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Sample records for box thalamic dopamine

  1. Dopamine, fronto-striato-thalamic circuits and risk for psychosis.

    PubMed

    Dandash, Orwa; Pantelis, Christos; Fornito, Alex

    2017-02-01

    A series of parallel, integrated circuits link distinct regions of prefrontal cortex with specific nuclei of the striatum and thalamus. Dysfunction of these fronto-striato-thalamic systems is thought to play a major role in the pathogenesis of psychosis. In this review, we examine evidence from human and animal investigations that dysfunction of a specific dorsal fronto-striato-thalamic circuit, linking the dorsolateral prefrontal cortex, dorsal (associative) striatum, and mediodorsal nucleus of the thalamus, is apparent across different stages of psychosis, including prior to the onset of a first episode, suggesting that it represents a candidate risk biomarker. We consider how abnormalities at distinct points in the circuit may give rise to the pattern of findings seen in patient populations, and how these changes relate to disruptions in dopamine, glutamate and GABA signaling.

  2. The effects of nigrostriatal dopamine depletion on the thalamic parafascicular nucleus.

    PubMed

    Kusnoor, Sheila V; Bubser, Michael; Deutch, Ariel Y

    2012-03-29

    Neuronal loss in Parkinson's disease (PD) is seen in a number of brain regions in addition to the substantia nigra (SN). Among these is the thalamic parafascicular nucleus (PF), which sends glutamatergic projections to the striatum and receives GABAergic inputs from the SN. Recent data suggest that lesions of nigrostriatal dopamine axons cause a loss of PF neurons, which has been interpreted to suggest that the PF cell loss seen in PD is secondary to dopamine denervation. However, the extent of a PF dopamine innervation in the rat is unclear, and it is possible that PF cell loss in parkinsonism is independent of nigrostriatal dopamine degeneration. We characterized the dopamine innervation of the PF in the rat and determined if 6-hydroxydopamine SN lesions cause PF neuron degeneration. Dual-label immunohistochemistry revealed that almost all tyrosine hydroxylase-immunoreactive (TH-ir) axons in the PF also expressed dopamine-beta-hydroxylase and were therefore noradrenergic or adrenergic. Moreover, an antibody directed against dopamine revealed only very rare PF dopaminergic axons. Retrograde-tract tracing-immunohistochemistry did not uncover an innervation of the PF from midbrain dopamine neurons. Nigrostriatal dopamine neuron lesions did not elicit degeneration of PF cells, as reflected by a lack of FluoroJade C staining. Similarly, neither unilateral 6-OHDA lesions of nigrostriatal axons nor the dorsal noradrenergic bundle decreased the number of PF neurons or the number of PF neurons retrogradely-labeled from the striatum. These data suggest that the loss of thalamostriatal PF neurons in Parkinson's Disease is a primary event rather than secondary to nigrostriatal dopamine degeneration.

  3. Striatal dopamine D2 receptor availability predicts the thalamic and medial prefrontal responses to reward in cocaine abusers three years later

    SciTech Connect

    Asensio, S.; Goldstein, R.; Asensio, S.; Romero, M.J.; Romero, F.J.; Wong, C.T.; Alia-Klein, N.; Tomasi, D.; Wang, G.-J.; Telang, F..; Volkow, N.D.; Goldstein, R.Z.

    2010-05-01

    Low levels of dopamine (DA) D2 receptor availability at a resting baseline have been previously reported in drug addicted individuals and have been associated with reduced ventral and dorsal prefrontal metabolism. The reduction in DA D2 receptor availability along with the reduced ventral frontal metabolism is thought to underlie compromised sensitivity to nondrug reward, a core characteristic of drug addiction. We therefore hypothesized that variability in DA D2 receptor availability at baseline will covary with dynamic responses to monetary reward in addicted individuals. Striatal DA D2 receptor availability was measured with [{sup 11}C]raclopride and positron emission tomography and response to monetary reward was measured (an average of three years later) with functional magnetic resonance imaging in seven cocaine-addicted individuals. Results show that low DA D2 receptor availability in the dorsal striatum was associated with decreased thalamic response to monetary reward; while low availability in ventral striatum was associated with increased medial prefrontal (Brodmann Area 6/8/32) response to monetary reward. These preliminary results, that need to be replicated in larger sample sizes and validated with healthy controls, suggest that resting striatal DA D2 receptor availability predicts variability in functional responses to a nondrug reinforcer (money) in prefrontal cortex, implicated in behavioral monitoring, and in thalamus, implicated in conditioned responses and expectation, in cocaine-addicted individuals.

  4. Striatal dopamine D2 receptor availability predicts the thalamic and medial prefrontal responses to reward in cocaine abusers three years later

    PubMed Central

    Asensio, Samuel; Romero, Maria J.; Romero, Francisco J.; Wong, Christopher; Alia-Klein, Nelly; Tomasi, Dardo; Wang, Gene-Jack; Telang, Frank; Volkow, Nora D.; Goldstein, Rita Z.

    2009-01-01

    Low levels of dopamine (DA) D2 receptor availability at a resting baseline have been previously reported in drug addicted individuals and have been associated with reduced ventral and dorsal prefrontal metabolism. The reduction in DA D2 receptor availability along with the reduced ventral frontal metabolism is thought to underlie compromised sensitivity to non-drug reward, a core characteristic of drug addiction. We therefore hypothesized that variability in DA D2 receptor availability at baseline will covary with dynamic responses to monetary reward in addicted individuals. Striatal DA D2 receptor availability was measured with [11C]raclopride and positron emission tomography and response to monetary reward was measured (an average of 3 years later) with functional magnetic resonance imaging in seven cocaine addicted individuals. Results show that low DA D2 receptor availability in the dorsal striatum was associated with decreased thalamic response to monetary reward; while low availability in ventral striatum was associated with increased medial prefrontal (Brodmann Area 6/8/32) response to monetary reward. These preliminary results, that need to be replicated in larger sample sizes and validated with healthy controls, suggest that resting striatal DA D2 receptor availability predicts variability in functional responses to a non-drug reinforcer (money) in prefrontal cortex, implicated in behavioral monitoring, and in thalamus, implicated in conditioned responses and expectation, in cocaine addicted individuals. PMID:20034014

  5. Thalamic neglect.

    PubMed

    Watson, R T; Heilman, K M

    1979-05-01

    Three patients with right thalamic hemorrhage showed contralateral neglect and limb akinesia. They also had anosognosia, visuospatial disorders, and emotional flattening. In animals, neglect can be induced by lesions along a cortico-limbic-reticular loop including the intralaminar thalamic nuclei. We propose that an activation defect is responsible not only for the neglect and akinesia, but also for the visuospatial and emotional defects usually associated with right-hemisphere cortical dysfunction.

  6. Immunohistochemical localization of the D1 dopamine receptor in rat brain reveals its axonal transport, pre- and postsynaptic localization, and prevalence in the basal ganglia, limbic system, and thalamic reticular nucleus.

    PubMed Central

    Huang, Q; Zhou, D; Chase, K; Gusella, J F; Aronin, N; DiFiglia, M

    1992-01-01

    D1 dopamine receptor localization was examined by immunohistochemistry using a polyclonal anti-peptide antibody which (i) immunoprecipitated a protein fragment encoded by a D1 receptor cDNA and (ii) on Western blots of solubilized striatal and hippocampal membranes recognized two proteins of approximately 50 kDa and 75 kDa, corresponding to reported sizes of D1 receptor proteins. Immunoreactivity overlapped with dopamine-containing pathways, patterns of D1 receptor binding, and mRNA expression. Staining was concentrated in prefrontal, cingulate, parietal, piriform, entorhinal, and hippocampal cortical areas and subcortically in the basal ganglia, amygdala, septal area, substantia inominata, thalamus, hypothalamus, and neurohypophysis. Prominent labeling was seen in the thalamic reticular nucleus, a region known to integrate ascending basal forebrain inputs with thalamocortical and corticothalamic pathways and in fiber bundles interconnecting limbic areas. In striatal neuropil, staining appeared in spines (heads and necks), at postsynaptic sites in dendrites, and in axon terminals; in the pars reticulata of the substantia nigra, labeling was prevalent in myelinated and unmyelinated axons and dendrites. These data provide direct evidence for the regional and subcellular distribution of D1 receptor protein in the brain and for its pre- and postsynaptic localization in the basal ganglia. The prominent immunoreactivity seen in the limbic system and thalamic reticular nucleus supports an important role for this receptor subtype in mediating integrative processes involved with learning, memory, and cognition. Images PMID:1281547

  7. Frontal-thalamic circuits associated with language.

    PubMed

    Barbas, Helen; García-Cabezas, Miguel Ángel; Zikopoulos, Basilis

    2013-07-01

    Thalamic nuclei associated with language including the ventral lateral, ventral anterior, intralaminar and mediodorsal form a hub that uniquely receives the output of the basal ganglia and cerebellum, and is connected with frontal (premotor and prefrontal) cortices through two parallel circuits: a thalamic pathway targets the middle frontal cortical layers focally, and the other innervates widely cortical layer 1, poised to recruit other cortices and thalamic nuclei for complex cognitive operations. Return frontal pathways to the thalamus originate from cortical layers 6 and 5. Information through this integrated thalamo-cortical system is gated by the inhibitory thalamic reticular nucleus and modulated by dopamine, representing a specialization in primates. The intricate dialogue of distinct thalamic nuclei with the basal ganglia, cerebellum, and specific dorsolateral prefrontal and premotor cortices associated with language, suggests synergistic roles in the complex but seemingly effortless sequential transformation of cognitive operations for speech production in humans.

  8. Dopamine D4 receptor stimulation in GABAergic projections of the globus pallidus to the reticular thalamic nucleus and the substantia nigra reticulata of the rat decreases locomotor activity.

    PubMed

    Erlij, David; Acosta-García, Jacqueline; Rojas-Márquez, Martín; González-Hernández, Brenda; Escartín-Perez, Erick; Aceves, Jorge; Florán, Benjamín

    2012-02-01

    Dopamine D4 receptors are localized in the GABAergic projections that globus pallidus (GP) neurons send to the reticular nucleus of the thalamus (RTN), the substantia nigra reticulata (SNr) and the subthalamic nucleus (STN). Deficient D4 function in this network could lead to hyperactivity and thus be important in generating some of the symptoms of ADHD (attention deficit hyperactivity disorder), a condition associated with polymorphisms of dopamine D4 receptors. It is then, unexpected that systemic injections of D4 ligands have no significant effects on the motor activity of normal rats. We further examined this issue by microinjecting D4 ligands and psychostimulant drugs in relevant structures. Interstitial dopamine overflow in the RTN was increased by reverse microdialysis of both methylphenidate and methamphetamine. Intranuclear injections in the RTN of methylphenidate, methamphetamine and the selective D4 agonist PD 168,077 reduced motor activity. Intraperitoneal injection of the D4 antagonist L 745,870 blocked the effects of these intranuclear injections. Similarly, intranuclear injections of PD 168,077 in the SNr inhibited motor activity, an effect that was also blocked by intraperitoneal L 745,870. In rats with 6-OHDA induced hemiparkinsonism, intraperitoneal PD 168,077 produced ipsilateral turning behavior that was blocked by L 745,870. Our results suggest that diminished D4 signaling in GP projections could lead to increased traffic through the relay nuclei of the thalamus and hyperactivity. Hence this basal-ganglia-thalamus network may be one of the targets of the beneficial effects that psychostimulant drugs have in disorders associated with D4 receptor abnormalities. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.

  9. Subsequent bilateral thalamic haemorrhage

    PubMed Central

    Perez, Jesus; Scherle, Claudio; Machado, Calixto

    2009-01-01

    Simultaneous or subsequent bilateral thalamic haemorrhage is rare, and most reported cases are from Asian countries. An 80-year-old white Cuban man, with a history of arterial hypertension, suffered sudden onset of right hemiparesis. Computed tomography (CT) scan showed a left posteromedial thalamic haemorrhage. Two days later his condition suddenly deteriorated: blood pressure was 220/105 mm Hg, he was stuporous and tetraplegic, respiration was ataxic, and his gaze was fixed and deviated downward and inward. CT scan showed haemorrhages in both thalami, extending to the ventricles. 32 h later the patient died. There are few previous publications of simultaneous or subsequent bilateral thalamic haemorrhages and this is the first report involving a Hispanic patient. Prognosis in patients with bilateral thalamic haemorrhage is poor, and the mechanism underlying the development of subsequent and symmetrical bleeding is not clear. PMID:21709830

  10. Genetics Home Reference: dopamine transporter deficiency syndrome

    MedlinePlus

    ... Genetics Home Health Conditions dopamine transporter deficiency syndrome dopamine transporter deficiency syndrome Enable Javascript to view the ... boxes. Download PDF Open All Close All Description Dopamine transporter deficiency syndrome is a rare movement disorder. ...

  11. Thalamic alexia with agraphia

    PubMed Central

    de Gobbi Porto, Fábio Henrique; d'Ávila Freitas, Maria Isabel; de Oliveira, Maira Okada; Lucato, Leandro Tavares; Orsini, Marco; de Menezes, Sara Lúcia Silveira; Magaldi, Regina Miksian; Porto, Cláudia Sellitto; Dozzi Brucki, Sonia Maria; Nitrini, Ricardo

    2012-01-01

    Alexia with agraphia is defined as an acquired impairment affecting reading and writing ability. It can be associated with aphasia, but can also occur as an isolated entity. This impairment has classically been associated with a left angular gyrus lesion In the present study, we describe a case involving a patient who developed alexia with agraphia and other cognitive deficits after a thalamic hemorrhage. In addition, we discuss potential mechanisms of this cortical dysfunction syndrome caused by subcortical injury. We examined a patient who presented with alexia with agraphia and other cognitive deficits due to a hemorrhage in the left thalamus. Neuropsychological evaluation showed attention, executive function, arithmetic and memory impairments. In addition, language tests revealed severe alexia with agraphia in the absence of aphasia. Imaging studies disclosed an old thalamic hemorrhage involving the anterior, dorsomedial and pulvinar nuclei. Tractography revealed asymmetric thalamocortical radiations in the parietal region (left thalamic lesions. The probable mechanism is a diaschisis phenomenon involving thalamic tract disconnections. PMID:22593808

  12. Central Thalamic Deep-Brain Stimulation Alters Striatal-Thalamic Connectivity in Cognitive Neural Behavior

    PubMed Central

    Lin, Hui-Ching; Pan, Han-Chi; Lin, Sheng-Huang; Lo, Yu-Chun; Shen, Elise Ting-Hsin; Liao, Lun-De; Liao, Pei-Han; Chien, Yi-Wei; Liao, Kuei-Da; Jaw, Fu-Shan; Chu, Kai-Wen; Lai, Hsin-Yi; Chen, You-Yin

    2016-01-01

    Central thalamic deep brain stimulation (CT-DBS) has been proposed as an experimental therapeutic approach to produce consistent sustained regulation of forebrain arousal for several neurological diseases. We investigated local field potentials (LFPs) induced by CT-DBS from the thalamic central lateral nuclei (CL) and the striatum as potential biomarkers for the enhancement of lever-pressing skill learning. LFPs were simultaneously recorded from multiple sites in the CL, ventral striatum (Vstr), and dorsal striatum (Dstr). LFP oscillation power and functional connectivity were assessed and compared between the CT-DBS and sham control groups. The theta and alpha LFP oscillations were significantly increased in the CL and striatum in the CT-DBS group. Furthermore, interhemispheric coherences between bilateral CL and striatum were increased in the theta band. Additionally, enhancement of c-Fos activity, dopamine D2 receptor (Drd2), and α4-nicotinic acetylcholine receptor (α4-nAChR) occurred after CT-DBS treatment in the striatum and hippocampus. CT-DBS strengthened thalamic-striatal functional connectivity, which demonstrates that the inter-regional connectivity enhancement might contribute to synaptic plasticity in the striatum. Altered dopaminergic and cholinergic receptors resulted in modulation of striatal synaptic plasticity's ability to regulate downstream signaling cascades for higher brain functions of lever-pressing skill learning. PMID:26793069

  13. Central Thalamic Deep-Brain Stimulation Alters Striatal-Thalamic Connectivity in Cognitive Neural Behavior.

    PubMed

    Lin, Hui-Ching; Pan, Han-Chi; Lin, Sheng-Huang; Lo, Yu-Chun; Shen, Elise Ting-Hsin; Liao, Lun-De; Liao, Pei-Han; Chien, Yi-Wei; Liao, Kuei-Da; Jaw, Fu-Shan; Chu, Kai-Wen; Lai, Hsin-Yi; Chen, You-Yin

    2015-01-01

    Central thalamic deep brain stimulation (CT-DBS) has been proposed as an experimental therapeutic approach to produce consistent sustained regulation of forebrain arousal for several neurological diseases. We investigated local field potentials (LFPs) induced by CT-DBS from the thalamic central lateral nuclei (CL) and the striatum as potential biomarkers for the enhancement of lever-pressing skill learning. LFPs were simultaneously recorded from multiple sites in the CL, ventral striatum (Vstr), and dorsal striatum (Dstr). LFP oscillation power and functional connectivity were assessed and compared between the CT-DBS and sham control groups. The theta and alpha LFP oscillations were significantly increased in the CL and striatum in the CT-DBS group. Furthermore, interhemispheric coherences between bilateral CL and striatum were increased in the theta band. Additionally, enhancement of c-Fos activity, dopamine D2 receptor (Drd2), and α4-nicotinic acetylcholine receptor (α4-nAChR) occurred after CT-DBS treatment in the striatum and hippocampus. CT-DBS strengthened thalamic-striatal functional connectivity, which demonstrates that the inter-regional connectivity enhancement might contribute to synaptic plasticity in the striatum. Altered dopaminergic and cholinergic receptors resulted in modulation of striatal synaptic plasticity's ability to regulate downstream signaling cascades for higher brain functions of lever-pressing skill learning.

  14. Genetics Home Reference: dopamine beta-hydroxylase deficiency

    MedlinePlus

    ... Genetics Home Health Conditions dopamine beta-hydroxylase deficiency dopamine beta-hydroxylase deficiency Enable Javascript to view the ... boxes. Download PDF Open All Close All Description Dopamine beta (β)-hydroxylase deficiency is a condition that ...

  15. The primate thalamus is a key target for brain dopamine.

    PubMed

    Sánchez-González, Miguel Angel; García-Cabezas, Miguel Angel; Rico, Beatriz; Cavada, Carmen

    2005-06-29

    The thalamus relays information to the cerebral cortex from subcortical centers or other cortices; in addition, it projects to the striatum and amygdala. The thalamic relay function is subject to modulation, so the flow of information to the target regions may change depending on behavioral demands. Modulation of thalamic relay by dopamine is not currently acknowledged, perhaps because dopamine innervation is reportedly scant in the rodent thalamus. We show that dopaminergic axons profusely target the human and macaque monkey thalamus using immunolabeling with three markers of the dopaminergic phenotype (tyrosine hydroxylase, dopamine, and the dopamine transporter). The dopamine innervation is especially prominent in specific association, limbic, and motor thalamic nuclei, where the densities of dopaminergic axons are as high as or higher than in the cortical area with the densest dopamine innervation. We also identified the dopaminergic neurons projecting to the macaque thalamus using retrograde tract-tracing combined with immunohistochemistry. The origin of thalamic dopamine is multiple, and thus more complex, than in any other dopaminergic system defined to date: dopaminergic neurons of the hypothalamus, periaqueductal gray matter, ventral mesencephalon, and the lateral parabrachial nucleus project bilaterally to the monkey thalamus. We propose a novel dopaminergic system that targets the primate thalamus and is independent from the previously defined nigrostriatal, mesocortical, and mesolimbic dopaminergic systems. Investigating this "thalamic dopaminergic system" should further our understanding of higher brain functions and conditions such as Parkinson's disease, schizophrenia, and drug addiction.

  16. Magical Boxes

    ERIC Educational Resources Information Center

    Costello, Judith

    2005-01-01

    Students get excited when they realize that they can transform a flat sheet of paper into a box. By using different sizes of paper, they can make different sizes of boxes and put a box inside a box, inside a box. These magical boxes within boxes can contain unwanted emotions or special treasures. The project described in this article incorporates…

  17. Thalamic role in spatial memory.

    PubMed

    Greene, E; Naranjo, J N

    1986-02-01

    The contribution of structures in the limbic diencephalon to spatial memory function was investigated. Rats with lesions of either the anteroventral thalamus, anteromedial thalamus, dorsomedial thalamus or mammillary bodies were compared in their ability to perform a delayed alternation task. The results indicate the ablation of the thalamic nuclei did not impair delayed-alternation memory, but there was impairment following damage to the mammillary bodies. Placement of the discrete lesions was verified using Nissl sections and by tracing the pattern of projections using a silver degeneration stain. The results suggest that individual thalamic nuclei are not essential in the storage and/or retrieval of spatial memory. The data are discussed in terms of spatial deficits resulting from damage to the hippocampus proper or to the pathways connecting it to other brain structures.

  18. Jeweled Boxes

    ERIC Educational Resources Information Center

    Coy, Mary

    2009-01-01

    While an empty cardboard box from a ream of copy paper may be the most coveted box among teachers in the author's school, for other people, brass boxes from India, Khokhlova lacquer boxes from Russia, and puzzle boxes from Japan are more the type that are collected and admired. Whether it is used for storage or decoration, a box can evoke a sense…

  19. Excitatory actions of peptide histidine isoleucine on thalamic relay neurons.

    PubMed

    Lee, Sang-Hun; Cox, Charles L

    2008-12-01

    Peptide histidine isoleucine (PHI) and vasoactive intestinal peptide (VIP) are neuropeptides synthesized from a common precursor, prepro-VIP, and share structural similarity and biological functions in many systems. Within the central nervous system and peripheral tissues, PHI and VIP have overlapping distribution. PHI-mediated functions are generally via activation of VIP receptors; however, the potency and affinity of PHI for VIP receptors are significantly lower than VIP. In addition, several studies suggest distinct PHI receptors that are independent of VIP receptors. PHI receptors have been cloned and characterized in fish, but their existence in mammals is still unknown. This study focuses on the functional role of PHI in the thalamus because of the localization of both PHI and VIP receptors in this brain region. Using extracellular multiple-unit recording techniques, we found that PHI strongly attenuated the slow intrathalamic rhythmic activity. Using intracellular recording techniques, we found that PHI selectively depolarized thalamic relay neurons via an enhancement of the hyperpolarization-activated mixed cation current, Ih. Further, the actions of PHI were occluded by VIP and dopamine, indicating these modulators converge onto a common mechanism. In contrast to previous work, we found that PHI was more potent than VIP in producing excitatory actions on thalamic neurons. We next used the transgenic mice lacking a specific VIP receptor, VPAC2, to identify its possible role in PHI-mediated actions in the thalamus. PHI depolarized all relay neurons tested from wild-type mice (VPAC2(+/+)); however, in knockout mice (VPAC2(-/-)), PHI produced no change in membrane potential in all neurons tested. Our findings indicate that excitatory actions of PHI are mediated by VPAC2 receptors, not by its own PHI receptors and the excitatory actions of PHI clearly attenuate intrathalamic rhythmic activities, and likely influence information transfer through thalamocortical

  20. Thalamic Pain Misdiagnosed as Cervical Disc Herniation.

    PubMed

    Lim, Tae Ha; Choi, Soo Il; Yoo, Jee In; Choi, Young Soon; Lim, Young Su; Sang, Bo Hyun; Bang, Yun Sic; Kim, Young Uk

    2016-04-01

    Thalamic pain is a primary cause of central post-stroke pain (CPSP). Clinical symptoms vary depending on the location of the infarction and frequently accompany several pain symptoms. Therefore, correct diagnosis and proper examination are not easy. We report a case of CPSP due to a left acute thalamic infarction with central disc protrusion at C5-6. A 45-year-old-male patient experiencing a tingling sensation in his right arm was referred to our pain clinic under the diagnosis of cervical disc herniation. This patient also complained of right cramp-like abdominal pain. After further evaluations, he was diagnosed with an acute thalamic infarction. Therefore detailed history taking should be performed and examiners should always be aware of other symptoms that could suggest a more dangerous disease.

  1. Thalamic pain alleviated by stellate ganglion block

    PubMed Central

    Liao, Chenlong; Yang, Min; Liu, Pengfei; Zhong, Wenxiang; Zhang, Wenchuan

    2017-01-01

    Abstract Rationale: Thalamic pain is a distressing and treatment-resistant type of central post-stroke pain. Although stellate ganglion block is an established intervention used in pain management, its use in the treatment of thalamic pain has never been reported. Patient concerns: A 66-year-old woman presented with a 3-year history of severe intermittent lancinating pain on the right side of the face and the right hand. The pain started from the ulnar side of the right forearm after a mild ischemic stroke in bilateral basal ganglia and left thalamus. Weeks later, the pain extended to the dorsum of the finger tips and the whole palmar surface, becoming more severe. Meanwhile, there was also pain with similar characteristics emerging on her right face, resembling atypical trigeminal neuralgia. Diagnoses: Thalamic pain was diagnosed. Interventions: After refusing the further invasive treatment, she was suggested to try stellate ganglion block. Outcomes: After a 3-day period of pain free (numerical rating scale: 0) postoperatively, she reported moderate to good pain relief with a numerical rating scale of about 3 to 4 lasting 1 month after the first injection. Pain as well as the quality of life was markedly improved with less dose of analgesic agents. Lessons: Stellate ganglion block may be an optional treatment for thalamic pain. PMID:28151918

  2. Bento Boxes

    ERIC Educational Resources Information Center

    Hasio, Cindy

    2010-01-01

    Bento boxes are common objects in Japanese culture, designed to hold enough lunch for one person. They have individual compartments and sometimes multiple tiers for rice, vegetables, and other side dishes. They are made of materials ranging from wood, cloth, aluminum, or plastic. In general, the greater the number of foods, the better the box is…

  3. Film Boxes.

    ERIC Educational Resources Information Center

    Osterer, Irv

    2002-01-01

    Presents an art lesson in which students created three-dimensional designs for 35mm film packages to improve graphic arts learning. Describes how the students examined and created film boxes using QuarkXPress software. (CMK)

  4. Neurochemical pathways that converge on thalamic trigeminovascular neurons: potential substrate for modulation of migraine by sleep, food intake, stress and anxiety.

    PubMed

    Noseda, Rodrigo; Kainz, Vanessa; Borsook, David; Burstein, Rami

    2014-01-01

    Dynamic thalamic regulation of sensory signals allows the cortex to adjust better to rapidly changing behavioral, physiological and environmental demands. To fulfill this role, thalamic neurons must themselves be subjected to constantly changing modulatory inputs that originate in multiple neurochemical pathways involved in autonomic, affective and cognitive functions. Our overall goal is to define an anatomical framework for conceptualizing how a 'decision' is made on whether a trigeminovascular thalamic neuron fires, for how long, and at what frequency. To begin answering this question, we determine which neuropeptides/neurotransmitters are in a position to modulate thalamic trigeminovascular neurons. Using a combination of in-vivo single-unit recording, juxtacellular labeling with tetramethylrhodamine dextran (TMR) and in-vitro immunohistochemistry, we found that thalamic trigeminovascular neurons were surrounded by high density of axons containing biomarkers of glutamate, GABA, dopamine and serotonin; moderate density of axons containing noradrenaline and histamine; low density of axons containing orexin and melanin concentrating hormone (MCH); but not axons containing CGRP, serotonin 1D receptor, oxytocin or vasopressin. In the context of migraine, the findings suggest that the transmission of headache-related nociceptive signals from the thalamus to the cortex may be modulated by opposing forces (i.e., facilitatory, inhibitory) that are governed by continuous adjustments needed to keep physiological, behavioral, cognitive and emotional homeostasis.

  5. [Disappearance of essential tremor after thalamic infarction].

    PubMed

    Nakamura, Y; Miura, K; Yamada, I; Takada, K

    1999-01-01

    Stereotactic thalamotomy has been used with some benefit in the treatment of essential tremor. We report a 73-year-old woman whose essential tremor of the right hand spontaneously disappeared after thalamic infarction. She had suffered hand tremor of the right hand for seven years. One morning, she noticed mild muscular weakness in her right upper and lower extremities, numbness around her mouth and paresthesia in her right arm. Simultaneously, she noticed disappearance of the tremor of her right hand. Several days later, right hemiplegia and paresthesia completely resolved. Neurological examination revealed no postural tremor or resting tremor. T 2-weighted brain MR imaging showed a high-intensity signal in the left thalamus that involved the ventralis intermedius nucleus. Clinical recovery from the effect of the infarct on essential tremor was complete. Therefore, it seems that thalamic infarction in this patient had an effect on essential tremor similar to that achieved with thalamotomy.

  6. Midline thalamic reuniens lesions improve executive behaviors.

    PubMed

    Prasad, J A; Abela, A R; Chudasama, Y

    2017-03-14

    The role of the thalamus in complex cognitive behavior is a topic of increasing interest. Here we demonstrate that lesions of the nucleus reuniens (NRe), a midline thalamic nucleus interconnected with both hippocampal and prefrontal circuitry, lead to enhancement of executive behaviors typically associated with the prefrontal cortex. Rats were tested on four behavioral tasks: (1) the combined attention-memory (CAM) task, which simultaneously assessed attention to a visual target and memory for that target over a variable delay; (2) spatial memory using a radial arm maze, (3) discrimination and reversal learning using a touchscreen operant platform, and (4) decision-making with delayed outcomes. Following NRe lesions, the animals became more efficient in their performance, responding with shorter reaction times but also less impulsively than controls. This change, combined with a decrease in perseverative responses, led to focused attention in the CAM task and accelerated learning in the visual discrimination task. There were no observed changes in tasks involving either spatial memory or value-based decision making. These data complement ongoing efforts to understand the role of midline thalamic structures in human cognition, including the development of thalamic stimulation as a therapeutic strategy for acquired cognitive disabilities (Schiff, 2008; Mair et al., 2011), and point to the NRe as a potential target for clinical intervention.

  7. Enlarged thalamic volumes and increased fractional anisotropy in the thalamic radiations in veterans with suicide behaviors.

    PubMed

    Lopez-Larson, Melissa; King, Jace B; McGlade, Erin; Bueler, Elliott; Stoeckel, Amanda; Epstein, Daniel J; Yurgelun-Todd, Deborah

    2013-01-01

    Post-mortem studies have suggested a link between the thalamus, psychiatric disorders, and suicide. We evaluated the thalamus and anterior thalamic radiations (ATR) in a group of Veterans with and without a history of suicidal behavior (SB) to determine if thalamic abnormalities were associated with an increased risk of SB. Forty Veterans with mild traumatic brain injury (TBI) and no SB (TBI-SB), 19 Veterans with mild TBI and a history of SB (TB + SB), and 15 healthy controls (HC) underwent magnetic resonance imaging scanning including a structural and diffusion tensor imaging scan. SBs were evaluated utilizing the Columbia Suicide Rating Scale and impulsivity was measured using the Barratt Impulsiveness Scale (BIS). Differences in thalamic volumes and ATR fractional anisotropy (FA) were examined between (1) TBI + SB versus HC and (2) TBI + SB versus combined HC and TBI-SB and (3) between TBI + SB and TBI-SB. Left and right thalamic volumes were significantly increased in those with TBI + SB compared to the HC, TBI-SB, and the combined group. Veterans with TBI + SB had increased FA bilaterally compared to the HC, HC and TBI-SB group, and the TBI-SB only group. Significant positive associations were found for bilateral ATR and BIS in the TBI + SB group. Our findings of thalamic enlargement and increased FA in individuals with TBI + SB suggest that this region may be a biomarker for suicide risk. Our findings are consistent with previous evidence indicating that suicide may be associated with behavioral disinhibition and frontal-thalamic-limbic dysfunction and suggest a neurobiologic mechanism that may increase vulnerability to suicide.

  8. Enlarged Thalamic Volumes and Increased Fractional Anisotropy in the Thalamic Radiations in Veterans with Suicide Behaviors

    PubMed Central

    Lopez-Larson, Melissa; King, Jace B.; McGlade, Erin; Bueler, Elliott; Stoeckel, Amanda; Epstein, Daniel J.; Yurgelun-Todd, Deborah

    2013-01-01

    Post-mortem studies have suggested a link between the thalamus, psychiatric disorders, and suicide. We evaluated the thalamus and anterior thalamic radiations (ATR) in a group of Veterans with and without a history of suicidal behavior (SB) to determine if thalamic abnormalities were associated with an increased risk of SB. Forty Veterans with mild traumatic brain injury (TBI) and no SB (TBI-SB), 19 Veterans with mild TBI and a history of SB (TB + SB), and 15 healthy controls (HC) underwent magnetic resonance imaging scanning including a structural and diffusion tensor imaging scan. SBs were evaluated utilizing the Columbia Suicide Rating Scale and impulsivity was measured using the Barratt Impulsiveness Scale (BIS). Differences in thalamic volumes and ATR fractional anisotropy (FA) were examined between (1) TBI + SB versus HC and (2) TBI + SB versus combined HC and TBI-SB and (3) between TBI + SB and TBI-SB. Left and right thalamic volumes were significantly increased in those with TBI + SB compared to the HC, TBI-SB, and the combined group. Veterans with TBI + SB had increased FA bilaterally compared to the HC, HC and TBI-SB group, and the TBI-SB only group. Significant positive associations were found for bilateral ATR and BIS in the TBI + SB group. Our findings of thalamic enlargement and increased FA in individuals with TBI + SB suggest that this region may be a biomarker for suicide risk. Our findings are consistent with previous evidence indicating that suicide may be associated with behavioral disinhibition and frontal-thalamic-limbic dysfunction and suggest a neurobiologic mechanism that may increase vulnerability to suicide. PMID:23964245

  9. Dopaminergic projections of the subparafascicular thalamic nucleus to the auditory brainstem

    PubMed Central

    Nevue, Alexander A.; Felix, Richard A.

    2016-01-01

    Neuromodulators can alter the response properties of sensory neurons, including those in the auditory system. Dopamine, which plays a major role in reward and movement, has been shown to alter neural responses in the auditory brainstem and midbrain. Recently we identified the subparafascicular thalamic nucleus (SPF), part of the A11 dopaminergic cell group, as the source of dopamine to the inferior colliculus (IC). The superior olivary complex (SOC) is also a likely target of dopaminergic projections from the SPF because it receives projections from the SPF and contains fibers and terminals immunoreactive for tyrosine hydroxylase, the rate limiting enzyme in dopamine synthesis. However, it is unknown if the projections from the SPF to SOC are dopaminergic, and if single neurons in the SPF project to both the IC and SOC. Using anterograde tracing combined with fluorescent immunohistochemistry, we found that the SPF sends dopaminergic projections to the superior paraolivary nucleus and the medial nucleus of the trapezoid body, but not the lateral superior olive. We confirmed these projections using a retrograde tracer. By making dual retrograde deposits in the IC and SOC, we found that individual dopaminergic cells innervate both the IC and SOC. These results suggest dopaminergic innervation, likely released in a context dependent manner, occurs at multiple levels of the auditory pathway. PMID:27620513

  10. Exploding Boxes

    ERIC Educational Resources Information Center

    Kinney; Jan

    2011-01-01

    How do you teach the "same old, same old" in an interesting and inexpensive way? Art teachers are forever looking for new angles on the good-old elements and principles. And, as budgets tighten, they are trying to be as frugal as possible while still holding their students' attention. Enter exploding boxes! In conceptualizing the three types of…

  11. Bilateral thalamic infarction and DSA demonstrated AOP after thrombosis.

    PubMed

    Cao, Wenjie; Dong, Qiang; Li, Linxin; Dong, Yi

    2012-01-01

    Bilateral paramedian thalamic stroke is a special ischemic pattern that results from occlusion of the artery of Percheron (AOP), a rare anatomic variant of the paramedian arteries. We report a case of bilateral thalamic infarctions, with a dramatic improvement after thrombolysis. DSA demonstrated recanalization of AOP with possible unreported variation.

  12. Bilateral thalamic infarction and DSA demonstrated AOP after thrombosis

    PubMed Central

    Cao, Wenjie; Dong, Qiang; Li, Linxin; Dong, Yi

    2012-01-01

    Bilateral paramedian thalamic stroke is a special ischemic pattern that results from occlusion of the artery of Percheron (AOP), a rare anatomic variant of the paramedian arteries. We report a case of bilateral thalamic infarctions, with a dramatic improvement after thrombolysis. DSA demonstrated recanalization of AOP with possible unreported variation. PMID:23986825

  13. Thalamic Shape and Cognitive Performance in Amnestic Mild Cognitive Impairment

    PubMed Central

    Hahn, Changtae; Lee, Chang-Uk; Won, Wang Yeon; Joo, Soo-Hyun

    2016-01-01

    Objective This study aimed to investigate thalamic shape alterations and their relationships with various episodic memory impairments in subjects with amnestic mild cognitive impairment (aMCI). Methods We compared volumes and morphological alterations of the thalamus between aMCI subjects and healthy controls. In addition, we investigated the correlation between thalamic deformations and various memory impairments in aMCI subjects using a comprehensive neuropsychological battery. Results The normalized left thalamic volumes of the aMCI group were significantly smaller than those of the healthy control group (p<0.0001). aMCI subjects exhibited significant thalamic deformations in the left thalamic dorso-medial and antero-medial areas compared with healthy individuals. CERAD-K Word List Memory scores were significantly correlated with the left dorso-medial areas in aMCI subjects. There were no significant correlations between verbal fluency, Boston naming test, constructional praxis, Word List Recognition, and Visuospatial Recall scores and thalamic shape in aMCI subjects. Verbal delayed recall scores were also significantly correlated with the left dorso-medial areas in the aMCI group. Conclusion Structural alterations in the thalamic deformations in the left dorso-medial and antero-medial areas might be core underlying neurobiological mechanisms of thalamic dysfunction related to Word List Memory and delayed verbal recall in individuals with aMCI. PMID:27757128

  14. [Increased level of Gerstmann's syndrome secondary to thalamic hematoma].

    PubMed

    Casado, J L; Jarrín, S; Madrid, A; Gil-Peralta, A

    1995-01-01

    A patient developed enlarged Gerstmann syndrome after left thalamic haematoma. Single photon emission computerised tomography (SPECT) showed left parietal-temporal cortical hypocapture. These findings would lead us to believe that the clinical picture of our patient was due to a thalamic-cortical diaschitic phenomenon.

  15. In vivo monitoring of evoked noradrenaline release in the rat anteroventral thalamic nucleus by continuous amperometry.

