the trim-recovered group, the number of tongue sites and jaw/tongue overlapping sites was greater in the left face-M1 than in the right face-M1 (P = 0.0032, 0.0016, respectively), and the center of gravity was deeper in the left than in the right face-M1 (P = 0.026). Therefore, incisor trimming and subsequent restoration of occlusal contacts induced face-M1 neuroplasticity, reflected in significant disparities between the left and right face-M1 in some ICMS-defined features of the tongue motor representations. Such neuroplasticity may reflect or contribute to subjects' ability to adapt their

  4. rTMS of the Left Dorsolateral Prefrontal Cortex Modulates Dopamine Release in the Ipsilateral Anterior Cingulate Cortex and Orbitofrontal Cortex

    PubMed Central

    Cho, Sang Soo; Strafella, Antonio P.

    2009-01-01

    Background Brain dopamine is implicated in the regulation of movement, attention, reward and learning and plays an important role in Parkinson's disease, schizophrenia and drug addiction. Animal experiments have demonstrated that brain stimulation is able to induce significant dopaminergic changes in extrastriatal areas. Given the up-growing interest of non-invasive brain stimulation as potential tool for treatment of neurological and psychiatric disorders, it would be critical to investigate dopaminergic functional interactions in the prefrontal cortex and more in particular the effect of dorsolateral prefrontal cortex (DLPFC) (areas 9/46) stimulation on prefrontal dopamine (DA). Methodology/Principal Findings Healthy volunteers were studied with a high-affinity DA D2-receptor radioligand, [11C]FLB 457-PET following 10 Hz repetitive transcranial magnetic stimulation (rTMS) of the left and right DLPFC. rTMS on the left DLPFC induced a significant reduction in [11C]FLB 457 binding potential (BP) in the ipsilateral subgenual anterior cingulate cortex (ACC) (BA 25/12), pregenual ACC (BA 32) and medial orbitofrontal cortex (BA 11). There were no significant changes in [11C]FLB 457 BP following right DLPFC rTMS. Conclusions/Significance To our knowledge, this is the first study to provide evidence of extrastriatal DA modulation following acute rTMS of DLPFC with its effect limited to the specific areas of medial prefrontal cortex. [11C]FLB 457-PET combined with rTMS may allow to explore the neurochemical functions of specific cortical neural networks and help to identify the neurobiological effects of TMS for the treatment of different neurological and psychiatric diseases. PMID:19696930

  5. Adaptive Processes in Thalamus and Cortex Revealed by Silencing of Primary Visual Cortex during Contrast Adaptation.

    PubMed

    King, Jillian L; Lowe, Matthew P; Stover, Kurt R; Wong, Aimee A; Crowder, Nathan A

    2016-05-23

    Visual adaptation illusions indicate that our perception is influenced not only by the current stimulus but also by what we have seen in the recent past. Adaptation to stimulus contrast (the relative luminance created by edges or contours in a scene) induces the perception of the stimulus fading away and increases the contrast detection threshold in psychophysical tests [1, 2]. Neural correlates of contrast adaptation have been described throughout the visual system including the retina [3], dorsal lateral geniculate nucleus (dLGN) [4, 5], primary visual cortex (V1) [6], and parietal cortex [7]. The apparent ubiquity of adaptation at all stages raises the question of how this process cascades across brain regions [8]. Focusing on V1, adaptation could be inherited from pre-cortical stages, arise from synaptic depression at the thalamo-cortical synapse [9], or develop locally, but what is the weighting of these contributions? Because contrast adaptation in mouse V1 is similar to classical animal models [10, 11], we took advantage of the optogenetic tools available in mice to disentangle the processes contributing to adaptation in V1. We disrupted cortical adaptation by optogenetically silencing V1 and found that adaptation measured in V1 now resembled that observed in dLGN. Thus, the majority of adaptation seen in V1 neurons arises through local activity-dependent processes, with smaller contributions from dLGN inheritance and synaptic depression at the thalamo-cortical synapse. Furthermore, modeling indicates that divisive scaling of the weakly adapted dLGN input can predict some of the emerging features of V1 adaptation. PMID:27112300

  6. The neocortex of cetaceans: cytoarchitecture and comparison with other aquatic and terrestrial species.

    PubMed

    Butti, Camilla; Raghanti, Mary Ann; Sherwood, Chet C; Hof, Patrick R

    2011-04-01

    The evolutionary process of readaptation to the aquatic environment was accompanied by extreme anatomical and physiological changes in the brain. This review discusses cortical specializations in the three major lineages of marine mammals in comparison to related terrestrial and semiaquatic species. Different groups of marine mammals adopted a wide range of strategies to cope with the challenges of aquatic living. Cetaceans and hippopotamids possess a completely agranular neocortex in contrast to phocids and sirenians; vertical modules are observed in deep layers V and VI in manatees, cetaceans, phocids, and hippopotamids, but in different cortical areas; and clustering in layer II appears in the insular cortex of hippopotamids, phocids, and cetaceans. Finally, von Economo neurons are present in cetaceans, hippopotamids, sirenians, and some phocids, with specific, yet different, cortical distributions. The interpretation of the evolutionary and functional significance of such specializations, and their relationships with the degrees of adaptation to the aquatic environment and phylogeny, remain difficult to trace, at least until comprehensive data, including representative species from all of the major mammalian families, become available. PMID:21534992

  7. Long-Term Synaptic Plasticity in Rat Barrel Cortex.

    PubMed

    Han, Yong; Huang, Ming-De; Sun, Man-Li; Duan, Shumin; Yu, Yan-Qin

    2015-09-01

    Rats generate sweeping whisker movements in order to explore their environments and identify objects. In somatosensory pathways, neuronal activity is modulated by the frequency of whisker vibration. However, the potential role of rhythmic neuronal activity in the cerebral processing of sensory signals and its mechanism remain unclear. Here, we showed that rhythmic vibrissal stimulation with short duration in anesthetized rats resulted in an increase or decrease in the amplitude of somatosensory-evoked potentials (SEPs) in the contralateral barrel cortex. The plastic change of the SEPs was frequency dependent and long lasting. The long-lasting enhancement of the vibrissa-to-cortex evoked response was side- but not barrel-specific. Local application of dl-2-amino-5-phosphonopentanoic acid into the barrel cortex revealed that this vibrissa-to-cortex long-term plasticity in adult rats was N-methyl-d-aspartate receptor-dependent. Most interestingly, whisker trimming through postnatal day (P)1-7 but not P29-35 impaired the long-term plasticity induced by 100 Hz vibrissal stimulation. The short period of rhythmic vibrissal stimulation did not induce long-lasting plasticity of field potentials in the thalamus. In conclusion, our results suggest that natural rhythmic whisker activity modifies sensory information processing in cerebral cortex, providing further insight into sensory perception. PMID:24735674

  8. The syncytial nature of epithelial cells in the thymic cortex.

    PubMed Central

    Kendall, M D

    1986-01-01

    The epithelial cells of the cortex of human and rodent thymus glands were examined by light and electron microscopy, and the intracellular membrane potentials measured from the subcapsular, cortical and medullary regions. In the human thymus cortex, there is a highly correlated age-independent relationship (r = 0.78) between the distance in micron from one adjacent Type 2/3 epithelial nucleus to another, and the number of thymocytes between them. In rodent glands that had undergone some degree of involution due to hypoxia simulating an altitude of 17 000 feet or following the injection of phenylhydrazine, Type 2/3 epithelial cells were often found to be bi- or multinucleated. Electrophysiological studies of 10 mouse thymus lobes using 0.2 micron tipped electrodes showed that there were highly significant differences (P less than 0.0001) between the intracellular membrane potentials of the subcapsular zone, the cortex and the medulla. When dyes were injected intracellularly (through 0.5 micron tipped electrodes) into individual epithelial cells, methylene blue remained within the cytoplasm, but procion yellow passed in 30 minutes into the nuclei of all the epithelial cells of the cortex but not those of the subcapsular zone, nor the medulla. This indicates that the cortex must be a functional syncytium and it differs in this respect from the rest of the gland. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 PMID:3319999

  9. Changes in Cerebral Cortex of Children Treated for Medulloblastoma

    SciTech Connect

    Liu, Arthur K. . E-mail: aliu1@partners.org; Marcus, Karen J.; Fischl, Bruce; Grant, P. Ellen; Young Poussaint, Tina; Rivkin, Michael J.; Davis, Peter; Tarbell, Nancy J.; Yock, Torunn I.

    2007-07-15

    Purpose: Children with medulloblastoma undergo surgery, radiotherapy, and chemotherapy. After treatment, these children have numerous structural abnormalities. Using high-resolution magnetic resonance imaging, we measured the thickness of the cerebral cortex in a group of medulloblastoma patients and a group of normally developing children. Methods and Materials: We obtained magnetic resonance imaging scans and measured the cortical thickness in 9 children after treatment of medulloblastoma. The measurements from these children were compared with the measurements from age- and gender-matched normally developing children previously scanned. For additional comparison, the pattern of thickness change was compared with the cortical thickness maps from a larger group of 65 normally developing children. Results: In the left hemisphere, relatively thinner cortex was found in the perirolandic region and the parieto-occipital lobe. In the right hemisphere, relatively thinner cortex was found in the parietal lobe, posterior superior temporal gyrus, and lateral temporal lobe. These regions of cortical thinning overlapped with the regions of cortex that undergo normal age-related thinning. Conclusion: The spatial distribution of cortical thinning suggested that the areas of cortex that are undergoing development are more sensitive to the effects of treatment of medulloblastoma. Such quantitative methods may improve our understanding of the biologic effects that treatment has on the cerebral development and their neuropsychological implications.