    PubMed

    Dugast, C; Cespuglio, R; Suaud-Chagny, M F

    2002-08-01

    Continuous amperometry coupled with untreated carbon-fibre electrodes was used in anaesthetized rats to measure the noradrenaline release evoked in the anteroventral thalamic nucleus by electrical stimulation of the dorsal noradrenergic bundle. As expected, the variations in the oxidation current detected in the anteroventral thalamic nucleus exhibited the characteristics of the in vivo noradrenaline release. They were closely correlated with stimulation and consistent with the anatomy of the noradrenergic system involved. They were abolished by the ejection of tetrodotoxin in the vicinity of the carbon-fibre electrode, diminished by clonidine, an alpha-2 agonist, and restored by yohimbine, an alpha-2 antagonist. Furthermore, the time course of these variations was dramatically increased by desipramine, a specific noradrenaline reuptake blocker. In contrast, neither dopamine nor serotonin reuptake blockers, nor the monoamine oxidase inhibitor pargyline were able to alter them. The main advantage of the present approach is its excellent time resolution. We show here for the first time that after single pulse stimulation, noradrenaline is released and eliminated in 118 milliseconds, this time lapse corresponding to the maximal period beyond which subsequent noradrenaline releases could not add up. These observations are in good agreement with the physiological relationship previously observed between impulse flow and noradrenaline overflow.

  16. Contributions of the paraventricular thalamic nucleus in the regulation of stress, motivation, and mood

    PubMed Central

    Hsu, David T.; Kirouac, Gilbert J.; Zubieta, Jon-Kar; Bhatnagar, Seema

    2014-01-01

    The purpose of this review is to describe how the function and connections of the paraventricular thalamic nucleus (Pa) may play a role in the regulation of stress and negative emotional behavior. Located in the dorsal midline thalamus, the Pa is heavily innervated by serotonin, norepinephrine, dopamine (DA), corticotropin-releasing hormone, and orexins (ORX), and is the only thalamic nucleus connected to the group of structures comprising the amygdala, bed nucleus of the stria terminalis (BNST), nucleus accumbens (NAcc), and infralimbic/subgenual anterior cingulate cortex (sgACC). These neurotransmitter systems and structures are involved in regulating motivation and mood, and display abnormal functioning in several psychiatric disorders including anxiety, substance use, and major depressive disorders (MDD). Furthermore, rodent studies show that the Pa is consistently and potently activated following a variety of stressors and has a unique role in regulating responses to chronic stressors. These observations provide a compelling rationale for investigating the Pa in the link between stress and negative emotional behavior, and for including the Pa in the neural pathways of stress-related psychiatric disorders. PMID:24653686

  17. Lesion of the Centromedian Thalamic Nucleus in MPTP-Treated Monkeys

    PubMed Central

    Lanciego, Jose L.; Rodríguez-Oroz, Maria C.; Blesa, Francisco J.; Alvarez-Erviti, Lydia; Guridi, Jorge; Barroso-Chinea, Pedro; Smith, Yoland; Obeso, Jose A.

    2015-01-01

    The caudal intralaminar nuclei are a major source of glutamatergic afferents to the basal ganglia. Experiments in the 6-hydroxydopamine rat model have shown that the parafascicular nucleus is overactive and its lesion alleviates basal ganglia neurochemical abnormalities associated with dopamine depletion. Accordingly, removal of this excitatory innervation of the basal ganglia could have a beneficial value in the parkinsonian state. To test this hypothesis, unilateral kainate-induced chemical ablation of the centromedian thalamic nucleus (CM) has been performed in MPTP-treated monkeys. Successful lesions restricted to the CM boundaries (n = 2) without spreading over other neighboring thalamic nuclei showed an initial, short-lasting, and mild change in the parkinsonian motor scale but no effect against levodopa-induced dyskinesias. The lack of significant and persistent motor improvement leads us to conclude that unilateral selective lesion of the CM alone cannot be considered as a suitable surgical approach for the treatment of PD or levo-dopa-induced dyskinesias. The role of the caudal intralaminar nuclei in the pathophysiology of movement disorders of basal ganglia origin remains to be clarified. PMID:18175345

  18. Subthalamic Nucleus Stimulation Modulates Thalamic Neuronal Activity

    PubMed Central

    Xu, Weidong; Russo, Gary S.; Hashimoto, Takao; Zhang, Jianyu; Vitek, Jerrold L.

    2009-01-01

    Deep brain stimulation (DBS) in the subthalamic nucleus (STN) is an effective tool for the treatment of advanced Parkinson’s disease. The mechanism by which STN DBS elicits its beneficial effect, however, remains unclear. We previously reported STN stimulation increased the rate and produced a more regular and periodic pattern of neuronal activity in the internal segment of the globus pallidus (GPi). Here we extend our observations to neurons in the pallidal (ventralis lateralis pars oralis (VLo) and ventralis anterior (VA)) and cerebellar (ventralis lateralis posterior pars oralis (VPLo)) receiving areas of the motor thalamus during STN DBS. Stimulation parameters that produced improvement in rigidity and bradykinesia resulted in changes in the pattern and power of oscillatory activity of neuronal activity that were similar in both regions of the motor thalamus. Neurons in both VA/VLo and VPLo tended to become more periodic and regular with a shift in oscillatory activity from low to high frequencies. Burst activity was reduced in VA/VLo, but was not significantly changed in VPLo. There was also a significant shift in the population of VA/VLo neurons that were inhibited during STN DBS, while VPLo neurons tended to be activated. These data are consistent with the hypothesis that STN DBS increases output from the nucleus and produces a change in the pattern and periodicity of neuronal activity in the basal ganglia thalamic network, and that these changes include cerebellar pathways likely via activation of adjacent cerebello-thalamic fiber bundles. PMID:19005057

  19. Dopamine controls Parkinson's tremor by inhibiting the cerebellar thalamus.

    PubMed

    Dirkx, Michiel F; den Ouden, Hanneke E M; Aarts, Esther; Timmer, Monique H M; Bloem, Bastiaan R; Toni, Ivan; Helmich, Rick C

    2017-01-09

    Parkinson's resting tremor is related to altered cerebral activity in the basal ganglia and the cerebello-thalamo-cortical circuit. Although Parkinson's disease is characterized by dopamine depletion in the basal ganglia, the dopaminergic basis of resting tremor remains unclear: dopaminergic medication reduces tremor in some patients, but many patients have a dopamine-resistant tremor. Using pharmacological functional magnetic resonance imaging, we test how a dopaminergic intervention influences the cerebral circuit involved in Parkinson's tremor. From a sample of 40 patients with Parkinson's disease, we selected 15 patients with a clearly tremor-dominant phenotype. We compared tremor-related activity and effective connectivity (using combined electromyography-functional magnetic resonance imaging) on two occasions: ON and OFF dopaminergic medication. Building on a recently developed cerebral model of Parkinson's tremor, we tested the effect of dopamine on cerebral activity associated with the onset of tremor episodes (in the basal ganglia) and with tremor amplitude (in the cerebello-thalamo-cortical circuit). Dopaminergic medication reduced clinical resting tremor scores (mean 28%, range -12 to 68%). Furthermore, dopaminergic medication reduced tremor onset-related activity in the globus pallidus and tremor amplitude-related activity in the thalamic ventral intermediate nucleus. Network analyses using dynamic causal modelling showed that dopamine directly increased self-inhibition of the ventral intermediate nucleus, rather than indirectly influencing the cerebello-thalamo-cortical circuit through the basal ganglia. Crucially, the magnitude of thalamic self-inhibition predicted the clinical dopamine response of tremor. Dopamine reduces resting tremor by potentiating inhibitory mechanisms in a cerebellar nucleus of the thalamus (ventral intermediate nucleus). This suggests that altered dopaminergic projections to the cerebello-thalamo-cortical circuit have a role

  20. Cortical connections of the rat lateral posterior thalamic nucleus.

    PubMed

    Kamishina, Hiroaki; Conte, William L; Patel, Sarika S; Tai, Rachel J; Corwin, James V; Reep, Roger L

    2009-04-06

    Spatial processing related to directed attention is thought to be mediated by a specific cortical-basal ganglia-thalamic-cortical network in the rat. Key components of this network are associative cortical areas medial agranular cortex (AGm) and posterior parietal cortex (PPC), dorsocentral striatum (DCS), and lateral posterior (LP) thalamic nucleus, all of which are interconnected. Previously, we found that thalamostriatal projections reaching DCS arise from separate populations of neurons of the mediorostral part of LP (LPMR). The far medial LPMR (fmLPMR) terminates in central DCS, a projection area of AGm, whereas central LPMR terminates in dorsal DCS, a projection area of PPC. This represents segregated regional convergence in DCS from different sources of thalamic and cortical inputs. In the present study, thalamocortical and corticothalamic projections arising from and terminating in LPMR and neighboring thalamic nuclei were studied by anterograde and retrograde tracing techniques in order to further understand the anatomical basis of this neural circuitry. A significant finding was that within LPMR, separate neuronal populations provide thalamic inputs to AGm or PPC and that these cortical areas project to separate regions in LPMR, from which they receive thalamic inputs. Other cortical areas adjacent to AGm or PPC also demonstrated reciprocal connections with LP or surrounding nuclei in a topographic manner. Our findings suggest that the cortical-basal ganglia-thalamic network mediating directed attention in the rat is formed by multiple loops, each having reciprocal connections that are organized in a precise and segregated topographical manner.

  1. Fatal thalamic abscess secondary to dental infection.

    PubMed

    Basyuni, Shadi; Sharma, Valmiki; Santhanam, Vijay; Ferro, Ashley

    2015-12-17

    We present the case of poor neurological recovery and subsequent death secondary to a thalamic abscess in a 53-year-old man. This patient initially presented with sudden dysarthria and left hemiparesis while driving. Neuroimaging showed a multilobular abscess involving the right thalamus with oedema extending to the basal ganglionic region and brainstem. The source of the abscess was initially unknown and it required draining multiple times while the different causes were being explored. The patient's neurological state along with intubation made for a difficult and inconclusive oral examination. It was only after neuroimaging included tooth-bearing areas that it became evident that this patient had extensive periodontal disease with multiple areas of periapical radiolucencies. The patient underwent complete dental clearance alongside repeated drainage of the abscess. Despite initial postoperative improvement, the patient never recovered from the neurological damage and died 3 weeks later.

  2. Hypersexuality and dysexecutive syndrome after a thalamic infarct.

    PubMed

    Spinella, Marcello

    2004-12-01

    Hypersexuality can result from insults to several neuroanatomical structures that regulate sexual behavior. A case is presented of an adult male with a thalamic infarct resulting in a paramedian thalamic syndrome, consisting of hypersomnolence, confabulatory anterograde amnesia (including reduplicative paramnesia), vertical gaze deficits, and hypophonic speech. A dysexecutive syndrome also manifested, consisting of social disinhibition, apathy, witzelsucht, motor inhibition deficits, and environmental dependence. Hypersexuality uncharacteristic of his premorbid behavior was evident in instances of exhibitionism, public masturbation, and verbal sexual obscenities. In contrast to the few previous reports of hypersexuality following thalamic infarct, this case neither involved mania nor hemichorea. The relevance of the mediodorsal thalamic nucleus in limbic and prefrontal circuits is discussed.

  3. Disrupted thalamic resting-state functional networks in schizophrenia

    PubMed Central

    Wang, Hsiao-Lan Sharon; Rau, Chi-Lun; Li, Yu-Mei; Chen, Ya-Ping; Yu, Rongjun

    2015-01-01

    The thalamus plays a key role in filtering or gating information and has extensive interconnectivity with other brain regions. Recent studies provide evidence of thalamus abnormality in schizophrenia, but the resting functional networks of the thalamus in schizophrenia is still unclear. We characterize the thalamic resting-state networks (RSNs) in 72 patients with schizophrenia and 73 healthy controls, using a standard seed-based whole-brain correlation. In comparison with controls, patients exhibited enhance thalamic connectivity with bilateral precentral gyrus, dorsal medial frontal gyrus, middle occipital gyrus, and lingual gyrus. Reduced thalamic connectivity in schizophrenia was found in bilateral superior frontal gyrus, anterior cingualte cortex, inferior parietal lobe, and cerebellum. Our findings question the “disconnectivity model” of schizophrenia by showing the over-connected thalamic network during resting state in schizophrenia and highlight the thalamus as a key hub in the schizophrenic network abnormality. PMID:25762911

  4. Midline thalamic neurons are differentially engaged during hippocampus network oscillations

    PubMed Central

    Lara-Vásquez, Ariel; Espinosa, Nelson; Durán, Ernesto; Stockle, Marcelo; Fuentealba, Pablo

    2016-01-01

    The midline thalamus is reciprocally connected with the medial temporal lobe, where neural circuitry essential for spatial navigation and memory formation resides. Yet, little information is available on the dynamic relationship between activity patterns in the midline thalamus and medial temporal lobe. Here, we report on the functional heterogeneity of anatomically-identified thalamic neurons and the differential modulation of their activity with respect to dorsal hippocampal rhythms in the anesthetized mouse. Midline thalamic neurons expressing the calcium-binding protein calretinin, irrespective of their selective co-expression of calbindin, discharged at overall low levels, did not increase their activity during hippocampal theta oscillations, and their firing rates were inhibited during hippocampal sharp wave-ripples. Conversely, thalamic neurons lacking calretinin discharged at higher rates, increased their activity during hippocampal theta waves, but remained unaffected during sharp wave-ripples. Our results indicate that the midline thalamic system comprises at least two different classes of thalamic projection neuron, which can be partly defined by their differential engagement by hippocampal pathways during specific network oscillations that accompany distinct behavioral contexts. Thus, different midline thalamic neuronal populations might be selectively recruited to support distinct stages of memory processing, consistent with the thalamus being pivotal in the dialogue of cortical circuits. PMID:27411890

  5. Midline thalamic neurons are differentially engaged during hippocampus network oscillations.

    PubMed

    Lara-Vásquez, Ariel; Espinosa, Nelson; Durán, Ernesto; Stockle, Marcelo; Fuentealba, Pablo

    2016-07-14

    The midline thalamus is reciprocally connected with the medial temporal lobe, where neural circuitry essential for spatial navigation and memory formation resides. Yet, little information is available on the dynamic relationship between activity patterns in the midline thalamus and medial temporal lobe. Here, we report on the functional heterogeneity of anatomically-identified thalamic neurons and the differential modulation of their activity with respect to dorsal hippocampal rhythms in the anesthetized mouse. Midline thalamic neurons expressing the calcium-binding protein calretinin, irrespective of their selective co-expression of calbindin, discharged at overall low levels, did not increase their activity during hippocampal theta oscillations, and their firing rates were inhibited during hippocampal sharp wave-ripples. Conversely, thalamic neurons lacking calretinin discharged at higher rates, increased their activity during hippocampal theta waves, but remained unaffected during sharp wave-ripples. Our results indicate that the midline thalamic system comprises at least two different classes of thalamic projection neuron, which can be partly defined by their differential engagement by hippocampal pathways during specific network oscillations that accompany distinct behavioral contexts. Thus, different midline thalamic neuronal populations might be selectively recruited to support distinct stages of memory processing, consistent with the thalamus being pivotal in the dialogue of cortical circuits.

  6. Subjective cognitive-affective status following thalamic stroke.

    PubMed

    Liebermann, Daniela; Ostendorf, Florian; Kopp, Ute A; Kraft, Antje; Bohner, Georg; Nabavi, Darius G; Kathmann, Norbert; Ploner, Christoph J

    2013-02-01

    Previous patient studies suggest that thalamic stroke may yield persistent deficits in several cognitive domains. At present, the subjective dimension and everyday relevance of these impairments is unclear, since many patients with thalamic stroke only show minor changes on physical examination. Here, we have studied subjective consequences of focal thalamic lesions. A sample of 68 patients with a history of ischemic thalamic stroke was examined by using established clinical self-report questionnaires assessing memory, attention, executive functions, emotional status and health-related quality of life. In order to control for general factors related to cerebrovascular disease, self-reports were compared to an age-matched group of 34 patients with a history of transient ischemic attack. Thalamic lesions were co-registered to an atlas of the human thalamus. Lesion overlap and subtraction analyses were used for lesion-to-symptom mapping. When both patient groups were compared, no significant differences were found for either questionnaire. However, when subgroups were compared, patients with infarctions involving the posterior thalamus showed significant emotional disturbances and elevated anxiety levels compared to patients with more anterior lesions. Our findings thus point to the existence of a persistent affective impairment associated with chronic lesions of the posterior thalamus. This syndrome may result from damage to connections between medial pulvinar and extra-thalamic regions involved in affective processing. Our findings suggest that the posterior thalamus may contribute significantly to the regulation of mood.

  7. Thalamic Circuit Diversity: Modulation of the Driver/Modulator Framework

    PubMed Central

    Bickford, Martha E.

    2016-01-01

    The idea that dorsal thalamic inputs can be divided into “drivers”, which provide the primary excitatory drive for the relay of information to cortex, and “modulators”, which alter the gain of signal transmission, has provided a valuable organizing principle for the study of thalamic function. This view further promoted the identification of “first order” and “higher order” thalamic nuclei, based on the origin of their driving inputs. Since the introduction of this influential terminology, a number of studies have revealed the existence of a wide variety of thalamic organizational schemes. For example, some thalamic nuclei are not innervated by typical driver inputs, but instead receive input from terminals which exhibit features distinct from those of either classic drivers or modulators. In addition, many thalamic nuclei contain unique combinations of convergent first order, higher order, and/or other “driver-like” inputs that do not conform with the driver/modulator framework. The assortment of synaptic arrangements identified in the thalamus are reviewed and discussed from the perspective that this organizational diversity can dramatically increase the computational capabilities of the thalamus, reflecting its essential roles in sensory, motor, and sensory-motor circuits. PMID:26793068

  8. Thalamic nuclei in the opossum Monodelphis domestica.

    PubMed

    Olkowicz, Seweryn; Turlejski, Kris; Bartkowska, Katarzyna; Wielkopolska, Ewa; Djavadian, Rouzanna L

    2008-10-01

    We investigated nuclear divisions of the thalamus in the gray short-tailed opossum (Monodelphis domestica) to gain detailed information for further developmental and comparative studies. Nissl and myelin staining, histochemistry for acetylcholinesterase and immunohistochemistry for calretinin and parvalbumin were performed on parallel series of sections. Many features of the Monodelphis opossum thalamus resemble those in Didelphis and small eutherians showing no particular sensory specializations, particularly in small murid rodents. However, several features of thalamic organization in Monodelphis were distinct from those in rodents. In the opossum the anterior and midline nuclear groups are more clearly separated from adjacent structures than in eutherians. The dorsal lateral geniculate nucleus (LGNd) starts more rostrally and occupies a large part of the lateral wall of the thalamus. As in other marsupials, two cytoarchitectonically different parts, alpha and beta are discernible in the LGNd of the opossum. Each of them may be subdivided into two additional bands in acetylcholinesterase staining, while in murid rodents the LGNd consists of a homogeneous mass of cells. Therefore, differentiation of the LGNd of the Monodelphis opossum is more advanced than in murid rodents. The medial geniculate body consists of three nuclei (medial, dorsal and ventral) that are cytoarchitectonically distinct and stain differentially for parvalbumin. The relatively large size of the MG and LGNd points to specialization of the visual and auditory systems in the Monodelphis opossum. In contrast to rodents, the lateral dorsal and lateral posterior nuclei in the opossum are poorly differentiated cytoarchitectonically.

  9. Thalamic mediation of hypoxic respiratory depression in lambs.

    PubMed

    Koos, Brian J; Rajaee, Arezoo; Ibe, Basil; Guerra, Catalina; Kruger, Lawrence

    2016-04-01

    Immaturity of respiratory controllers in preterm infants dispose to recurrent apnea and oxygen deprivation. Accompanying reductions in brain oxygen tensions evoke respiratory depression, potentially exacerbating hypoxemia. Central respiratory depression during moderate hypoxia is revealed in the ventilatory decline following initial augmentation. This study determined whether the thalamic parafascicular nuclear (Pf) complex involved in adult nociception and sensorimotor regulation (Bentivoglio M, Balerecia G, Kruger L. Prog Brain Res 87: 53-80, 1991) also becomes a postnatal controller of hypoxic ventilatory decline. Respiratory responses to moderate isocapnic hypoxia were studied in conscious lambs. Hypoxic ventilatory decline was compared with peak augmentation. Pf and/or adjacent thalamic structures were destroyed by the neuron-specific toxin ibotenic acid (IB). IB lesions involving the thalamic Pf abolished hypoxic ventilatory decline. Lesions of adjacent thalamic nuclei that spared Pf and control injections of vehicle failed to blunt hypoxic respiratory depression. Our findings reveal that the thalamic Pf region is a critical controller of hypoxic ventilatory depression and thus a key target for exploring molecular concomitants of forebrain pathways regulating hypoxic ventilatory depression in early development.

  10. Mechanisms Underlying Desynchronization of Cholinergic-Evoked Thalamic Network Activity

    PubMed Central

    Pita-Almenar, Juan Diego; Yu, Dinghui; Lu, Hui-Chen

    2014-01-01

    Synchronous neuronal activity in the thalamocortical system is critical for a number of behaviorally relevant computations, but hypersynchrony can limit information coding and lead to epileptiform responses. In the somatosensory thalamus, afferent inputs are transformed by networks of reciprocally connected thalamocortical neurons in the ventrobasal nucleus (VB) and GABAergic neurons in the thalamic reticular nucleus (TRN). These networks can generate oscillatory activity, and studies in vivo and in vitro have suggested that thalamic oscillations are often accompanied by synchronous neuronal activity, in part mediated by widespread divergence and convergence of both reticulothalamic and thalamoreticular pathways, as well as by electrical synapses interconnecting TRN neurons. However, the functional organization of thalamic circuits and its role in shaping input-evoked activity patterns remain poorly understood. Here we show that optogenetic activation of cholinergic synaptic afferents evokes near-synchronous firing in mouse TRN neurons that is rapidly desynchronized in thalamic networks. We identify several mechanisms responsible for desynchronization: (1) shared inhibitory inputs in local VB neurons leading to asynchronous and imprecise rebound bursting; (2) TRN-mediated lateral inhibition that further desynchronizes firing in the VB; and (3) powerful yet sparse thalamoreticular connectivity that mediates re-excitation of the TRN but preserves asynchronous firing. Our findings reveal how distinct local circuit features interact to desynchronize thalamic network activity. PMID:25339757

  11. Corticothalamic Activation Modulates Thalamic Firing Through Glutamate "Metabotropic" Receptors

    NASA Astrophysics Data System (ADS)

    McCormick, David A.; von Krosigk, Marcus

    1992-04-01

    The mammalian thalamus forms an obligatory relay for nearly all sensory information that reaches the cerebral cortex. The transmission of sensory information by the thalamus varies in a state-dependent manner, such that during slow wave sleep or drowsiness thalamic responsiveness is markedly reduced, whereas during the waking, attentive state transmission is enhanced. Although activation of brainstem inputs to thalamic neurons has long been assumed to underlie this gating of sensory transfer through the thalamus, numerically the largest input to thalamic relay neurons derives from layer VI cells of the cerebral cortex. Here we report that activation of corticothalamic fibers causes a prolonged excitatory postsynaptic potential in guinea pig dorsal lateral geniculate relay neurons resulting from the reduction of a potassium conductance, consistent with the activation of glutamatergic "metabotropic" receptors. This slow depolarization can switch firing of thalamic neurons from the burst firing mode, which is prevalent during slow wave sleep, to the single spike mode, which is prevalent during waking, thereby facilitating transmission of sensory information through the thalamus. This prolonged enhancement of thalamic transfer may allow the cerebral cortex to gate or control selective fields of sensory inputs in a manner that facilitates arousal, attention, and cognition.

  12. The turtle thalamic anterior entopeduncular nucleus shares connectional and neurochemical characteristics with the mammalian thalamic reticular nucleus.

    PubMed

    Kenigfest, Natalia; Belekhova, Margarita; Repérant, Jacques; Rio, Jean Paul; Ward, Roger; Vesselkin, Nikolai

    2005-10-01

    Neurochemical and key connectional characteristics of the anterior entopeduncular nucleus (Enta) of the turtle (Testudo horsfieldi) were studied by axonal tracing techniques and immunohistochemistry of parvalbumin, gamma-aminobutyric acid (GABA) and glutamic acid decarboxylase (GAD). We showed that the Enta, which is located within the dorsal peduncle of the lateral forebrain bundle (Pedd), has roughly topographically organized reciprocal connections with the dorsal thalamic visual nuclei, the nucleus rotundus (Rot) and dorsal lateral geniculate nucleus (GLd). The Enta receives projections from visual telencephalic areas, the anterior dorsal ventricular ridge and dorsolateral cortex/pallial thickening. Most Enta neurons contained GABA and parvalbumin, and some of them were retrogradely labeled when the tracer was injected into the visual dorsal thalamic nuclei. Further experiments using double immunofluorescence revealed colocalization of GAD and parvalbumin in the vast majority of Enta neurons, and many of these cells showed retrograde labeling with Fluoro-gold injected into the Rot and/or GLd. According to these data, the Enta may be considered as a structural substrate for recurrent inhibition of the visual thalamic nuclei. Based on morphological and neurochemical similarity of the turtle Enta, caiman Pedd nucleus, the superior reticular nucleus in birds, and the thalamic reticular nucleus in mammals, we suggest that these structures represent a characteristic component which is common to the thalamic organization in amniotes.

  13. Alleviation of acquired stuttering with human centremedian thalamic stimulation.

    PubMed Central

    Bhatnagar, S C; Andy, O J

    1989-01-01

    Despite many investigations, the cerebral mechanism for stuttering remains unknown. Recently, increased attention has been paid to acquired stuttering of adult onset in the hope that the events associated with it might provide clues to the biological mechanism underlying stuttering. This attention has focused exclusively on the cortical substrates. We present our observations of acquired dysfluency, presumably of subcortical origin in a neurosurgical subject with intractable pain. The stuttering was relieved by thalamic electric stimulation. The effect of thalamic stimulation on the stuttering suggests that the pathophysiology of transient asynchronisation in the balancing and sequencing of multiple impulses is amenable to a diffusely orchestrated functional tuning of the thalamic and brainstem implicated subcortical structures and pathways. Images PMID:2795045

  14. Bursting of thalamic neurons and states of vigilance.

    PubMed

    Llinás, Rodolfo R; Steriade, Mircea

    2006-06-01

    This article addresses the functional significance of the electrophysiological properties of thalamic neurons. We propose that thalamocortical activity, is the product of the intrinsic electrical properties of the thalamocortical (TC) neurons and the connectivity their axons weave. We begin with an overview of the electrophysiological properties of single neurons in different functional states, followed by a review of the phylogeny of the electrical properties of thalamic neurons, in several vertebrate species. The similarity in electrophysiological properties unambiguously indicates that the thalamocortical system must be as ancient as the vertebrate branch itself. We address the view that rather than simply relays, thalamic neurons have sui generis intrinsic electrical properties that govern their specific functional dynamics and regulate natural functional states such as sleep and vigilance. In addition, thalamocortical activity has been shown to be involved in the genesis of several neuropsychiatric conditions collectively described as thalamocortical dysrhythmia syndrome.

  15. Thalamic Circuit Mechanisms Link Sensory Processing in Sleep and Attention.

    PubMed

    Chen, Zhe; Wimmer, Ralf D; Wilson, Matthew A; Halassa, Michael M

    2015-01-01

    The correlation between sleep integrity and attentional performance is normally interpreted as poor sleep causing impaired attention. Here, we provide an alternative explanation for this correlation: common thalamic circuits regulate sensory processing across sleep and attention, and their disruption may lead to correlated dysfunction. Using multi-electrode recordings in mice, we find that rate and rhythmicity of thalamic reticular nucleus (TRN) neurons are predictive of their functional organization in sleep and suggestive of their participation in sensory processing across states. Surprisingly, TRN neurons associated with spindles in sleep are also associated with alpha oscillations during attention. As such, we propose that common thalamic circuit principles regulate sensory processing in a state-invariant manner and that in certain disorders, targeting these circuits may be a more viable therapeutic strategy than considering individual states in isolation.

  16. Dysexecutive syndrome following anterior thalamic ischemia in the dominant hemisphere.

    PubMed

    Línek, Vladimír; Sonka, Karel; Bauer, Jirí

    2005-03-15

    In the article, we describe a rare case: a 52-year-old male patient with an isolated lesion of the anterior thalamic nuclei in the dominant hemisphere due to an ischemic stroke. The patient's syndrome of disordered verbal fluency, working memory, learning and executive functions is seen as a part of a lesion in the dorsolateral complex circuit. During the following 6 months, we observed significant improvement in visual learning, recent memory and categorisation of subjects, while verbal learning and visuospatial planning remained insufficient. In this context, the preservation of thalamic structures in different types of cognitive deterioration is discussed.

  17. Thalamic syndrome as the heralding manifestation of atlantoaxial dislocation

    PubMed Central

    Verma, Rajesh; Sahu, Ritesh; Ojha, B K; Junewar, Vivek

    2013-01-01

    In India, Atlantoaxial dislocation (AAD) is the commonest skeletal craniovertebral junction (CVJ) anomaly, followed by occipitalisation of atlas and basilar invagination. The usual presentation is progressive neurological deficit (76–95% cases) involving the high cervical cord, lower brainstem and cranial nerves. The association between vertebro-basilar insufficiency and skeletal CVJ anomalies is well recognised and angiographic abnormalities of the vertebrobasilar arteries and their branches have been reported; however, initial presentation of CVJ anomaly as thalamic syndrome due to posterior circulation stroke is extremely rare. Here, we report one such rare case of thalamic syndrome as the initial presentation of CVJ anomaly with AAD. PMID:23314448

  18. Transient stabbing headache from an acute thalamic hemorrhage.

    PubMed

    Robbins, Matthew S

    2011-06-01

    Stabbing headache can be encountered in both primary and secondary forms, but has been infrequently reported among patients with stroke, and is not known to be associated with a small well-circumscribed brain lesion. A 95-year-old woman taking warfarin presented with the sudden onset of stabbing headache strictly in the right frontal and supraorbital regions, along with gait imbalance and dysarthria. Neuroimaging revealed a small left thalamic hematoma. This association of an acute thalamic lesion with stabbing headache in the contralateral trigeminal distribution is discussed, along with a brief review of stabbing headache occurring in cerebrovascular disease.

  19. Thalamic theta phase alignment predicts human memory formation and anterior thalamic cross-frequency coupling.

    PubMed

    Sweeney-Reed, Catherine M; Zaehle, Tino; Voges, Jürgen; Schmitt, Friedhelm C; Buentjen, Lars; Kopitzki, Klaus; Hinrichs, Hermann; Heinze, Hans-Jochen; Rugg, Michael D; Knight, Robert T; Richardson-Klavehn, Alan

    2015-05-20

    Previously we reported electrophysiological evidence for a role for the anterior thalamic nucleus (ATN) in human memory formation (Sweeney-Reed et al., 2014). Theta-gamma cross-frequency coupling (CFC) predicted successful memory formation, with the involvement of gamma oscillations suggesting memory-relevant local processing in the ATN. The importance of the theta frequency range in memory processing is well-established, and phase alignment of oscillations is considered to be necessary for synaptic plasticity. We hypothesized that theta phase alignment in the ATN would be necessary for memory encoding. Further analysis of the electrophysiological data reveal that phase alignment in the theta rhythm was greater during successful compared with unsuccessful encoding, and that this alignment was correlated with the CFC. These findings support an active processing role for the ATN during memory formation.

  20. Rationale for targeting the thalamic centre-median parafascicular complex in the surgical treatment of Parkinson's disease.

    PubMed

    Kerkerian-Le Goff, Lydia; Jouve, Loreline; Melon, Christophe; Salin, Pascal

    2009-12-01

    The thalamic centre median-parafascicular complex (CM/Pf), a main input and output station of the basal ganglia, is attracting increasing interest in the field of movement disorders, including Parkinson's disease (PD). CM/Pf undergoes partial neurodegeneration in PD patients and some rodent models. Cellular evidence has been provided in experimental animals that thalamic degeneration may not aggravate but rather counteract the effects of dopamine lesion. But functional changes in the circuits involving the spared neurons could play a detrimental role. This view fits with converging anecdotic and recent direct experience in patients that stress the potential of CM/PF deep brain stimulation (DBS) to alleviate motor disorders, notably tremor and dyskinesias. As a preclinical contribution to the characterization of this target, we investigated the functional impact of CM/Pf-DBS in the 6-hydroxydopamine hemiparkinsonian rat model of PD. When testing different frequencies (25, 60, 130 Hz), only high frequency stimulation (HFS) had significant antiakinetic action as evidenced by alleviation of limb use asymmetry in the cylinder test. Although less efficient than HFS of the subthalamic nucleus in the latter task, CM/PF-HFS completely corrected lateralized neglect in the corridor task. Unlike subthalamic nucleus, CM/Pf-HFS did not induce per se dyskinesias. Finally, the benefits provided by CM/Pf-HFS were associated with widespread impact on the changes in neuronal metabolic activity induced by the dopamine depletion in the basal ganglia. These data point to own particular outcome of CM/Pf-DBS that may be of interest in currently developing multi-target strategies.

  1. Lateral and Anterior Thalamic Lesions Impair Independent Memory Systems

    ERIC Educational Resources Information Center

    Mitchell, Anna S.; Dalrymple-Alford, John C.

    2006-01-01

    Damage to the medial region of the thalamus, both in clinical cases (e.g., patients with infarcts or the Korsakoff's syndrome) and animal lesion models, is associated with variable amnesic deficits. Some studies suggest that many of these memory deficits rely on the presence of lateral thalamic lesions (LT) that include the intralaminar nuclei,…

  2. Outcome After Pituitary Radiosurgery for Thalamic Pain Syndrome

    SciTech Connect

    Hayashi, Motohiro Chernov, Mikhail F.; Taira, Takaomi; Ochiai, Taku; Nakaya, Kotaro; Tamura, Noriko; Goto, Shinichi; Yomo, Shoji; Kouyama, Nobuo; Katayama, Yoko; Kawakami, Yoriko; Izawa, Masahiro; Muragaki, Yoshihiro

    2007-11-01

    Purpose: To evaluate outcomes after pituitary radiosurgery in patients with post-stroke thalamic pain syndrome. Methods and Materials: From 2002 to 2006, 24 patients with thalamic pain syndrome underwent pituitary radiosurgery at Tokyo Women's Medical University and were followed at least 12 months thereafter. The radiosurgical target was defined as the pituitary gland and its connection with the pituitary stalk. The maximum dose varied from 140 to 180 Gy. Mean follow-up after treatment was 35 months (range, 12-48 months). Results: Initial pain reduction, usually within 48 h after radiosurgery, was marked in 17 patients (71%). However, in the majority of cases the pain recurred within 6 months after treatment, and at the time of the last follow-up examination durable pain control was marked in only 5 patients (21%). Ten patients (42%) had treatment-associated side effects. Anterior pituitary abnormalities were marked in 8 cases and required hormonal replacement therapy in 3; transient diabetes insipidus was observed in 2 cases, transient hyponatremia in 1, and clinical deterioration due to increase of the numbness severity despite significant reduction of pain was seen once. Conclusions: Pituitary radiosurgery for thalamic pain results in a high rate of initial efficacy and is accompanied by acceptable morbidity. It can be used as a primary minimally invasive management option for patients with post-stroke thalamic pain resistant to medical therapy. However, in the majority of cases pain recurrence occurs within 1 year after treatment.

  3. Visual Orientation and Directional Selectivity through Thalamic Synchrony

    PubMed Central

    Stanley, Garrett B.; Jin, Jianzhong; Wang, Yushi; Desbordes, Gaëlle; Wang, Qi; Black, Michael J.; Alonso, Jose-Manuel

    2012-01-01

    Thalamic neurons respond to visual scenes by generating synchronous spike trains on the timescale of 10 – 20 ms that are very effective at driving cortical targets. Here we demonstrate that this synchronous activity contains unexpectedly rich information about fundamental properties of visual stimuli. We report that the occurrence of synchronous firing of cat thalamic cells with highly overlapping receptive fields is strongly sensitive to the orientation and the direction of motion of the visual stimulus. We show that this stimulus selectivity is robust, remaining relatively unchanged under different contrasts and temporal frequencies (stimulus velocities). A computational analysis based on an integrate-and-fire model of the direct thalamic input to a layer 4 cortical cell reveals a strong correlation between the degree of thalamic synchrony and the nonlinear relationship between cortical membrane potential and the resultant firing rate. Together, these findings suggest a novel population code in the synchronous firing of neurons in the early visual pathway that could serve as the substrate for establishing cortical representations of the visual scene. PMID:22745507

  4. Thalamic control of sensory selection in divided attention.

    PubMed

    Wimmer, Ralf D; Schmitt, L Ian; Davidson, Thomas J; Nakajima, Miho; Deisseroth, Karl; Halassa, Michael M

    2015-10-29

    How the brain selects appropriate sensory inputs and suppresses distractors is unknown. Given the well-established role of the prefrontal cortex (PFC) in executive function, its interactions with sensory cortical areas during attention have been hypothesized to control sensory selection. To test this idea and, more generally, dissect the circuits underlying sensory selection, we developed a cross-modal divided-attention task in mice that allowed genetic access to this cognitive process. By optogenetically perturbing PFC function in a temporally precise window, the ability of mice to select appropriately between conflicting visual and auditory stimuli was diminished. Equivalent sensory thalamocortical manipulations showed that behaviour was causally dependent on PFC interactions with the sensory thalamus, not sensory cortex. Consistent with this notion, we found neurons of the visual thalamic reticular nucleus (visTRN) to exhibit PFC-dependent changes in firing rate predictive of the modality selected. visTRN activity was causal to performance as confirmed by bidirectional optogenetic manipulations of this subnetwork. Using a combination of electrophysiology and intracellular chloride photometry, we demonstrated that visTRN dynamically controls visual thalamic gain through feedforward inhibition. Our experiments introduce a new subcortical model of sensory selection, in which the PFC biases thalamic reticular subnetworks to control thalamic sensory gain, selecting appropriate inputs for further processing.

  5. Effects of Intralaminar Thalamic Stimulation on Language Functions

    ERIC Educational Resources Information Center

    Bhatnagar, Subhash C.; Mandybur, George T.

    2005-01-01

    Fifteen neurosurgical subjects, who were undergoing thalamic chronic electrode implants as a treatment for dyskinesia and chronic pain, were evaluated on a series of neurolinguistic functions to determine if the stimulation of the centromedianum nucleus of the thalamus affected language and cognitive processing. Analysis of the data revealed that…

  6. [Complete recovery from transient coma in bilateral paramedian thalamic infarctions].

    PubMed

    Casado, J L; Arenas, C; Serrano, V; Moreno Rojas, A; Gil-Néciga, E; Gil-Peralta, A

    1995-01-01

    Bilateral paramedian thalamic infarcts (BPTI) can begin clinically with transient coma, after which symptoms of fluctuating hypersomnolence, irrational behaviour, or amnesic states may be observed. We present two patients with BPTI who began with coma, recovering spontaneously in under eight hours, with no accompanying symptoms.

  7. Thalamic Reorganization in Chronic Patients With Intracerebral Hemorrhage

    PubMed Central

    Jang, Sung Ho; Chang, Chul Hoon; Kim, Seong Ho; Jung, Young Jin; Hong, Ji Heon

    2015-01-01

    Abstract The aim of this study was to investigate changes of synaptic area of the spinothalamic tract and its thalamocortical pathway (STT) in the thalamus in chronic patients with putaminal hemorrhage. Twenty four patients with a lesion in the ventral posterior lateral nucleus (VPL) of the thalamus following putaminal hemorrhage were recruited for this study. The subscale for tactile sensation of the Nottingham Sensory Assessment (NSA) was used for the determination of somatosensory function. Diffusion tensor tractography of the STT was reconstructed using the Functional Magnetic Resonance Imaging of the Brain Software Library. We classified patients according to 2 groups: the VPL group, patients whose STTs were synapsed in the VPL; and the non-VPL group, patients whose STTs were synapsed in other thalamic areas, except for the VPL. Thirteen patients belonged to the VPL group, and 8 patients belonged to the non-VPL group. Three patients were excluded from grouping due to interrupted integrity of the STTs. The tactile sensation score of the NSA in the non-VPL group (10.50 ± 0.93) was significantly decreased compared with that of the VPL group (19.45 ± 1.33) (P < 0.05). We found that 2 types of patient had recovered via the VPL area or other areas of the STT. It appears that patients who showed shifting of the thalamic synaptic area of the STT might have recovered by the process of thalamic reorganization following thalamic injury. In addition, thalamic reorganization appears to be related to poorer somatosensory outcome. PMID:26313781

  8. Essential thalamic contribution to slow waves of natural sleep.

    PubMed

    David, François; Schmiedt, Joscha T; Taylor, Hannah L; Orban, Gergely; Di Giovanni, Giuseppe; Uebele, Victor N; Renger, John J; Lambert, Régis C; Leresche, Nathalie; Crunelli, Vincenzo

    2013-12-11

    Slow waves represent one of the prominent EEG signatures of non-rapid eye movement (non-REM) sleep and are thought to play an important role in the cellular and network plasticity that occurs during this behavioral state. These slow waves of natural sleep are currently considered to be exclusively generated by intrinsic and synaptic mechanisms within neocortical territories, although a role for the thalamus in this key physiological rhythm has been suggested but never demonstrated. Combining neuronal ensemble recordings, microdialysis, and optogenetics, here we show that the block of the thalamic output to the neocortex markedly (up to 50%) decreases the frequency of slow waves recorded during non-REM sleep in freely moving, naturally sleeping-waking rats. A smaller volume of thalamic inactivation than during sleep is required for observing similar effects on EEG slow waves recorded during anesthesia, a condition in which both bursts and single action potentials of thalamocortical neurons are almost exclusively dependent on T-type calcium channels. Thalamic inactivation more strongly reduces spindles than slow waves during both anesthesia and natural sleep. Moreover, selective excitation of thalamocortical neurons strongly entrains EEG slow waves in a narrow frequency band (0.75-1.5 Hz) only when thalamic T-type calcium channels are functionally active. These results demonstrate that the thalamus finely tunes the frequency of slow waves during non-REM sleep and anesthesia, and thus provide the first conclusive evidence that a dynamic interplay of the neocortical and thalamic oscillators of slow waves is required for the full expression of this key physiological EEG rhythm.

  9. Heterogeneity of firing properties among rat thalamic reticular nucleus neurons

    PubMed Central

    Lee, Sang-Hun; Govindaiah, G; Cox, Charles L

    2007-01-01

    The thalamic reticular nucleus (TRN) provides inhibitory innervation to most thalamic relay nuclei and receives excitatory innervation from both cortical and thalamic neurons. Ultimately, information transfer through the thalamus to the neocortex is strongly influenced by TRN. In addition, the reciprocal synaptic connectivity between TRN with associated thalamic relay nuclei is critical in generating intrathalamic rhythmic activities that occur during certain arousal states and pathophysiological conditions. Despite evidence suggesting morphological heterogeneity amongst TRN neurons, the heterogeneity of intrinsic properties of TRN neurons has not been systematically examined. One key characteristic of virtually all thalamic neurons is the ability to produce action potentials in two distinct modes: burst and tonic. In this study, we have examined the prevalence of burst discharge within TRN neurons. Our intracellular recordings revealed that TRN neurons can be differentiated by their action potential discharge modes. The majority of neurons in the dorsal TRN (56%) lack burst discharge, and the remaining neurons (35%) show an atypical burst that consists of an initial action potential followed by small amplitude, long duration depolarizations. In contrast, most neurons in ventral TRN (82%) display a stereotypical burst discharge consisting of a transient, high frequency discharge of multiple action potentials. TRN neurons that lack burst discharge typically did not produce low threshold calcium spikes or produced a significantly reduced transient depolarization. Our findings clearly indicate that TRN neurons can be differentiated by differences in their spike discharge properties and these subtypes are not uniformly distributed within TRN. The functional consequences of such intrinsic differences may play an important role in modality-specific thalamocortical information transfer as well as overall circuit level activities. PMID:17463035

  10. Segregation of parallel inputs to the anteromedial and anteroventral thalamic nuclei of the rat.

    PubMed

    Wright, Nicholas F; Vann, Seralynne D; Erichsen, Jonathan T; O'Mara, Shane M; Aggleton, John P

    2013-09-01

    Many brain structures project to both the anteroventral thalamic nucleus and the anteromedial thalamic nucleus. In the present study, pairs of different tracers were placed into these two thalamic sites in the same rats to determine the extent to which these nuclei receive segregated inputs. Only inputs from the laterodorsal tegmental nucleus, the principal extrinsic cholinergic source for these thalamic nuclei, showed a marked degree of collateralization, with approximately 13% of all cells labeled in this tegmental area projecting to both nuclei. Elsewhere, double-labeled cells were very scarce, making up ∼1% of all labeled cells. Three general patterns of anterior thalamic innervation were detected in these other areas. In some sites, e.g., prelimbic cortex, anterior cingulate cortex, and secondary motor area, cells projecting to the anteromedial and anteroventral thalamic nuclei were closely intermingled, with often only subtle distribution differences. These same projections were also often intermingled with inputs to the mediodorsal thalamic nucleus, but again there was little or no collateralization. In other sites, e.g., the subiculum and retrosplenial cortex, there was often less overlap of cells projecting to the two anterior thalamic nuclei. A third pattern related to the dense inputs from the medial mammillary nucleus, where well-defined topographies ensured little intermingling of the neurons that innervate the two thalamic nuclei. The finding that a very small minority of cortical and limbic inputs bifurcates to innervate both anterior thalamic nuclei highlights the potential for parallel information streams to control their functions, despite arising from common regions.

  11. Assessing the risk of central post-stroke pain of thalamic origin by lesion mapping.

    PubMed

    Sprenger, Till; Seifert, Christian L; Valet, Michael; Andreou, Anna P; Foerschler, Annette; Zimmer, Claus; Collins, D Louis; Goadsby, Peter J; Tölle, Thomas R; Chakravarty, M Mallar

    2012-08-01

    Central post-stroke pain of thalamic origin is an extremely distressing and often refractory disorder. There are no well-established predictors for pain development after thalamic stroke, and the role of different thalamic nuclei is unclear. Here, we used structural magnetic resonance imaging to identify the thalamic nuclei, specifically implicated in the generation of central post-stroke pain of thalamic origin. Lesions of 10 patients with central post-stroke pain of thalamic origin and 10 control patients with thalamic strokes without pain were identified as volumes of interest on magnetic resonance imaging data. Non-linear deformations were estimated to match each image with a high-resolution template and were applied to each volume of interest. By using a digital atlas of the thalamus, we elucidated the involvement of different nuclei with respect to each lesion. Patient and control volumes of interest were summed separately to identify unique areas of involvement. Voxelwise odds ratio maps were calculated to localize the anatomical site where lesions put patients at risk of developing central post-stroke pain of thalamic origin. In the patients with pain, mainly lateral and posterior thalamic nuclei were affected, whereas a more anterior-medial lesion pattern was evident in the controls. The lesions of 9 of 10 pain patients overlapped at the border of the ventral posterior nucleus and the pulvinar, coinciding with the ventrocaudalis portae nucleus. The lesions of this area showed an odds ratio of 81 in favour of developing thalamic pain. The high odds ratio at the ventral posterior nucleus-pulvinar border zone indicates that this area is crucial in the pathogenesis of thalamic pain and demonstrates the feasibility of identifying patients at risk of developing central post-stroke pain of thalamic origin early after thalamic insults. This provides a basis for pre-emptive treatment studies.

  12. Pseudocortical and dissociate discriminative sensory dysfunction in a thalamic stroke.

    PubMed

    Notturno, Francesca; Sepe, Rosamaria; Caulo, Massimo; Uncini, Antonino; Committeri, Giorgia

    2013-01-01

    In thalamic lesions a pseudocortical syndrome has been occasionally described but the effect of the lesion on the cortical network of tactile recognition has never been studied. We report a patient who developed tactile agnosia in the left hand after right thalamic stroke, configuring a pseudocortical sensory syndrome. The discriminative sensory dysfunction was dissociate because only tactile agnosia and mild pseudoathetosis were present. A functional magnetic resonance imaging (fMRI) study showed that tactile recognition with the unaffected hand recruited a bilateral fronto-parietal network. During recognition with the left hand the activation was restricted and lateralized to the ipsilateral hemisphere. In this patient with pseudocortical discriminative sensory dysfunction the lack of activation of the whole cortical network, implicated in tactile recognition, demonstrates that pseudocortical is functionally equivalent to cortical tactile agnosia.

  13. Synaptic mechanisms underlying cholinergic control of thalamic reticular nucleus neurons

    PubMed Central

    Beierlein, Michael

    2014-01-01

    Neuronal networks of the thalamus are the target of extensive cholinergic projections from the basal forebrain and the brainstem. Activation of these afferents can regulate neuronal excitability, transmitter release, and firing patterns in thalamic networks, thereby altering the flow of sensory information during distinct behavioural states. However, cholinergic regulation in the thalamus has been primarily examined by using receptor agonist and antagonist, which has precluded a detailed understanding of the spatiotemporal dynamics that govern cholinergic signalling under physiological conditions. This review summarizes recent studies on cholinergic synaptic transmission in the thalamic reticular nucleus (TRN), a brain structure intimately involved in the control of sensory processing and the generation of rhythmic activity in the thalamocortical system. This work has shown that acetylcholine (ACh) released from individual axons can rapidly and reliably activate both pre- and postsynaptic cholinergic receptors, thereby controlling TRN neuronal activity with high spatiotemporal precision. PMID:24973413

  14. Thalamic abscess caused by a rare pathogen: streptococcus constellatus

    PubMed Central

    Şenol, Özgür; Süslü, Hikmet Turan; Tatarlı, Necati; Tiryaki, Mehmet; Güçlü, Bülent

    2016-01-01

    Streptococcus constellatus is a microorganism that lives commensally in the oropharyngeal region, urogenital region, and intestinal tract. However, it can cause infection in patients with certain predisposing factors. Rarely, this microorganism can cause a brain abscess. Thalamic localization of brain abscesses is much rarer than abscesses in other locations of the brain. Brain abscess caused by streptococcus constellatus are very rarely been reported in the literature. We present a rare case of a left-sided thalamic abscess caused by streptococcus constellatus in a 25-year-old male patient who was injured by shrapnel pieces in the head and who was malnourished. The patient was successfully treated by stereotactic aspiration and antibiotherapy. PMID:27800109

  15. Holmes' tremor as a delayed complication of thalamic stroke.

    PubMed

    Martins, William Alves; Marrone, Luiz Carlos Porcello; Fussiger, Helena; Vedana, Viviane Maria; Cristovam, Rafael do Amaral; Taietti, Marjorye Z; Marrone, Antonio Carlos Huf

    2016-04-01

    Movement disorders are not commonly associated with stroke. Accordingly, thalamic strokes have rarely been associated with tremor, pseudo-athetosis and dystonic postures. We present a 75-year-old man who developed a disabling tremor 1 year after a posterolateral thalamic stroke. This tremor had low frequency (3-4 Hz), did not disappear on focus and was exacerbated by maintaining a static posture and on target pursuit, which made it very difficult to perform basic functions. MRI demonstrated an old ischemic lesion at the left posterolateral thalamus. Treatment with levodopa led to symptom control. Lesions in the midbrain, cerebellum and thalamus may cause Holmes' tremor. Delayed onset of symptoms is usually seen, sometimes appearing 2 years after the original injury. This may be due to maturation of a complex neuronal network, leading to slow dopaminergic denervation. Further studies are needed to improve our understanding of this unique disconnection syndrome.

  16. Bilateral paramedian thalamic artery infarcts: report of eight cases.

    PubMed Central

    Gentilini, M; De Renzi, E; Crisi, G

    1987-01-01

    Eight consecutive patients with CT scan evidence of a bilateral infarct in the territory of the paramedian thalamic artery are reported. In seven cases the infarct also extended to the territory of the polar artery. The main symptoms were: disorder of vigilance which cleared in a few days, and hypersomnolence which lasted longer and in two patients was still present a year later; amnesia, detectable clinically in four patients and only with tests in two patients, which persisted in one patient for three years; changes of mood and bulimia present in five and four patients respectively; and vertical gaze paresis in five patients. Only one patient died, and in the remainder the symptoms tended to subside, but none of the patients who could be followed-up for a year returned to normal behaviour. Clinical and CT scan correlations pointed to the mammillo-thalamic tract as the structure whose damage was responsible for the memory disorders. Images PMID:3625213

  17. Successful thalamic deep brain stimulation for orthostatic tremor.

    PubMed

    Guridi, Jorge; Rodriguez-Oroz, Maria C; Arbizu, Javier; Alegre, Manuel; Prieto, Elena; Landecho, Ignacio; Manrique, Miguel; Artieda, Julio; Obeso, Jose A

    2008-10-15

    We report a patient with severe orthostatic tremor (OT) unresponsive to pharmacological treatments that was successfully controlled with thalamic (Vim, ventralis intermedius nucleus) deep brain stimulation (DBS) over a 4-year period. Cortical activity associated with the OT revealed by EEG back-averaging and fluoro-deoxi-glucose PET were also suppressed in parallel with tremor arrest. This case suggests that Vim-DBS may be a useful therapeutic approach for patients highly disabled by OT.

  18. Thalamic volume as a biomarker for disorders of consciousness

    NASA Astrophysics Data System (ADS)

    Rubeaux, Mathieu; Mahalingam, Jamuna Jayashri; Gomez, Francisco; Nelson, Marvin; Vanhaudenhuyse, Audrey; Bruno, Marie-Aurélie; Gosseries, Olivia; Laureys, Steven; Soddu, Andrea; Lepore, Natasha

    2015-01-01

    Disorders of consciousness (DOC) may be characterized by the degree at which consciousness is impaired, and include for example vegetative state (VS) and minimally conscious state (MCS) patients. Using a reliable marker as a measure of the level of consciousness in such patients is of utmost necessity and importance for their appropriate diagnosis and prognosis. Identification of VS and MCS states based on their behaviors sometimes leads to incorrect inferences due to the influence of a range of factors like motor impairment, fluctuating arousal levels and rapidly habituating responses to name a few.1 The extent of damage in the thalamus, a structure known for its role in arousal regulation, may provide an imaging biomarker to better differentiate between VS and MCS. In this study, we manually segmented the thalamus from T1-weighted brain MRI images in a large cohort of 19 VS and 23 MCS subjects that were examined using the French version of the Coma Recovery Scale Revised (CRS-R).2 This scale is the most trustworthy behavioural diagnosis tool3 for patients with DOC available. The aim was to determine whether a relationship between thalamus volume and consciousness level exists. Results show that total thalamic volume tends to decrease over time after a severe brain injury. Moreover, for subjects in chronic state, the thalamic volume seems to differ with respect to the degree of consciousness that was diagnosed. Finally, for these same chronic patients, the total thalamic volume is varying linearly as a function of the CRS-R score obtained, indicating that thalamic volume may be used as a biomarker to measure the level of consciousness.

  19. How do mammillary body inputs contribute to anterior thalamic function?

    PubMed Central

    Dillingham, Christopher M.; Frizzati, Aura; Nelson, Andrew J.D.; Vann, Seralynne D.

    2015-01-01

    It has long been assumed that the main function of the mammillary bodies is to provide a relay for indirect hippocampal inputs to the anterior thalamic nuclei. Such models afford the mammillary bodies no independent role in memory and overlook the importance of their other, non-hippocampal, inputs. This review focuses on recent advances that herald a new understanding of the importance of the mammillary bodies, and their inputs from the limbic midbrain, for anterior thalamic function. It has become apparent that the mammillary bodies’ contribution to memory is not dependent on afferents from the subicular complex. Rather, the ventral tegmental nucleus of Gudden is a vital source of inputs that support memory processes within the medial mammillary bodies. In parallel, the lateral mammillary bodies, via their connections with the dorsal tegmental nucleus of Gudden, are critical for generating head-direction signals. These two parallel, but distinct, information streams converge on the anterior thalamic nuclei and support different aspects of spatial memory. PMID:25107491

  20. Reproducibility of thalamic segmentation based on probabilistic tractography.

    PubMed

    Traynor, Catherine; Heckemann, Rolf A; Hammers, Alexander; O'Muircheartaigh, Jonathan; Crum, William R; Barker, Gareth J; Richardson, Mark P

    2010-08-01

    Reliable identification of thalamic nuclei is required to improve targeting of electrodes used in Deep Brain Stimulation (DBS), and for exploring the role of thalamus in health and disease. A previously described method using probabilistic tractography to segment the thalamus based on connections to cortical target regions was implemented. Both within- and between-subject reproducibility were quantitatively assessed by the overlap of the resulting segmentations; the effect of two different numbers of target regions (6 and 31) on reproducibility of the segmentation results was also investigated. Very high reproducibility was observed when a single dataset was processed multiple times using different starting conditions. Thalamic segmentation was also very reproducible when multiple datasets from the same subject were processed using six cortical target regions. Within-subject reproducibility was reduced when the number of target regions was increased, particularly in medial and posterior regions of the thalamus. A large degree of overlap in segmentation results from different subjects was obtained, particularly in thalamic regions classified as connecting to frontal, parietal, temporal and pre-central cortical target regions.

  1. An Improved Box Theater

    NASA Astrophysics Data System (ADS)

    Huster, Michael E.

    2011-09-01

    While designing an optics lab for a conceptual physics course, I came across a "box theater" activity. The box theater is a pinhole camera obscura made from a box that students put over their heads and shoulders. I use the activity as a capstone experience to explain optical systems. (Classroom demonstrations of the camera obscura have been described by others.2) First, the students build and experiment with a camera obscura made from a plastic cup and a convex lens with a focal length of 7.5 cm, and then "wear" the box theater. The difficulty with the box theater is the dimness of the image. A cloth drape has to be hung from the bottom of the box around the shoulders of the students to prevent light leakage, and the students have to wait a few minutes for their eyes to adjust to the darkness.

  2. GLOVE BOX ATTACHMENT

    DOEpatents

    Butts, H.L.

    1962-02-13

    This invention comprises a housing unit to be fitted between a glove box port and a glove so that a slidable plate within the housing seals off the glove box port for evacuation of the glove box without damage to the glove. The housing and the glove may be evacuated without damage to the glove since movement of the glove is restricted during evacuation by the slidable plate. (AEC)

  3. Cortical Control of Striatal Dopamine Transmission via Striatal Cholinergic Interneurons

    PubMed Central

    Kosillo, Polina; Zhang, Yan-Feng; Threlfell, Sarah; Cragg, Stephanie J.

    2016-01-01

    Corticostriatal regulation of striatal dopamine (DA) transmission has long been postulated, but ionotropic glutamate receptors have not been localized directly to DA axons. Striatal cholinergic interneurons (ChIs) are emerging as major players in striatal function, and can govern DA transmission by activating nicotinic receptors (nAChRs) on DA axons. Cortical inputs to ChIs have historically been perceived as sparse, but recent evidence indicates that they strongly activate ChIs. We explored whether activation of M1/M2 corticostriatal inputs can consequently gate DA transmission, via ChIs. We reveal that optogenetic activation of channelrhodopsin-expressing corticostriatal axons can drive striatal DA release detected with fast-scan cyclic voltammetry and requires activation of nAChRs on DA axons and AMPA receptors on ChIs that promote short-latency action potentials. By contrast, DA release driven by optogenetic activation of intralaminar thalamostriatal inputs involves additional activation of NMDA receptors on ChIs and action potential generation over longer timescales. Therefore, cortical and thalamic glutamate inputs can modulate DA transmission by regulating ChIs as gatekeepers, through ionotropic glutamate receptors. The different use of AMPA and NMDA receptors by cortical versus thalamic inputs might lead to distinct input integration strategies by ChIs and distinct modulation of the function of DA and striatum. PMID:27566978

  4. Thinking outside the Box

    ERIC Educational Resources Information Center

    Fanshawe, Simon; Sriskandarajah, Dhananjayan

    2010-01-01

    Britain is not only more diverse than ever before, but that diversity itself is growing more diverse. Britain's simplistic "tick-box" approach to identity is in danger of inhibiting the very equality it seeks to promote. To question the tick-box is not to accuse local authorities of "political correctness gone mad". The notion…

  5. Math in the Box

    ERIC Educational Resources Information Center

    DeYoung, Mary J.

    2009-01-01

    This article describes how to make an origami paper box and explores the algebra, geometry, and other mathematics that unfolds. A set of origami steps that transforms the paper into an open box can hold mathematical surprises for both students and teachers. An origami lesson can engage students in an open-ended exploration of the relationship…

  6. Straw in a Box

    ERIC Educational Resources Information Center

    Jerrard, Richard; Schneider, Joel; Smallberg, Ralph; Wetzel, John

    2006-01-01

    A problem on a state's high school exit exam asked for the longest straw that would fit in a box. The examiners apparently wanted the length of a diagonal of the box, but the figure accompanying the question suggested otherwise--that the radius of the straw be considered. This article explores that more general problem.

  7. Modulation of GABA release from the thalamic reticular nucleus by cocaine and caffeine: role of serotonin receptors.

    PubMed

    Goitia, Belén; Rivero-Echeto, María Celeste; Weisstaub, Noelia V; Gingrich, Jay A; Garcia-Rill, Edgar; Bisagno, Verónica; Urbano, Francisco J

    2016-02-01

    Serotonin receptors are targets of drug therapies for a variety of neuropsychiatric and neurodegenerative disorders. Cocaine inhibits the re-uptake of serotonin (5-HT), dopamine, and noradrenaline, whereas caffeine blocks adenosine receptors and opens ryanodine receptors in the endoplasmic reticulum. We studied how 5-HT and adenosine affected spontaneous GABAergic transmission from thalamic reticular nucleus. We combined whole-cell patch clamp recordings of miniature inhibitory post-synaptic currents (mIPSCs) in ventrobasal thalamic neurons during local (puff) application of 5-HT in wild type (WT) or knockout mice lacking 5-HT2A receptors (5-HT2A -/-). Inhibition of mIPSCs frequency by low (10 μM) and high (100 μM) 5-HT concentrations was observed in ventrobasal neurons from 5-HT2A -/- mice. In WT mice, only 100 μM 5-HT significantly reduced mIPSCs frequency. In 5-HT2A -/- mice, NAN-190, a specific 5-HT1A antagonist, prevented the 100 μM 5-HT inhibition while blocking H-currents that prolonged inhibition during post-puff periods. The inhibitory effects of 100 μM 5-HT were enhanced in cocaine binge-treated 5-HT2A -/- mice. Caffeine binge treatment did not affect 5-HT-mediated inhibition. Our findings suggest that both 5-HT1A and 5-HT2A receptors are present in pre-synaptic thalamic reticular nucleus terminals. Serotonergic-mediated inhibition of GABA release could underlie aberrant thalamocortical physiology described after repetitive consumption of cocaine. Our findings suggest that both 5-HT1A , 5-HT2A and A1 receptors are present in pre-synaptic TRN terminals. 5-HT1A and A1 receptors would down-regulate adenylate cyclase, whereas 5-HT1A would also increase the probability of the opening of G-protein-activated inwardly rectifying K(+) channels (GIRK). Sustained opening of GIRK channels would hyperpolarize pre-synaptic terminals activating H-currents, resulting in less GABA release. 5-HT2A -would activate PLC and IP3 , increasing intracellular [Ca(2+) ] and

  8. Direct inhibition of the N-methyl-D-aspartate receptor channel by dopamine and (+)-SKF38393.

    PubMed

    Castro, N G; de Mello, M C; de Mello, F G; Aracava, Y

    1999-04-01

    1. Dopamine is known to modulate glutamatergic synaptic transmission in the retina and in several brain regions by activating specific G-protein-coupled receptors. We have examined the possibility of a different type of mechanism for this modulation, one involving direct interaction of dopamine with ionotropic glutamate receptors. 2. Ionic currents induced by fast application of N-methyl-D-aspartate (NMDA) were recorded under whole-cell patch-clamp in cultured striatal, thalamic and hippocampal neurons of the rat and in retinal neurons of the chick. Dopamine at concentrations above 100 microM inhibited the NMDA response in all four neuron types, exhibiting an IC50 of 1.2 mM in hippocampal neurons. The time course of this inhibition was fast, developing in less than 100 ms. 3. The D1 receptor agonist (+)-SKF38393 mimicked the effect of dopamine, with an IC50 of 58.9 microM on the NMDA response, while the enantiomer (-)-SKF38393 was ineffective at 50 microM. However, the D1 antagonist R(+)-SCH23390 did not prevent the inhibitory effect of (+)-SKF38393. 4. The degree of inhibition by dopamine and (+)-SKF38393 depended on transmembrane voltage, increasing 2.7 times with a hyperpolarization of about 80 mV. The voltage-dependent block by dopamine was also observed in the presence of MgCl2 1 mM. 5. Single-channel recordings showed that the open times of NMDA-gated channels were shortened by (+)-SKF38393. 6. These data suggested that the site to which the drugs bound to produce the inhibitory effect was distinct from the classical D1-type dopamine receptor sites, possibly being located inside the NMDA channel pore. It is concluded that dopamine and (+)-SKF38393 are NMDA channel ligands.

  9. Direct inhibition of the N-methyl-D-aspartate receptor channel by dopamine and (+)-SKF38393

    PubMed Central

    Castro, Newton G; de Mello, Maria Christina F; de Mello, Fernando G; Aracava, Yasco

    1999-01-01

    Dopamine is known to modulate glutamatergic synaptic transmission in the retina and in several brain regions by activating specific G-protein-coupled receptors. We have examined the possibility of a different type of mechanism for this modulation, one involving direct interaction of dopamine with ionotropic glutamate receptors.Ionic currents induced by fast application of N-methyl-D-aspartate (NMDA) were recorded under whole-cell patch-clamp in cultured striatal, thalamic and hippocampal neurons of the rat and in retinal neurons of the chick. Dopamine at concentrations above 100 μM inhibited the NMDA response in all four neuron types, exhibiting an IC50 of 1.2 mM in hippocampal neurons. The time course of this inhibition was fast, developing in less than 100 ms.The D1 receptor agonist (+)-SKF38393 mimicked the effect of dopamine, with an IC50 of 58.9 μM on the NMDA response, while the enantiomer (−)-SKF38393 was ineffective at 50 μM. However, the D1 antagonist R(+)-SCH23390 did not prevent the inhibitory effect of (+)-SKF38393.The degree of inhibition by dopamine and (+)-SKF38393 depended on transmembrane voltage, increasing 2.7 times with a hyperpolarization of about 80 mV. The voltage-dependent block by dopamine was also observed in the presence of MgCl2 1 mM.Single-channel recordings showed that the open times of NMDA-gated channels were shortened by (+)-SKF38393.These data suggested that the site to which the drugs bound to produce the inhibitory effect was distinct from the classical D1-type dopamine receptor sites, possibly being located inside the NMDA channel pore. It is concluded that dopamine and (+)-SKF38393 are NMDA channel ligands. PMID:10372829

  10. X-box-binding protein 1-modified neural stem cells for treatment of Parkinson's disease.

    PubMed

    Si, Lihui; Xu, Tianmin; Wang, Fengzhang; Liu, Qun; Cui, Manhua

    2012-04-05

    X-box-binding protein 1-transfected neural stem cells were transplanted into the right lateral ventricles of rats with rotenone-induced Parkinson's disease. The survival capacities and differentiation rates of cells expressing the dopaminergic marker tyrosine hydroxylase were higher in X-box-binding protein 1-transfected neural stem cells compared to non-transfected cells. Moreover, dopamine and 3,4-dihydroxyphenylacetic acid levels in the substantia nigra were significantly increased, α-synuclein expression was decreased, and neurological behaviors were significantly ameliorated in rats following transplantation of X-box-binding protein 1-transfected neural stem cells. These results indicate that transplantation of X-box-binding protein 1-transfected neural stem cells can promote stem cell survival and differentiation into dopaminergic neurons, increase dopamine and 3,4-dihydroxyphenylacetic acid levels, reduce α-synuclein aggregation in the substantia nigra, and improve the symptoms of Parkinson's disease in rats.

  11. Decreased striatal and enhanced thalamic dopaminergic responsivity in detoxified cocaine abusers

    SciTech Connect

    Volkow, N.D.; Wang, G.J.; Fowler, J.S.

    1997-05-01

    It has been hypothesized that cocaine addiction could result from decreased brain dopamine (DA) function. However, little is known about changes in (DA) neurotransmission in human cocaine addiction. We used PET and [C-11]raclopride, a DA D2 receptor ligand sensitive to competition with endogenous DA, to measure relative changes in extracellular DA induced by methylphenidate (MP) in 20 cocaine abusers (3-6 weeks after cocaine discontinuation) and 23 controls. MP did not affect the transport of [C-11]raclopride from blood to brain (K1); however it induced a significant reduction in DA D2 receptor availability (Bmax/Kd) in striatum. The magnitude of ND-induced changes in striatal [C-11]raclopride binding were significantly larger in controls (21 + 13% change from baseline) than in cocaine abusers (9 {+-} 13 %) (ANOVA p < 0.005). In cocaine abusers, but not in controls, MP also decreased Bmax/Kd values in thalamus (29 {+-} 35 %) (ANOVA p < 0.005). There were no differences in plasma MP concentration between the groups. In striatum MP-induced changes in Bmax/Kd were significantly correlated with MP-induced changes in self reports of restlessness (r = 0.49, df 42, p < 0.002). In thalamus MP-induced changes in Bmax/Kd were significantly correlated with ND-induced changes in self reports of cocaine craving (r = 0.57, df 42, p < 0.0001). These results are compatible with a decrease in striatal DA brain function in cocaine abusers. They also suggest a participation of thalamic DA pathways in cocaine addiction.

  12. Fornical and nonfornical projections from the rat hippocampal formation to the anterior thalamic nuclei.

    PubMed

    Dillingham, Christopher M; Erichsen, Jonathan T; O'Mara, Shane M; Aggleton, John P; Vann, Seralynne D

    2015-09-01

    The hippocampal formation and anterior thalamic nuclei form part of an interconnected network thought to support memory. A central pathway in this mnemonic network comprises the direct projections from the hippocampal formation to the anterior thalamic nuclei, projections that, in the primate brain, originate in the subicular cortices to reach the anterior thalamic nuclei by way of the fornix. In the rat brain, additional pathways involving the internal capsule have been described, linking the dorsal subiculum to the anteromedial thalamic nucleus, as well as the postsubiculum to the anterodorsal thalamic nucleus. Confirming such pathways is essential in order to appreciate how information is transferred from the hippocampal formation to the anterior thalamus and how it may be disrupted by fornix pathology. Accordingly, in the present study, pathway tracers were injected into the anterior thalamic nuclei and the dorsal subiculum of rats with fornix lesions. Contrary to previous descriptions, projections from the subiculum to the anteromedial thalamic nucleus overwhelmingly relied on the fornix. Dorsal subiculum projections to the majority of the anteroventral nucleus also predominantly relied on the fornix, although postsubicular inputs to the lateral dorsal part of the anteroventral nucleus, as well as to the anterodorsal and laterodorsal thalamic nuclei, largely involved a nonfornical pathway, via the internal capsule.

  13. Altered thalamocortical and intra-thalamic functional connectivity during light sleep compared with wake.

    PubMed

    Hale, Joanne R; White, Thomas P; Mayhew, Stephen D; Wilson, Rebecca S; Rollings, David T; Khalsa, Sakhvinder; Arvanitis, Theodoros N; Bagshaw, Andrew P

    2016-01-15

    The transition from wakefulness into sleep is accompanied by modified activity in the brain's thalamocortical network. Sleep-related decreases in thalamocortical functional connectivity (FC) have previously been reported, but the extent to which these changes differ between thalamocortical pathways, and patterns of intra-thalamic FC during sleep remain untested. To non-invasively investigate thalamocortical and intra-thalamic FC as a function of sleep stage we recorded simultaneous EEG-fMRI data in 13 healthy participants during their descent into light sleep. Visual scoring of EEG data permitted sleep staging. We derived a functional thalamic parcellation during wakefulness by computing seed-based FC, measured between thalamic voxels and a set of pre-defined cortical regions. Sleep differentially affected FC between these distinct thalamic subdivisions and their associated cortical projections, with significant increases in FC during sleep restricted to sensorimotor connections. In contrast, intra-thalamic FC, both within and between functional thalamic subdivisions, showed significant increases with advancement into sleep. This work demonstrates the complexity and state-specific nature of functional thalamic relationships--both with the cortex and internally--over the sleep/wake cycle, and further highlights the importance of a thalamocortical focus in the study of sleep mechanisms.

  14. Thalamic activity and biochemical changes in individuals with neuropathic pain after spinal cord injury.

    PubMed

    Gustin, S M; Wrigley, P J; Youssef, A M; McIndoe, L; Wilcox, S L; Rae, C D; Edden, R A E; Siddall, P J; Henderson, L A

    2014-05-01

    There is increasing evidence relating thalamic changes to the generation and/or maintenance of neuropathic pain. We have recently reported that neuropathic orofacial pain is associated with altered thalamic anatomy, biochemistry, and activity, which may result in disturbed thalamocortical oscillatory circuits. Despite this evidence, it is possible that these thalamic changes are not responsible for the presence of pain per se, but result as a consequence of the injury. To clarify this subject, we compared brain activity and biochemistry in 12 people with below-level neuropathic pain after complete thoracic spinal cord injury with 11 people with similar injuries and no neuropathic pain and 21 age- and gender-matched healthy control subjects. Quantitative arterial spinal labelling was used to measure thalamic activity, and magnetic resonance spectroscopy was used to determine changes in neuronal variability quantifying N-acetylaspartate and alterations in inhibitory function quantifying gamma amino butyric acid. This study revealed that the presence of neuropathic pain is associated with significant changes in thalamic biochemistry and neuronal activity. More specifically, the presence of neuropathic pain after spinal cord injury is associated with significant reductions in thalamic N-acetylaspartate, gamma amino butyric acid content, and blood flow in the region of the thalamic reticular nucleus. Spinal cord injury on its own did not account for these changes. These findings support the hypothesis that neuropathic pain is associated with altered thalamic structure and function, which may disturb central processing and play a key role in the experience of neuropathic pain.

  15. The Role of Thalamic Population Synchrony in the Emergence of Cortical Feature Selectivity

    PubMed Central

    Kelly, Sean T.; Kremkow, Jens; Jin, Jianzhong; Wang, Yushi; Wang, Qi; Alonso, Jose-Manuel; Stanley, Garrett B.

    2014-01-01

    In a wide range of studies, the emergence of orientation selectivity in primary visual cortex has been attributed to a complex interaction between feed-forward thalamic input and inhibitory mechanisms at the level of cortex. Although it is well known that layer 4 cortical neurons are highly sensitive to the timing of thalamic inputs, the role of the stimulus-driven timing of thalamic inputs in cortical orientation selectivity is not well understood. Here we show that the synchronization of thalamic firing contributes directly to the orientation tuned responses of primary visual cortex in a way that optimizes the stimulus information per cortical spike. From the recorded responses of geniculate X-cells in the anesthetized cat, we synthesized thalamic sub-populations that would likely serve as the synaptic input to a common layer 4 cortical neuron based on anatomical constraints. We used this synchronized input as the driving input to an integrate-and-fire model of cortical responses and demonstrated that the tuning properties match closely to those measured in primary visual cortex. By modulating the overall level of synchronization at the preferred orientation, we show that efficiency of information transmission in the cortex is maximized for levels of synchronization which match those reported in thalamic recordings in response to naturalistic stimuli, a property which is relatively invariant to the orientation tuning width. These findings indicate evidence for a more prominent role of the feed-forward thalamic input in cortical feature selectivity based on thalamic synchronization. PMID:24415930

  16. Transient Relay Function of Midline Thalamic Nuclei during Long-Term Memory Consolidation in Humans

    ERIC Educational Resources Information Center

    Thielen, Jan-Willem; Takashima, Atsuko; Rutters, Femke; Tendolkar, Indira; Fernández, Guillén

    2015-01-01

    To test the hypothesis that thalamic midline nuclei play a transient role in memory consolidation, we reanalyzed a prospective functional MRI study, contrasting recent and progressively more remote memory retrieval. We revealed a transient thalamic connectivity increase with the hippocampus, the medial prefrontal cortex (mPFC), and a…

  17. Thalamic activity and biochemical changes in individuals with neuropathic pain following spinal cord injury

    PubMed Central

    Gustin, S.M.; Wrigley, P.J.; Youssef, A.M.; McIndoe, L.; Wilcox, S.L.; Rae, C.D.; Edden, R; Siddall, P.J.; Henderson, L.A.

    2015-01-01

    There is increasing evidence relating thalamic changes to the generation and/or maintenance of neuropathic pain. We have recently reported that neuropathic orofacial pain is associated with altered thalamic anatomy, biochemistry and activity, which may result in disturbed thalamocortical oscillatory circuits. Despite this evidence, it is possible that these thalamic changes are not responsible for the presence of pain per se, but result as a consequence of the injury. To clarify this subject, we compared brain activity and biochemistry in 12 people with below-level neuropathic pain after complete thoracic spinal cord injury to 11 people with similar injuries and no neuropathic pain and 21 age and gender matched healthy controls. Quantitative arterial spinal labelling was used to measure thalamic activity and magnetic resonance spectroscopy was used to determine changes in neuronal variability quantifying N-acetylaspartate and alterations in inhibitory function quantifying gamma amino butyric acid. This study revealed that the presence of neuropathic pain is associated with significant changes in thalamic biochemistry and neuronal activity. More specifically, the presence of neuropathic pain following spinal cord injury is associated with significant reductions in thalamic N-acetylaspartate, gamma amino butyric acid content and blood flow in the region of the thalamic reticular nucleus. Spinal cord injury on its own did not account for these changes. These findings support the hypothesis that neuropathic pain is associated with altered thalamic structure and function, which may disturb central processing and play a key role in the experience of neuropathic pain. PMID:24530612

  18. Developmental Alterations of Frontal-Striatal-Thalamic Connectivity in Obsessive-Compulsive Disorder

    ERIC Educational Resources Information Center

    Fitzgerald, Kate Dimond; Welsh, Robert C.; Stern, Emily R.; Angstadt, Mike; Hanna, Gregory L.; Abelson, James L.; Taylor, Stephan F.