  10. Infralimbic cortex activation and motivated arousal induce histamine release

    PubMed Central

    Forray, María Inés; Torrealba, Fernando

    2015-01-01

    Appetitive behaviours occur in a state of behavioural and physiological activation that allows the optimal performance of these goal-directed behaviours. Here, we tested the hypothesis that histamine neurons under the command of the infralimbic cortex are important to provide behavioural activation. Extracellular histamine and serotonin were measured by microdialysis of the medial prefrontal cortex in behaving rats in parallel with a picrotoxin microinjection into the infralimbic cortex. The injection aroused the rats behaviourally, increased histamine release and decreased serotonin levels. Inhibition of the infralimbic cortex with muscimol produced the opposite effects on neurotransmitter release. The behavioural activation induced by motivating hungry rats with caged food was paralleled by an immediate histamine release, whereas awakening induced by tapping their microdialysis bowl increased serotonin, but not histamine levels. In conclusion, picrotoxin injection into the infralimbic cortex produces behavioural activation together with histamine release; in a similar manner, induction of an appetitive state produced histamine release, likely related to increased behavioural activation characteristic of an appetitive behaviour. PMID:25746330

  11. Responses of primate frontal cortex neurons during natural vocal communication

    PubMed Central

    Thomas, A. Wren; Nummela, Samuel U.; de la Mothe, Lisa A.

    2015-01-01

    The role of primate frontal cortex in vocal communication and its significance in language evolution have a controversial history. While evidence indicates that vocalization processing occurs in ventrolateral prefrontal cortex neurons, vocal-motor activity has been conjectured to be primarily subcortical and suggestive of a distinctly different neural architecture from humans. Direct evidence of neural activity during natural vocal communication is limited, as previous studies were performed in chair-restrained animals. Here we recorded the activity of single neurons across multiple regions of prefrontal and premotor cortex while freely moving marmosets engaged in a natural vocal behavior known as antiphonal calling. Our aim was to test whether neurons in marmoset frontal cortex exhibited responses during vocal-signal processing and/or vocal-motor production in the context of active, natural communication. We observed motor-related changes in single neuron activity during vocal production, but relatively weak sensory responses for vocalization processing during this natural behavior. Vocal-motor responses occurred both prior to and during call production and were typically coupled to the timing of each vocalization pulse. Despite the relatively weak sensory responses a population classifier was able to distinguish between neural activity that occurred during presentations of vocalization stimuli that elicited an antiphonal response and those that did not. These findings are suggestive of the role that nonhuman primate frontal cortex neurons play in natural communication and provide an important foundation for more explicit tests of the functional contributions of these neocortical areas during vocal behaviors. PMID:26084912

  12. Deficits in prospective memory following damage to the prefrontal cortex.

    PubMed

    Umeda, Satoshi; Kurosaki, Yoshiko; Terasawa, Yuri; Kato, Motoichiro; Miyahara, Yasuyuki

    2011-07-01

    Neuropsychological investigations of prospective memory (PM), representing memory of future intentions or plans, have evolved over the past two decades. The broadly accepted divisions involved in PM consist of a prospective memory component (PMC), a process for remembering to remember, and a retrospective memory component, a process for remembering the content of the intended action. Previous functional neuroimaging studies have provided some evidence that the rostral prefrontal cortex (BA10) is one of areas that is critical for prospective remembering. However, the question of whether damage to part of the prefrontal cortex affects attenuated performance for PMC remains unresolved. In this study, 74 participants with traumatic brain injury (TBI) including focal damage to frontal or temporal lobe areas were administered thirteen standard neuropsychological tests and the PM task. To identify influential areas contributing to PM performance, discriminant function analysis was conducted. The results indicated that the following three areas are highly contributory to PM performance: the right dorsolateral prefrontal cortex; the right ventromedial prefrontal cortex; and the left dorsomedial prefrontal cortex. Comparing differences in neuropsychological test scores showed that orientation scores were significantly higher in the greater PM performance group, suggesting that PMC represents an integrated memory function associated with awareness of current status. These data contribute to our understanding of the neural substrates and functional characteristics of the PMC. PMID:21477605

  13. Immature cortex lesions alter retinotopic maps and interhemispheric connections.

    PubMed

    Restrepo, C Ernesto; Manger, Paul R; Spenger, Christian; Innocenti, Giorgio M

    2003-07-01

    Unilateral lesions of the occipital visual areas performed on postnatal day 5 (P5) in the ferret are not compensated by the appearance, in the lesioned hemisphere, of visual responses at ectopic locations. Instead, when parts of the visual areas are spared, they show abnormal retinotopic organizations; furthermore, callosal connections are abnormally distributed in relation to the retinotopic maps. Lesions that completely eliminate the visual areas including the posterior parietal cortex cause the appearance of abnormal callosal connections from the primary somatosensory cortex on the lesion side to the contralateral, intact, posterior parietal cortex. The occipital visual areas (17, 18, 19, and 21) of the intact hemisphere show a normal retinotopy but lose callosal connections in territories homotopic to the lesions. These findings clarify the nature and limits of structural developmental plasticity in the visual cortex. Early in life, certain regions of cortex have been irreversibly allocated to the visual areas, but two properties defining the areas, that is, retinotopy and connections, remain modifiable. The findings might be relevant for understanding the consequences of early-onset visual cortical lesions in humans. PMID:12838520

  14. Extensive lesions in the gustatory cortex in the rat do not disrupt the retention of a presurgically conditioned taste aversion and do not impair unconditioned concentration-dependent licking of sucrose and quinine.