    2011-01-01

    Objective: Pediatric obsessive-compulsive disorder is characterized by abnormalities of frontal-striatal-thalamic circuitry that appear near illness onset and persist over its course. Distinct frontal-striatal-thalamic loops through cortical centers for cognitive control (anterior cingulate cortex) and emotion processing (ventral medial frontal…

  19. Local and thalamic origins of correlated ongoing and sensory-evoked cortical activities

    PubMed Central

    Cohen-Kashi Malina, Katayun; Mohar, Boaz; Rappaport, Akiva N.; Lampl, Ilan

    2016-01-01

    Thalamic inputs of cells in sensory cortices are outnumbered by local connections. Thus, it was suggested that robust sensory response in layer 4 emerges due to synchronized thalamic activity. To investigate the role of both inputs in the generation of correlated cortical activities, we isolated the thalamic excitatory inputs of cortical cells by optogenetically silencing cortical firing. In anaesthetized mice, we measured the correlation between isolated thalamic synaptic inputs of simultaneously patched nearby layer 4 cells of the barrel cortex. Here we report that in contrast to correlated activity of excitatory synaptic inputs in the intact cortex, isolated thalamic inputs exhibit lower variability and asynchronous spontaneous and sensory-evoked inputs. These results are further supported in awake mice when we recorded the excitatory inputs of individual cortical cells simultaneously with the local field potential in a nearby site. Our results therefore indicate that cortical synchronization emerges by intracortical coupling. PMID:27615520

  20. Glove box shield

    DOEpatents

    Brackenbush, Larry W.; Hoenes, Glenn R.

    1981-01-01

    According to the present invention, a shield for a glove box housing radioactive material is comprised of spaced apart clamping members which maintain three overlapping flaps in place therebetween. There is a central flap and two side flaps, the side flaps overlapping at the interior edges thereof and the central flap extending past the intersection of the side flaps in order to insure that the shield is always closed when the user withdraws his hand from the glove box. Lead loaded neoprene rubber is the preferred material for the three flaps, the extent of lead loading depending upon the radiation levels within the glove box.

  1. Glove box shield

    DOEpatents

    Brackenbush, L.W.; Hoenes, G.R.

    A shield for a glove box housing radioactive material is comprised of spaced apart clamping members which maintain three overlapping flaps in place therebetween. There is a central flap and two side flaps, the side flaps overlapping at the interior edges thereof and the central flap extending past the intersection of the side flaps in order to insure that the shield is always closed when the user wthdraws his hand from the glove box. Lead loaded neoprene rubber is the preferred material for the three flaps, the extent of lead loading depending upon the radiation levels within the glove box.

  2. Climate in a Box

    NASA Video Gallery

    NASA's Climate in a Box Project is exploring the utility of supercomputers in providing a complete, pre-packaged, ready-to-use toolkit of climate research products and on-demand access to a high-pe...

  3. Voice box (image)

    MedlinePlus

    The larynx, or voice box, is located in the neck and performs several important functions in the body. The larynx is involved in swallowing, breathing, and voice production. Sound is produced when the air which ...

  4. Localization of dopamine D4 receptors in GABAergic neurons of the primate brain.

    PubMed

    Mrzljak, L; Bergson, C; Pappy, M; Huff, R; Levenson, R; Goldman-Rakic, P S

    1996-05-16

    Dopamine receptors are the principal targets of drugs used in the treatment of schizophrenia. Among the five mammalian dopamine-receptor subtypes, the D4 subtype is of particular interest because of its high affinity for the atypical neuroleptic clozapine. Interest in clozapine stems from its effectiveness in reducing positive and negative symptoms in acutely psychotic and treatment-resistant schizophrenic patients without eliciting extrapyramidal side effects. We have produced a subtype-specific antibody against the D4 receptor and localized it within specific cellular elements and synaptic circuits of the central nervous system. The D4-receptor antibody labelled GABAergic neurons in the cerebral cortex, hippocampus, thalamic reticular nucleus, globus pallidus and the substantia nigra (pars reticulata). Labelling was also observed in a subset of cortical pyramidal cells. Our findings suggest that clozapine's beneficial effects in schizophrenia may be achieved, in part, through D4-mediated GABA modulation, possibly implicating disinhibition of excitatory transmission in intrinsic cortical, thalamocortical and extrapyramidal pathways.

  5. Thalamic segmentation based on improved fuzzy connectedness in structural MRI.

    PubMed

    Yang, Chunlan; Wang, Qian; Wu, Weiwei; Xue, Yanqing; Lu, Wangsheng; Wu, Shuicai

    2015-11-01

    Thalamic segmentation serves an important function in localizing targets for deep brain stimulation (DBS). However, thalamic nuclei are still difficult to identify clearly from structural MRI. In this study, an improved algorithm based on the fuzzy connectedness framework was developed. Three-dimensional T1-weighted images in axial orientation were acquired through a 3D SPGR sequence by using a 1.5 T GE magnetic resonance scanner. Twenty-five normal images were analyzed using the proposed method, which involved adaptive fuzzy connectedness combined with confidence connectedness (AFCCC). After non-brain tissue removal and contrast enhancement, the seed point was selected manually, and confidence connectedness was used to perform an ROI update automatically. Both image intensity and local gradient were taken as image features in calculating the fuzzy affinity. Moreover, the weight of the features could be automatically adjusted. Thalamus, ventrointermedius (Vim), and subthalamic nucleus were successfully segmented. The results were evaluated with rules, such as similarity degree (SD), union overlap, and false positive. SD of thalamus segmentation reached values higher than 85%. The segmentation results were also compared with those achieved by the region growing and level set methods, respectively. Higher SD of the proposed method, especially in Vim, was achieved. The time cost using AFCCC was low, although it could achieve high accuracy. The proposed method is superior to the traditional fuzzy connectedness framework and involves reduced manual intervention in time saving.

  6. Thalamic, brainstem, and cerebellar glucose metabolism in the hemiplegic monkey

    SciTech Connect

    Shimoyama, I.; Dauth, G.W.; Gilman, S.; Frey, K.A.; Penney, J.B. Jr.

    1988-12-01

    Unilateral ablation of cerebral cortical areas 4 and 6 of Brodmann in the macaque monkey results in a contralateral hemiplegia that resolves partially with time. During the phase of dense hemiplegia, local cerebral metabolic rate for glucose (1CMRG1c) is decreased significantly in most of the thalamic nuclei ipsilateral to the ablation, and there are slight contralateral decreases. The lCMRGlc is reduced bilaterally in most of the brainstem nuclei and bilaterally in the deep cerebellar nuclei, but only in the contralateral cerebellar cortex. During the phase of partial motor recovery, lCMRGlc is incompletely restored in many of the thalamic nuclei ipsilateral to the ablation and completely restored in the contralateral nuclei. In the brainstem and deep cerebellar nuclei, poor to moderate recovery occurs bilaterally. Moderate recovery occurs in the contralateral cerebellar cortex. The findings demonstrate that a unilateral cerebral cortical lesion strongly affects lCMRGlc in the thalamus ipsilaterally and in the cerebellar cortex contralaterally, but in the brainstem bilaterally. Partial recovery of lCMRGlc accompanies the progressive motor recovery. The structures affected include those with direct, and also those with indirect, connections to the areas ablated.

  7. [Boxing: traumatology and prevention].

    PubMed

    Cabanis, Emmanuel-Alain; Iba-Zizen, Marie-Thérèse; Perez, Georges; Senegas, Xavier; Furgoni, Julien; Pineau, Jean-Claude; Louquet, Jean-Louis; Henrion, Roger

    2010-10-01

    In 1986, a surgeon who, as an amateur boxer himself was concerned with boxers' health, approached a pioneering Parisian neuroimaging unit. Thus began a study in close cooperation with the French Boxing Federation, spanning 25 years. In a first series of 52 volunteer boxers (13 amateurs and 39 professionals), during which MRI gradually replaced computed tomography, ten risk factors were identified, which notably included boxing style: only one of 40 "stylists" with a good boxing technique had cortical atrophy (4.5 %), compared to 15 % of "sloggers". Changes to the French Boxing Federation rules placed the accent on medical prevention. The second series, of 247 boxers (81 amateurs and 266 professionals), showed a clear improvement, as lesions were suspected in 14 individuals, of which only 4 (1.35 %) were probably due to boxing. The third and fourth series were part of a protocol called "Brain-Boxing-Ageing", which included 76 boxers (11 having suffered KOs) and 120 MRI scans, with reproducible CT and MRI acquisitions (9 sequences with 1.5 T then 3 T, and CT). MRI anomalies secondary to boxing were found in 11 % of amateurs and 38 % of professionals (atrophy, high vascular T2 signal areas, 2 cases of post-KO subdural bleeding). CT revealed sinus damage in 13 % of the amateurs and 19 % of the professionals. The risk of acute and chronic facial and brain damage was underline, along with detailed precautionary measures (organization of bouts, role of the referee and ringside doctor, and application of French Boxing Federation rules).

  8. Nonneurologic emergencies in boxing.

    PubMed

    Coletta, Domenic F

    2009-10-01

    Professional boxing has done an admirable job in promoting safety standards in its particular sport. However, injuries occur during the normal course of competition and, unfortunately, an occasional life-threatening emergency may arise. Although most common medical emergencies in boxing are injuries from closed head trauma, in this article those infrequent but potentially catastrophic nonneurologic conditions are reviewed along with some less serious emergencies that the physician must be prepared to address.

  9. Infectious disease and boxing.

    PubMed

    King, Osric S

    2009-10-01

    There are no unique boxing diseases but certain factors contributing to the spread of illnesses apply strongly to the boxer, coach, and the training facility. This article examines the nature of the sport of boxing and its surrounding environment, and the likelihood of spread of infection through airborne, contact, or blood-borne routes of transmission. Evidence from other sports such as running, wrestling, and martial arts is included to help elucidate the pathophysiologic elements that could be identified in boxers.

  10. Automatic box loader

    DOEpatents

    Eldridge, Harry H.; Jones, Robert A.; Lindner, Gordon M.; Hight, Paul H.

    1976-01-01

    This invention relates to a system for repetitively forming an assembly consisting of a single layer of tubes and a row of ferromagnetic armatures underlying the same, electromagnetically conveying the resulting assembly to a position overlying a storage box, and depositing the assembly in the box. The system includes means for simultaneously depositing a row of the armatures on the inclined surface of a tube retainer. Tubes then are rolled down the surface to form a single tube layer bridging the armatures. A magnet assembly carrying electromagnets respectively aligned with the armatures is advanced close to the tube layer, and in the course of this advance is angularly displaced to bring the pole pieces of the electromagnets into parallelism with the tube layer. The magnets then are energized to pick up the assembly. The loaded magnet assembly is retracted to a position overlying the box, and during this retraction is again displaced to bring the pole pieces of the electromagnets into a horizontal plane. Means are provided for inserting the loaded electromagnets in the box and then de-energizing the electromagnets to deposit the assembly therein. The system accomplishes the boxing of fragile tubes at relatively high rates. Because the tubes are boxed as separated uniform layers, subsequent unloading operations are facilitated.

  11. Cable Tester Box

    NASA Technical Reports Server (NTRS)

    Lee, Jason H.

    2011-01-01

    Cables are very important electrical devices that carry power and signals across multiple instruments. Any fault in a cable can easily result in a catastrophic outcome. Therefore, verifying that all cables are built to spec is a very important part of Electrical Integration Procedures. Currently, there are two methods used in lab for verifying cable connectivity. (1) Using a Break-Out Box and an ohmmeter this method is time-consuming but effective for custom cables and (2) Commercial Automated Cable Tester Boxes this method is fast, but to test custom cables often requires pre-programmed configuration files, and cables used on spacecraft are often uniquely designed for specific purposes. The idea is to develop a semi-automatic continuity tester that reduces human effort in cable testing, speeds up the electrical integration process, and ensures system safety. The JPL-Cable Tester Box is developed to check every single possible electrical connection in a cable in parallel. This system indicates connectivity through LED (light emitting diode) circuits. Users can choose to test any pin/shell (test node) with a single push of a button, and any other nodes that are shorted to the test node, even if they are in the same connector, will light up with the test node. The JPL-Cable Tester Boxes offers the following advantages: 1. Easy to use: The architecture is simple enough that it only takes 5 minutes for anyone to learn how operate the Cable Tester Box. No pre-programming and calibration are required, since this box only checks continuity. 2. Fast: The cable tester box checks all the possible electrical connections in parallel at a push of a button. If a cable normally takes half an hour to test, using the Cable Tester Box will improve the speed to as little as 60 seconds to complete. 3. Versatile: Multiple cable tester boxes can be used together. As long as all the boxes share the same electrical potential, any number of connectors can be tested together.

  12. From Parkinsonian thalamic activity to restoring thalamic relay using deep brain stimulation: new insights from computational modeling

    NASA Astrophysics Data System (ADS)

    Meijer, H. G. E.; Krupa, M.; Cagnan, H.; Lourens, M. A. J.; Heida, T.; Martens, H. C. F.; Bour, L. J.; van Gils, S. A.

    2011-10-01

    We present a computational model of a thalamocortical relay neuron for exploring basal ganglia thalamocortical loop behavior in relation to Parkinson's disease and deep brain stimulation (DBS). Previous microelectrode, single-unit recording studies demonstrated that oscillatory interaction within and between basal ganglia nuclei is very often accompanied by synchronization at Parkinsonian rest tremor frequencies (3-10 Hz). These oscillations have a profound influence on thalamic projections and impair the thalamic relaying of cortical input by generating rebound action potentials. Our model describes convergent inhibitory input received from basal ganglia by the thalamocortical cells based on characteristics of normal activity, and/or low-frequency oscillations (activity associated with Parkinson's disease). In addition to simulated input, we also used microelectrode recordings as inputs for the model. In the resting state, and without additional sensorimotor input, pathological rebound activity is generated for even mild Parkinsonian input. We have found a specific stimulation window of amplitudes and frequencies for periodic input, which corresponds to high-frequency DBS, and which also suppresses rebound activity for mild and even more prominent Parkinsonian input. When low-frequency pathological rebound activity disables the thalamocortical cell's ability to relay excitatory cortical input, a stimulation signal with parameter settings corresponding to our stimulation window can restore the thalamocortical cell's relay functionality.

  13. Progressive deterioration of thalamic nuclei relates to cortical network decline in schizophrenia.

    PubMed

    Cobia, Derin J; Smith, Matthew J; Salinas, Ilse; Ng, Charlene; Gado, Mokhtar; Csernansky, John G; Wang, Lei

    2017-02-01

    Thalamic abnormalities are considered part of the complex pathophysiology of schizophrenia, particularly the involvement of specific thalamic nuclei. The goals of this study were to: introduce a novel atlas-based parcellation scheme for defining various thalamic nuclei; compare their integrity in a schizophrenia sample against healthy individuals at baseline and follow-up time points, as well as rates of change over time; examine relationships between the nuclei and abnormalities in known connected cortical regions; and finally, to determine if schizophrenia-related thalamic nuclei changes relate to cognitive functioning and clinical symptoms. Subjects were from a larger longitudinal 2-year follow-up study, schizophrenia (n=20) and healthy individuals (n=20) were group-matched for age, gender, and recent-alcohol use. We used high-dimensional brain mapping to obtain thalamic morphology, and applied a novel atlas-based method for delineating anterior, mediodorsal, and pulvinar nuclei. Results from cross sectional GLMs revealed group differences in bilateral mediodorsal and anterior nuclei, while longitudinal models revealed significant group-by-time interactions for the mediodorsal and pulvinar nuclei. Cortical correlations were the strongest for the pulvinar in frontal, temporal and parietal regions, followed by the mediodorsal nucleus in frontal regions, but none in the anterior nucleus. Thalamic measures did not correlate with cognitive and clinical scores at any time point or longitudinally. Overall, findings revealed a pattern of persistent progressive abnormalities in thalamic nuclei that relate to advancing cortical decline in schizophrenia, but not with measures of behavior.

  14. Developmental synergy between thalamic structure and interhemispheric connectivity in the visual system of preterm infants

    PubMed Central

    Ceschin, Rafael; Wisnowski, Jessica L.; Paquette, Lisa B.; Nelson, Marvin D.; Blüml, Stefan; Panigrahy, Ashok

    2015-01-01

    Thalamic structural co-variation with cortical regions has been demonstrated in preterm infants, but its relationship to cortical function and severity of non-cystic white matter injury (non-cystic WMI) is unclear. The relationship between thalamic morphology and both cortical network synchronization and cortical structural connectivity has not been established. We tested the hypothesis that in preterm neonates, thalamic volume would correlate with primary cortical visual function and microstructural integrity of cortico-cortical visual association pathways. A total of 80 term-equivalent preterm and 44 term-born infants underwent high-resolution structural imaging coupled with visual functional magnetic resonance imaging or diffusion tensor imaging. There was a strong correlation between thalamic volume and primary visual cortical activation in preterms with non-cystic WMI (r = 0.81, p-value = 0.001). Thalamic volume also correlated strongly with interhemispheric cortico-cortical connectivity (splenium) in preterm neonates with a relatively higher severity of non-cystic WMI (p-value < 0.001). In contrast, there was lower correlation between thalamic volume and intrahemispheric cortico-cortical connectivity, including the inferior longitudinal fasciculus and inferior frontal orbital fasciculus. This study shows distinct temporal overlap in the disruption of thalamo-cortical and interhemispheric cortico-cortical connectivity in preterm infants suggesting developmental synergy between thalamic morphology and the emergence of cortical networks in the last trimester. PMID:26106571

  15. Dystonia after striatopallidal and thalamic stroke: clinicoradiological correlations and pathophysiological mechanisms

    PubMed Central

    Krystkowiak, P; Martinat, P; Defebvre, L; Pruvo, J; Leys, D; Destee, A

    1998-01-01

    OBJECTIVE—To establish the pathophysiological mechanisms of striatopallidal and thalamic dystonia.
METHODS—Five patients from among 26 who presented (between March 1987 and July 1996) with focal dystonia, segmental dystonia, or hemidystonia caused by a single localised vascular lesion, were selected. Patients with lesions with indefinite boundaries, and diffuse, or multiple, or large brain lesions were excluded. Three dimensional T1 weighted MRI (1.5 tesla) was performed to determine the topography of the lesions. The atlas of Hassler allowed the stereotactic localisation of the lesions to be specified exactly.
RESULTS—Three patients had dystonic spasms associated with striatopallidal lesions and one with a thalamic and striatopallidal lesion. One other patient presented with a myoclonic dystonia related to a thalamic lesion. The striatopallidal lesions were located in the sensorimotor area with a somatotopical distribution. The pure thalamic lesion involved the centromedian nucleus, the sensory nuclei, and the pulvinar whereas the thalamic and striatopallidal lesion was located in the pallidonigral thalamic territory, which receives pallidonigral inputs.
CONCLUSION—The striatopallidal dystonia might be the consequence of the interruption of the cortico-striato-pallido-thalamo-cortical loop induced by lesions located within the sensorimotor part of the striatopallidal complex. By contrast, it is suggested that thalamic dystonia might be caused by lesions located in the centromedian or the ventral intermediate nuclei, outside the pallidonigral territory, but leading also to a dysfunction of the cort ico -striat o - pallido - thalamo - cort ica l loop.

 PMID:9810942

  16. Acute Pseudobulbar Palsy After Bilateral Paramedian Thalamic Infarction: A Case Report

    PubMed Central

    2016-01-01

    Bilateral paramedian thalamic infarction is a rare subtype of stroke caused by occlusion of the artery of Percheron, an uncommon variant originating from one of the posterior cerebral arteries. This type of stroke has several major clinical presentations: altered mental status, behavioral amnestic impairment, aphasia or dysarthria, ocular movement disorders, motor deficits, cerebellar signs, and others. Few cases of bilateral paramedian thalamic infarction-related pseudobulbar palsy characterized by dysarthria, dysphagia, and facial and tongue weakness have been reported. We report here a rare case of acute severe pseudobulbar palsy as a manifestation of bilateral paramedian thalamic infarction. PMID:27606284

  17. Thalamic Volume Is Reduced in Cervical and Laryngeal Dystonias

    PubMed Central

    Waugh, Jeff L.; Kuster, John K.; Levenstein, Jacob M.; Makris, Nikos; Multhaupt-Buell, Trisha J.; Sudarsky, Lewis R.; Breiter, Hans C.; Sharma, Nutan; Blood, Anne J.

    2016-01-01

    Background Dystonia, a debilitating movement disorder characterized by abnormal fixed positions and/or twisting postures, is associated with dysfunction of motor control networks. While gross brain lesions can produce secondary dystonias, advanced neuroimaging techniques have been required to identify network abnormalities in primary dystonias. Prior neuroimaging studies have provided valuable insights into the pathophysiology of dystonia, but few directly assessed the gross volume of motor control regions, and to our knowledge, none identified abnormalities common to multiple types of idiopathic focal dystonia. Methods We used two gross volumetric segmentation techniques and one voxelwise volumetric technique (voxel based morphometry, VBM) to compare regional volume between matched healthy controls and patients with idiopathic primary focal dystonia (cervical, n = 17, laryngeal, n = 7). We used (1) automated gross volume measures of eight motor control regions using the FreeSurfer analysis package; (2) blinded, anatomist-supervised manual segmentation of the whole thalamus (also gross volume); and (3) voxel based morphometry, which measures local T1-weighted signal intensity and estimates gray matter density or volume at the level of single voxels, for both whole-brain and thalamus. Results Using both automated and manual gross volumetry, we found a significant volume decrease only in the thalamus in two focal dystonias. Decreases in whole-thalamic volume were independent of head and brain size, laterality of symptoms, and duration. VBM measures did not differ between dystonia and control groups in any motor control region. Conclusions Reduced thalamic gross volume, detected in two independent analyses, suggests a common anatomical abnormality in cervical dystonia and spasmodic dysphonia. Defining the structural underpinnings of dystonia may require such complementary approaches. PMID:27171035

  18. Neuropsychological correlates of a right unilateral lacunar thalamic infarction

    PubMed Central

    Werf, Y; Weerts, J; Jolles, J; Witter, M; Lindeboom, J; Scheltens, P.

    1999-01-01

    OBJECTIVES—To report on a patient with a lacunar infarction in the right intralaminar nuclei of the thalamus. The role of the thalamic intralaminar nuclei in cognitive function is as yet insufficiently known. The patient described has shown signs of apathy and loss of initiative, in combination with cognitive deficits, which have persisted essentially unaltered up to the present day since an abrupt onset 17 years ago.
METHODS—High resolution MRI was performed to show the extent of the lesion; a combination of published and experimental neuropsychological techniques was administered to show the nature of the cognitive defects; Single photon emission computed tomography (SPECT) was employed to obtain a measure of cortical perfusion.
RESULTS—Brain MRI disclosed an isolated lacunar infarction in the dorsal caudal intralaminar nuclei of the thalamus. Neuropsychological evaluation indicated problems with attention and concentration, executive disturbances, and memory deficits both in the visual and verbal domains. The memory deficits could not be attributed to problems in the early stages of information processing, and are hence regarded as resulting from a failure of retrieval rather than encoding or storage. Brain SPECT disclosed a hypoperfusion of the right frontal cortex.
CONCLUSION—The data indicate that the cognitive profile is the result of a dysfunction of executive functions. This is corroborated by the finding of decreased blood flow in the right frontal cortex, and by evidence from the neuroanatomical literature. Thus the dysexecutive symptoms are thought to be caused by disconnection of the prefrontal cortex from the brainstem activating nuclei through the strategic localisation of the right thalamic infarction.

 PMID:9886448

  19. Dopamine and anorexia nervosa.

    PubMed

    Södersten, P; Bergh, C; Leon, M; Zandian, M

    2016-01-01

    We have suggested that reduced food intake increases the risk for anorexia nervosa by engaging mesolimbic dopamine neurons, thereby initially rewarding dieting. Recent fMRI studies have confirmed that dopamine neurons are activated in anorexia nervosa, but it is not clear whether this response is due to the disorder or to its resulting nutritional deficit. When the body senses the shortage of nutrients, it rapidly shifts behavior toward foraging for food as a normal physiological response and the mesolimbic dopamine neurons may be involved in that process. On the other hand, the altered dopamine status of anorexics has been suggested to result from a brain abnormality that underlies their complex emotional disorder. We suggest that the outcomes of the treatments that emerge from that perspective remain poor because they target the mental symptoms that are actually the consequences of the food deprivation that accompanies anorexia. On the other hand, a method that normalizes the disordered eating behavior of anorexics results in much better physiological, behavioral, and emotional outcomes.

  20. Multiple clusters of release sites formed by individual thalamic afferents onto cortical interneurons ensure reliable transmission.

    PubMed

    Bagnall, Martha W; Hull, Court; Bushong, Eric A; Ellisman, Mark H; Scanziani, Massimo

    2011-07-14

    Thalamic afferents supply the cortex with sensory information by contacting both excitatory neurons and inhibitory interneurons. Interestingly, thalamic contacts with interneurons constitute such a powerful synapse that even one afferent can fire interneurons, thereby driving feedforward inhibition. However, the spatial representation of this potent synapse on interneuron dendrites is poorly understood. Using Ca imaging and electron microscopy we show that an individual thalamic afferent forms multiple contacts with the interneuronal proximal dendritic arbor, preferentially near branch points. More contacts are correlated with larger amplitude synaptic responses. Each contact, consisting of a single bouton, can release up to seven vesicles simultaneously, resulting in graded and reliable Ca transients. Computational modeling indicates that the release of multiple vesicles at each contact minimally reduces the efficiency of the thalamic afferent in exciting the interneuron. This strategy preserves the spatial representation of thalamocortical inputs across the dendritic arbor over a wide range of release conditions.

  1. Characteristics of thalamic local field potentials in patients with disorders of consciousness.

    PubMed

    Huang, Yongzhi; He, Jianghong; Green, Alexander L; Aziz, Tipu Z; Stein, John F; Wang, Shouyan

    2015-08-01

    A functioning thalamus is essential for treatment of patients with disorders of consciousness (DOC) using deep brain stimulation (DBS). This work aims to identify the potential biomarkers related to consciousness from the thalamic deep brain local field potentials (LFPs) in DOC patients. The frequency features of central thalamic LFPs were characterized with spectral analysis. The features were further compared to those of LFPs from the ventroposterior lateral nucleus of the thalamus (VPL) in patients with pain. There are several distinct characteristics of thalamic LFPs found in patients with DOC. The most important feature is the oscillation around 10Hz which could be relevant to the existence of residual consciousness, whereas high power below 8Hz seemed to be associated with loss of consciousness. The invasive deep brain recording tool opens a unique way to explore the brain function in consciousness, awareness and alertness and clarify the potential mechanisms of thalamic stimulation in DOC.

  2. Prenatal thalamic waves regulate cortical area size prior to sensory processing.

    PubMed

    Moreno-Juan, Verónica; Filipchuk, Anton; Antón-Bolaños, Noelia; Mezzera, Cecilia; Gezelius, Henrik; Andrés, Belen; Rodríguez-Malmierca, Luis; Susín, Rafael; Schaad, Olivier; Iwasato, Takuji; Schüle, Roland; Rutlin, Michael; Nelson, Sacha; Ducret, Sebastien; Valdeolmillos, Miguel; Rijli, Filippo M; López-Bendito, Guillermina

    2017-02-03

    The cerebral cortex is organized into specialized sensory areas, whose initial territory is determined by intracortical molecular determinants. Yet, sensory cortical area size appears to be fine tuned during development to respond to functional adaptations. Here we demonstrate the existence of a prenatal sub-cortical mechanism that regulates the cortical areas size in mice. This mechanism is mediated by spontaneous thalamic calcium waves that propagate among sensory-modality thalamic nuclei up to the cortex and that provide a means of communication among sensory systems. Wave pattern alterations in one nucleus lead to changes in the pattern of the remaining ones, triggering changes in thalamic gene expression and cortical area size. Thus, silencing calcium waves in the auditory thalamus induces Rorβ upregulation in a neighbouring somatosensory nucleus preluding the enlargement of the barrel-field. These findings reveal that embryonic thalamic calcium waves coordinate cortical sensory area patterning and plasticity prior to sensory information processing.

  3. Fast cortical oscillation after thalamic degeneration: pivotal role of NMDA receptor.

    PubMed

    Kyuhou, Shin-ichi; Gemba, Hisae

    2007-04-27

    We examined electrophysiological and molecular changes of the thalamocortical system after thalamic degeneration in Purkinje cell degeneration (pcd) mice. In pcd mice, neurons in specific thalamic nuclei including the ventral medial geniculate nucleus began to degenerate around postnatal day 50, whereas the visual thalamic nucleus and nonspecific thalamic nuclei remained almost intact. In association with the morphological changes, auditory evoked potentials in the primary auditory cortex (AC) began to decrease gradually. Fast Fourier transform analysis of spontaneous cortical field potentials revealed that fast oscillation (FO) around 25 Hz occurred in the AC but not in the visual cortex. Quantitative mRNA analysis demonstrated that expression of the N-methyl-D-aspartate (NMDA) receptor was up-regulated in the AC but not in the visual cortex. Systemic administration of an NMDA antagonist abolished the FO in the AC. These results indicate that increased NMDA activity may cause the FO in the AC of pcd mice.

  4. Clinical and topographic magnetic resonance imaging characteristics of suspected thalamic infarcts in 16 dogs.

    PubMed

    Gonçalves, Rita; Carrera, Inés; Garosi, Laurent; Smith, Peter M; Fraser McConnell, J; Penderis, Jacques

    2011-04-01

    Sixteen dogs with acute-onset, non-progressive signs of brain dysfunction and magnetic resonance imaging (MRI) characteristics compatible with thalamic infarction are described. Topographically the MRI lesions could be grouped in three thalamic regions, namely, paramedian (8/16), extensive dorsal (5/16) and ventrolateral (3/16). Paramedian lesions resulted in signs typical of vestibular dysfunction. Extensive dorsal lesions were associated with vestibular ataxia, circling and contralateral menace response deficits. Ventrolateral lesions resulted in circling and contralateral proprioceptive deficits. In several dogs, regions other than the thalamus were also affected: four extended into the midbrain; six extended to the internal capsule, and two dogs had a second lesion in the cerebellum. Three clinical syndromes were identified in association with thalamic infarction. These signs varied somewhat, most likely because lesions were not confined to specific nuclear boundaries and involved different combinations of thalamic nuclei.

  5. Prenatal thalamic waves regulate cortical area size prior to sensory processing

    PubMed Central

    Moreno-Juan, Verónica; Filipchuk, Anton; Antón-Bolaños, Noelia; Mezzera, Cecilia; Gezelius, Henrik; Andrés, Belen; Rodríguez-Malmierca, Luis; Susín, Rafael; Schaad, Olivier; Iwasato, Takuji; Schüle, Roland; Rutlin, Michael; Nelson, Sacha; Ducret, Sebastien; Valdeolmillos, Miguel; Rijli, Filippo M.; López-Bendito, Guillermina

    2017-01-01

    The cerebral cortex is organized into specialized sensory areas, whose initial territory is determined by intracortical molecular determinants. Yet, sensory cortical area size appears to be fine tuned during development to respond to functional adaptations. Here we demonstrate the existence of a prenatal sub-cortical mechanism that regulates the cortical areas size in mice. This mechanism is mediated by spontaneous thalamic calcium waves that propagate among sensory-modality thalamic nuclei up to the cortex and that provide a means of communication among sensory systems. Wave pattern alterations in one nucleus lead to changes in the pattern of the remaining ones, triggering changes in thalamic gene expression and cortical area size. Thus, silencing calcium waves in the auditory thalamus induces Rorβ upregulation in a neighbouring somatosensory nucleus preluding the enlargement of the barrel-field. These findings reveal that embryonic thalamic calcium waves coordinate cortical sensory area patterning and plasticity prior to sensory information processing. PMID:28155854

  6. Thalamus parcellation using multi-modal feature classification and thalamic nuclei priors

    PubMed Central

    Glaister, Jeffrey; Carass, Aaron; Stough, Joshua V.; Calabresi, Peter A.; Prince, Jerry L.

    2016-01-01

    Segmentation of the thalamus and thalamic nuclei is useful to quantify volumetric changes from neurodegenerative diseases. Most thalamus segmentation algorithms only use T1-weighted magnetic resonance images and current thalamic parcellation methods require manual interaction. Smaller nuclei, such as the lateral and medial geniculates, are challenging to locate due to their small size. We propose an automated segmentation algorithm using a set of features derived from diffusion tensor image (DTI) and thalamic nuclei location priors. After extracting features, a hierarchical random forest classifier is trained to locate the thalamus. A second random forest classifies thalamus voxels as belonging to one of six thalamic nuclei classes. The proposed algorithm was tested using a leave-one-out cross validation scheme and compared with state-of-the-art algorithms. The proposed algorithm has a higher Dice score compared to other methods for the whole thalamus and several nuclei. PMID:27582600

  7. Thinking "Inside" the Box

    ERIC Educational Resources Information Center

    Jeffries, Carolyn

    2011-01-01

    The authors conducted a test to determine whether they could incorporate a discovery box into a preschool setting was successful. It stimulated the students' natural inquiry processes while promoting understanding of healthy foods and allowing for practice of fine-motor skills. It was easily incorporated into the curriculum and classroom space.…

  8. Drawing inside the Box

    ERIC Educational Resources Information Center

    Franklin, Ranella

    2007-01-01

    When working with very young children and/or students with special needs, it is beneficial for teachers to think "outside the box" in order to preserve and enhance a child's natural curiosity. In an effort to teach young children to control their drawing tools, they are often presented with coloring book-type pages and instructed to "stay inside…

  9. EPA ExpoBox

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases, mode

  10. Mystery Box Marvels

    ERIC Educational Resources Information Center

    Santos, Joel; Centurio, Tina

    2012-01-01

    What happens in the first week of school could very well set the stage for the rest of the school year. Setting high standards for science activities based in inquiry can start on the first day of science class and develop as the year unfolds. With the use of simple, readily available, inexpensive materials, an efficient mystery box lesson can be…

  11. The Idea Box.

    ERIC Educational Resources Information Center

    National Association for the Education of Young Children, Washington, DC.

    Five pamphlets offer helpful ideas and instructions on teacher planning, learning environments, teaching with nature, a creative curriculum, and ideas for administrators in "The Idea Box," compiled by members of the Austin Association for the Education of Young Children. Each pamphlet contains useful information for working with young children.…

  12. Shoe Box Circuits

    ERIC Educational Resources Information Center

    Sandifer, Cody

    2009-01-01

    Students' eyes grow wide with wonder as they get a motor to work or make a bulb light for the first time. As these daunting feats of electrical engineering remind us, teaching electricity is invariably rewarding and worthwhile. In this inquiry-based science project, elementary students work in pairs to design and wire a shoe box "room" that meets…

  13. Teaching with Box Tops.

    ERIC Educational Resources Information Center

    Raiser, Lynne; D'Zamko, Mary Elizabeth

    1984-01-01

    Using environmental materials (such as the phone book and placemats from fast food restaurants) can be a motivating way to teach learning disabled students skills and concepts, as shown in an approach to reading, math, science and nutrition, and social studies instruction using a JELL-O brand gelatin box. (CL)

  14. Hydrophobic, Porous Battery Boxes

    NASA Technical Reports Server (NTRS)

    Bragg, Bobby J.; Casey, John E., Jr.

    1995-01-01

    Boxes made of porous, hydrophobic polymers developed to contain aqueous potassium hydroxide electrolyte solutions of zinc/air batteries while allowing air to diffuse in as needed for operation. Used on other types of batteries for in-cabin use in which electrolytes aqueous and from which gases generated during operation must be vented without allowing electrolytes to leak out.

  15. Cereal Box Totems.

    ERIC Educational Resources Information Center

    Jones, AnnMarie

    2002-01-01

    Presents a multicultural project used with fourth-grade students in which they created a three-dimensional totem pole using leftover cereal boxes. Discusses in detail how to create the totem pole. Explains that students learned about Northwest American Indians in class. (CMK)

  16. "Can" the Black Box

    ERIC Educational Resources Information Center

    Lestingi, Francis S.

    1975-01-01

    Describes the use of the "Arcane (mysterious) Can" which is a "tin" can which is permanently sealed, both air- and water-tight, by means of a home canning device. The canning procedure permits the use of a large variety of materials which can not be utilized in the ordinary mystery box. This Can activity is valuable for…

  17. Looking Southwest at Reactor Box Furnaces With Reactor Boxes and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking Southwest at Reactor Box Furnaces With Reactor Boxes and Repossessed Uranium in Recycle Recovery Building - Hematite Fuel Fabrication Facility, Recycle Recovery Building, 3300 State Road P, Festus, Jefferson County, MO

  18. 6. VIEW OF INTERIOR GLOVE BOX DURING CONSTRUCTION. GLOVE BOXES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF INTERIOR GLOVE BOX DURING CONSTRUCTION. GLOVE BOXES CONTAINED ALL PRODUCTION OPERATIONS AND WERE INTERCONNECTED BY CONVEYORS. (9/21/59) - Rocky Flats Plant, Plutonium Fabrication, Central section of Plant, Golden, Jefferson County, CO

  19. Dissociable spatial and non-spatial attentional deficits after circumscribed thalamic stroke.

    PubMed

    Kraft, Antje; Irlbacher, Kerstin; Finke, Kathrin; Kaufmann, Christian; Kehrer, Stefanie; Liebermann, Daniela; Bundesen, Claus; Brandt, Stephan A

    2015-03-01

    Thalamic nuclei act as sensory, motor and cognitive relays between multiple subcortical areas and the cerebral cortex. They play a crucial role in cognitive functions such as executive functioning, memory and attention. In the acute period after thalamic stroke attentional deficits are common. The precise functional relevance of specific nuclei or vascular sub regions of the thalamus for attentional sub functions is still unclear. The theory of visual attention (TVA) allows the measurement of four independent attentional parameters (visual short term memory storage capacity (VSTM), visual perceptual processing speed, selective control and spatial weighting). We combined parameter-based assessment based on TVA with lesion symptom mapping in standard stereotactic space in sixteen patients (mean age 41.2 ± 11.0 SD, 6 females), with focal thalamic lesions in the medial (N = 9), lateral (N = 5), anterior (N = 1) or posterior (N = 1) vascular territories of the thalamus. Compared with an age-matched control group of 52 subjects (mean age 40.1 ± 6.4, 35 females), the patients with thalamic lesions were, on the group level, mildly impaired in visual processing speed and VSTM. Patients with lateral thalamic lesions showed a deficit in processing speed while all other TVA parameters were within the normal range. Medial thalamic lesions can be associated with a spatial bias and extinction of targets either in the ipsilesional or the contralesional field. A posterior case with a thalamic lesion of the pulvinar replicated a finding of Habekost and Rostrup (2006), demonstrating a spatial bias to the ipsilesional field, as suggested by the neural theory of visual attention (NTVA) (Bundesen, Habekost, & Kyllingsbæk, 2011). A case with an anterior-medial thalamic lesion showed reduced selective attentional control. We conclude that lesions in distinct vascular sub regions of the thalamus are associated with distinct attentional syndromes (medial = spatial bias, lateral

  20. Ocular complications of boxing

    PubMed Central

    Bianco, M; Vaiano, A; Colella, F; Coccimiglio, F; Moscetti, M; Palmieri, V; Focosi, F; Zeppilli, P; Vinger, P

    2005-01-01

    Objectives: To investigate the prevalence of ocular injuries in a large population of boxers over a period of 16 years, in particular, the most severe lesions that may be vision threatening. Methods: Clinical records of the medical archive of the Italian Boxing Federation were analysed. A total of 1032 boxers were examined from February 1982 to October 1998. A complete ophthalmological history was available for 956, who formed the study population (a total of 10 697 examinations). The following data were collected: age when started boxing; duration of competitive boxing career (from the date of the first bout); weight category; a thorough ocular history. The following investigations were carried out: measurement of visual acuity and visual fields, anterior segment inspection, applanation tonometry, gonioscopy, and examination of ocular fundus. Eighty age matched healthy subjects, who had never boxed, formed the control group. Results: Of the 956 boxers examined, 428 were amateur (44.8%) and 528 professional (55.2%). The median age at first examination was 23.1 (4.3) years (range 15–36). The prevalence of conjunctival, corneal, lenticular, vitreal, ocular papilla, and retinal alterations in the study population was 40.9% compared with 3.1% in the control group (p⩽0.0001). The prevalence of serious ocular findings (angle, lens, macula, and peripheral retina alterations) was 5.6% in boxers and 3.1% in controls (NS). Conclusions: Boxing does not result in a higher prevalence of severe ocular lesions than in the general population. However, the prevalence of milder lesions (in particular with regard to the conjunctiva and cornea) is noteworthy, justifying the need for adequate ophthalmological surveillance. PMID:15665199

  1. Why do lesions in the rodent anterior thalamic nuclei cause such severe spatial deficits?

    PubMed

    Aggleton, John P; Nelson, Andrew J D

    2015-07-01

    Lesions of the rodent anterior thalamic nuclei cause severe deficits to multiple spatial learning tasks. Possible explanations for these effects are examined, with particular reference to T-maze alternation. Anterior thalamic lesions not only impair allocentric place learning but also disrupt other spatial processes, including direction learning, path integration, and relative length discriminations, as well as aspects of nonspatial learning, e.g., temporal discriminations. Working memory tasks, such as T-maze alternation, appear particularly sensitive as they combine an array of these spatial and nonspatial demands. This sensitivity partly reflects the different functions supported by individual anterior thalamic nuclei, though it is argued that anterior thalamic lesion effects also arise from covert pathology in sites distal to the thalamus, most critically in the retrosplenial cortex and hippocampus. This two-level account, involving both local and distal lesion effects, explains the range and severity of the spatial deficits following anterior thalamic lesions. These findings highlight how the anterior thalamic nuclei form a key component in a series of interdependent systems that support multiple spatial functions.

  2. Selective importance of the rat anterior thalamic nuclei for configural learning involving distal spatial cues.

    PubMed

    Dumont, Julie R; Amin, Eman; Aggleton, John P

    2014-01-01

    To test potential parallels between hippocampal and anterior thalamic function, rats with anterior thalamic lesions were trained on a series of biconditional learning tasks. The anterior thalamic lesions did not disrupt learning two biconditional associations in operant chambers where a specific auditory stimulus (tone or click) had a differential outcome depending on whether it was paired with a particular visual context (spot or checkered wall-paper) or a particular thermal context (warm or cool). Likewise, rats with anterior thalamic lesions successfully learnt a biconditional task when they were reinforced for digging in one of two distinct cups (containing either beads or shredded paper), depending on the particular appearance of the local context on which the cup was placed (one of two textured floors). In contrast, the same rats were severely impaired at learning the biconditional rule to select a specific cup when in a particular location within the test room. Place learning was then tested with a series of go/no-go discriminations. Rats with anterior thalamic nuclei lesions could learn to discriminate between two locations when they were approached from a constant direction. They could not, however, use this acquired location information to solve a subsequent spatial biconditional task where those same places dictated the correct choice of digging cup. Anterior thalamic lesions produced a selective, but severe, biconditional learning deficit when the task incorporated distal spatial cues. This deficit mirrors that seen in rats with hippocampal lesions, so extending potential interdependencies between the two sites.

  3. Why do lesions in the rodent anterior thalamic nuclei cause such severe spatial deficits?

    PubMed Central

    Aggleton, John P.; Nelson, Andrew J.D.

    2015-01-01

    Lesions of the rodent anterior thalamic nuclei cause severe deficits to multiple spatial learning tasks. Possible explanations for these effects are examined, with particular reference to T-maze alternation. Anterior thalamic lesions not only impair allocentric place learning but also disrupt other spatial processes, including direction learning, path integration, and relative length discriminations, as well as aspects of nonspatial learning, e.g., temporal discriminations. Working memory tasks, such as T-maze alternation, appear particularly sensitive as they combine an array of these spatial and nonspatial demands. This sensitivity partly reflects the different functions supported by individual anterior thalamic nuclei, though it is argued that anterior thalamic lesion effects also arise from covert pathology in sites distal to the thalamus, most critically in the retrosplenial cortex and hippocampus. This two-level account, involving both local and distal lesion effects, explains the range and severity of the spatial deficits following anterior thalamic lesions. These findings highlight how the anterior thalamic nuclei form a key component in a series of interdependent systems that support multiple spatial functions. PMID:25195980

  4. Selective importance of the rat anterior thalamic nuclei for configural learning involving distal spatial cues

    PubMed Central

    Dumont, Julie R; Amin, Eman; Aggleton, John P

    2013-01-01

    To test potential parallels between hippocampal and anterior thalamic function, rats with anterior thalamic lesions were trained on a series of biconditional learning tasks. The anterior thalamic lesions did not disrupt learning two biconditional associations in operant chambers where a specific auditory stimulus (tone or click) had a differential outcome depending on whether it was paired with a particular visual context (spot or checkered wall-paper) or a particular thermal context (warm or cool). Likewise, rats with anterior thalamic lesions successfully learnt a biconditional task when they were reinforced for digging in one of two distinct cups (containing either beads or shredded paper), depending on the particular appearance of the local context on which the cup was placed (one of two textured floors). In contrast, the same rats were severely impaired at learning the biconditional rule to select a specific cup when in a particular location within the test room. Place learning was then tested with a series of go/no-go discriminations. Rats with anterior thalamic nuclei lesions could learn to discriminate between two locations when they were approached from a constant direction. They could not, however, use this acquired location information to solve a subsequent spatial biconditional task where those same places dictated the correct choice of digging cup. Anterior thalamic lesions produced a selective, but severe, biconditional learning deficit when the task incorporated distal spatial cues. This deficit mirrors that seen in rats with hippocampal lesions, so extending potential interdependencies between the two sites. PMID:24215178

  5. Changes in Activity of the Same Thalamic Neurons to Repeated Nociception in Behaving Mice.

    PubMed

    Huh, Yeowool; Cho, Jeiwon

    2015-01-01

    The sensory thalamus has been reported to play a key role in central pain sensory modulation and processing, but its response to repeated nociception at thalamic level is not well known. Current study investigated thalamic response to repeated nociception by recording and comparing the activity of the same thalamic neuron during the 1st and 2nd formalin injection induced nociception, with a week interval between injections, in awake and behaving mice. Behaviorally, the 2nd injection induced greater nociceptive responses than the 1st. Thalamic activity mirrored these behavioral changes with greater firing rate during the 2nd injection. Analysis of tonic and burst firing, characteristic firing pattern of thalamic neurons, revealed that tonic firing activity was potentiated while burst firing activity was not significantly changed by the 2nd injection relative to the 1st. Likewise, burst firing property changes, which has been consistently associated with different phases of nociception, were not induced by the 2nd injection. Overall, data suggest that repeated nociception potentiated responsiveness of thalamic neurons and confirmed that tonic firing transmits nociceptive signals.

  6. Damage to the dorsomedial thalamic nucleus, central lateral intralaminar thalamic nucleus, and midline thalamic nuclei on the right-side impair executive function and attention under conditions of high demand but not low demand.

    PubMed

    Edelstyn, N M J; Mayes, A R; Ellis, S J

    2014-04-01

    This study reports a patient, OG, with a unilateral right-sided thalamic lesion. High resolution 3T magnetic resonance imaging revealed damage to the parvicellular and magnocellular subdivisions of the dorsomedial thalamus (DMT), the central lateral intralaminar nucleus (also known as the paralamellar DMT), the paraventricular and the central medial midline thalamic nuclei. According to the neuropsychological literature, the DMT, the midline and intralaminar thalamic nuclei influence a wide array of cognitive functions by virtue of their modulatory influences on executive function and attention, and this is particularly indicated under conditions of low arousal or high cognitive demand. We explored this prediction in OG, and compared his performance on a range of low and high demand versions of tests that tapped executive function and attention to a group of 6 age- and IQ-matched controls. OG, without exception, significantly under performed on the high-demand attention and executive function tasks, but performed normally on the low-demand versions. These findings extend and refine current understanding of the effects of thalamic lesion on attention and executive function.

  7. Growth of dopamine crystals

    NASA Astrophysics Data System (ADS)

    Patil, Vidya; Patki, Mugdha

    2016-05-01

    Many nonlinear optical (NLO) crystals have been identified as potential candidates in optical and electro-optical devices. Use of NLO organic crystals is expected in photonic applications. Hence organic nonlinear optical materials have been intensely investigated due to their potentially high nonlinearities, and rapid response in electro-optic effect compared to inorganic NLO materials. There are many methods to grow organic crystals such as vapor growth method, melt growth method and solution growth method. Out of these methods, solution growth method is useful in providing constraint free crystal. Single crystals of Dopamine have been grown by evaporating the solvents from aqueous solution. Crystals obtained were of the size of orders of mm. The crystal structure of dopamine was determined using XRD technique. Images of crystals were obtained using FEG SEM Quanta Series under high vacuum and low KV.

  8. Updating dopamine reward signals

    PubMed Central

    Schultz, Wolfram

    2013-01-01

    Recent work has advanced our knowledge of phasic dopamine reward prediction error signals. The error signal is bidirectional, reflects well the higher order prediction error described by temporal difference learning models, is compatible with model-free and model-based reinforcement learning, reports the subjective rather than physical reward value during temporal discounting and reflects subjective stimulus perception rather than physical stimulus aspects. Dopamine activations are primarily driven by reward, and to some extent risk, whereas punishment and salience have only limited activating effects when appropriate controls are respected. The signal is homogeneous in terms of time course but heterogeneous in many other aspects. It is essential for synaptic plasticity and a range of behavioural learning situations. PMID:23267662

  9. Hermit Points on a Box

    ERIC Educational Resources Information Center

    Hess, Richard; Grinstead, Charles; Grindstead, Marshall; Bergstrand, Deborah

    2008-01-01

    Suppose that we are given a rectangular box in 3-space. Given any two points on the surface of this box, we can define the surface distance between them to be the length of the shortest path between them on the surface of the box. This paper determines the pairs of points of maximum surface distance for all boxes. It is often the case that these…

  10. Making Connections with Memory Boxes.

    ERIC Educational Resources Information Center

    Whatley, April

    2000-01-01

    Addresses the use of children's literature within the social studies classroom on the topic of memory boxes. Includes discussions of four books: (1) "The Littlest Angel" (Charles Tazewell); (2) "The Hundred Penny Box" (Sharon Bell Mathis); (3) "Wilfrid Gordon McDonald Partridge" (Mem Fox); and (4) "The Memory Box" (Mary Bahr). (CMK)

  11. Multicultural and Nonsexist Prop Boxes.

    ERIC Educational Resources Information Center

    Boutte, Gloria S.; And Others

    1996-01-01

    Discusses how prop boxes enhance learning and are resources in multicultural and nonsexist primary education, focusing on play, experimentation, and cooperation. Examines integration of prop boxes into the curricula and activities, and presents examples of generic and specific multicultural prop boxes that incorporate art, music, foods,…

  12. Stimulation of movement in a quiescent, hibernation-like form of Caenorhabditis elegans by dopamine signaling.

    PubMed

    Gaglia, Marta Maria; Kenyon, Cynthia

    2009-06-03

    One of the characteristics of animals in hibernation is reduced behavioral activity. The Caenorhabditis elegans dauer state is a hibernation-like state of diapause that displays a dramatic reduction in spontaneous locomotion. A similar dauer-like quiescent state is produced in adults by relatively strong mutations in the insulin/IGF-1 receptor homolog daf-2. In this study, we show that mutations affecting the neurotransmitter dopamine, which regulates voluntary movement in many organisms, can stimulate movement in dauers and dauer-like quiescent adults. Surprisingly, the movement of quiescent animals is stimulated by conditions that reduce dopamine signaling and also by conditions predicted to increase dopamine signaling. Reducing dopamine signaling is likely to stimulate movement by activating a foraging response also seen in nondauers after withdrawal of food. In contrast, the stimulation of movement by increased dopamine is much more pronounced in quiescent daf-2(-) dauer and dauer-like adult animals than in nondauaer animals. This altered response to dopamine is primarily attributable to activity of the FOXO (forkhead box O) transcription factor DAF-16 in neurons. We suggest that dauers and dauer-like quiescent adults may have underlying changes in the dopamine system that enable them to respond differently to environmental stimulation.

  13. Learning with Box Kernels.

    PubMed

    Melacci, Stefano; Gori, Marco

    2013-04-12

    Supervised examples and prior knowledge on regions of the input space have been profitably integrated in kernel machines to improve the performance of classifiers in different real-world contexts. The proposed solutions, which rely on the unified supervision of points and sets, have been mostly based on specific optimization schemes in which, as usual, the kernel function operates on points only. In this paper, arguments from variational calculus are used to support the choice of a special class of kernels, referred to as box kernels, which emerges directly from the choice of the kernel function associated with a regularization operator. It is proven that there is no need to search for kernels to incorporate the structure deriving from the supervision of regions of the input space, since the optimal kernel arises as a consequence of the chosen regularization operator. Although most of the given results hold for sets, we focus attention on boxes, whose labeling is associated with their propositional description. Based on different assumptions, some representer theorems are given which dictate the structure of the solution in terms of box kernel expansion. Successful results are given for problems of medical diagnosis, image, and text categorization.

  14. Learning with box kernels.

    PubMed

    Melacci, Stefano; Gori, Marco

    2013-11-01

    Supervised examples and prior knowledge on regions of the input space have been profitably integrated in kernel machines to improve the performance of classifiers in different real-world contexts. The proposed solutions, which rely on the unified supervision of points and sets, have been mostly based on specific optimization schemes in which, as usual, the kernel function operates on points only. In this paper, arguments from variational calculus are used to support the choice of a special class of kernels, referred to as box kernels, which emerges directly from the choice of the kernel function associated with a regularization operator. It is proven that there is no need to search for kernels to incorporate the structure deriving from the supervision of regions of the input space, because the optimal kernel arises as a consequence of the chosen regularization operator. Although most of the given results hold for sets, we focus attention on boxes, whose labeling is associated with their propositional description. Based on different assumptions, some representer theorems are given that dictate the structure of the solution in terms of box kernel expansion. Successful results are given for problems of medical diagnosis, image, and text categorization.

  15. In vivo electrophysiology of nigral and thalamic neurons in alpha-synuclein-overexpressing mice highlights differences from toxin-based models of parkinsonism

    PubMed Central

    Lobb, C. J.; Zaheer, A. K.; Smith, Y.

    2013-01-01

    Numerous studies have suggested that alpha-synuclein plays a prominent role in both familial and idiopathic Parkinson's disease (PD). Mice in which human alpha-synuclein is overexpressed (ASO) display progressive motor deficits and many nonmotor features of PD. However, it is unclear what in vivo pathophysiological mechanisms drive these motor deficits. It is also unknown whether previously proposed pathophysiological features (i.e., increased beta oscillations, bursting, and synchronization) described in toxin-based, nigrostriatal dopamine-depletion models are also present in ASO mice. To address these issues, we first confirmed that 5- to 6-mo-old ASO mice have robust motor dysfunction, despite the absence of significant nigrostriatal dopamine degeneration. In the same animals, we then recorded simultaneous single units and local field potentials (LFPs) in the substantia nigra pars reticulata (SNpr), the main basal ganglia output nucleus, and one of its main thalamic targets, the ventromedial nucleus, as well as LFPs in the primary motor cortex in anesthetized ASO mice and their age-matched, wild-type littermates. Neural activity was examined during slow wave activity and desynchronized cortical states, as previously described in 6-hydroxydopamine-lesioned rats. In contrast to toxin-based models, we found a small decrease, rather than an increase, in beta oscillations in the desynchronized state. Similarly, synchronized burst firing of nigral neurons observed in toxin-based models was not observed in ASO mice. Instead, we found more subtle changes in pauses of SNpr firing compared with wild-type control mice. Our results suggest that the pathophysiology underlying motor dysfunction in ASO mice is distinctly different from striatal dopamine-depletion models of parkinsonism. PMID:24068758

  16. Improvement of Learning and Increase in Dopamine Level in the Frontal Cortex by Methylphenidate in Mice Lacking Dopamine Transporter

    PubMed Central

    Takamatsu, Y.; Hagino, Y.; Sato, A.; Takahashi, T.; Nagasawa, S.Y.; Kubo, Y.; Mizuguchi, M.; Uhl, G.R.; Sora, I.; Ikeda, K.

    2015-01-01

    The symptoms of attention-deficit/hyperactivity disorder (ADHD) are characterized by inattention and hyperactivity-impulsivity. It is a common childhood neurodevelopmental disorder that often persists into adulthood. Improvements in ADHD symptoms using psychostimulants have been recognized as a paradoxical calming effect. The psychostimulant methylphenidate (MPH) is currently used as the first-line medication for the management of ADHD. Recent studies have drawn attention to altered dopamine-mediated neurotransmission in ADHD, particularly reuptake by the dopamine transporter (DAT). This hypothesis is supported by the observation that DAT knockout mice exhibit marked hyperactivity that is responsive to acute MPH treatment. However, other behaviors relevant to ADHD have not been fully clarified. In the present study, we observed learning impairment in shuttle-box avoidance behavior together with hyperactivity in a novel environment in DAT knockout mice. Methylphenidate normalized these behaviors and enhanced escape activity in the tail suspension test. Interestingly, the effective dose of MPH increased extracellular dopamine in the prefrontal cortex but not striatum, suggesting an important role for changes in prefrontal dopamine in ADHD. Research that uses rodent models such as DAT knockout mice may be useful for elucidating the pathophysiology of ADHD. PMID:25817856

  17. 'Distorteidolias' - fantastic perceptive distortion. A new, pure dorsomedial thalamic syndrome.

    PubMed

    Delgado, Montserrat G; Bogousslavsky, Julien

    2013-01-01

    The role of the thalamus in the pathogenesis of the visual and auditory hallucinations has been reported under the name of peduncular hallucinosis, usually with coexisting midbrain involvement. These hallucinations typically take the form of dreamy de novo productions (phanteidolias), less often that of transformations of perceptions into new items (such as seeing faces in clouds) called pareidolias. However, hallucinations taking the form of a complex distortion of perception is a different phenomenon, which to our knowledge has not been reported. We studied 2 patients with complex, 'fantastic', perceptive distortion involving the visual and auditory systems after thalamic stroke limited to the region of the dorsomedial nucleus, sparing the intralaminar nuclei and the midbrain (explaining the lack of disorders of consciousness and confusional state). Our patients reported the modification of usual stimuli (face, body, voices) into unreal, fantastically distorted perceptions (monstrous change of shapes or sounds without appearance of new items). While the exact mechanism leading to such perceptive distortions remains unknown, a release phenomenon due to damage to the dorsomedial thalamus (probably affecting cholinergic system) responsible for a disinhibition of cortical function involved in familiarity of perception seems likely. We suggest that these hallucinations should be called 'distorteidolias'.

  18. Intralaminar and medial thalamic influence on cortical synchrony, information transmission and cognition

    PubMed Central

    Saalmann, Yuri B.

    2014-01-01

    The intralaminar and medial thalamic nuclei are part of the higher-order thalamus, which receives little sensory input, and instead forms extensive cortico-thalamo-cortical pathways. The large mediodorsal thalamic nucleus predominantly connects with the prefrontal cortex, the adjacent intralaminar nuclei connect with fronto-parietal cortex, and the midline thalamic nuclei connect with medial prefrontal cortex and medial temporal lobe. Taking into account this connectivity pattern, it is not surprising that the intralaminar and medial thalamus has been implicated in a variety of cognitive functions, including memory processing, attention and orienting, as well as reward-based behavior. This review addresses how the intralaminar and medial thalamus may regulate information transmission in cortical circuits. A key neural mechanism may involve intralaminar and medial thalamic neurons modulating the degree of synchrony between different groups of cortical neurons according to behavioral demands. Such a thalamic-mediated synchronization mechanism may give rise to large-scale integration of information across multiple cortical circuits, consequently influencing the level of arousal and consciousness. Overall, the growing evidence supports a general role for the higher-order thalamus in the control of cortical information transmission and cognitive processing. PMID:24847225

  19. Pure amnesia after unilateral left polar thalamic infarct: topographic and sequential neuropsychological and metabolic (PET) correlations.

    PubMed Central

    Clarke, S; Assal, G; Bogousslavsky, J; Regli, F; Townsend, D W; Leenders, K L; Blecic, S

    1994-01-01

    A 54-year-old patient who had an isolated small polar thalamic infarct and acute global amnesia with slight frontal type dysfunction but without other neurological dysfunction was studied. Memory improved partially within 8 months. At all stages the impairment was more severe for verbal than non-verbal memory. Autobiographic recollections and newly acquired information tended to be disorganised with respect to temporal order. Procedural memory was unaffected. Both emotional involvement and pleasure in reading were lost. On MRI, the infarct was limited to the left anterior thalamic nuclei and the adjacent mamillothalamic tract. The regional cerebral metabolic rate of glucose (measured with PET) was decreased on the left in the thalamus, amygdala, and posterior cingulate cortex 2 weeks after the infarct, and in the thalamus and posterior cingulate cortex 9 months later. These findings stress the specific role of the left anterior thalamic region in memory and confirm that longlasting amnesia from a thalamic lesion can occur without significant structural damage to the dorsomedial nucleus. Furthermore, they suggest that the anterior thalamic nuclei and possibly their connections with the posterior cingulate cortex play a role in emotional involvement linked to ipsilateral hemispheric functions. Images PMID:8301301

  20. Neuromodulation of the inferior thalamic peduncle for major depression and obsessive compulsive disorder.

    PubMed

    Jiménez, F; Velasco, F; Salín-Pascual, R; Velasco, M; Nicolini, H; Velasco, A L; Castro, G

    2007-01-01

    Neuromodulation of the inferior thalamic peduncle is a new surgical treatment for major depression and obsessive-compulsive disorder. The inferior thalamic peduncle is a bundle of fibers connecting the orbito-frontal cortex with the non-specific thalamic system in a small area behind the fornix and anterior to the polar reticular thalamic nucleus. Electrical stimulation elicits characteristic frontal cortical responses (recruiting responses and direct current (DC)-shift) that confirm correct localization of this anatomical structure. A female with depression for 23 years and a male with obsessive-compulsive disorder for 9 years had stereotactic implantation of electrodes in the inferior thalamic peduncle and were evaluated over a long-term period. Initial OFF stimulation period (1 month) showed no consistent changes in the Hamilton Depression Scale (HAM-D), Yale Brown Obsessive Compulsive Scale (YBOCS), or Global Assessment of Functioning scale (GAF). The ON stimulation period (3-5 V, 130-Hz frequency, 450-msec pulse width in a continuous program) showed significant decrease in depression, obsession, and compulsion symptoms. GAF improved significantly in both cases. The neuropsychological tests battery showed no significant changes except from a reduction in the perseverative response of the obsessive-compulsive patient and better performance in manual praxias of the female depressive patient. Moderate increase in weight (5 kg on average) was observed in both cases.

  1. REDUCED THALAMIC VOLUME IN PRETERM INFANTS IS ASSOCIATED WITH ABNORMAL WHITE MATTER METABOLISM INDEPENDENT OF INJURY

    PubMed Central

    Wisnowski, Jessica L.; Ceschin, Rafael C.; Choi, So Young; Schmithorst, Vincent J.; Painter, Michael J.; Nelson, Marvin D.; Blüml, Stefan; Panigrahy, Ashok

    2015-01-01

    Introduction Altered thalamocortical development is hypothesized to be a key substrate underlying neurodevelopmental disabilities in preterm infants. However, the pathogenesis of this abnormality is not well-understood. We combined magnetic resonance spectroscopy of the parietal white matter and morphometric analyses of the thalamus to investigate the association between white matter metabolism and thalamic volume and tested the hypothesis that thalamic volume would be associated with diminished N-acetyl-aspartate (NAA), a measure of neuronal/axonal maturation, independent of white matter injury. Methods Data from 106 preterm infants (mean gestational age at birth: 31.0 weeks ± 4.3; range 23–36 weeks) who underwent MR examinations under clinical indications were included in this study. Results Linear regression analyses demonstrated a significant association between parietal white matter NAA concentration and thalamic volume. This effect was above and beyond the effect of white matter injury and age at MRI and remained significant even when preterm infants with punctate white matter lesions (pWMLs) were excluded from the analysis. Furthermore, choline, and amongst the preterm infants without pWMLs, lactate concentrations were also associated with thalamic volume. Of note, the associations between NAA and choline concentration and thalamic volume remained significant even when the sample was restricted to neonates who were term-equivalent age or older. Conclusion These observations provide convergent evidence of a neuroimaging phenotype characterized by widespread abnormal thalamocortical development and suggest that the pathogenesis may involve impaired axonal maturation. PMID:25666231

  2. Differential impact of thalamic versus subthalamic deep brain stimulation on lexical processing.

    PubMed

    Krugel, Lea K; Ehlen, Felicitas; Tiedt, Hannes O; Kühn, Andrea A; Klostermann, Fabian

    2014-10-01

    Roles of subcortical structures in language processing are vague, but, interestingly, basal ganglia and thalamic Deep Brain Stimulation can go along with reduced lexical capacities. To deepen the understanding of this impact, we assessed word processing as a function of thalamic versus subthalamic Deep Brain Stimulation. Ten essential tremor patients treated with thalamic and 14 Parkinson׳s disease patients with subthalamic Deep Brain Stimulation performed an acoustic Lexical Decision Task ON and OFF stimulation. Combined analysis of task performance and event-related potentials allowed the determination of processing speed, priming effects, and N400 as neurophysiological correlate of lexical stimulus processing. 12 age-matched healthy participants acted as control subjects. Thalamic Deep Brain Stimulation prolonged word decisions and reduced N400 potentials. No comparable ON-OFF effects were present in patients with subthalamic Deep Brain Stimulation. In the latter group of patients with Parkinson' disease, N400 amplitudes were, however, abnormally low, whether under active or inactive Deep Brain Stimulation. In conclusion, performance speed and N400 appear to be influenced by state functions, modulated by thalamic, but not subthalamic Deep Brain Stimulation, compatible with concepts of thalamo-cortical engagement in word processing. Clinically, these findings specify cognitive sequels of Deep Brain Stimulation in a target-specific way.

  3. Differential effects of methylphenidate and cocaine on GABA transmission in sensory thalamic nuclei

    PubMed Central

    Goitia, Belén; Raineri, Mariana; González, Laura E.; Rozas, José L.; Garcia-Rill, Edgar; Bisagno, Verónica; Urbano, Francisco J.

    2013-01-01

    Methylphenidate (MPH) is widely used to treat children and adolescents diagnosed with attention deficit/hyperactivity disorder. Although MPH shares mechanistic similarities to cocaine, its effects on GABAergic transmission in sensory thalamic nuclei are unknown. Our aim was to compare cocaine and MPH effects on GABAergic projections between thalamic reticular and ventrobasal (VB) nuclei. Mice (P18-30) were subjected to binge-like cocaine and MPH acute and sub-chronic administrations. Cocaine and MPH enhanced hyperlocomotion, though sub-chronic cocaine-mediated effects were stronger than MPH effects. Cocaine and MPH sub-chronic administration altered paired-pulse and spontaneous GABAergic input differently. The effects of cocaine on evoked paired-pulse GABA-A mediated currents changed from depression to facilitation with the duration of the protocols used, while MPH induced a constant increase throughout administration protocols. Thalamic reticular nucleus GAD67 and VB CaV3.1 protein levels were measured using Western blot in order to better understand their link to increased GABA release. Both proteins were increased by sub-chronic administration of cocaine. These results suggest that cocaine and MPH produced distinct presynaptic alterations on GABAergic transmission. MPH showed effects on GABAergic transmission that seems less disruptive than cocaine. Unique effects of cocaine on postsynaptic VB calcium currents might explain deleterious cocaine effects on sensory thalamic nuclei. These results might help to understand the impact of MPH repetitive administration on sensory thalamic nuclei. PMID:23205768

  4. Effect of Spinal Cord Stimulation on Gait in a Patient with Thalamic Pain

    PubMed Central

    Shin, Masahiro; Ishi, Kazuhiko; Osumi, Michihiro; Katsuhira, Junji; Chiba, Ryosuke; Haga, Nobuhiko

    2016-01-01

    Thalamic pain is a central neuropathic pain disorder which occurs after stroke. Its severe chronic pain is often intractable to pharmacotherapies and affects the patients' activities of daily living (ADL) and quality of life (QOL). Recently, spinal cord stimulation (SCS) has been reported to be effective in relieving the pain of thalamic pain; however, the effect of SCS on gait performance in patients is unknown. Therefore, we evaluated the gait performance before and after SCS in a case with thalamic pain. A 73-year-old male with thalamic pain participated in this study. We evaluated the gait of the patient two times: before SCS insertion and after 6 days of SCS. At the second evaluation, we measured the gait in three conditions: stimulation off, comfortable stimulation, and strong stimulation. SCS succeeded in improving the pain from 7 to 2 on an 11-point numerical rating scale. Step frequency and the velocity of gait tended to increase between pre- and poststimulation periods. There were no apparent differences in gait among the three stimulation conditions (off, comfortable, and strong) at the poststimulation period. SCS may be effective on gait in patients with thalamic pain. PMID:27579198

  5. Small, Lightweight, Collapsible Glove Box

    NASA Technical Reports Server (NTRS)

    James, Jerry

    2009-01-01

    A small, lightweight, collapsible glove box enables its user to perform small experiments and other tasks. Originally intended for use aboard a space shuttle or the International Space Station (ISS), this glove box could also be attractive for use on Earth in settings in which work space or storage space is severely limited and, possibly, in which it is desirable to minimize weight. The development of this glove box was prompted by the findings that in the original space-shuttle or ISS setting, (1) it was necessary to perform small experiments in a large general-purpose work station, so that, in effect, they occupied excessive space; and it took excessive amounts of time to set up small experiments. The design of the glove box reflects the need to minimize the space occupied by experiments and the time needed to set up experiments, plus the requirement to limit the launch weight of the box and the space needed to store the box during transport into orbit. To prepare the glove box for use, the astronaut or other user has merely to insert hands through the two fabric glove ports in the side walls of the box and move two hinges to a locking vertical position (see figure). The user could do this while seated with the glove box on the user fs lap. When stowed, the glove box is flat and has approximately the thickness of two pieces of 8-in. (.20 cm) polycarbonate.

  6. Reticular thalamic responses to nociceptive inputs in anesthetized rats.

    PubMed

    Yen, Chen-Tung; Shaw, Fu-Zen

    2003-04-11

    The present study compares nociceptive responses of neurons in the reticular thalamic nucleus (RT) to those of the ventroposterior lateral nucleus (VPL). Extracellular single-unit activities of cells in the RT and VPL were recorded in anesthetized rats. Only units with identified tactile receptive fields in the forepaw or hindpaw were studied. In the first series of experiments, RT and VPL responses to pinching with a small artery clamp were tested with the rats under pentobarbital, urethane, ketamine, or halothane anesthesia. Under all types of anesthesia, many RT units were inhibited. Second, the specificity of the nociceptive response was tested by pinching and noxious heating of the unit's tactile receptive field. Of the 39 VPL units tested, 20 were excited by both types of noxious stimuli. In sharp contrast, of the 30 RT units tested, none were excited and 17 were inhibited. In a third series of experiments, low-intensity and beam-diffused CO(2) laser irradiation was used to activate peripheral nociceptive afferents. Wide-dynamic-range VPL units responded with short- and long-latency excitations. In contrast, RT units had short-latency excitation followed by long-latency inhibition. Nociceptive input inhibited RT units in less than 500 ms. We conclude that a significant portion of RT neurons were polysynaptically inhibited by nociceptive inputs. Since all the cells tested were excited by light tactile inputs, the somatosensory RT may serve in the role of a modality gate, which modifies (i.e. inhibits) tactile inputs while letting noxious inputs pass.

  7. Thalamic control of human attention driven by memory and learning.

    PubMed

    de Bourbon-Teles, José; Bentley, Paul; Koshino, Saori; Shah, Kushal; Dutta, Agneish; Malhotra, Paresh; Egner, Tobias; Husain, Masud; Soto, David

    2014-05-05

    The role of the thalamus in high-level cognition-attention, working memory (WM), rule-based learning, and decision making-remains poorly understood, especially in comparison to that of cortical frontoparietal networks [1-3]. Studies of visual thalamus have revealed important roles for pulvinar and lateral geniculate nucleus in visuospatial perception and attention [4-10] and for mediodorsal thalamus in oculomotor control [11]. Ventrolateral thalamus contains subdivisions devoted to action control as part of a circuit involving the basal ganglia [12, 13] and motor, premotor, and prefrontal cortices [14], whereas anterior thalamus forms a memory network in connection with the hippocampus [15]. This connectivity profile suggests that ventrolateral and anterior thalamus may represent a nexus between mnemonic and control functions, such as action or attentional selection. Here, we characterize the role of thalamus in the interplay between memory and visual attention. We show that ventrolateral lesions impair the influence of WM representations on attentional deployment. A subsequent fMRI study in healthy volunteers demonstrates involvement of ventrolateral and, notably, anterior thalamus in biasing attention through WM contents. To further characterize the memory types used by the thalamus to bias attention, we performed a second fMRI study that involved learning of stimulus-stimulus associations and their retrieval from long-term memory to optimize attention in search. Responses in ventrolateral and anterior thalamic nuclei tracked learning of the predictiveness of these abstract associations and their use in directing attention. These findings demonstrate a key role for human thalamus in higher-level cognition, notably, in mnemonic biasing of attention.

  8. Membrane Bistability in Thalamic Reticular Neurons During Spindle Oscillations

    PubMed Central

    Fuentealba, Pablo; Timofeev, Igor; Bazhenov, Maxim; Sejnowski, Terrence J.; Steriade, Mircea

    2010-01-01

    The thalamic reticular (RE) nucleus is a major source of inhibition in the thalamus. It plays a crucial role in regulating the excitability of thalamocortical networks and in generating some sleep rhythms. Current-clamp intracellular recordings of RE neurons in cats under barbiturate anesthesia revealed the presence of membrane bistability in ~20% of neurons. Bistability consisted of two alternate membrane potentials, separated by ~17–20 mV. While non-bistable (common) RE neurons fired rhythmic spike-bursts during spindles, bistable RE neurons fired tonically, with burst modulation, throughout spindle sequences. Bistability was strongly voltage dependent and only expressed under resting conditions (i.e. no current injection). The transition from the silent to the active state was a regenerative event that could be activated by brief depolarization, whereas brief hyperpolarizations could switch the membrane potential from the active to the silent state. These effects outlasted the current pulses. Corticothalamic stimulation could also switch the membrane potential from silent to active states. Addition of QX-314 in the recording micropipette either abolished or disrupted membrane bistability, suggesting INa(p) to be responsible for its generation. Thalamocortical cells presented various patterns of spindling that reflected the membrane bistability in RE neurons. Finally, experimental data and computer simulations predicted a role for RE neurons’ membrane bistability in inducing various patterns of spindling in target thalamocortical cells. We conclude that membrane bistability of RE neurons is an intrinsic property, likely generated by INa(p) and modulated by cortical influences, as well as a factor that determines different patterns of spindle rhythms in thalamocortical neurons. PMID:15331618

  9. Association between striatal dopamine D2/D3 receptors and brain activation during visual attention: effects of sleep deprivation

    PubMed Central

    Tomasi, D; Wang, G-J; Volkow, N D

    2016-01-01

    Sleep deprivation (SD) disrupts dopamine (DA) signaling and impairs attention. However, the interpretation of these concomitant effects requires a better understanding of dopamine's role in attention processing. Here we test the hypotheses that D2/D3 receptors (D2/D3R) in dorsal and ventral striatum would distinctly regulate the activation of attention regions and that, by decreasing D2/D3, SD would disrupt these associations. We measured striatal D2/D3R using positron emission tomography with [11C]raclopride and brain activation to a visual attention (VA) task using 4-Tesla functional magnetic resonance imaging. Fourteen healthy men were studied during rested wakefulness and also during SD. Increased D2/D3R in striatum (caudate, putamen and ventral striatum) were linearly associated with higher thalamic activation. Subjects with higher D2/D3R in caudate relative to ventral striatum had higher activation in superior parietal cortex and ventral precuneus, and those with higher D2/D3R in putamen relative to ventral striatum had higher activation in anterior cingulate. SD impaired the association between striatal D2/D3R and VA-induced thalamic activation, which is essential for alertness. Findings suggest a robust DAergic modulation of cortical activation during the VA task, such that D2/D3R in dorsal striatum counterbalanced the stimulatory influence of D2/D3R in ventral striatum, which was not significantly disrupted by SD. In contrast, SD disrupted thalamic activation, which did not show counterbalanced DAergic modulation but a positive association with D2/D3R in both dorsal and ventral striatum. The counterbalanced dorsal versus ventral striatal DAergic modulation of VA activation mirrors similar findings during sensorimotor processing (Tomasi et al., 2015) suggesting a bidirectional influence in signaling between the dorsal caudate and putamen and the ventral striatum. PMID:27219347

  10. Projection optics box

    DOEpatents

    Hale, Layton C.; Malsbury, Terry; Hudyma, Russell M.; Parker, John M.