    PubMed

    Hashimoto, Koji; Spector, Alan C

    2014-01-01

    Although damage to gustatory cortex (GC) in the rat has been reported to severely impair, if not eliminate, retention of a presurgically conditioned taste aversion (CTA), it has equivocal effects on taste preference as measured by intake tests. Because intake tests can be influenced by nongustatory (e.g., postingestive) factors, we employed the brief-access taste test to assess the effects of ibotenic acid-induced lesions targeting the GC on unconditioned licking to a sucrose and then a quinine concentration series in a specialized lickometer. As a functional lesion assessment, a presurgical CTA to 0.1M NaCl was established in thirsty rats by following 15-min intake with intraperitoneal administration of either LiCl (or NaCl for control) on 2 occasions. Both conditioned sham-operated (SHAM) rats and rats with histologically confirmed extensive damage to the GC (GCX) avoided a NaCl concentration series relative to unconditioned controls in a postsurgical brief-access CTA test, with no difference between the surgical groups in their responses to NaCl or similar concentrations of KCl. GCX rats also did not differ from SHAM rats in the EC50 of concentration-response functions for sucrose or quinine. Clearly, the critical cortical area required for the retention of a presurgical CTA falls outside of the extensive area of damage, which was well centered within the conventionally defined gustatory zone of the insular cortex. The absence of an effect on unconditioned responsiveness to sucrose and quinine suggests that the damaged region is also unnecessary for the normal expression of affective licking responses to tastants. PMID:24226296

  15. Spatial clustering of tuning in mouse primary visual cortex.

    PubMed

    Ringach, Dario L; Mineault, Patrick J; Tring, Elaine; Olivas, Nicholas D; Garcia-Junco-Clemente, Pablo; Trachtenberg, Joshua T

    2016-01-01

    The primary visual cortex of higher mammals is organized into two-dimensional maps, where the preference of cells for stimulus parameters is arranged regularly on the cortical surface. In contrast, the preference of neurons in the rodent appears to be arranged randomly, in what is termed a salt-and-pepper map. Here we revisited the spatial organization of receptive fields in mouse primary visual cortex by measuring the tuning of pyramidal neurons in the joint orientation and spatial frequency domain. We found that the similarity of tuning decreases as a function of cortical distance, revealing a weak but statistically significant spatial clustering. Clustering was also observed across different cortical depths, consistent with a columnar organization. Thus, the mouse visual cortex is not strictly a salt-and-pepper map. At least on a local scale, it resembles a degraded version of the organization seen in higher mammals, hinting at a possible common origin. PMID:27481398

  16. Capturing the temporal evolution of choice across prefrontal cortex.

    PubMed

    Hunt, Laurence T; Behrens, Timothy E J; Hosokawa, Takayuki; Wallis, Jonathan D; Kennerley, Steven W

    2015-01-01

    Activity in prefrontal cortex (PFC) has been richly described using economic models of choice. Yet such descriptions fail to capture the dynamics of decision formation. Describing dynamic neural processes has proven challenging due to the problem of indexing the internal state of PFC and its trial-by-trial variation. Using primate neurophysiology and human magnetoencephalography, we here recover a single-trial index of PFC internal states from multiple simultaneously recorded PFC subregions. This index can explain the origins of neural representations of economic variables in PFC. It describes the relationship between neural dynamics and behaviour in both human and monkey PFC, directly bridging between human neuroimaging data and underlying neuronal activity. Moreover, it reveals a functionally dissociable interaction between orbitofrontal cortex, anterior cingulate cortex and dorsolateral PFC in guiding cost-benefit decisions. We cast our observations in terms of a recurrent neural network model of choice, providing formal links to mechanistic dynamical accounts of decision-making. PMID:26653139

  17. Neural coding in barrel cortex during whisker-guided locomotion.

    PubMed

    Sofroniew, Nicholas James; Vlasov, Yurii A; Andrew Hires, Samuel; Freeman, Jeremy; Svoboda, Karel

    2015-01-01

    Animals seek out relevant information by moving through a dynamic world, but sensory systems are usually studied under highly constrained and passive conditions that may not probe important dimensions of the neural code. Here, we explored neural coding in the barrel cortex of head-fixed mice that tracked walls with their whiskers in tactile virtual reality. Optogenetic manipulations revealed that barrel cortex plays a role in wall-tracking. Closed-loop optogenetic control of layer 4 neurons can substitute for whisker-object contact to guide behavior resembling wall tracking. We measured neural activity using two-photon calcium imaging and extracellular recordings. Neurons were tuned to the distance between the animal snout and the contralateral wall, with monotonic, unimodal, and multimodal tuning curves. This rich representation of object location in the barrel cortex could not be predicted based on simple stimulus-response relationships involving individual whiskers and likely emerges within cortical circuits. PMID:26701910

  18. Orbitofrontal cortex encodes willingness to pay in everyday economic transactions.

    PubMed

    Plassmann, Hilke; O'Doherty, John; Rangel, Antonio

    2007-09-12

    An essential component of every economic transaction is a willingness-to-pay (WTP) computation in which buyers calculate the maximum amount of financial resources that they are willing to give up in exchange for the object being sold. Despite its pervasiveness, little is known about how the brain makes this computation. We investigated the neural basis of the WTP computation by scanning hungry subjects' brains using functional magnetic resonance imaging while they placed real bids for the right to eat different foods. We found that activity in the medial orbitofrontal cortex and in the dorsolateral prefrontal cortex encodes subjects' WTP for the items. Our results support the hypothesis that the medial orbitofrontal cortex encodes the value of goals in decision making. PMID:17855612

  19. Optogenetic Assessment of Horizontal Interactions in Primary Visual Cortex

    PubMed Central

    Huang, Xiaoying; Elyada, Yishai M.; Bosking, William H.; Walker, Theo

    2014-01-01

    Columnar organization of orientation selectivity and clustered horizontal connections linking orientation columns are two of the distinctive organizational features of primary visual cortex in many mammalian species. However, the functional role of these connections has been harder to characterize. Here we examine the extent and nature of horizontal interactions in V1 of the tree shrew using optical imaging of intrinsic signals, optogenetic stimulation, and multi-unit recording. Surprisingly, we find the effects of optogenetic stimulation depend primarily on distance and not on the specific orientation domains or axes in the cortex, which are stimulated. In addition, across a wide range of variation in both visual and optogenetic stimulation we find linear addition of the two inputs. These results emphasize that the cortex provides a rich substrate for functional interactions that are not limited to the orientation-specific interactions predicted by the monosynaptic distribution of horizontal connections. PMID:24695715

  20. Adaptation to sensory input tunes visual cortex to criticality

    NASA Astrophysics Data System (ADS)

    Shew, Woodrow L.; Clawson, Wesley P.; Pobst, Jeff; Karimipanah, Yahya; Wright, Nathaniel C.; Wessel, Ralf

    2015-08-01

    A long-standing hypothesis at the interface of physics and neuroscience is that neural networks self-organize to the critical point of a phase transition, thereby optimizing aspects of sensory information processing. This idea is partially supported by strong evidence for critical dynamics observed in the cerebral cortex, but the impact of sensory input on these dynamics is largely unknown. Thus, the foundations of this hypothesis--the self-organization process and how it manifests during strong sensory input--remain unstudied experimentally. Here we show in visual cortex and in a computational model that strong sensory input initially elicits cortical network dynamics that are not critical, but adaptive changes in the network rapidly tune the system to criticality. This conclusion is based on observations of multifaceted scaling laws predicted to occur at criticality. Our findings establish sensory adaptation as a self-organizing mechanism that maintains criticality in visual cortex during sensory information processing.

  1. Individuals' and groups' intentions in the medial prefrontal cortex.

    PubMed

    Chaminade, Thierry; Kawato, Mitsuo; Frith, Chris

    2011-11-16

    Functional MRI signal was recorded while participants perceived stimuli presented using moving dots. In two conditions of interest, the motion of dots depicted intentions: dots representing the joints of an agent performing an action, and dots representing individual agents behaving contingently. The finding of a common cluster in the posterior part of the medial frontal cortex involved in intentional action representation validates the hypothesis that perception of these two conditions requires a similar internal representation. A cluster responding to the behaving group only is found in the anterior medial frontal cortex. These results support a division of the medial frontal cortex according to social stimuli attributes, with anterior areas responding to higher-order group behaviours integrating the action of multiple individual agents. PMID:21897305

  2. Double dissociation of 'what' and 'where' processing in auditory cortex.

    PubMed

    Lomber, Stephen G; Malhotra, Shveta

    2008-05-01

    Studies of cortical connections or neuronal function in different cerebral areas support the hypothesis that parallel cortical processing streams, similar to those identified in visual cortex, may exist in the auditory system. However, this model has not yet been behaviorally tested. We used reversible cooling deactivation to investigate whether the individual regions in cat nonprimary auditory cortex that are responsible for processing the pattern of an acoustic stimulus or localizing a sound in space could be doubly dissociated in the same animal. We found that bilateral deactivation of the posterior auditory field resulted in deficits in a sound-localization task, whereas bilateral deactivation of the anterior auditory field resulted in deficits in a pattern-discrimination task, but not vice versa. These findings support a model of cortical organization that proposes that identifying an acoustic stimulus ('what') and its spatial location ('where') are processed in separate streams in auditory cortex. PMID:18408717

  3. Associative Hebbian Synaptic Plasticity in Primate Visual Cortex

    PubMed Central

    Huang, Shiyong; Rozas, Carlos; Treviño, Mario; Contreras, Jessica; Yang, Sunggu; Song, Lihua; Yoshioka, Takashi; Lee, Hey-Kyoung

    2014-01-01

    In primates, the functional connectivity of adult primary visual cortex is susceptible to be modified by sensory training during perceptual learning. It is widely held that this type of neural plasticity might involve mechanisms like long-term potentiation (LTP) and long-term depression (LTD). NMDAR-dependent forms of LTP and LTD are particularly attractive because in rodents they can be induced in a Hebbian manner by near coincidental presynaptic and postsynaptic firing, in a paradigm termed spike timing-dependent plasticity (STDP). These fundamental properties of LTP and LTD, Hebbian induction and NMDAR dependence, have not been examined in primate cortex. Here we demonstrate these properties in the primary visual cortex of the rhesus macaque (Macaca mulatta), and also show that, like in rodents, STDP is gated by neuromodulators. These findings indicate that the cellular principles governing cortical plasticity are conserved across mammalian species, further validating the use of rodents as a model system. PMID:24872561