    2000-01-01

    A projection optics box or assembly for use in an optical assembly, such as in an extreme ultraviolet lithography (EUVL) system using 10-14 nm soft x-ray photons. The projection optics box utilizes a plurality of highly reflective optics or mirrors, each mounted on a precision actuator, and which reflects an optical image, such as from a mask, in the EUVL system onto a point of use, such as a target or silicon wafer, the mask, for example, receiving an optical signal from a source assembly, such as a developed from laser system, via a series of highly reflective mirrors of the EUVL system. The plurality of highly reflective optics or mirrors are mounted in a housing assembly comprised of a series of bulkheads having wall members secured together to form a unit construction of maximum rigidity. Due to the precision actuators, the mirrors must be positioned precisely and remotely in tip, tilt, and piston (three degrees of freedom), while also providing exact constraint.

  11. Complexity of dopamine metabolism

    PubMed Central

    2013-01-01

    Parkinson’s disease (PD) coincides with a dramatic loss of dopaminergic neurons within the substantia nigra. A key player in the loss of dopaminergic neurons is oxidative stress. Dopamine (DA) metabolism itself is strongly linked to oxidative stress as its degradation generates reactive oxygen species (ROS) and DA oxidation can lead to endogenous neurotoxins whereas some DA derivatives show antioxidative effects. Therefore, DA metabolism is of special importance for neuronal redox-homeostasis and viability. In this review we highlight different aspects of dopamine metabolism in the context of PD and neurodegeneration. Since most reviews focus only on single aspects of the DA system, we will give a broader overview by looking at DA biosynthesis, sequestration, degradation and oxidation chemistry at the metabolic level, as well as at the transcriptional, translational and posttranslational regulation of all enzymes involved. This is followed by a short overview of cellular models currently used in PD research. Finally, we will address the topic from a medical point of view which directly aims to encounter PD. PMID:23683503

  12. 46 CFR 111.81-1 - Outlet boxes and junction boxes; general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Outlet boxes and junction boxes; general. 111.81-1... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Outlet Boxes and Junction Boxes § 111.81-1 Outlet boxes and junction boxes; general. (a) The requirements of this subpart apply to each outlet box used with a...

  13. Mediodorsal thalamic nucleus receives a direct retinal input in marmoset monkey (Callithrix jacchus): a subunit B cholera toxin study.

    PubMed

    de Sousa, Twyla Barros; de Santana, Melquisedec Abiaré Dantas; Silva, Alane de Medeiros; Guzen, Fausto Pierdoná; Oliveira, Francisco Gilberto; Cavalcante, Judney Cley; Cavalcante, Jeferson de Souza; Costa, Miriam Stela Maris Oliveira; Nascimento, Expedito Silva do

    2013-01-01

    The mediodorsal thalamic nucleus is a prominent nucleus in the thalamus, positioned lateral to the midline nuclei and medial to the intralaminar thalamic complex in the dorsal thalamus. Several studies identify the mediodorsal thalamic nucleus as a key structure in learning and memory, as well as in emotional mechanisms and alertness due to reciprocal connections with the limbic system and prefrontal cortex. Fibers from the retina to the mediodorsal thalamic nucleus have recently been described for the first time in a crepuscular rodent, suggesting a possible regulation of the mediodorsal thalamic nucleus by visual activity. The present study shows retinal afferents in the mediodorsal thalamic nucleus of a new world primate, the marmoset (Callithrix jacchus), using B subunit of cholera toxin (CTb) as an anterograde tracer. A small population of labeled retinofugal axonal arborizations is consistently labeled in small domains of the medial and lateral periphery of the caudal half of the mediodorsal nucleus. Retinal projections in the mediodorsal thalamic nucleus are exclusively contralateral and the morphology of the afferent endings was examined. Although the functional significance of this projection remains unknown, this retina-mediodorsal thalamic nucleus pathway may be involved in a wide possibility of functional implications.

  14. Mood disorder in a patient with a benign thalamic cystic lesion: a case report

    PubMed Central

    2013-01-01

    Introduction The thalamus is increasingly gaining importance in psychiatric disorders. There are case reports in the literature of neuropsychiatric symptoms associated with thalamic infarcts. The present report elucidates the complexities of linking neuropsychiatric symptoms to a benign thalamic brain lesion, and its impact on management. Case presentation We present the case of a Caucasian man in his early 30s, who presented with a difficult to treat bipolar illness and coexisting thalamic lesion. Conclusions In this report we explore the possible links between our patient’s symptoms and his brain lesion. We discuss the possible neuronal mechanisms that may be involved and debate the most appropriate management strategies. We hope this report will assist further insights into the role of the thalamus in psychiatric disorders. PMID:23594838

  15. T-Type Calcium Channels Mediate the Transition between Tonic and Phasic Firing in Thalamic Neurons

    NASA Astrophysics Data System (ADS)

    Suzuki, Setsuo; Rogawski, Michael A.

    1989-09-01

    Thalamic neurons undergo a shift from tonic to phasic (burst) firing upon hyperpolarization. This state transition results from deinactivation of a regenerative depolarizing event referred to as the low-threshold spike. Isolated adult guinea pig thalamic (dorsal lateral geniculate) neurons exhibited low-threshold spikes that could be blocked by low concentrations of nickel but were unaffected by the dihydropyridine nimodipine. Whole-cell voltage-clamp recordings from these cells demonstrated a low-threshold, rapidly inactivating (T) Ca2+ current that manifested similar voltage dependency and time course as the low-threshold spike. Like low-threshold spikes, the T-type Ca2+ current was eliminated by nickel but was unaffected by nimodipine. In thalamic neurons, T-type Ca2+ channels underlie the low-threshold spike and, therefore, play a critical role in regulating the firing pattern of these cells.

  16. The Classroom Animal: Box Turtles.

    ERIC Educational Resources Information Center

    Kramer, David C.

    1986-01-01

    Provides basic information on the anatomy, physiology, behaviors, and distribution patterns of the box turtle. Offers suggestions for the turtle's care and maintenance in a classroom environment. (ML)

  17. Dissociation of Recognition and Recency Memory Judgments After Anterior Thalamic Nuclei Lesions in Rats

    PubMed Central

    Dumont, Julie R.; Aggleton, John P.

    2013-01-01

    The anterior thalamic nuclei form part of a network for episodic memory in humans. The importance of these nuclei for recognition and recency judgments remains, however, unclear. Rats with anterior thalamic nuclei lesions and their controls were tested on object recognition, along with two types of recency judgment. The spontaneous discrimination of a novel object or a novel odor from a familiar counterpart (recognition memory) was not affected by anterior thalamic lesions when tested after retention delays of 1 and 60 min. To measure recency memory, rats were shown two familiar objects, one of which had been explored more recently. In one condition, rats were presented with two lists (List A, List B) of objects separated by a delay, thereby creating two distinct blocks of stimuli. After an additional delay, rats were presented with pairs of objects, one from List A and one from List B (between-block recency). No lesion-induced deficit was apparent for recency discriminations between objects from different lists, despite using three different levels of task difficulty. In contrast, rats with anterior thalamic lesions were significantly impaired when presented with a continuous list of objects and then tested on their ability to distinguish between those items early and late in the same list (within-block recency). The contrasting effects on recognition and recency support the notion that interlinked hippocampal–anterior thalamic interconnections support aspects of both spatial and nonspatial learning, although the role of the anterior thalamic nuclei may be restricted to a subclass of recency judgments (within-block). PMID:23731076

  18. Topographic organization of subcortical projections to the anterior thalamic nuclei in the rat.

    PubMed

    Shibata, H

    1992-09-01

    Subcortical projections to the anterior thalamic nuclei were studied in the rat, with special reference to projections from the mammillary nuclei, by retrograde and anterograde transport of wheat germ agglutinin conjugated to horseradish peroxidase. The medial mammillary nucleus (MM) projects predominantly ipsilaterally to the entire anterior thalamic nuclei, whereas the lateral mammillary nucleus projects bilaterally to the anterodorsal nucleus (AD) of the anterior thalamic nuclei. A topographic relationship was recognized between the MM and the anterior thalamic nuclei. The dorsal region of the pars mediana of the MM projects to the interanteromedial nucleus (IAM), whereas the ventral region projects to the rostral part of the anteromedial nucleus (AM). The dorsal and the ventral regions of the pars medialis project to the dorsomedial part of the AM at its caudal and rostral levels, respectively. The dorsomedial region of the pars lateralis projects to the ventral AM. The ventrolateral region of the pars lateralis projects to the ventral part of the anteroventral nucleus (AV) in such a manner that rostral cells project rostrally and caudal cells project caudally. The pars basalis projects predominantly ipsilaterally to the dorsolateral AV and bilaterally to the AD. The rostrolateral region of the pars posterior projects to the lateral AV, whereas the medial and the caudal regions of the pars posterior project to the dorsomedial AV. The rostrodorsal part of the nucleus reticularis thalami was found to project to the anterior thalamic nuclei; cells located rostrally in this part project to the IAM and AM, whereas cells located caudodorsally project to the AV and AD. The laterodorsal tegmental nucleus projects predominantly ipsilaterally to the AV, especially to its dorsolateral part. The present study demonstrates that subdivisions of the subcortical structures are connected to the subnuclei of the anterior thalamic nuclei, with a clear-cut topography arranged in

  19. Validation of connectivity-based thalamic segmentation with direct electrophysiologic recordings from human sensory thalamus.

    PubMed

    Elias, W Jeffrey; Zheng, Zhong A; Domer, Paul; Quigg, Mark; Pouratian, Nader

    2012-02-01

    Connectivity-based segmentation has been used to identify functional gray matter subregions that are not discernable on conventional magnetic resonance imaging. However, the accuracy and reliability of this technique has only been validated using indirect means. In order to provide direct electrophysiologic validation of connectivity-based thalamic segmentations within human subjects, we assess the correlation of atlas-based thalamic anatomy, connectivity-based thalamic maps, and somatosensory evoked thalamic potentials in two adults with medication-refractory epilepsy who were undergoing intracranial EEG monitoring with intrathalamic depth and subdural cortical strip electrodes. MRI with atlas-derived localization was used to delineate the anatomic boundaries of the ventral posterolateral (VPL) nucleus of the thalamus. Somatosensory evoked potentials with intrathalamic electrodes physiologically identified a discrete region of phase reversal in the ventrolateral thalamus. Finally, DTI was obtained so that probabilistic tractography and connectivity-based segmentation could be performed to correlate the region of thalamus linked to sensory areas of the cortex, namely the postcentral gyrus. We independently utilized these three different methods in a blinded fashion to localize the "sensory" thalamus, demonstrating a high-degree of reproducible correlation between electrophysiologic and connectivity-based maps of the thalamus. This study provides direct electrophysiologic validation of probabilistic tractography-based thalamic segmentation. Importantly, this study provides an electrophysiological basis for using connectivity-based segmentation to further study subcortical anatomy and physiology while also providing the clinical basis for targeting deep brain nuclei with therapeutic stimulation. Finally, these direct recordings from human thalamus confirm early inferences of a sensory thalamic component of the N18 waveform in somatosensory evoked potentials.

  20. Leading role of thalamic over cortical neurons during postinhibitory rebound excitation

    PubMed Central

    Grenier, F.; Timofeev, I.; Steriade, M.

    1998-01-01

    The postinhibitory rebound excitation is an intrinsic property of thalamic and cortical neurons that is implicated in a variety of normal and abnormal operations of neuronal networks, such as slow or fast brain rhythms during different states of vigilance as well as seizures. We used dual simultaneous intracellular recordings of thalamocortical neurons from the ventrolateral nucleus and neurons from the motor cortex, together with thalamic and cortical field potentials, to investigate the temporal relations between thalamic and cortical events during the rebound excitation that follows prolonged periods of stimulus-induced inhibition. Invariably, the rebound spike-bursts in thalamocortical cells occurred before the rebound depolarization in cortical neurons and preceded the peak of the depth-negative, rebound field potential in cortical areas. Also, the inhibitory-rebound sequences were more pronounced and prolonged in cortical neurons when elicited by thalamic stimuli, compared with cortical stimuli. The role of thalamocortical loops in the rebound excitation of cortical neurons was shown further by the absence of rebound activity in isolated cortical slabs. However, whereas thalamocortical neurons remained hyperpolarized after rebound excitation, because of the prolonged spike-bursts in inhibitory thalamic reticular neurons, the rebound depolarization in cortical neurons was prolonged, suggesting the role of intracortical excitatory circuits in this sustained activity. The role of intrathalamic events in triggering rebound cortical activity should be taken into consideration when analyzing information processes at the cortical level; at each step, corticothalamic volleys can set into action thalamic inhibitory neurons, leading to rebound spike-bursts that are transferred back to the cortex, thus modifying cortical activities. PMID:9811903

  1. 2. UPPER NOTTINGHAM MINE, WOODEN BOXES. BOXES ARE LOCATED APPROXIMATELY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. UPPER NOTTINGHAM MINE, WOODEN BOXES. BOXES ARE LOCATED APPROXIMATELY 10 YARDS TO THE RIGHT AND DOWNSLOPE OF THE ADIT IN ID-31-F-1. CAMERA IS POINTED EAST-SOUTHEAST. - Florida Mountain Mining Sites, Upper Nottingham Mine, West face of Florida Mountain, head of Jacobs Gulch, Silver City, Owyhee County, ID

  2. Apathy, cognitive dysfunction and impaired social cognition in a patient with bilateral thalamic infarction.

    PubMed

    Ioannidis, Anestis E; Kimiskidis, Vasilios K; Loukopoulou, Eleni; Geroukis, Triantafyllos; Vlaikidis, Nikolaos; Kosmidis, Mary H

    2013-01-01

    We describe the case of a patient with bilateral thalamic lesions due to brain infarcts in the paramedian thalamic artery territories. The patient demonstrated symptoms of apathy (e.g., loss of initiative and interest in others, poor motivation, flattened affect). Neuropsychological assessment 3 and 5 years post-infarct revealed severe deficits in verbal and non-verbal immediate and delayed memory, attention, and executive functioning, with minimal improvement over time. Also, he demonstrated difficulties in social cognition (i.e., perception of facial expressions of others and of sarcasm). These findings are discussed and interpreted in light of current theories regarding the neurobiological substrate of apathy.

  3. ACYSYS in a box

    SciTech Connect

    Briegel, C.; Finstrom, D.; Hendricks, B.; King, C.; Lackey, S.; Neswold, R.; Nicklaus, D.; Patrick, J.; Petrov, A.; Rechenmacher, R.; Schumann, C.; /Fermilab

    2011-11-01

    The Accelerator Control System at Fermilab has evolved to enable this relatively large control system to be encapsulated into a 'box' such as a laptop. The goal was to provide a platform isolated from the 'online' control system. This platform can be used internally for making major upgrades and modifications without impacting operations. It also provides a standalone environment for research and development including a turnkey control system for collaborators. Over time, the code base running on Scientific Linux has enabled all the salient features of the Fermilab's control system to be captured in an off-the-shelf laptop. The anticipated additional benefits of packaging the system include improved maintenance, reliability, documentation, and future enhancements.

  4. More box codes

    NASA Technical Reports Server (NTRS)

    Solomon, G.

    1992-01-01

    A new investigation shows that, starting from the BCH (21,15;3) code represented as a 7 x 3 matrix and adding a row and column to add even parity, one obtains an 8 x 4 matrix (32,15;8) code. An additional dimension is obtained by specifying odd parity on the rows and even parity on the columns, i.e., adjoining to the 8 x 4 matrix, the matrix, which is zero except for the fourth column (of all ones). Furthermore, any seven rows and three columns will form the BCH (21,15;3) code. This box code has the same weight structure as the quadratic residue and BCH codes of the same dimensions. Whether there exists an algebraic isomorphism to either code is as yet unknown.

  5. Impedance Measurement Box

    ScienceCinema

    Christophersen, Jon

    2016-07-12

    Energy storage devices, primarily batteries, are now more important to consumers, industries and the military. With increasing technical complexity and higher user expectations, there is also a demand for highly accurate state-of-health battery assessment techniques. IMB incorporates patented, proprietary, and tested capabilities using control software and hardware that can be part of an embedded monitoring system. IMB directly measures the wideband impedance spectrum in seconds during battery operation with no significant impact on service life. It also can be applied to batteries prior to installation, confirming health before entering active service, as well as during regular maintenance. For more information about this project, visit http://www.inl.gov/rd100/2011/impedance-measurement-box/

  6. Spirit Boxes: Expressions of Culture.

    ERIC Educational Resources Information Center

    DeMuro, Ted

    1984-01-01

    After studying the culture and art of the ancient civilizations of South America, Mesopotamia, Greece, and Egypt, secondary level art students made spirit boxes as expressions of the various cultures. How to make the boxes and how to prepare the face molds are described. (RM)

  7. Being Creative "Inside the Box"

    ERIC Educational Resources Information Center

    Tomascoff, Rocky

    2011-01-01

    Artist Joseph Cornell (1903-1972) created wonderful environments inside boxes using mostly found objects. They were often Surrealistic in nature. Some boxes were designed with glass fronts, and others were meant to be interactive with the viewer, wherein the objects could be handled. With Joseph Cornell in mind, the author introduces an art…

  8. What Makes a Better Box?

    ERIC Educational Resources Information Center

    Moyer, Richard; Everett, Susan

    2010-01-01

    Every morning, many Americans start their day with a bowl of cereal. Some spend time while they eat breakfast reading the back of the cereal box, but few consider its size, shape, and construction, or realize that it was designed by an engineer. This article describes a lesson in which students design, build, and critique cereal boxes. The lesson…

  9. Cardboard Boxes: Learning Concepts Galore!

    ERIC Educational Resources Information Center

    Warner, Laverne; Wilmoth, Linda

    2007-01-01

    Mrs. Keenan, a preschool teacher, observed her 3-year-old granddaughter Riley pull, tug, and stack piles of holiday boxes on the floor. She remembered that her child care director had suggested using boxes as a curriculum theme, but she hadn't given much thought about the idea until now. She said to herself, "I wonder if my children would be as…

  10. Thalamic thermo-algesic transmission: ventral posterior (VP) complex versus VMpo in the light of a thalamic infarct with central pain.

    PubMed

    Montes, Carmen; Magnin, Michel; Maarrawi, Joseph; Frot, Maud; Convers, Philippe; Mauguière, François; Garcia-Larrea, Luis

    2005-01-01

    The respective roles of the ventral posterior complex (VP) and of the more recently described VMpo (posterior part of the ventral medial nucleus) as thalamic relays for pain and temperature pathways have recently been the subject of controversy. Data we obtained in one patient after a limited left thalamic infarct bring some new insights into this debate. This patient presented sudden right-sided hypesthesia for both lemniscal (touch, vibration, joint position) and spinothalamic (pain and temperature) modalities. He subsequently developed right-sided central pain with allodynia. Projection of 3D magnetic resonance images onto a human thalamic atlas revealed a lesion involving the anterior two thirds of the ventral posterior lateral nucleus (VPL) and, to a lesser extent, the ventral posterior medial (VPM) and inferior (VPI) nuclei. Conversely, the lesion did not extend posterior and ventral enough to concern the putative location of the spinothalamic-afferented nucleus VMpo. Neurophysiological studies showed a marked reduction (67%) of cortical responses depending on dorsal column-lemniscal transmission, while spinothalamic-specific, CO2-laser induced cortical responses were only moderately attenuated (33%). Our results show that the VP is definitely involved in thermo-algesic transmission in man, and that its selective lesion can lead to central pain. However, results also suggest that much of the spino-thalamo-cortical volley elicited by painful heat stimuli does not transit through VP, supporting the hypothesis that a non-VP locus lying more posteriorly in the human thalamus is important for thermo-algesic transmission.

  11. Dopamine reward prediction error coding.

    PubMed

    Schultz, Wolfram

    2016-03-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards-an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware.

  12. Dopamine reward prediction error coding

    PubMed Central

    Schultz, Wolfram

    2016-01-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards—an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware. PMID:27069377

  13. Dopamine, Affordance and Active Inference

    PubMed Central

    Friston, Karl J.; Shiner, Tamara; FitzGerald, Thomas; Galea, Joseph M.; Adams, Rick; Brown, Harriet; Dolan, Raymond J.; Moran, Rosalyn; Stephan, Klaas Enno; Bestmann, Sven

    2012-01-01

    The role of dopamine in behaviour and decision-making is often cast in terms of reinforcement learning and optimal decision theory. Here, we present an alternative view that frames the physiology of dopamine in terms of Bayes-optimal behaviour. In this account, dopamine controls the precision or salience of (external or internal) cues that engender action. In other words, dopamine balances bottom-up sensory information and top-down prior beliefs when making hierarchical inferences (predictions) about cues that have affordance. In this paper, we focus on the consequences of changing tonic levels of dopamine firing using simulations of cued sequential movements. Crucially, the predictions driving movements are based upon a hierarchical generative model that infers the context in which movements are made. This means that we can confuse agents by changing the context (order) in which cues are presented. These simulations provide a (Bayes-optimal) model of contextual uncertainty and set switching that can be quantified in terms of behavioural and electrophysiological responses. Furthermore, one can simulate dopaminergic lesions (by changing the precision of prediction errors) to produce pathological behaviours that are reminiscent of those seen in neurological disorders such as Parkinson's disease. We use these simulations to demonstrate how a single functional role for dopamine at the synaptic level can manifest in different ways at the behavioural level. PMID:22241972

  14. Discovering frequency sensitive thalamic nuclei from EEG microstate informed resting state fMRI.

    PubMed

    Schwab, Simon; Koenig, Thomas; Morishima, Yosuke; Dierks, Thomas; Federspiel, Andrea; Jann, Kay

    2015-09-01

    Microstates (MS), the fingerprints of the momentarily and time-varying states of the brain derived from electroencephalography (EEG), are associated with the resting state networks (RSNs). However, using MS fluctuations along different EEG frequency bands to model the functional MRI (fMRI) signal has not been investigated so far, or elucidated the role of the thalamus as a fundamental gateway and a putative key structure in cortical functional networks. Therefore, in the current study, we used MS predictors in standard frequency bands to predict blood oxygenation level dependent (BOLD) signal fluctuations. We discovered that multivariate modeling of BOLD-fMRI using six EEG-MS classes in eight frequency bands strongly correlated with thalamic areas and large-scale cortical networks. Thalamic nuclei exhibited distinct patterns of correlations for individual MS that were associated with specific EEG frequency bands. Anterior and ventral thalamic nuclei were sensitive to the beta frequency band, medial nuclei were sensitive to both alpha and beta frequency bands, and posterior nuclei such as the pulvinar were sensitive to delta and theta frequency bands. These results demonstrate that EEG-MS informed fMRI can elucidate thalamic activity not directly observable by EEG, which may be highly relevant to understand the rapid formation of thalamocortical networks.

  15. Anterior Thalamic Lesions Alter Both Hippocampal-Dependent Behavior and Hippocampal Acetylcholine Release in the Rat

    ERIC Educational Resources Information Center

    Savage, Lisa M.; Hall, Joseph M.; Vetreno, Ryan P.

    2011-01-01

    The anterior thalamic nuclei (ATN) are important for learning and memory as damage to this region produces a persistent amnestic syndrome. Dense connections between the ATN and the hippocampus exist, and importantly, damage to the ATN can impair hippocampal functioning. Acetylcholine (ACh) is a key neurotransmitter in the hippocampus, and in vivo…

  16. Chronic thalamic stimulation improves tremor and levodopa induced dyskinesias in Parkinson's disease.

    PubMed Central

    Caparros-Lefebvre, D; Blond, S; Vermersch, P; Pécheux, N; Guieu, J D; Petit, H

    1993-01-01

    Chronic thalamic stimulation was performed in 10 Parkinsonian patients with disabling tremor and poor response to drug therapy. During the stereotactic procedure, an electrode was introduced in the ventralis intermediate nucleus of the thalamus. Test stimulation was performed during the intra-operative procedure and a few days after surgery using an external stimulator. When tremor was obviously reduced by thalamic stimulation, an internal stimulator was implanted under the clavicle. Tremor was initially suppressed in all cases and reappeared whenever stimulation was stopped. Patients were followed for 22 to 34 months. Tremor was controlled in eight cases but reappeared after three months in two cases. Levodopa induced dyskinesias were observed before electrode implantation in 5 cases. They consisted of peak-dose choreic or ballistic dyskinesias in 4 cases and biphasic dystonic dyskinesias in 3 cases. Peak-dose dyskinesias were greatly improved or suppressed in all cases. Biphasic dyskinesias were improved in 2 cases. Thalamic stimulation was well tolerated. Mild dystonic hand posture related to the deep brain stimulation was observed in one case. No neuropsychological side-effects were noted. Thalamic stimulation could prove to be an adequate treatment for resistant tremor and levodopa induced dyskinesias. PMID:8459243

  17. Short Pauses in Thalamic Deep Brain Stimulation Promote Tremor and Neuronal Bursting

    PubMed Central

    Swan, Brandon D.; Brocker, David T.; Hilliard, Justin D.; Tatter, Stephen B.; Gross, Robert E.; Turner, Dennis A.; Grill, Warren M.

    2015-01-01

    Objective We conducted intraoperative measurements of tremor during DBS containing short pauses (≤50 ms) to determine if there is a minimum pause duration that preserves tremor suppression. Methods Nine subjects with ET and thalamic DBS participated during IPG replacement surgery. Patterns of DBS included regular 130 Hz stimulation interrupted by 0, 15, 25 or 50 ms pauses. The same patterns were applied to a model of the thalamic network to quantify effects of pauses on activity of model neurons. Results All patterns of DBS decreased tremor relative to ‘off’. Patterns with pauses generated less tremor reduction than regular high frequency DBS. The model revealed that rhythmic burst-driver inputs to thalamus were masked during DBS, but pauses in stimulation allowed propagation of bursting activity. The mean firing rate of bursting-type model neurons as well as the firing pattern entropy of model neurons were both strongly correlated with tremor power across stimulation conditions. Conclusion The temporal pattern of stimulation influences the efficacy of thalamic DBS. Pauses in stimulation resulted in decreased tremor suppression indicating that masking of pathological bursting is a mechanism of thalamic DBS for tremor. Significance Pauses in stimulation decreased the efficacy of open-loop DBS for suppression of tremor. PMID:26330131

  18. Central Neurogenic Hyperventilation Related to Post-Hypoxic Thalamic Lesion in a Child

    PubMed Central

    Gençpinar, Pinar; Karaali, Kamil; Haspolat, Şenay; Dursun, Oğuz

    2016-01-01

    Central neurogenic hyperventilation (CNH) is a rare clinical condition, whose mechanism is still unclear. Here, we report a 3-year-old male patient, who had bilateral thalamic, putaminal and globus pallideal infarction resulted in CNH without brainstem involvement. This case may illustrate a possible role for the thalamus in regulating ventilation. PMID:27127601

  19. Complex neurological symptoms in bilateral thalamic stroke due to Percheron artery occlusion

    PubMed Central

    Caruso, Paola; Manganotti, Paolo; Moretti, Rita

    2017-01-01

    The artery of Percheron is a rare anatomical variant where a single thalamic perforating artery arises from the proximal posterior cerebral artery (P1 segment) between the basilar artery and the posterior communicating artery and supplies the rostral mesencephalon and both paramedian territories of the thalami. Almost one-third of human brains present this variant. Occlusion of the artery of Percheron mostly results in a bilateral medial thalamic infarction, which usually manifests with altered consciousness (including coma), vertical gaze paresis, and cognitive disturbance. The presentation is similar to the “top of the basilar syndrome”, and early recognition should be prompted. We describe the case of a young female with this vessel variant who experienced a bilateral thalamic stroke. Magnetic resonance angiography demonstrated bilateral thalamic infarcts and a truncated artery of Percheron. Occlusion of the vessel was presumably due to embolism from a patent foramen ovale. Thrombolysis was performed, with incomplete symptom remission, cognitive impairment, and persistence of speech disorders. Early recognition and treatment of posterior circulation strokes is mandatory, and further investigation for underlying stroke etiologies is needed. PMID:28053539

  20. Alertness opens the effective flow of sensory information through rat thalamic posterior nucleus.

    PubMed

    Sobolewski, Aleksander; Kublik, Ewa; Swiejkowski, Daniel A; Kamiński, Jan; Wróbel, Andrzej

    2015-05-01

    Behavioural reactions to sensory stimuli vary with the level of arousal, but little is known about the underlying reorganization of neuronal networks. In this study, we use chronic recordings from the somatosensory regions of the thalamus and cortex of behaving rats together with a novel analysis of functional connectivity to show that during low arousal tactile signals are transmitted via the ventral posteromedial thalamic nucleus (VPM), a first-order thalamic relay, to the primary somatosensory (barrel) cortex and then from the cortex to the posterior medial thalamic nucleus (PoM), which plays a role of a higher-order thalamic relay. By contrast, during high arousal this network scheme is modified and both VPM and PoM transmit peripheral input to the barrel cortex acting as first-order relays. We also show that in urethane anaesthesia PoM is largely excluded from the thalamo-cortical loop. We thus demonstrate a way in which the thalamo-cortical system, despite its fixed anatomy, is capable of dynamically reconfiguring the transmission route of a sensory signal in concert with the behavioural state of an animal.

  1. Impairment of Syntax and Lexical Semantics in a Patient with Bilateral Paramedian Thalamic Infarction

    ERIC Educational Resources Information Center

    De Witte, Lieve; Wilssens, Ineke; Engelborghs, Sebastian; De Deyn, Peter P.; Marien, Peter

    2006-01-01

    Bilateral vascular thalamic lesions are rare. Although a variety of neurobehavioral manifestations have been described, the literature is less documented with regard to accompanying linguistic disturbances. This article presents an in-depth neurolinguistic analysis of the language symptoms of a patient who incurred bilateral paramedian ischemic…

  2. Differential effects of methylphenidate and cocaine on GABA transmission in sensory thalamic nuclei.

    PubMed

    Goitia, Belén; Raineri, Mariana; González, Laura E; Rozas, José L; Garcia-Rill, Edgar; Bisagno, Verónica; Urbano, Francisco J

    2013-03-01

    Methylphenidate (MPH) is widely used to treat children and adolescents diagnosed with attention deficit/hyperactivity disorder. Although MPH shares mechanistic similarities to cocaine, its effects on GABAergic transmission in sensory thalamic nuclei are unknown. Our objective was to compare cocaine and MPH effects on GABAergic projections between thalamic reticular and ventrobasal (VB) nuclei. Mice (P18-30) were subjected to binge-like cocaine and MPH acute and sub-chronic administrations. Cocaine and MPH enhanced hyperlocomotion, although sub-chronic cocaine-mediated effects were stronger than MPH effects. Cocaine and MPH sub-chronic administration altered paired-pulse and spontaneous GABAergic input differently. The effects of cocaine on evoked paired-pulse GABA-mediated currents changed from depression to facilitation with the duration of the protocols used, while MPH induced a constant increase throughout the administration protocols. Thalamic reticular nucleus GAD67 and VB Ca(V) 3.1 protein levels were measured using western blot to better understand their link to increased GABA release. Both proteins were increased by sub-chronic administration of cocaine. MPH showed effects on GABAergic transmission that seems less disruptive than cocaine. Unique effects of cocaine on postsynaptic VB calcium currents might explain deleterious cocaine effects on sensory thalamic nuclei. These results suggest that cocaine and MPH produced distinct presynaptic alterations on GABAergic transmission.

  3. Aphasia and unilateral spatial neglect due to acute thalamic hemorrhage: clinical correlations and outcomes.

    PubMed

    Osawa, Aiko; Maeshima, Shinichiro

    2016-04-01

    Thalamic hemorrhages are associated with a variety of cognitive dysfunctions, and it is well known that such cognitive changes constitute a limiting factor of recovery of the activities of daily living (ADL). The relationship between cognitive dysfunction and hematomas is unclear. In this study, we investigated the relationship between aphasia/neglect and hematoma volume, hematoma type, and the ADL. One hundred fifteen patients with thalamic hemorrhage (70 men and 45 women) were studied. Their mean age was 68.9 ± 10.3 years, and patients with both left and right lesions were included. We calculated hematoma volume and examined the presence or absence of aphasia/neglect and the relationships between these dysfunctions and hematoma volume, hematoma type, and the ADL. Fifty-nine patients were found to have aphasia and 35 were found to have neglect. Although there was no relationship between hematoma type and cognitive dysfunction, hematoma volume showed a correlation with the severity of cognitive dysfunction. The ADL score and ratio of patient discharge for patients with aphasia/neglect were lower than those for patients without aphasia/neglect. We observed a correlation between the hematoma volume in thalamic hemorrhage and cognitive dysfunction. Aphasia/neglect is found frequently in patients with acute thalamic hemorrhage and may influence the ADL.

  4. Contrary roles of kainate receptors in transmitter release at corticothalamic synapses onto thalamic relay and reticular neurons.

    PubMed

    Miyata, Mariko; Imoto, Keiji

    2009-03-01

    Corticothalamic fibres, which originate from layer VI pyramidal neurons in the cerebral cortex, provide excitatory synaptic inputs to both thalamic relay neurons and reticular neurons; reticular neurons in turn supply inhibitory inputs to thalamic relay neurons. Pyramidal cells in layer VI in the mouse somatosensory cortex highly express mRNA encoding kainate receptors, which facilitate or depress transmitter release at several synapses in the central nervous system. We report here that contrary modulation of transmitter release from corticothalamic fibres onto thalamic relay and reticular neurons is mediated by activation of kainate receptors in mouse thalamic ventrobasal complex and thalamic reticular nucleus. Exogenous kainate presynaptically depresses the synaptic transmission at corticothalamic synapses onto thalamic relay neurons, but facilitates it at corticothalamic synapses onto reticular neurons. Meanwhile, the lemniscal synaptic transmission, which sends primary somatosensory inputs to relay neurons, is not affected by kainate. In addition, GluR5-containing kainate receptors are involved in the depression of corticothalamic synaptic transmission onto relay neurons, but not onto reticular neurons. Furthermore, synaptically activated kainate receptors mimic these effects; high-frequency stimulation of corticothalamic fibres depresses synaptic transmission onto relay neurons, but facilitates it onto reticular neurons. Our results suggest that the opposite sensitivity of kainate receptors at the two corticothalamic synapses is governed by cortical activity and regulates the balance of excitatory and inhibitory inputs to thalamic relay neurons and therefore their excitability.

  5. Visualization of intra-thalamic nuclei with optimized white-matter-nulled MPRAGE at 7T.

    PubMed

    Tourdias, Thomas; Saranathan, Manojkumar; Levesque, Ives R; Su, Jason; Rutt, Brian K

    2014-01-01

    Novel MR image acquisition strategies have been investigated to elicit contrast within the thalamus, but direct visualization of individual thalamic nuclei remains a challenge because of their small size and the low intrinsic contrast between adjacent nuclei. We present a step-by-step specific optimization of the 3D MPRAGE pulse sequence at 7T to visualize the intra-thalamic nuclei. We first measured T1 values within different sub-regions of the thalamus at 7T in 5 individuals. We used these to perform simulations and sequential experimental measurements (n=17) to tune the parameters of the MPRAGE sequence. The optimal set of parameters was used to collect high-quality data in 6 additional volunteers. Delineation of thalamic nuclei was performed twice by one rater and MR-defined nuclei were compared to the classic Morel histological atlas. T1 values within the thalamus ranged from 1400ms to 1800ms for adjacent nuclei. Using these values for theoretical evaluations combined with in vivo measurements, we showed that a short inversion time (TI) close to the white matter null regime (TI=670ms) enhanced the contrast between the thalamus and the surrounding tissues, and best revealed intra-thalamic contrast. At this particular nulling regime, lengthening the time between successive inversion pulses (TS=6000ms) increased the thalamic signal and contrast and lengthening the α pulse train time (N*TR) further increased the thalamic signal. Finally, a low flip angle during the gradient echo acquisition (α=4°) was observed to mitigate the blur induced by the evolution of the magnetization along the α pulse train. This optimized set of parameters enabled the 3D delineation of 15 substructures in all 6 individuals; these substructures corresponded well with the known anatomical structures of the thalamus based on the classic Morel atlas. The mean Euclidean distance between the centers of mass of MR- and Morel atlas-defined nuclei was 2.67mm (±1.02mm). The reproducibility of

  6. Mouse Thalamic Differentiation: Gli-Dependent Pattern and Gli-Independent Prepattern

    PubMed Central

    Haddad-Tóvolli, Roberta; Heide, Michael; Zhou, Xunlei; Blaess, Sandra; Alvarez-Bolado, Gonzalo

    2012-01-01

    Sonic hedgehog (Shh) signaling is essential for thalamic development. The Gli transcription factors act downstream of Shh – while Gli2 is the major activator (GliA), Gli3 acts primarily as a repressor (GliR). The thalamus is remarkable among dorsal structures because of its proximity to the mid-diencephalic organizer, a unique dorsal Shh source. This lends complexity to the interactions between Shh, Gli2, and Gli3, suggesting the presence of a dorsal Gli activator which elsewhere is found only ventrally, and making the dissection of thalamic Gli functions particularly interesting. A current model based on mutant phenotypes in telencephalon and midbrain postulates a degree of reciprocal antagonism of Shh and Gli3 in dorsal brain regions. To approach the role of Gli factors in thalamic specification we first analyzed mice deficient in Gli2 or Gli3. In Gli2 mutants, the thalamus is small and poorly differentiated with the exception of the medial and intralaminar nuclei which, in contrast, are specifically and severely affected by Gli3 inactivation. Gbx2 expression is very reduced in the Gli3 mutant. Most thalamic nuclei are present in both mutants, although incompletely differentiated, as reflected by the loss of specific markers. The ventral posterior group, revealed by novel specific marker Hes1, is present in both mutants and extends axons to the telencephalon. To test the Gli3/Shh interaction we generated a novel mutant deficient in Gli3 and neuroepithelial Shh. The thalamus of the n-Shh/Gli3 double mutants is very large and very poorly differentiated except for a broad domain of Gbx2, Lhx2, and Calb2 expression. In utero electroporation experiments on wild type embryos suggest that a stage-specific factor acting early is responsible for this prepattern. We show that, in the thalamus, GliA acts downstream of Shh to specify pattern and size of the thalamic nuclei to the exception of the medial and intralaminar groups. Gli3A can partially substitute for Gli2A in

  7. Visualization of intra-thalamic nuclei with optimized white-matter-nulled MPRAGE at 7T

    PubMed Central

    Tourdias, Thomas; Saranathan, Manojkumar; Levesque, Ives R.; Su, Jason; Rutt, Brian K.