  4. Interplay of hippocampus and prefrontal cortex in memory

    PubMed Central

    Preston, Alison R.; Eichenbaum, Howard

    2013-01-01

    Recent studies on the hippocampus and the prefrontal cortex have considerably advanced our understanding of the distinct roles of these brain areas in the encoding and retrieval of memories, and of how they interact in the prolonged process by which new memories are consolidated into our permanent storehouse of knowledge. These studies have led to a new model of how the hippocampus forms and replays memories and how the prefrontal cortex engages representations of the meaningful contexts in which related memories occur, as well as how these areas interact during memory retrieval. Furthermore, they have provided new insights into how interactions between the hippocampus and prefrontal cortex support the assimilation of new memories into pre-existing networks of knowledge, called schemas, and how schemas are modified in this process as the foundation of memory consolidation. PMID:24028960

  5. Computer assisted measurement of femoral cortex thickening on radiographs

    NASA Astrophysics Data System (ADS)

    Yao, Jianhua; Liu, Yixun; Chen, Foster; Summers, Ronald M.; Bhattacharyya, Timothy

    2013-03-01

    Radiographic features such as femoral cortex thickening have been frequently observed with atypical subtrochanteric fractures. These features may be a valuable finding to help prevent fractures before they happen. The current practice of manual measurement is often subjective and inconsistent. We developed a semi-automatic tool to consistently measure and monitor the progress of femoral cortex thickening on radiographs. By placing two seed points on each side of the femur, the program automatically extracts the periosteal and endosteal layers of the cortical shell by active contour models and B-spline fitting. Several measurements are taken along the femur shaft, including shaft diameter, cortical thickness, and integral area for medial and lateral cortex. The experiment was conducted on 52 patient datasets. The semi-automatic measurements were validated against manual measurements on 52 patients and demonstrated great improvement in consistency and accuracy (p<0.001).

  6. Pulvinar-Cortex Interactions in Vision and Attention.

    PubMed

    Zhou, Huihui; Schafer, Robert John; Desimone, Robert

    2016-01-01

    The ventro-lateral pulvinar is reciprocally connected with the visual areas of the ventral stream that are important for object recognition. To understand the mechanisms of attentive stimulus processing in this pulvinar-cortex loop, we investigated the interactions between the pulvinar, area V4, and IT cortex in a spatial-attention task. Sensory processing and the influence of attention in the pulvinar appeared to reflect its cortical inputs. However, pulvinar deactivation led to a reduction of attentional effects on firing rates and gamma synchrony in V4, a reduction of sensory-evoked responses and overall gamma coherence within V4, and severe behavioral deficits in the affected portion of the visual field. Conversely, pulvinar deactivation caused an increase in low-frequency cortical oscillations, often associated with inattention or sleep. Thus, cortical interactions with the ventro-lateral pulvinar are necessary for normal attention and sensory processing and for maintaining the cortex in an active state. PMID:26748092

  7. Spatial clustering of tuning in mouse primary visual cortex

    PubMed Central

    Ringach, Dario L.; Mineault, Patrick J.; Tring, Elaine; Olivas, Nicholas D.; Garcia-Junco-Clemente, Pablo; Trachtenberg, Joshua T.

    2016-01-01

    The primary visual cortex of higher mammals is organized into two-dimensional maps, where the preference of cells for stimulus parameters is arranged regularly on the cortical surface. In contrast, the preference of neurons in the rodent appears to be arranged randomly, in what is termed a salt-and-pepper map. Here we revisited the spatial organization of receptive fields in mouse primary visual cortex by measuring the tuning of pyramidal neurons in the joint orientation and spatial frequency domain. We found that the similarity of tuning decreases as a function of cortical distance, revealing a weak but statistically significant spatial clustering. Clustering was also observed across different cortical depths, consistent with a columnar organization. Thus, the mouse visual cortex is not strictly a salt-and-pepper map. At least on a local scale, it resembles a degraded version of the organization seen in higher mammals, hinting at a possible common origin. PMID:27481398

  8. Mapping the Structural Core of Human Cerebral Cortex

    PubMed Central

    Hagmann, Patric; Cammoun, Leila; Gigandet, Xavier; Meuli, Reto; Honey, Christopher J; Wedeen, Van J; Sporns, Olaf

    2008-01-01

    Structurally segregated and functionally specialized regions of the human cerebral cortex are interconnected by a dense network of cortico-cortical axonal pathways. By using diffusion spectrum imaging, we noninvasively mapped these pathways within and across cortical hemispheres in individual human participants. An analysis of the resulting large-scale structural brain networks reveals a structural core within posterior medial and parietal cerebral cortex, as well as several distinct temporal and frontal modules. Brain regions within the structural core share high degree, strength, and betweenness centrality, and they constitute connector hubs that link all major structural modules. The structural core contains brain regions that form the posterior components of the human default network. Looking both within and outside of core regions, we observed a substantial correspondence between structural connectivity and resting-state functional connectivity measured in the same participants. The spatial and topological centrality of the core within cortex suggests an important role in functional integration. PMID:18597554

  9. Altered intrinsic connectivity of the auditory cortex in congenital amusia.

    PubMed

    Leveque, Yohana; Fauvel, Baptiste; Groussard, Mathilde; Caclin, Anne; Albouy, Philippe; Platel, Hervé; Tillmann, Barbara