    2013-01-01

    Novel MR image acquisition strategies have been investigated to elicit contrast within the thalamus, but direct visualization of individual thalamic nuclei remains a challenge because of their small size and the low intrinsic contrast between adjacent nuclei. We present a step-by-step specific optimization of the 3D MPRAGE pulse sequence at 7T to visualize the intra-thalamic nuclei. We first measured T1 values within different sub-regions of the thalamus at 7T in 5 individuals. We used these to perform simulations and sequential experimental measurements (n=17) to tune the parameters of the MPRAGE sequence. The optimal set of parameters was used to collect high-quality data in 6 additional volunteers. Delineation of thalamic nuclei was performed twice by one rater and MR-defined nuclei were compared to the classic Morel histological atlas. T1 values within the thalamus ranged from 1400ms to 1800ms for adjacent nuclei. Using these values for theoretical evaluations combined with in vivo measurements, we showed that a short inversion time (TI) close to the white matter null regime (TI=670ms) enhanced the contrast between the thalamus and the surrounding tissues, and best revealed intra-thalamic contrast. At this particular nulling regime, lengthening the time between successive inversion pulses (TS=6000ms) increased the thalamic signal and contrast and lengthening the α pulse train time (N*TR) further increased the thalamic signal. Finally, a low flip angle during the gradient echo acquisition (α=4°) was observed to mitigate the blur induced by the evolution of the magnetization along the α pulse train. This optimized set of parameters enabled the 3D delineation of 15 substructures in all 6 individuals; these substructures corresponded well with the known anatomical structures of the thalamus based on the classical Morel atlas. The mean Euclidean distance between the centers of mass of MR- and Morel atlas-defined nuclei was 2.67mm (±1.02mm). The reproducibility

  8. Altered Neurocircuitry in the Dopamine Transporter Knockout Mouse Brain

    PubMed Central

    Zhang, Xiaowei; Bearer, Elaine L.; Boulat, Benoit; Hall, F. Scott; Uhl, George R.; Jacobs, Russell E.

    2010-01-01

    The plasma membrane transporters for the monoamine neurotransmitters dopamine, serotonin, and norepinephrine modulate the dynamics of these monoamine neurotransmitters. Thus, activity of these transporters has significant consequences for monoamine activity throughout the brain and for a number of neurological and psychiatric disorders. Gene knockout (KO) mice that reduce or eliminate expression of each of these monoamine transporters have provided a wealth of new information about the function of these proteins at molecular, physiological and behavioral levels. In the present work we use the unique properties of magnetic resonance imaging (MRI) to probe the effects of altered dopaminergic dynamics on meso-scale neuronal circuitry and overall brain morphology, since changes at these levels of organization might help to account for some of the extensive pharmacological and behavioral differences observed in dopamine transporter (DAT) KO mice. Despite the smaller size of these animals, voxel-wise statistical comparison of high resolution structural MR images indicated little morphological change as a consequence of DAT KO. Likewise, proton magnetic resonance spectra recorded in the striatum indicated no significant changes in detectable metabolite concentrations between DAT KO and wild-type (WT) mice. In contrast, alterations in the circuitry from the prefrontal cortex to the mesocortical limbic system, an important brain component intimately tied to function of mesolimbic/mesocortical dopamine reward pathways, were revealed by manganese-enhanced MRI (MEMRI). Analysis of co-registered MEMRI images taken over the 26 hours after introduction of Mn2+ into the prefrontal cortex indicated that DAT KO mice have a truncated Mn2+ distribution within this circuitry with little accumulation beyond the thalamus or contralateral to the injection site. By contrast, WT littermates exhibit Mn2+ transport into more posterior midbrain nuclei and contralateral mesolimbic structures at

  9. Thalamic neuron models encode stimulus information by burst-size modulation

    PubMed Central

    Elijah, Daniel H.; Samengo, Inés; Montemurro, Marcelo A.

    2015-01-01

    Thalamic neurons have been long assumed to fire in tonic mode during perceptive states, and in burst mode during sleep and unconsciousness. However, recent evidence suggests that bursts may also be relevant in the encoding of sensory information. Here, we explore the neural code of such thalamic bursts. In order to assess whether the burst code is generic or whether it depends on the detailed properties of each bursting neuron, we analyzed two neuron models incorporating different levels of biological detail. One of the models contained no information of the biophysical processes entailed in spike generation, and described neuron activity at a phenomenological level. The second model represented the evolution of the individual ionic conductances involved in spiking and bursting, and required a large number of parameters. We analyzed the models' input selectivity using reverse correlation methods and information theory. We found that n-spike bursts from both models transmit information by modulating their spike count in response to changes to instantaneous input features, such as slope, phase, amplitude, etc. The stimulus feature that is most efficiently encoded by bursts, however, need not coincide with one of such classical features. We therefore searched for the optimal feature among all those that could be expressed as a linear transformation of the time-dependent input current. We found that bursting neurons transmitted 6 times more information about such more general features. The relevant events in the stimulus were located in a time window spanning ~100 ms before and ~20 ms after burst onset. Most importantly, the neural code employed by the simple and the biologically realistic models was largely the same, implying that the simple thalamic neuron model contains the essential ingredients that account for the computational properties of the thalamic burst code. Thus, our results suggest the n-spike burst code is a general property of thalamic neurons. PMID

  10. High frequency stimulation abolishes thalamic network oscillations: an electrophysiological and computational analysis

    NASA Astrophysics Data System (ADS)

    Lee, Kendall H.; Hitti, Frederick L.; Chang, Su-Youne; Lee, Dongchul C.; Roberts, David W.; McIntyre, Cameron C.; Leiter, James C.

    2011-08-01

    Deep brain stimulation (DBS) of the thalamus has been demonstrated to be effective for the treatment of epilepsy. To investigate the mechanism of action of thalamic DBS, we examined the effects of high frequency stimulation (HFS) on spindle oscillations in thalamic brain slices from ferrets. We recorded intracellular and extracellular electrophysiological activity in the nucleus reticularis thalami (nRt) and in thalamocortical relay (TC) neurons in the lateral geniculate nucleus, stimulated the slice using a concentric bipolar electrode, and recorded the level of glutamate within the slice. HFS (100 Hz) of TC neurons generated excitatory post-synaptic potentials, increased the number of action potentials in both TC and nRt neurons, reduced the input resistance, increased the extracellular glutamate concentration, and abolished spindle wave oscillations. HFS of the nRt also suppressed spindle oscillations. In both locations, HFS was associated with significant and persistent elevation in extracellular glutamate levels and suppressed spindle oscillations for many seconds after the cessation of stimulation. We simulated HFS within a computational model of the thalamic network, and HFS also disrupted spindle wave activity, but the suppression of spindle activity was short-lived. Simulated HFS disrupted spindle activity for prolonged periods of time only after glutamate release and glutamate-mediated activation of a hyperpolarization-activated current (Ih) was incorporated into the model. Our results suggest that the mechanism of action of thalamic DBS as used in epilepsy may involve the prolonged release of glutamate, which in turn modulates specific ion channels such as Ih, decreases neuronal input resistance, and abolishes thalamic network oscillatory activity.

  11. Biphasic cholinergic synaptic transmission controls action potential activity in thalamic reticular nucleus neurons.

    PubMed

    Sun, Yan-Gang; Pita-Almenar, Juan D; Wu, Chia-Shan; Renger, John J; Uebele, Victor N; Lu, Hui-Chen; Beierlein, Michael

    2013-01-30

    Cholinergic neurons in the basal forebrain and the brainstem form extensive projections to a number of thalamic nuclei. Activation of cholinergic afferents during distinct behavioral states can regulate neuronal firing, transmitter release at glutamatergic and GABAergic synapses, and synchrony in thalamic networks, thereby controlling the flow of sensory information. These effects are thought to be mediated by slow and persistent increases in extracellular ACh levels, resulting in the modulation of populations of thalamic neurons over large temporal and spatial scales. However, the synaptic mechanisms underlying cholinergic signaling in the thalamus are not well understood. Here, we demonstrate highly reliable cholinergic transmission in the mouse thalamic reticular nucleus (TRN), a brain structure essential for sensory processing, arousal, and attention. We find that ACh release evoked by low-frequency stimulation leads to biphasic excitatory-inhibitory (E-I) postsynaptic responses, mediated by the activation of postsynaptic α4β2 nicotinic ACh receptors (nAChRs) and M2 muscarinic ACh receptors (mAChRs), respectively. In addition, ACh can bind to mAChRs expressed near cholinergic release sites, resulting in autoinhibition of release. We show that the activation of postsynaptic nAChRs by transmitter release from only a small number of individual axons is sufficient to trigger action potentials in TRN neurons. Furthermore, short trains of cholinergic synaptic inputs can powerfully entrain ongoing TRN neuronal activity. Our study demonstrates fast and precise synaptic E-I signaling mediated by ACh, suggesting novel computational mechanisms for the cholinergic control of neuronal activity in thalamic circuits.

  12. The effects of DBS patterns on basal ganglia activity and thalamic relay : a computational study.

    PubMed

    Agarwal, Rahul; Sarma, Sridevi V

    2012-08-01

    Thalamic neurons receive inputs from cortex and their responses are modulated by the basal ganglia (BG). This modulation is necessary to properly relay cortical inputs back to cortex and downstream to the brain stem when movements are planned. In Parkinson's disease (PD), the BG input to thalamus becomes pathological and relay of motor-related cortical inputs is compromised, thereby impairing movements. However, high frequency (HF) deep brain stimulation (DBS) may be used to restore relay reliability, thereby restoring movements in PD patients. Although therapeutic, HF stimulation consumes significant power forcing surgical battery replacements, and may cause adverse side effects. Here, we used a biophysical-based model of the BG-Thalamus motor loop in both healthy and PD conditions to assess whether low frequency stimulation can suppress pathological activity in PD and enable the thalamus to reliably relay movement-related cortical inputs. We administered periodic pulse train DBS waveforms to the sub-thalamic nucleus (STN) with frequencies ranging from 0-140 Hz, and computed statistics that quantified pathological bursting, oscillations, and synchronization in the BG as well as thalamic relay of cortical inputs. We found that none of the frequencies suppressed all pathological activity in BG, though the HF waveforms recovered thalamic reliability. Our rigorous study, however, led us to a novel DBS strategy involving low frequency multi-input phase-shifted DBS, which successfully suppressed pathological symptoms in all BG nuclei and enabled reliable thalamic relay. The neural restoration remained robust to changes in the model parameters characterizing early to late PD stages.

  13. Dopamine Receptors and Neurodegeneration

    PubMed Central

    Rangel-Barajas, Claudia; Coronel, Israel; Florán, Benjamín

    2015-01-01

    Dopamine (DA) is one of the major neurotransmitters and participates in a number of functions such as motor coordination, emotions, memory, reward mechanism, neuroendocrine regulation etc. DA exerts its effects through five DA receptors that are subdivided in 2 families: D1-like DA receptors (D1 and D5) and the D2-like (D2, D3 and D4). All DA receptors are widely expressed in the central nervous system (CNS) and play an important role in not only in physiological conditions but also pathological scenarios. Abnormalities in the DAergic system and its receptors in the basal ganglia structures are the basis Parkinson’s disease (PD), however DA also participates in other neurodegenerative disorders such as Huntington disease (HD) and multiple sclerosis (MS). Under pathological conditions reorganization of DAergic system has been observed and most of the times, those changes occur as a mechanism of compensation, but in some cases contributes to worsening the alterations. Here we review the changes that occur on DA transmission and DA receptors (DARs) at both levels expression and signals transduction pathways as a result of neurotoxicity, inflammation and in neurodegenerative processes. The better understanding of the role of DA receptors in neuropathological conditions is crucial for development of novel therapeutic approaches to treat alterations related to neurodegenerative diseases. PMID:26425390

  14. Breaking out of Our Boxes.

    ERIC Educational Resources Information Center

    Patterson, William

    2003-01-01

    Argues that educators must "think outside the box" to improve school performance. Suggests several areas for expanded thought, including school size, curriculum coverage, grading practices, use of time, organization of students, time management, and belief statement. (PKP)

  15. Center Spot: Shoe Box Science

    ERIC Educational Resources Information Center

    Hoffman, Jan

    1976-01-01

    This is the second "Center Spot" devoted to Jan Hoffman's "Shoe Box Science," a program that organizes manipulative materials so that children can identify, describe, order, construct, name and distinguish on their own.

  16. Dopamine regulates body size in Caenorhabditis elegans.

    PubMed

    Nagashima, Takashi; Oami, Eitaro; Kutsuna, Natsumaro; Ishiura, Shoichi; Suo, Satoshi

    2016-04-01

    The nervous system plays a critical role in the regulation of animal body sizes. In Caenorhabditis elegans, an amine neurotransmitter, dopamine, is required for the tactile perception of food and food-dependent behavioral changes, while its role in development is unknown. In this study, we show that dopamine negatively regulates body size through a D2-like dopamine receptor, DOP-3, in C. elegans. Dopamine alters body size without affecting food intake or developmental rate. We also found that dopamine promotes egg-laying, although the regulation of body size by dopamine was not solely caused by this effect. Furthermore, dopamine negatively regulates body size through the suppression of signaling by octopamine and Gq-coupled octopamine receptors, SER-3 and SER-6. Our results demonstrate that dopamine and octopamine regulate the body size of C. elegans and suggest a potential role for perception in addition to ingestion of food for growth.

  17. Dopamine, reward learning, and active inference

    PubMed Central

    FitzGerald, Thomas H. B.; Dolan, Raymond J.; Friston, Karl

    2015-01-01

    Temporal difference learning models propose phasic dopamine signaling encodes reward prediction errors that drive learning. This is supported by studies where optogenetic stimulation of dopamine neurons can stand in lieu of actual reward. Nevertheless, a large body of data also shows that dopamine is not necessary for learning, and that dopamine depletion primarily affects task performance. We offer a resolution to this paradox based on an hypothesis that dopamine encodes the precision of beliefs about alternative actions, and thus controls the outcome-sensitivity of behavior. We extend an active inference scheme for solving Markov decision processes to include learning, and show that simulated dopamine dynamics strongly resemble those actually observed during instrumental conditioning. Furthermore, simulated dopamine depletion impairs performance but spares learning, while simulated excitation of dopamine neurons drives reward learning, through aberrant inference about outcome states. Our formal approach provides a novel and parsimonious reconciliation of apparently divergent experimental findings. PMID:26581305

  18. The lithium vapor box divertor

    NASA Astrophysics Data System (ADS)

    Goldston, R. J.; Myers, R.; Schwartz, J.

    2016-02-01

    It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m-2, implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et al as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. At the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma.

  19. Dopamine controls neurogenesis in the adult salamander midbrain in homeostasis and during regeneration of dopamine neurons.

    PubMed

    Berg, Daniel A; Kirkham, Matthew; Wang, Heng; Frisén, Jonas; Simon, András

    2011-04-08

    Appropriate termination of regenerative processes is critical for producing the correct number of cells in tissues. Here we provide evidence for an end-product inhibition of dopamine neuron regeneration that is mediated by dopamine. Ablation of midbrain dopamine neurons leads to complete regeneration in salamanders. Regeneration involves extensive neurogenesis and requires activation of quiescent ependymoglia cells, which express dopamine receptors. Pharmacological compensation for dopamine loss by L-dopa inhibits ependymoglia proliferation and regeneration in a dopamine receptor-signaling-dependent manner, specifically after ablation of dopamine neurons. Systemic administration of the dopamine receptor antagonist haloperidol alone causes ependymoglia proliferation and the appearance of excessive number of neurons. Our data show that stem cell quiescence is under dopamine control and provide a model for termination once normal homeostasis is restored. The findings establish a role for dopamine in the reversible suppression of neurogenesis in the midbrain and have implications for regenerative strategies in Parkinson's disease.

  20. Can Chronic Remote Cortical Hypoperfusion Induced by Thalamic Infarction Cause Damage of Tracts Passing through Those Hypoperfused Regions?

    PubMed

    Magnin, Eloi; Chamard, Ludivine; Vuillier, Fabrice; Tatu, Laurent; Berger, Eric

    2013-01-01

    We report the case of a woman presenting with changes on cerebral imaging a year and a half after a bi-thalamic (predominantly left-sided) infarction including lateral and medial thalamic nuclei. Lateral geniculate body and pulvinar were not damaged. Hypoperfusion was observed in left cortical and basal structures. White matter FLAIR hyperintense lesions occurred in the left hemisphere and the occipital region 1 year and half after stroke. Medial and lateral thalamic nuclei are not highly connected to the occipital cortex. Therefore, in addition to Wallerian degeneration after thalamic stroke, we hypothesize that the chronic left temporal hypoperfusion induced by diaschisis can lead to a lateralized chronic hypoxic damage of the occipital fiber tract (optic radiation) that passes through the temporal lobe.

  1. 30 CFR 57.12006 - Distribution boxes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distribution boxes. 57.12006 Section 57.12006... and Underground § 57.12006 Distribution boxes. Distribution boxes shall be provided with a... deenergized, and the distribution box shall be labeled to show which circuit each device controls....

  2. Plate forming and break down pizza box

    DOEpatents

    Pantisano, Frank; Devine, Scott M.

    1992-01-01

    A standard corrugated paper pizza box is provided with slit cuts cut through the top panel of the pizza box in a shape to form four circular serving plates with a beveled raised edge and cross slit cuts through the bottom panel of the pizza box separating the box into four essentially equal portions for easy disposal.

  3. Chaotic behavior in dopamine neurodynamics.

    PubMed Central

    King, R; Barchas, J D; Huberman, B A

    1984-01-01

    We report the results of the dynamics of a model of the central dopaminergic neuronal system. In particular, for certain values of a parameter k, which monitors the efficacy of dopamine at the postsynaptic receptor, chaotic solutions of the dynamical equations appear--a prediction that correlates with the observed increased variability in behavior among schizophrenics, the rapid fluctuations in motor activity among Parkinsonian patients treated chronically with L-dopa, and the lability of mood in some patients with an affective disorder. Moreover our hypothesis offers specific results concerning the appearance or disappearance of erratic solutions as a function of k and the external input to the dopamine neuronal system. PMID:6583705

  4. Chaotic behavior in dopamine neurodynamics.

    PubMed

    King, R; Barchas, J D; Huberman, B A

    1984-02-01

    We report the results of the dynamics of a model of the central dopaminergic neuronal system. In particular, for certain values of a parameter k, which monitors the efficacy of dopamine at the postsynaptic receptor, chaotic solutions of the dynamical equations appear--a prediction that correlates with the observed increased variability in behavior among schizophrenics, the rapid fluctuations in motor activity among Parkinsonian patients treated chronically with L-dopa, and the lability of mood in some patients with an affective disorder. Moreover our hypothesis offers specific results concerning the appearance or disappearance of erratic solutions as a function of k and the external input to the dopamine neuronal system.

  5. Restriction of dopamine signaling to the dorsolateral striatum is sufficient for many cognitive behaviors

    PubMed Central

    Darvas, Martin; Palmiter, Richard D.

    2009-01-01

    The striatum is a vital substrate for performance, procedural memory, and learning. The ventral and medial striatum are thought to be critical for acquisition of tasks while the dorsolateral striatum is important for performance and habitual enactment of skills. Evidence based on cortical, thalamic, and amygdaloid inputs to the striatum suggests a medio-lateral zonation imposed on the classical dorso-ventral distinction. We therefore investigated the functional significance of dopaminergic signaling in cognitive tasks by studying dopamine-deficient (DD) mice and mice with dopamine signaling restored to only the dorsolateral (DL) striatum by viral rescue (vrDD-DL mice). Whereas DD mice failed in all of the tasks examined here, vrDD-DL mice displayed intact discriminatory learning, object recognition, visuospatial learning and spatial memory. Acquisition of operant behavior for food rewards was delayed in vrDD-DL mice and their motivation in a progressive ratio experiments was reduced. Therefore, dopaminergic signaling in the dorsolateral striatum is sufficient for mice to learn several different cognitive tasks although the rate of learning some of them was reduced. These results indicate that dopaminergic signaling in the ventromedial striatum is not absolutely necessary for mastery of these behaviors, but may facilitate them. PMID:19667174

  6. Thalamic structures and associated cognitive functions: Relations with age and aging

    PubMed Central

    Fama, Rosemary; Sullivan, Edith V.

    2015-01-01

    The thalamus, with its cortical, subcortical, and cerebellar connections, is a critical node in networks supporting cognitive functions known to decline in normal aging, including component processes of memory and executive functions of attention and information processing. The macrostructure, microstructure, and neural connectivity of the thalamus changes across the adult lifespan. Structural and functional magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) have demonstrated, regional thalamic volume shrinkage and microstructural degradation, with anterior regions generally more compromised than posterior regions. The integrity of selective thalamic nuclei and projections decline with advancing age, particularly those in thalamofrontal, thalamoparietal, and thalamolimbic networks. This review presents studies that assess the relations between age and aging and the structure, function, and connectivity of the thalamus and associated neural networks and focuses on their relations with processes of attention, speed of information processing, and working and episodic memory. PMID:25862940

  7. Crossed cerebellar and uncrossed basal ganglia and thalamic diaschisis in Alzheimer's disease

    SciTech Connect

    Akiyama, H.; Harrop, R.; McGeer, P.L.; Peppard, R.; McGeer, E.G.

    1989-04-01

    We detected crossed cerebellar as well as uncrossed basal ganglia and thalamic diaschisis in Alzheimer's disease by positron emission tomography (PET) using /sup 18/F-fluorodeoxyglucose. We studied a series of 26 consecutive, clinically diagnosed Alzheimer cases, including 6 proven by later autopsy, and compared them with 9 age-matched controls. We calculated asymmetry indices (AIs) of cerebral metabolic rate for matched left-right regions of interest (ROIs) and determined the extent of diaschisis by correlative analyses. For the Alzheimer group, we found cerebellar AIs correlated negatively, and thalamic AIs positively, with those of the cerebral hemisphere and frontal, temporal, parietal, and angular cortices, while basal ganglia AIs correlated positively with frontal cortical AIs. The only significant correlation of AIs for normal subjects was between the thalamus and cerebral hemisphere. These data indicate that PET is a sensitive technique for detecting diaschisis.

  8. The olfactory thalamus: unanswered questions about the role of the mediodorsal thalamic nucleus in olfaction

    PubMed Central

    Courtiol, Emmanuelle; Wilson, Donald A.

    2015-01-01

    The mediodorsal thalamic nucleus (MDT) is a higher order thalamic nucleus and its role in cognition is increasingly well established. Interestingly, components of the MDT also have a somewhat unique sensory function as they link primary olfactory cortex to orbitofrontal associative cortex. In fact, anatomical evidence firmly demonstrates that the MDT receives direct input from primary olfactory areas including the piriform cortex and has dense reciprocal connections with the orbitofrontal cortex. The functions of this olfactory pathway have been poorly explored but lesion, imaging, and electrophysiological studies suggest that these connections may be involved in olfactory processing including odor perception, discrimination, learning, and attention. However, many important questions regarding the MDT and olfaction remain unanswered. Our goal here is not only to briefly review the existing literature but also to highlight some of the remaining questions that need to be answered to better define the role(s) of the MDT in olfactory processing. PMID:26441548

  9. Bilateral paramedian thalamic syndrome: abnormal circadian wake-sleep and autonomic functions

    PubMed Central

    Montagna, P; Provini, F; Plazzi, G; Vetrugno, R; Gallassi, R; Pierangeli, G; Ragno, M; Cortelli, P; Perani, D

    2002-01-01

    Methods: Patients underwent (18F)FDG PET scans and 24 hour polygraphic recordings of wake-sleep and t°. Results: PET showed bilateral thalamic hypometabolism in both patients with additional basal ganglia or mesiolateral frontal and cingular hypometabolism. Wake-sleep studies showed abnormal sleep organisation and in the case with frontal and limbic PET hypometabolism, pre-sleep behaviour associated with "subwakefulness" EEG activities, lack of EEG spindles and K complexes, and features of status dissociatus. The t° rhythms showed increased mesor in both (37.4°C and 37.75°C) and inverted rhythm in one patient. Conclusions: Paramedian thalamic structures and interconnected, especially frontal and cingular, areas play a part in the organisation of the wake-sleep cycle and attendant autonomic functions. PMID:12438490

  10. Lesions of the paraventricular thalamic nucleus attenuates prepulse inhibition of the acoustic startle reflex.

    PubMed

    Öz, Pınar; Kaya Yertutanol, F Duygu; Gözler, Tayfun; Özçetin, Ayşe; Uzbay, I Tayfun

    2017-03-06

    The paraventricular thalamic nucleus (PVT) is a midline nucleus with strong connections to cortical and subcortical brain regions such as the prefrontal cortex, amygdala, nucleus accumbens and hippocampus and receives strong projections from brain stem nuclei. Prepulse inhibition (PPI) is mediated and modulated by complex cortical and subcortical networks that are yet to be fully identified in detail. Here, we suggest that the PVT may be an important brain region for the modulation of PPI. In our study, the paraventricular thalamic nuclei of rats were electrolytically lesioned. Two weeks after the surgery, the PPI responses of the animals were monitored and recorded using measurements of acoustic startle reflex. Our results show that disruption of the PVT dramatically attenuated PPI at prepulse intensities of 74, 78 and 86dB compared to that in the sham lesion group. Thus, we suggest that the PVT may be an important part of the PPI network in the rat brain.

  11. Thalamic rosette-forming a glioneuronal tumor in an elderly patient: Case report and literature review.

    PubMed

    Cebula, H; Chibbaro, S; Santin, M N; Kremer, S; Chaussemy, D; Proust, F

    2016-02-01

    The rosette-forming glioneuronal tumor (RGNT) is a novel type of brain tumor recently listed in the WHO 2007 classification of central nervous system (CNS) tumors. We report the case of a 75-year-old woman harboring a thalamic RGNT with third ventricle dissemination. Age and location make the present case exceptional and which has never previously been reported. A review of the clinical, pathological and radiological features is presented along with the relevant literature.

  12. Effect of Spinal Manipulation Thrust Magnitude on Trunk Mechanical Thresholds of Lateral Thalamic Neurons

    PubMed Central

    Reed, William R.; Pickar, Joel G.; Sozio, Randall S.; Long, Cynthia R.

    2014-01-01

    Objectives High velocity low amplitude spinal manipulation (HVLA-SM), as performed by manual therapists (eg, doctors of chiropractic and osteopathy) results in mechanical hypoalgesia in clinical settings. This hypoalgesic effect has previously been attributed to alterations in peripheral and/or central pain processing. The objective of this study was to determine whether thrust magnitude of a simulated HVLA-SM alters mechanical trunk response thresholds in wide dynamic range (WDR) and/or nociceptive specific (NS) lateral thalamic neurons. Methods Extracellular recordings were carried out in the thalamus of 15 anesthetized Wistar rats. Lateral thalamic neurons having receptive fields which included the lumbar dorsal-lateral trunk were characterized as either WDR (n=22) or NS (n=25). Response thresholds to electronic von Frey (rigid tip) mechanical trunk stimuli were determined in three directions (dorsal-ventral, 45°caudalward, and 45°cranialward) prior to and immediately following the dorsal-ventral delivery of a 100ms HVLA-SM at three thrust magnitudes (control, 55%, 85% body weight; (BW)). Results There was a significant difference in mechanical threshold between 85% BW manipulation and control thrust magnitudes in the dorsal-ventral direction in NS neurons (p=.01). No changes were found in WDR neurons at either HVLA-SM thrust magnitude. Conclusions This study is the first to investigate the effect of HVLA-SM thrust magnitude on WDR and NS lateral thalamic mechanical response threshold. Our data suggest that at the single lateral thalamic neuron level, there may be a minimal spinal manipulative thrust magnitude required to elicit an increase in trunk mechanical response thresholds. PMID:24928636

  13. [Typical Patterns of Neuronal Activity in Relay and Nonspecific Thalamic Nuclei in Patients with Spasmodic Torticollis].

    PubMed

    Devetiarov, D A; Semenova, U N; Butiaeva, L I; Sedov, A S

    2015-01-01

    Neuronal activity of 50 neurons in nonspecific (Rt, MD) and relay (Voi, Voa) thalamic nuclei was analyzed. Data were obtained by microelectrode technique during 14 stereotactic operations in patients with spasmodic torticollis. Application of Poincare maps and Gap-statistics allowed to reveal 3 main patterns of neuronal activity: irregular single spikes, low-threshold Ca(2+)-dependent rhythmic (3-5 Hz) bursts and combination of bursts and single spikes. In some cases, grouping (in Voi and Rt nuclei) and long burst (in Voa nucleus) patterns were observed. Grouping pattern consist of low-density groups of spikes with tendency to periodicity in range 1-1.5 Hz. Long burst pattern consist of long dense groups of spikes with random length and invariant interburst intervals. Main numerical estimations of 3 most spread patterns of neuronal activity were obtained by parametric analysis. In results, investigated thalamic nuclei significantly distinguished from each other by characteristics of burst activity but average firing rate of these nuclei hadn't significant differences. These data may be useful for functional identification of thalamic nuclei during stereotactic neurosurgery operation in patients with movement disorders.

  14. Multicentre European study of thalamic stimulation in parkinsonian and essential tremor

    PubMed Central

    Limousin, P; Speelman, J; Gielen, F; Janssens, M; study, c

    1999-01-01

    OBJECTIVES—Thalamic stimulation has been proposed to treat disabling tremor. The aims of this multicentre study were to evaluate the efficacy and the morbidity of thalamic stimulation in a large number of patients with parkinsonian or essential tremor.
METHODS—One hundred and eleven patients were included in the study and 110 were implanted either unilaterally or bilaterally. Patients were evaluated with clinical scales, before and up to 12 months after surgery.
RESULTS—Upper and lower limb tremor scores were reduced in both groups. Eighty five per cent of the electrodes satisfied the arbitrary criteria of two point reduction in rest tremor reduction in the parkinsonian tremor group and 89% for postural tremor reduction in the essential tremor group. In the parkinsonian tremor group, limb akinesia and limb rigidity scores were moderately but significantly reduced. Axial scores were unchanged. In the essential tremor group, head tremor was significantly reduced only at 3 months and voice tremor was non-significantly reduced. Activities of daily living were improved in both groups. Changes in medication were moderate. Adverse effects related to the surgery were mild and reversible.
CONCLUSIONS—Thalamic stimulation was shown to be an effective and relatively safe treatment for disabling tremor. This procedure initially applied in a very limited number of centres has been successfully used in 13 participating centres.

 PMID:10084526

  15. Feature-linked synchronization of thalamic relay cell firing induced by feedback from the visual cortex

    NASA Astrophysics Data System (ADS)

    Sillito, Adam M.; Jones, Helen E.; Gerstein, George L.; West, David C.

    1994-06-01

    THE function of the massive feedback projection from visual cortex to its thalamic relay nucleus1,2 has so far eluded any clear overview. This feedback exerts a range of effects3-6, including an increase in the inhibition elicited by moving contours7,8, but the functional logic of the direct connections to the thalamic cells that relay the retinal input to the cortex9-11 remains largely unknown. In contrast to its thalamic nucleus, the visual cortex is characterized by cells that are strongly sensitive to the orientation of moving contours. Here we report that when driven by moving oriented visual stimuli the cortical feedback induces correlated firing in relay cells. This cortically induced correlation of relay cell activity produces coherent firing in those groups of relay cells with receptive field alignments appropriate to signalling the particular orientation of the moving contour to the cortex. Synchronization of relay cell firing means that they will elicit temporally overlapping excitatory postsynaptic potentials in their cortical target cells, thus increasing the chance that the cortical cells will fire. Effectively this increases the gain of the input for feature-linked events detected by the cortex. We propose that this feedback loop serves to lock or focus the appropriate circuitry onto the stimulus feature.

  16. Simulation of thalamic prosthetic vision: reading accuracy, speed, and acuity in sighted humans

    PubMed Central

    Vurro, Milena; Crowell, Anne Marie; Pezaris, John S.

    2014-01-01

    The psychophysics of reading with artificial sight has received increasing attention as visual prostheses are becoming a real possibility to restore useful function to the blind through the coarse, pseudo-pixelized vision they generate. Studies to date have focused on simulating retinal and cortical prostheses; here we extend that work to report on thalamic designs. This study examined the reading performance of normally sighted human subjects using a simulation of three thalamic visual prostheses that varied in phosphene count, to help understand the level of functional ability afforded by thalamic designs in a task of daily living. Reading accuracy, reading speed, and reading acuity of 20 subjects were measured as a function of letter size, using a task based on the MNREAD chart. Results showed that fluid reading was feasible with appropriate combinations of letter size and phosphene count, and performance degraded smoothly as font size was decreased, with an approximate doubling of phosphene count resulting in an increase of 0.2 logMAR in acuity. Results here were consistent with previous results from our laboratory. Results were also consistent with those from the literature, despite using naive subjects who were not trained on the simulator, in contrast to other reports. PMID:25408641

  17. Effects of thalamic stimulation on tremor, balance, and step initiation: a single subject study.

    PubMed

    Burleigh, A L; Horak, F B; Burchiel, K J; Nutt, J G

    1993-10-01

    This study was conducted to evaluate the clinically apparent balance improvements in a patient with Parkinson's disease who had stimulating electrodes surgically implanted to the VIM nucleus of the right thalamus for control of left-upper-extremity tremor. Experiments were conducted to determine if balance improved simply because the large-amplitude upper-extremity tremor was reduced or if the neural control of balance improved. Using EMGs and forceplate recordings, we quantified the effects of the thalamic stimulation on the contralateral upper-extremity tremor and on the lower-extremity postural muscle activations for quiet stance, step initiation, and equilibrium responses to surface displacements. The results demonstrated that, beside reducing the amplitude and destabilizing effects of the upper-extremity tremor, the thalamic stimulation was also effective in reducing tremor activity of the trunk and contralateral lower-extremity muscles. In addition, the contralateral lower-extremity muscle activation patterns, strengths, and durations for the balance tasks were enhanced during stimulation. These results suggest that thalamic stimulation improved this patient's balance by reducing tremor in the contralateral extremities and by increasing burst duration and magnitude of the tibialis anterior, which functions as the postural prime mover for the step initiation and balance tasks.

  18. Simulation of thalamic prosthetic vision: reading accuracy, speed, and acuity in sighted humans.

    PubMed

    Vurro, Milena; Crowell, Anne Marie; Pezaris, John S

    2014-01-01

    The psychophysics of reading with artificial sight has received increasing attention as visual prostheses are becoming a real possibility to restore useful function to the blind through the coarse, pseudo-pixelized vision they generate. Studies to date have focused on simulating retinal and cortical prostheses; here we extend that work to report on thalamic designs. This study examined the reading performance of normally sighted human subjects using a simulation of three thalamic visual prostheses that varied in phosphene count, to help understand the level of functional ability afforded by thalamic designs in a task of daily living. Reading accuracy, reading speed, and reading acuity of 20 subjects were measured as a function of letter size, using a task based on the MNREAD chart. Results showed that fluid reading was feasible with appropriate combinations of letter size and phosphene count, and performance degraded smoothly as font size was decreased, with an approximate doubling of phosphene count resulting in an increase of 0.2 logMAR in acuity. Results here were consistent with previous results from our laboratory. Results were also consistent with those from the literature, despite using naive subjects who were not trained on the simulator, in contrast to other reports.

  19. Dissociable effects of anterior and mediodorsal thalamic lesions on spatial goal-directed behavior.

    PubMed

    Alcaraz, Fabien; Naneix, Fabien; Desfosses, Emilie; Marchand, Alain R; Wolff, Mathieu; Coutureau, Etienne

    2016-01-01

    Goal-directed behaviors are thought to be supported by a neural circuit encompassing the prefrontal cortex, the dorsomedial striatum, the amygdala, and, as more recently suggested, the limbic thalamus. Since evidence indicates that the various thalamic nuclei contribute to dissociable functions, we directly compared the functional contribution of the mediodorsal thalamus (MD) and of the anterior thalamic nuclei (ATN) in a new task assessing spatial goal-directed behavior in a cross-maze. Rats sustaining lesions of the mediodorsal or the anterior thalamus were trained to associate each of the two goal arms with a distinctive food reward. Unlike control rats, both lesioned groups failed to express a bias for the goal arm corresponding to the non-devalued outcome following devaluation by sensory-specific satiety. In addition, MD rats were slower than the other groups to complete the trials. When tested for spatial working memory using a standard non-matching-to-place procedure in the same apparatus, ATN rats were severely impaired but MD rats performed as well as controls, even when spatial or temporal challenges were introduced. Finally, all groups displayed comparable breaking points in a progressive ratio test, indicating that the slower choice performance of MD rats did not result from motivational factors. Thus, a spatial task requiring the integration of instrumental and Pavlovian contingencies reveals a fundamental deficit of MD rats in adapting their choice according to goal value. By contrast, the deficit associated with anterior thalamic lesions appears to simply reflect the inability to process spatial information.

  20. The neurobiology of thalamic amnesia: Contributions of medial thalamus and prefrontal cortex to delayed conditional discrimination.

    PubMed

    Mair, Robert G; Miller, Rikki L A; Wormwood, Benjamin A; Francoeur, Miranda J; Onos, Kristen D; Gibson, Brett M

    2015-07-01

    Although medial thalamus is well established as a site of pathology associated with global amnesia, there is uncertainty about which structures are critical and how they affect memory function. Evidence from human and animal research suggests that damage to the mammillothalamic tract and the anterior, mediodorsal (MD), midline (M), and intralaminar (IL) nuclei contribute to different signs of thalamic amnesia. Here we focus on MD and the adjacent M and IL nuclei, structures identified in animal studies as critical nodes in prefrontal cortex (PFC)-related pathways that are necessary for delayed conditional discrimination. Recordings of PFC neurons in rats performing a dynamic delayed non-matching-to position (DNMTP) task revealed discrete populations encoding information related to planning, execution, and outcome of DNMTP-related actions and delay-related activity signaling previous reinforcement. Parallel studies recording the activity of MD and IL neurons and examining the effects of unilateral thalamic inactivation on the responses of PFC neurons demonstrated a close coupling of central thalamic and PFC neurons responding to diverse aspects of DNMTP and provide evidence that thalamus interacts with PFC neurons to give rise to complex goal-directed behavior exemplified by the DNMTP task.

  1. Model-based iterative learning control of Parkinsonian state in thalamic relay neuron

    NASA Astrophysics Data System (ADS)

    Liu, Chen; Wang, Jiang; Li, Huiyan; Xue, Zhiqin; Deng, Bin; Wei, Xile

    2014-09-01

    Although the beneficial effects of chronic deep brain stimulation on Parkinson's disease motor symptoms are now largely confirmed, the underlying mechanisms behind deep brain stimulation remain unclear and under debate. Hence, the selection of stimulation parameters is full of challenges. Additionally, due to the complexity of neural system, together with omnipresent noises, the accurate model of thalamic relay neuron is unknown. Thus, the iterative learning control of the thalamic relay neuron's Parkinsonian state based on various variables is presented. Combining the iterative learning control with typical proportional-integral control algorithm, a novel and efficient control strategy is proposed, which does not require any particular knowledge on the detailed physiological characteristics of cortico-basal ganglia-thalamocortical loop and can automatically adjust the stimulation parameters. Simulation results demonstrate the feasibility of the proposed control strategy to restore the fidelity of thalamic relay in the Parkinsonian condition. Furthermore, through changing the important parameter—the maximum ionic conductance densities of low-threshold calcium current, the dominant characteristic of the proposed method which is independent of the accurate model can be further verified.