    2016-07-01

    Congenital amusia, a neurodevelopmental disorder of music perception and production, has been associated with abnormal anatomical and functional connectivity in a right frontotemporal pathway. To investigate whether spontaneous connectivity in brain networks involving the auditory cortex is altered in the amusic brain, we ran a seed-based connectivity analysis, contrasting at-rest functional MRI data of amusic and matched control participants. Our results reveal reduced frontotemporal connectivity in amusia during resting state, as well as an overconnectivity between the auditory cortex and the default mode network (DMN). The findings suggest that the auditory cortex is intrinsically more engaged toward internal processes and less available to external stimuli in amusics compared with controls. Beyond amusia, our findings provide new evidence for the link between cognitive deficits in pathology and abnormalities in the connectivity between sensory areas and the DMN at rest. PMID:27009161

  10. Modulation of inferotemporal cortex activation during verbal working memory maintenance

    PubMed Central

    Fiebach, Christian J.; Rissman, Jesse; D'Esposito, Mark

    2015-01-01

    Summary Regions of the left inferotemporal cortex are involved in visual word recognition and semantics. We utilized functional magnetic resonance imaging to localize an inferotemporal language area and to demonstrate that this area is involved in the active maintenance of visually presented words in working memory. Maintenance activity in this inferotemporal area showed an effect of memory load for words, but not pseudowords. The selective modulation of this language-related inferotemporal area for the maintenance of words, in the absence of visual input, is accompanied by an increased functional connectivity with left prefrontal cortex. These results are the first demonstration of an involvement of inferotemporal cortex in verbal working memory. They provide neurophysiological support for the notion that nonphonological language representations can be recruited in the service of verbal working memory. More generally, they suggest that verbal working memory should be conceptualized as the frontally-guided, sustained activation of pre-existing cortical language representations. PMID:16846859

  11. Cortical Connections of Functional Zones in Posterior Parietal Cortex and Frontal Cortex Motor Regions in New World Monkeys

    PubMed Central

    Stepniewska, Iwona; Kaas, Jon H.

    2011-01-01

    We examined the connections of posterior parietal cortex (PPC) with motor/premotor cortex (M1/PM) and other cortical areas. Electrical stimulation (500 ms trains) delivered to microelectrode sites evoked movements of reach, defense, and grasp, from distinct zones in M1/PM and PPC, in squirrel and owl monkeys. Tracer injections into M1/PM reach, defense, and grasp zones showed dense connections with M1/PM hand/forelimb representations. The densest inputs outside of frontal cortex were from PPC zones. M1 zones were additionally connected with somatosensory hand/forelimb representations in areas 3a, 3b, and 1 and the somatosensory areas of the upper bank of the lateral sulcus (S2/PV). Injections into PPC zones showed primarily local connections and the densest inputs outside of PPC originated from M1/PM zones. The PPC reach zone also received dense inputs from cortex caudal to PPC, which likely relayed visual information. In contrast, the PPC grasp zone was densely connected with the hand/forelimb representations of areas 3a, 3b, 1, and S2/PV. Thus, the dorsal parietal–frontal network involved in reaching was preferentially connected to visual cortex, whereas the more ventral network involved in grasping received somatosensory inputs. Additional weak interlinks between dissimilar zones (e.g., PPC reach and PPC grasp) were apparent and may coordinate actions. PMID:21263034

  12. Similarities between GCS and human motor cortex: complex movement coordination

    NASA Astrophysics Data System (ADS)

    Rodríguez, Jose A.; Macias, Rosa; Molgo, Jordi; Guerra, Dailos

    2014-07-01

    The "Gran Telescopio de Canarias" (GTC1) is an optical-infrared 10-meter segmented mirror telescope at the ORM observatory in Canary Islands (Spain). The GTC control system (GCS), the brain of the telescope, is is a distributed object & component oriented system based on RT-CORBA and it is responsible for the management and operation of the telescope, including its instrumentation. On the other hand, the Human motor cortex (HMC) is a region of the cerebrum responsible for the coordination of planning, control, and executing voluntary movements. If we analyze both systems, as far as the movement control of their mechanisms and body parts is concerned, we can find extraordinary similarities in their architectures. Both are structured in layers, and their functionalities are comparable from the movement conception until the movement action itself: In the GCS we can enumerate the Sequencer high level components, the Coordination libraries, the Control Kit library and the Device Driver library as the subsystems involved in the telescope movement control. If we look at the motor cortex, we can also enumerate the primary motor cortex, the secondary motor cortices, which include the posterior parietal cortex, the premotor cortex, and the supplementary motor area (SMA), the motor units, the sensory organs and the basal ganglia. From all these components/areas we will analyze in depth the several subcortical regions, of the the motor cortex, that are involved in organizing motor programs for complex movements and the GCS coordination framework, which is composed by a set of classes that allow to the high level components to transparently control a group of mechanisms simultaneously.

  13. Transcranial static magnetic field stimulation of the human motor cortex.

    PubMed

    Oliviero, Antonio; Mordillo-Mateos, Laura; Arias, Pablo; Panyavin, Ivan; Foffani, Guglielmo; Aguilar, Juan

    2011-10-15

    The aim of the present study was to investigate in healthy humans the possibility of a non-invasive modulation of motor cortex excitability by the application of static magnetic fields through the scalp. Static magnetic fields were obtained by using cylindrical NdFeB magnets. We performed four sets of experiments. In Experiment 1, we recorded motor potentials evoked by single-pulse transcranial magnetic stimulation (TMS) of the motor cortex before and after 10 min of transcranial static magnetic field stimulation (tSMS) in conscious subjects. We observed an average reduction of motor cortex excitability of up to 25%, as revealed by TMS, which lasted for several minutes after the end of tSMS, and was dose dependent (intensity of the magnetic field) but not polarity dependent. In Experiment 2, we confirmed the reduction of motor cortex excitability induced by tSMS using a double-blind sham-controlled design. In Experiment 3, we investigated the duration of tSMS that was necessary to modulate motor cortex excitability. We found that 10 min of tSMS (compared to 1 min and 5 min) were necessary to induce significant effects. In Experiment 4, we used transcranial electric stimulation (TES) to establish that the tSMS-induced reduction of motor cortex excitability was not due to corticospinal axon and/or spinal excitability, but specifically involved intracortical networks. These results suggest that tSMS using small static magnets may be a promising tool to modulate cerebral excitability in a non-invasive, painless, and reversible way. PMID:21807616

  14. The Organization of Dorsal Frontal Cortex in Humans and Macaques

    PubMed Central

    Mars, Rogier B.; Noonan, MaryAnn P.; Neubert, Franz-Xaver; Jbabdi, Saad; O'Reilly, Jill X.; Filippini, Nicola; Thomas, Adam G.; Rushworth, Matthew F.

    2013-01-01

    The human dorsal frontal cortex has been associated with the most sophisticated aspects of cognition, including those that are thought to be especially refined in humans. Here we used diffusion-weighted magnetic resonance imaging (DW-MRI) and functional MRI (fMRI) in humans and macaques to infer and compare the organization of dorsal frontal cortex in the two species. Using DW-MRI tractography-based parcellation, we identified 10 dorsal frontal regions lying between the human inferior frontal sulcus and cingulate cortex. Patterns of functional coupling between each area and the rest of the brain were then estimated with fMRI and compared with functional coupling patterns in macaques. Areas in human medial frontal cortex, including areas associated with high-level social cognitive processes such as theory of mind, showed a surprising degree of similarity in their functional coupling patterns with the frontal pole, medial prefrontal, and dorsal prefrontal convexity in the macaque. We failed to find evidence for “new” regions in human medial frontal cortex. On the lateral surface, comparison of functional coupling patterns suggested correspondences in anatomical organization distinct from those that are widely assumed. A human region sometimes referred to as lateral frontal pole more closely resembled area 46, rather than the frontal pole, of the macaque. Overall the pattern of results suggest important similarities in frontal cortex organization in humans and other primates, even in the case of regions thought to carry out uniquely human functions. The patterns of interspecies correspondences are not, however, always those that are widely assumed. PMID:23884933

  15. Purification and characterization of phytocystatins from kiwifruit cortex and seeds.

    PubMed

    Rassam, Maysoon; Laing, William A

    2004-01-01

    Kiwifruit cysteine proteinase inhibitors (KCPIs) were purified from the cortex and seeds of kiwifruit after inactivation of the abundant cortex cysteine proteinase actinidain. One major (KCPI1) and four minor cystatins were identified from Actinidia deliciosa ripe mature kiwifruit cortex as well as a seed KCPI from A. chinensis. The predominant cortex cystatin, KCPI1, inhibited clan CA, family C1 (papain family) cysteine proteinases (papain, chymopapain, bromelain, ficin, human cathepsins B, H and L, actinidain and the house dust mite endopeptidase 1), while cysteine proteinases belonging to other families, [clostripain (C11), streptopain (C10) and calpain (C2)] were not inhibited. Inhibition constants (K(I)) ranged between 0.001 nM for cathepsin L and 0.98 nM for endopeptidase 1. The K(I) (14 nM) for KCPI1 inhibiting actinidain is at least 2 orders of magnitude higher than for other plant proteinases measured. The cortex KCPI1 and a seed KCPI purified from seeds had the same N-terminal sequence (VAAGGWRPIESLNSAEVQDV). BLAST-matching the peptide sequence against an in-house generated Actinidia EST database, identified 81 cDNAs that exactly matched the measured KCPI1 peptide sequence. Peptide sequences of two other cortex KCPIs each exactly matched a predicted peptide sequence of a cDNA from kiwifruit. The predicted peptide sequence of KCPI1 of 116 amino acids encodes a signal peptide and does not contain cysteine. Without the signal peptide (mature protein), KCPI1 has a molecular mass of approximately 11 kDa, possesses the consensus sequence characteristic for the phytocystatins and shows the highest homology to a cystatin from Citrusxparadisi (52% identity). This is the first report of phytocystatins from the Ericales. PMID:14697268

  16. Visual cortex controls retinal output in the rat.

    PubMed

    Molotchnikoff, S; Tremblay, F

    1986-07-01

    The first o