  2. Psychostimulants affect dopamine transmission through both dopamine transporter-dependent and independent mechanisms.

    PubMed

    dela Peña, Ike; Gevorkiana, Ruzanna; Shi, Wei-Xing

    2015-10-05

    The precise mechanisms by which cocaine and amphetamine-like psychostimulants exert their reinforcing effects are not yet fully defined. It is widely believed, however, that these drugs produce their effects by enhancing dopamine neurotransmission in the brain, especially in limbic areas such as the nucleus accumbens, by inducing dopamine transporter-mediated reverse transport and/or blocking dopamine reuptake though the dopamine transporter. Here, we present the evidence that aside from dopamine transporter, non-dopamine transporter-mediated mechanisms also participate in psychostimulant-induced dopamine release and contribute to the behavioral effects of these drugs, such as locomotor activation and reward. Accordingly, psychostimulants could increase norepinephrine release in the prefrontal cortex, the latter then alters the firing pattern of dopamine neurons resulting in changes in action potential-dependent dopamine release. These alterations would further affect the temporal pattern of dopamine release in the nucleus accumbens, thereby modifying information processing in that area. Hence, a synaptic input to a nucleus accumbens neuron may be enhanced or inhibited by dopamine depending on its temporal relationship to dopamine release. Specific temporal patterns of dopamine release may also be required for certain forms of synaptic plasticity in the nucleus accumbens. Together, these effects induced by psychostimulants, mediated through a non-dopamine transporter-mediated mechanism involving norepinephrine and the prefrontal cortex, may also contribute importantly to the reinforcing properties of these drugs.

  3. The lithium vapor box divertor

    DOE PAGES

    Goldston, R. J.; Myers, R.; Schwartz, J.

    2016-01-13

    It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Our recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m-2, implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et al asmore » well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. Furthermore, at the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required in order to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma.« less

  4. The lithium vapor box divertor

    SciTech Connect

    Goldston, R. J.; Myers, R.; Schwartz, J.

    2016-01-13

    It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Our recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m-2, implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et al as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. Furthermore, at the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required in order to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma.

  5. Classical three-box 'paradox'

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, K. A.

    2003-05-01

    A simple classical probabilistic system (a simple card game) classically exemplifies Aharonov and Vaidman's 'three-box 'paradox'' (1991 J. Phys. A: Math. Gen. 24 2315), implying that the three-box example is neither quantal nor a paradox and leaving one with less difficulty to busy the interpreters of quantum mechanics. An ambiguity in the usual expression of the retrodiction formula is shown to have misled Albert et al (1985 Phys. Rev. Lett. 54 5) to a result not, in fact, 'curious'; the discussion illustrates how to avoid this ambiguity.

  6. Thalamic cholinergic innervation and postural sensory integration function in Parkinson's disease.

    PubMed

    Müller, Martijn L T M; Albin, Roger L; Kotagal, Vikas; Koeppe, Robert A; Scott, Peter J H; Frey, Kirk A; Bohnen, Nicolaas I

    2013-11-01

    The pathophysiology of postural instability in Parkinson's disease remains poorly understood. Normal postural function depends in part on the ability of the postural control system to integrate visual, proprioceptive, and vestibular sensory information. Degeneration of cholinergic neurons in the brainstem pedunculopontine nucleus complex and their thalamic efferent terminals has been implicated in postural control deficits in Parkinson's disease. Our aim was to investigate the relationship of cholinergic terminal loss in thalamus and cortex, and nigrostriatal dopaminergic denervation, on postural sensory integration function in Parkinson's disease. We studied 124 subjects with Parkinson's disease (32 female/92 male; 65.5 ± 7.4 years old; 6.0 ± 4.2 years motor disease duration; modified Hoehn and Yahr mean stage 2.4 ± 0.5) and 25 control subjects (10 female/15 male, 66.8 ± 10.1 years old). All subjects underwent (11)C-dihydrotetrabenazine vesicular monoaminergic transporter type 2 and (11)C-methylpiperidin-4-yl propionate acetylcholinesterase positron emission tomography and the sensory organization test balance platform protocol. Measures of dopaminergic and cholinergic terminal integrity were obtained, i.e. striatal vesicular monoaminergic transporter type 2 binding (distribution volume ratio) and thalamic and cortical acetylcholinesterase hydrolysis rate per minute (k3), respectively. Total centre of pressure excursion (speed), a measure of total sway, and sway variability were determined for individual sensory organization test conditions. Based on normative data, principal component analysis was performed to reduce postural sensory organization functions to robust factors for regression analysis with the dopaminergic and cholinergic terminal data. Factor analysis demonstrated two factors with eigenvalues >2 that explained 52.2% of the variance, mainly reflecting postural sway during sensory organization test Conditions 1-3 and 5, respectively. Regression

  7. Cortically-Controlled Population Stochastic Facilitation as a Plausible Substrate for Guiding Sensory Transfer across the Thalamic Gateway

    PubMed Central

    Béhuret, Sébastien; Deleuze, Charlotte; Gomez, Leonel; Frégnac, Yves; Bal, Thierry

    2013-01-01

    The thalamus is the primary gateway that relays sensory information to the cerebral cortex. While a single recipient cortical cell receives the convergence of many principal relay cells of the thalamus, each thalamic cell in turn integrates a dense and distributed synaptic feedback from the cortex. During sensory processing, the influence of this functional loop remains largely ignored. Using dynamic-clamp techniques in thalamic slices in vitro, we combined theoretical and experimental approaches to implement a realistic hybrid retino-thalamo-cortical pathway mixing biological cells and simulated circuits. The synaptic bombardment of cortical origin was mimicked through the injection of a stochastic mixture of excitatory and inhibitory conductances, resulting in a gradable correlation level of afferent activity shared by thalamic cells. The study of the impact of the simulated cortical input on the global retinocortical signal transfer efficiency revealed a novel control mechanism resulting from the collective resonance of all thalamic relay neurons. We show here that the transfer efficiency of sensory input transmission depends on three key features: i) the number of thalamocortical cells involved in the many-to-one convergence from thalamus to cortex, ii) the statistics of the corticothalamic synaptic bombardment and iii) the level of correlation imposed between converging thalamic relay cells. In particular, our results demonstrate counterintuitively that the retinocortical signal transfer efficiency increases when the level of correlation across thalamic cells decreases. This suggests that the transfer efficiency of relay cells could be selectively amplified when they become simultaneously desynchronized by the cortical feedback. When applied to the intact brain, this network regulation mechanism could direct an attentional focus to specific thalamic subassemblies and select the appropriate input lines to the cortex according to the descending influence of

  8. Thalamic haemorrhage vs internal capsule-basal ganglia haemorrhage: clinical profile and predictors of in-hospital mortality

    PubMed Central

    Arboix, Adrià; Rodríguez-Aguilar, Raquel; Oliveres, Montserrat; Comes, Emili; García-Eroles, Luis; Massons, Joan

    2007-01-01

    Background There is a paucity of clinical studies focused specifically on intracerebral haemorrhages of subcortical topography, a subject matter of interest to clinicians involved in stroke management. This single centre, retrospective study was conducted with the following objectives: a) to describe the aetiological, clinical and prognostic characteristics of patients with thalamic haemorrhage as compared with that of patients with internal capsule-basal ganglia haemorrhage, and b) to identify predictors of in-hospital mortality in patients with thalamic haemorrhage. Methods Forty-seven patients with thalamic haemorrhage were included in the "Sagrat Cor Hospital of Barcelona Stroke Registry" during a period of 17 years. Data from stroke patients are entered in the stroke registry following a standardized protocol with 161 items regarding demographics, risk factors, clinical features, laboratory and neuroimaging data, complications and outcome. The region of the intracranial haemorrhage was identified on computerized tomographic (CT) scans and/or magnetic resonance imaging (MRI) of the brain. Results Thalamic haemorrhage accounted for 1.4% of all cases of stroke (n = 3420) and 13% of intracerebral haemorrhage (n = 364). Hypertension (53.2%), vascular malformations (6.4%), haematological conditions (4.3%) and anticoagulation (2.1%) were the main causes of thalamic haemorrhage. In-hospital mortality was 19% (n = 9). Sensory deficit, speech disturbances and lacunar syndrome were significantly associated with thalamic haemorrhage, whereas altered consciousness (odds ratio [OR] = 39.56), intraventricular involvement (OR = 24.74) and age (OR = 1.23), were independent predictors of in-hospital mortality. Conclusion One in 8 patients with acute intracerebral haemorrhage had a thalamic hematoma. Altered consciousness, intraventricular extension of the hematoma and advanced age were determinants of a poor early outcome. PMID:17919332

  9. Expo-Box Contact Us

    EPA Pesticide Factsheets

    EPA-Expo-Box is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases, mode

  10. Black Boxes in Workplace Mathematics

    ERIC Educational Resources Information Center

    Williams, Julian; Wake, Geoff

    2007-01-01

    We ground Cultural-Historical Activity Theory (CHAT) in studies of workplace practices from a mathematical point of view. We draw on multiple case study visits by college students and teacher-researchers to workplaces. By asking questions that "open boxes", we "outsiders and boundary-crossers" sought to expose contradictions between College and…

  11. NETL's JIC in a box

    ScienceCinema

    David Anna

    2016-07-12

    The National Energy Technology Laboratory developed the idea of a portable joint information center AKA JIC in-a-box. This video discribes some of the equipment in the portable JIC as well as some of the methodology that NETL developed as a result of this portable JIC concept.

  12. The Bird Box Survey Project

    ERIC Educational Resources Information Center

    Willis, Patrick

    2014-01-01

    When high school students are asked what's the best part of science class, many will say it's the field trips. Students enjoy engaging in authentic, community-based science outside the classroom. To capitalize on this, Patrick Willis created the Bird Box Survey Project for his introductory field biology class. The project takes students…

  13. NETL's JIC in a box

    SciTech Connect

    David Anna

    2009-06-03

    The National Energy Technology Laboratory developed the idea of a portable joint information center AKA JIC in-a-box. This video discribes some of the equipment in the portable JIC as well as some of the methodology that NETL developed as a result of this portable JIC concept.

  14. EPA-Expo-Box Terminology

    EPA Pesticide Factsheets

    EPA-Expo-Box is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases,

  15. The Cereal Box Problem Revisited.

    ERIC Educational Resources Information Center

    Wilkins, Jesse L. M.

    1999-01-01

    Investigates the cereal box problem using both an experimental and theoretical framework, and Monte Carlo methods. Using empirical data, students can discover patterns and relationships that help them understand the origin of the theoretical solution to the problem. Contains 17 references. (Author/ASK)

  16. On the Dirichlet's Box Principle

    ERIC Educational Resources Information Center

    Poon, Kin-Keung; Shiu, Wai-Chee

    2008-01-01

    In this note, we will focus on several applications on the Dirichlet's box principle in Discrete Mathematics lesson and number theory lesson. In addition, the main result is an innovative game on a triangular board developed by the authors. The game has been used in teaching and learning mathematics in Discrete Mathematics and some high schools in…

  17. Antiferroptotic activity of non-oxidative dopamine.

    PubMed

    Wang, Ding; Peng, Yingpeng; Xie, Yangchun; Zhou, Borong; Sun, Xiaofang; Kang, Rui; Tang, Daolin

    2016-11-25

    Dopamine is a neurotransmitter that has many functions in the nervous and immune systems. Ferroptosis is a non-apoptotic form of regulated cell death that is involved in cancer and neurodegenerative diseases. However, the role of dopamine in ferroptosis remains unidentified. Here, we show that the non-oxidative form of dopamine is a strong inhibitor of ferroptotic cell death. Dopamine dose-dependently blocked ferroptosis in cancer (PANC1 and HEY) and non-cancer (MEF and HEK293) cells following treatment with erastin, a small molecule ferroptosis inducer. Notably, dopamine reduced erastin-induced ferrous iron accumulation, glutathione depletion, and malondialdehyde production. Mechanically, dopamine increased the protein stability of glutathione peroxidase 4, a phospholipid hydroperoxidase that protects cells against membrane lipid peroxidation. Moreover, dopamine suppressed dopamine receptor D4 protein degradation and promoted dopamine receptor D5 gene expression. Thus, our findings uncover a novel function of dopamine in cell death and provide new insight into the regulation of iron metabolism and lipid peroxidation by neurotransmitters.

  18. The H3.3 K27M mutation results in a poorer prognosis in brainstem gliomas than thalamic gliomas in adults.

    PubMed

    Feng, Jie; Hao, Shuyu; Pan, Changcun; Wang, Yu; Wu, Zhen; Zhang, Junting; Yan, Hai; Zhang, Liwei; Wan, Hong

    2015-11-01

    Brainstem and thalamic gliomas are rare, and they are poorly understood in adults. Genetic aberrations that occur in these tumors are still unknown. In this study, we investigated whether thalamic gliomas have different genetic aberrations and clinical outcomes compared with brainstem gliomas in adults. Forty-three glioma samples were selected, including 28 brainstem and 15 thalamic gliomas. The frequency of the K27M mutation in adult midline gliomas was 58.1%. High-grade gliomas in the thalamus were statistically significantly more numerous than brainstem gliomas. Patients with K27M mutant brainstem gliomas had a significantly shorter overall survival than patients with wild-type tumors (P = .020) by Cox regression after adjustment for other independent risk factors. However, there was no statistical tendency toward a poorer overall survival in thalamic gliomas containing the K27M mutation compared with wild-type tumors. The presence of the K27M mutation significantly corresponded with mutations in TP53 in thalamic gliomas. Interestingly, the K27M mutation was mutually exclusive with mutations in IDH1, which was detected only in brainstem gliomas. The microarray data identified 86 differentially expressed genes between brainstem and thalamic gliomas with the K27M mutation. The cyclin-dependent kinase 6 (CDK6) gene, which plays an important role in cancer pathways, was found to be differentially expressed between brainstem and thalamic gliomas with K27M mutations. Although the K27M mutation was frequently observed in adult brainstem and thalamic gliomas, this mutation tended to be associated with a poorer prognosis in brainstem gliomas but not in thalamic gliomas. Brainstem gliomas may present different genetic aberrations from thalamic gliomas. These differences may provide guidance for therapeutic decisions for the treatment of adult brainstem and thalamic gliomas, which may have different molecular targets.

  19. Automatic Measurement of Thalamic Diameter in 2D Fetal Ultrasound Brain Images using Shape Prior Constrained Regularized Level Sets.

    PubMed

    Sridar, Pradeeba; Kumar, Ashnil; Li, Changyang; Woo, Joyce; Quinton, Ann; Benzie, Ron; Peek, Michael; Feng, Dagan; Ramarathnam, Krishna Kumar; Nanan, Ralph; Kim, Jinman

    2016-06-20

    We derived an automated algorithm for accurately measuring the thalamic diameter from 2D fetal ultrasound (US) brain images. The algorithm overcomes the inherent limitations of the US image modality: non-uniform density, missing boundaries, and strong speckle noise. We introduced a 'guitar' structure that represents the negative space surrounding the thalamic regions. The guitar acts as a landmark for deriving the widest points of the thalamus even when its boundaries are not identifiable. We augmented a generalized level-set framework with a shape prior and constraints derived from statistical shape models of the guitars; this framework was used to segment US images and measure the thalamic diameter. Our segmentation method achieved a higher mean Dice similarity coefficient, Hausdorff distance, specificity and reduced contour leakage when compared to other well-established methods. The automatic thalamic diameter measurement had an inter-observer variability of -0.56±2.29 millimeters compared to manual measurement by an expert sonographer. Our method was capable of automatically estimating the thalamic diameter, with the measurement accuracy on par with clinical assessment. Our method can be used as part of computer-assisted screening tools that automatically measure the biometrics of the fetal thalamus; these biometrics are linked to neuro-developmental outcomes.

  20. Gamma Knife surgery targeting the centromedian nucleus of the thalamus for the palliative management of thalamic pain: durable response in stroke-induced thalamic pain syndrome.

    PubMed

    Keep, Marcus F; Mastrofrancesco, Lois; Craig, Arthur D; Ashby, Lynn S

    2006-12-01

    The authors report the neuroimaging features, treatment planning, and outcome in a case of radiosurgical thalamotomy targeting the centromedian nucleus (CMN) for stroke-induced thalamic pain. A 79-year-old man, with embolic occlusion of the left middle cerebral artery and large hemispheric infarction involving the thalamus, suffered a right hemiplegia and expressive aphasia. One year poststroke, severe right-sided facial, scalp, arm, and trunk pain developed and was exacerbated by any tactile contact. Medical treatment had failed. Medical illness, including mandatory anticoagulation therapy for atrial fibrillation, precluded surgical procedures. Minimally invasive radiosurgery was offered as an alternative. Magnetic resonance imaging and computed tomography were used to localize the left CMN. A single shot of 140 Gy was delivered to the 100% isodose line by using the 4-mm collimator helmet. The patient was evaluated at regular intervals. By 12 weeks posttreatment, he had significant improvements in pain control and his ability to tolerate physical contact during activities of daily living. Magnetic resonance imaging demonstrated baseline encephalomalacia from his prior stroke, and signal changes in the left CMN consistent with gamma irradiation-based thalamotomy. Currently, nearly 7 years after radiosurgery, he continues to enjoy a marked reduction in pain without the need of analgesic medications. Thalamic pain syndrome is generally refractory to conventional treatment. Neurosurgical interventions provide modest benefit and carry associated risks of invasive surgery and anesthesia. The CMN is readily localized with neuroimaging and is an approximate target to reduce the suffering aspect of pain. In this case, radiosurgery was a safe and effective treatment, providing durable symptom control and improved quality of life.

  1. Methylphenidate elevates resting dopamine which lowers the impulse-triggered release of dopamine: a hypothesis.

    PubMed

    Seeman, Philip; Madras, Bertha

    2002-03-10

    How do 'stimulants' reduce hyperactivity in children and adults? How can drugs which raise extracellular dopamine result in psychomotor slowing of hyperactive children when dopamine is known to enhance motor activity, such as in Parkinson's disease? In summary, the hypothesis for the anti-hyperactivity effects of the stimulants is as follows: during normal nerve activity, extracellular dopamine levels transiently rise 60-fold. At low therapeutic doses (0.2-0.5 mg/kg) to treat attention-deficit hyperactivity disorder, stimulant drugs such as methylphenidate and dextroamphetamine reduce locomotion in both humans and animals. The drugs raise resting extracellular levels of dopamine several-fold, but reduce the extent to which dopamine is released with nerve impulses, compared to the impulse-associated release in the absence of the drug. This relatively reduced amplitude of impulse-associated dopamine would result in less activation of post-synaptic dopamine receptors which drive psychomotor activity. At higher doses, stimulants produce generalized stimulation of the nervous system, as a result of the very high concentrations of extracellular dopamine at rest, and the markedly increased release of dopamine with nerve impulses. These high levels of resting and pulsatile dopamine cause widespread stimulation of post-synaptic dopamine receptors, overcoming any concomitant presynaptic inhibition of dopamine release.

  2. Glove box for water pit applications

    DOEpatents

    Mills, William C.; Rabe, Richard A.

    2005-01-18

    A glove box assembly that includes a glove box enclosure attached to a longitudinally extending hollow tube having an entranceway, wherein the portion of the tube is in a liquid environment. An elevator member is provided for raising an object that is introduced into the hollow tube from the liquid environment to a gas environment inside the glove box enclosure while maintaining total containment.

  3. The Guide to the Ecology Box.

    ERIC Educational Resources Information Center

    Ontario Inst. for Studies in Education, Toronto.

    Cooperating with the Canadian Commission for UNESCO, the Ontario Institute for Studies in Education has prepared boxes of experimental curriculum materials on the subject of ecology. This guide summarizes the design and contents of the boxes and provides instructions for those using the boxes--principals, teachers, parents, librarians, and…

  4. The Heuristic Interpretation of Box Plots

    ERIC Educational Resources Information Center

    Lem, Stephanie; Onghena, Patrick; Verschaffel, Lieven; Van Dooren, Wim

    2013-01-01

    Box plots are frequently used, but are often misinterpreted by students. Especially the area of the box in box plots is often misinterpreted as representing number or proportion of observations, while it actually represents their density. In a first study, reaction time evidence was used to test whether heuristic reasoning underlies this…

  5. Dopamine receptors – IUPHAR Review 13

    PubMed Central

    Beaulieu, Jean-Martin; Espinoza, Stefano; Gainetdinov, Raul R

    2015-01-01

    The variety of physiological functions controlled by dopamine in the brain and periphery is mediated by the D1, D2, D3, D4 and D5 dopamine GPCRs. Drugs acting on dopamine receptors are significant tools for the management of several neuropsychiatric disorders including schizophrenia, bipolar disorder, depression and Parkinson's disease. Recent investigations of dopamine receptor signalling have shown that dopamine receptors, apart from their canonical action on cAMP-mediated signalling, can regulate a myriad of cellular responses to fine-tune the expression of dopamine-associated behaviours and functions. Such signalling mechanisms may involve alternate G protein coupling or non-G protein mechanisms involving ion channels, receptor tyrosine kinases or proteins such as β-arrestins that are classically involved in GPCR desensitization. Another level of complexity is the growing appreciation of the physiological roles played by dopamine receptor heteromers. Applications of new in vivo techniques have significantly furthered the understanding of the physiological functions played by dopamine receptors. Here we provide an update of the current knowledge regarding the complex biology, signalling, physiology and pharmacology of dopamine receptors. PMID:25671228

  6. Grafted dopamine neurons: Morphology, neurochemistry, and electrophysiology.

    PubMed

    Strömberg, Ingrid; Bickford, Paula; Gerhardt, Greg A

    2010-02-09

    Grafting of dopamine-rich tissue to counteract the symptoms in Parkinson's disease became a promising tool for future treatment. This article discusses how to improve the functional outcome with respect to graft outgrowth and functions of dopamine release and electrophysiological responses to graft implantation in the host brain striatal target. It has been documented that a subpopulation of the dopamine neurons innervates the host brain in a target-specific manner, while some of the grafted dopamine neurons never project to the host striatum. Neurochemical studies have demonstrated that the graft-induced outgrowth synthesize, store, metabolize and release dopamine and possibly other neurotransmitters such as 5-HT. Furthermore, the released dopamine affects the dopamine-depleted brain in areas that are larger than the graft-derived nerve fibers reach. While stem cells will most likely be the future source of cells to be used in grafting, it is important to find the guiding cues for how to reinnervate the dopamine-depleted striatum in a proper way with respect to the dopamine subpopulations of A9 and A10 to efficiently treat the motor abnormalities seen in Parkinson's disease.

  7. Mesolimbic Dopamine Signals the Value of Work

    PubMed Central

    Hamid, Arif A.; Pettibone, Jeffrey R.; Mabrouk, Omar S.; Hetrick, Vaughn L.; Schmidt, Robert; Vander Weele, Caitlin M.; Kennedy, Robert T.; Aragona, Brandon J.; Berke, Joshua D.

    2015-01-01

    Dopamine cell firing can encode errors in reward prediction, providing a learning signal to guide future behavior. Yet dopamine is also a key modulator of motivation, invigorating current behavior. Existing theories propose that fast (“phasic”) dopamine fluctuations support learning, while much slower (“tonic”) dopamine changes are involved in motivation. We examined dopamine release in the nucleus accumbens across multiple time scales, using complementary microdialysis and voltammetric methods during adaptive decision-making. We first show that minute-by-minute dopamine levels covary with reward rate and motivational vigor. We then show that second-by-second dopamine release encodes an estimate of temporally-discounted future reward (a value function). We demonstrate that changing dopamine immediately alters willingness to work, and reinforces preceding action choices by encoding temporal-difference reward prediction errors. Our results indicate that dopamine conveys a single, rapidly-evolving decision variable, the available reward for investment of effort, that is employed for both learning and motivational functions. PMID:26595651

  8. Illumination box and camera system

    DOEpatents

    Haas, Jeffrey S.; Kelly, Fredrick R.; Bushman, John F.; Wiefel, Michael H.; Jensen, Wayne A.; Klunder, Gregory L.

    2002-01-01

    A hand portable, field-deployable thin-layer chromatography (TLC) unit and a hand portable, battery-operated unit for development, illumination, and data acquisition of the TLC plates contain many miniaturized features that permit a large number of samples to be processed efficiently. The TLC unit includes a solvent tank, a holder for TLC plates, and a variety of tool chambers for storing TLC plates, solvent, and pipettes. After processing in the TLC unit, a TLC plate is positioned in a collapsible illumination box, where the box and a CCD camera are optically aligned for optimal pixel resolution of the CCD images of the TLC plate. The TLC system includes an improved development chamber for chemical development of TLC plates that prevents solvent overflow.

  9. Serotonergic fibers distribution in the midline and intralaminar thalamic nuclei in the rock cavy (Kerodon rupestris).

    PubMed

    Silva, Alane de Medeiros; de Santana, Melquisedec Abiaré Dantas; Morais, Paulo Leonardo Araújo de Góis; de Sousa, Twyla Barros; Engelberth, Rovena Clara Galvão Januário; Lucena, Eudes Euler de Souza; Campêlo, Clarissa Loureiro das Chagas; Cavalcante, Jeferson Sousa; Cavalcante, Judney Cley; Costa, Miriam Stela Maris de Oliveira; do Nascimento, Expedito Silva

    2014-10-24

    The thalamic midline/intralaminar complex is part of the higher-order thalamus, which receives little sensory input, and instead forms extensive cortico-thalamo-cortical pathways. The midline thalamic nuclei connect with the medial prefrontal cortex and the medial temporal lobe. On the other hand, the intralaminar nuclei connect with the fronto-parietal cortex. Taking into account this connectivity pattern, it is not surprising that the midline/intralaminar complex has been implicated in a broad variety of cognitive functions, including memory process, attention and orientation, and also reward-based behavior. Serotonin (5-HT) is a neurotransmitter that exerts different post-synaptic roles. Serotonergic neurons are almost entirely restricted to the raphe nuclei and the 5-HT fibers are distributed widely throughout the brain, including the midline/intralaminar complex. The present study comprises a detailed description of the morphologic features and semiquantitative analysis of 5-HT fibers distribution in the midline/intralaminar complex in the rock cavy, a typical rodent of the Northeast region of Brazil, which has been used by our group as an anatomical model to expand the comprehension about phylogeny on the nervous system. The 5-HT fibers in the midline/intralaminar nuclei of the rock cavy were classified into three distinct categories: (1) beaded fibers, which are relatively fine and endowed with large varicosities; (2) fine fibers, with thin axons and small varicosities uniformly distributed in whole axon; and (3) stem axons, showing thick non-varicose axons. Moreover, the density of 5-HT fibers is variable among the analyzed nuclei. On the basis of this diversity of the morphological fibers and the differential profile of optical density among the midline/intralaminar nuclei of the rock cavy, we conclude that the serotonergic system uses a diverse morphologic apparatus to exert a large functional repertory in the midline/intralaminar thalamic nuclei.

  10. Thalamic adenylyl cyclase 1 is required for barrel formation in the somatosensory cortex.

    PubMed

    Suzuki, A; Lee, L-J; Hayashi, Y; Muglia, L; Itohara, S; Erzurumlu, R S; Iwasato, T

    2015-04-02

    Cyclic AMP signaling is critical for activity-dependent refinement of neuronal circuits. Global disruption of adenylyl cyclase 1 (AC1), the major calcium/calmodulin-stimulated adenylyl cyclase in the brain, impairs formation of whisker-related discrete neural modules (the barrels) in cortical layer 4 in mice. Since AC1 is expressed both in the thalamus and the neocortex, the question of whether pre- or postsynaptic (or both) AC1 plays a role in barrel formation has emerged. Previously, we generated cortex-specific AC1 knockout (Cx-AC1KO) mice and found that these animals develop histologically normal barrels, suggesting a potentially more prominent role for thalamic AC1 in barrel formation. To determine this, we generated three new lines of mice: one in which AC1 is disrupted in nearly half of the thalamic ventrobasal nucleus cells in addition to the cortical excitatory neurons (Cx/pTh-AC1KO mouse), and another in which AC1 is disrupted in the thalamus but not in the cortex or brainstem nuclei of the somatosensory system (Th-AC1KO mouse). Cx/pTh-AC1KO mice show severe deficits in barrel formation. Th-AC1KO mice show even more severe disruption in barrel patterning. In these two lines, single thalamocortical (TC) axon labeling revealed a larger lateral extent of TC axons in layer 4 compared to controls. In the third line, all calcium-stimulated adenylyl cyclases (both AC1 and AC8) are deleted in cortical excitatory neurons. These mice have normal barrels. Taken together, these results indicate that thalamic AC1 plays a major role in patterning and refinement of the mouse TC circuitry.

  11. Multimodal 7T Imaging of Thalamic Nuclei for Preclinical Deep Brain Stimulation Applications

    PubMed Central

    Xiao, YiZi; Zitella, Laura M.; Duchin, Yuval; Teplitzky, Benjamin A.; Kastl, Daniel; Adriany, Gregor; Yacoub, Essa; Harel, Noam; Johnson, Matthew D.

    2016-01-01

    Precise neurosurgical targeting of electrode arrays within the brain is essential to the successful treatment of a range of brain disorders with deep brain stimulation (DBS) therapy. Here, we describe a set of computational tools to generate in vivo, subject-specific atlases of individual thalamic nuclei thus improving the ability to visualize thalamic targets for preclinical DBS applications on a subject-specific basis. A sequential nonlinear atlas warping technique and a Bayesian estimation technique for probabilistic crossing fiber tractography were applied to high field (7T) susceptibility-weighted and diffusion-weighted imaging, respectively, in seven rhesus macaques. Image contrast, including contrast within thalamus from the susceptibility-weighted images, informed the atlas warping process and guided the seed point placement for fiber tractography. The susceptibility-weighted imaging resulted in relative hyperintensity of the intralaminar nuclei and relative hypointensity in the medial dorsal nucleus, pulvinar, and the medial/ventral border of the ventral posterior nuclei, providing context to demarcate borders of the ventral nuclei of thalamus, which are often targeted for DBS applications. Additionally, ascending fiber tractography of the medial lemniscus, superior cerebellar peduncle, and pallidofugal pathways into thalamus provided structural demarcation of the ventral nuclei of thalamus. The thalamic substructure boundaries were validated through in vivo electrophysiological recordings and post-mortem blockface tissue sectioning. Together, these imaging tools for visualizing and segmenting thalamus have the potential to improve the neurosurgical targeting of DBS implants and enhance the selection of stimulation settings through more accurate computational models of DBS. PMID:27375422

  12. Evolution of mammalian sensorimotor cortex: thalamic projections to parietal cortical areas in Monodelphis domestica.

    PubMed

    Dooley, James C; Franca, João G; Seelke, Adele M H; Cooke, Dylan F; Krubitzer, Leah A

    2014-01-01

    The current experiments build upon previous studies designed to reveal the network of parietal cortical areas present in the common mammalian ancestor. Understanding this ancestral network is essential for highlighting the basic somatosensory circuitry present in all mammals, and how this basic plan was modified to generate species specific behaviors. Our animal model, the short-tailed opossum (Monodelphis domestica), is a South American marsupial that has been proposed to have a similar ecological niche and morphology to the earliest common mammalian ancestor. In this investigation, we injected retrograde neuroanatomical tracers into the face and body representations of primary somatosensory cortex (S1), the rostral and caudal somatosensory fields (SR and SC), as well as a multimodal region (MM). Projections from different architectonically defined thalamic nuclei were then quantified. Our results provide further evidence to support the hypothesized basic mammalian plan of thalamic projections to S1, with the lateral and medial ventral posterior thalamic nuclei (VPl and VPm) projecting to S1 body and S1 face, respectively. Additional strong projections are from the medial division of posterior nucleus (Pom). SR receives projections from several midline nuclei, including the medial dorsal, ventral medial nucleus, and Pom. SC and MM show similar patterns of connectivity, with projections from the ventral anterior and ventral lateral nuclei, VPm and VPl, and the entire posterior nucleus (medial and lateral). Notably, MM is distinguished from SC by relatively dense projections from the dorsal division of the lateral geniculate nucleus and pulvinar. We discuss the finding that S1 of the short-tailed opossum has a similar pattern of projections as other marsupials and mammals, but also some distinct projections not present in other mammals. Further we provide additional support for a primitive posterior parietal cortex which receives input from multiple modalities.

  13. Thalamic GABA Predicts Fine Motor Performance in Manganese-Exposed Smelter Workers

    PubMed Central

    Long, Zaiyang; Li, Xiang-Rong; Xu, Jun; Edden, Richard A. E.; Qin, Wei-Ping; Long, Li-Ling; Murdoch, James B.; Zheng, Wei; Jiang, Yue-Ming; Dydak, Ulrike

    2014-01-01

    Overexposure to manganese (Mn) may lead to parkinsonian symptoms including motor deficits. The main inhibitory neurotransmitter gamma-aminobutyric acid (GABA) is known to play a pivotal role in the regulation and performance of movement. Therefore this study was aimed at testing the hypothesis that an alteration of GABA following Mn exposure may be associated with fine motor performance in occupationally exposed workers and may underlie the mechanism of Mn-induced motor deficits. A cohort of nine Mn-exposed male smelter workers from an Mn-iron alloy factory and 23 gender- and age-matched controls were recruited and underwent neurological exams, magnetic resonance spectroscopy (MRS) measurements, and Purdue pegboard motor testing. Short-echo-time MRS was used to measure N-Acetyl-aspartate (NAA) and myo-inositol (mI). GABA was detected with a MEGA-PRESS J-editing MRS sequence. The mean thalamic GABA level was significantly increased in smelter workers compared to controls (p = 0.009). Multiple linear regression analysis reveals (1) a significant association between the increase in GABA level and the duration of exposure (R2 = 0.660, p = 0.039), and (2) significant inverse associations between GABA levels and all Purdue pegboard test scores (for summation of all scores R2 = 0.902, p = 0.001) in the smelter workers. In addition, levels of mI were reduced significantly in the thalamus and PCC of smelter workers compared to controls (p = 0.030 and p = 0.009, respectively). In conclusion, our results show clear associations between thalamic GABA levels and fine motor performance. Thus in Mn-exposed subjects, increased thalamic GABA levels may serve as a biomarker for subtle deficits in motor control and may become valuable for early diagnosis of Mn poisoning. PMID:24505436

  14. A computational relationship between thalamic sensory neural responses and contrast perception.

    PubMed

    Jiang, Yaoguang; Purushothaman, Gopathy; Casagrande, Vivien A

    2015-01-01

    Uncovering the relationship between sensory neural responses and perceptual decisions remains a fundamental problem in neuroscience. Decades of experimental and modeling work in the sensory cortex have demonstrated that a perceptual decision pool is usually composed of tens to hundreds of neurons, the responses of which are significantly correlated not only with each other, but also with the behavioral choices of an animal. Few studies, however, have measured neural activity in the sensory thalamus of awake, behaving animals. Therefore, it remains unclear how many thalamic neurons are recruited and how the information from these neurons is pooled at subsequent cortical stages to form a perceptual decision. In a previous study we measured neural activity in the macaque lateral geniculate nucleus (LGN) during a two alternative forced choice (2AFC) contrast detection task, and found that single LGN neurons were significantly correlated with the monkeys' behavioral choices, despite their relatively poor contrast sensitivity and a lack of overall interneuronal correlations. We have now computationally tested a number of specific hypotheses relating these measured LGN neural responses to the contrast detection behavior of the animals. We modeled the perceptual decisions with different numbers of neurons and using a variety of pooling/readout strategies, and found that the most successful model consisted of about 50-200 LGN neurons, with individual neurons weighted differentially according to their signal-to-noise ratios (quantified as d-primes). These results supported the hypothesis that in contrast detection the perceptual decision pool consists of multiple thalamic neurons, and that the response fluctuations in these neurons can influence contrast perception, with the more sensitive thalamic neurons likely to exert a greater influence.

  15. Evolution of mammalian sensorimotor cortex: thalamic projections to parietal cortical areas in Monodelphis domestica

    PubMed Central

    Dooley, James C.; Franca, João G.; Seelke, Adele M. H.; Cooke, Dylan F.; Krubitzer, Leah A.

    2015-01-01

    The current experiments build upon previous studies designed to reveal the network of parietal cortical areas present in the common mammalian ancestor. Understanding this ancestral network is essential for highlighting the basic somatosensory circuitry present in all mammals, and how this basic plan was modified to generate species specific behaviors. Our animal model, the short-tailed opossum (Monodelphis domestica), is a South American marsupial that has been proposed to have a similar ecological niche and morphology to the earliest common mammalian ancestor. In this investigation, we injected retrograde neuroanatomical tracers into the face and body representations of primary somatosensory cortex (S1), the rostral and caudal somatosensory fields (SR and SC), as well as a multimodal region (MM). Projections from different architectonically defined thalamic nuclei were then quantified. Our results provide further evidence to support the hypothesized basic mammalian plan of thalamic projections to S1, with the lateral and medial ventral posterior thalamic nuclei (VPl and VPm) projecting to S1 body and S1 face, respectively. Additional strong projections are from the medial division of posterior nucleus (Pom). SR receives projections from several midline nuclei, including the medial dorsal, ventral medial nucleus, and Pom. SC and MM show similar patterns of connectivity, with projections from the ventral anterior and ventral lateral nuclei, VPm and VPl, and the entire posterior nucleus (medial and lateral). Notably, MM is distinguished from SC by relatively dense projections from the dorsal division of the lateral geniculate nucleus and pulvinar. We discuss the finding that S1 of the short-tailed opossum has a similar pattern of projections as other marsupials and mammals, but also some distinct projections not present in other mammals. Further we provide additional support for a primitive posterior parietal cortex which receives input from multiple modalities. PMID

  16. Comparison of numbers of interneurons in three thalamic nuclei of normal and epileptic rats.

    PubMed

    Cavdar, Safiye; Bay, Hüsniye Hacioğlu; Yildiz, Sercan D; Akakin, Dilek; Sirvanci, Serap; Onat, Filiz

    2014-06-01

    The inhibitory sources in the thalamic nuclei are local interneurons and neurons of the thalamic reticular nucleus. Studies of models of absence epilepsy have shown that the seizures are associated with an excess of inhibitory neurotransmission in the thalamus. In the present study, we used light-microscopic gamma-aminobutyric acid (GABA) immunocytochemistry to quantify the interneurons in the lateral geniculate (LGN), ventral posteromedial (VPM), and ventral posterolateral (VPL) thalamic nuclei, and compared the values from normal Wistar rats and genetic absence epilepsy rats from Strasbourg (GAERS). We found that in both Wistar rats and GAERS, the proportion of interneurons was significantly higher in the LGN than in the VPM and VPL. In the LGN of Wistar rats, 16.4% of the neurons were interneurons and in the GAERS, the value was 15.1%. In the VPM, the proportion of interneurons was 4.2% in Wistar and 14.9% in GAERS; in the VPL the values were 3.7% for Wistar and 11.1% for the GAERS. There was no significant difference between Wistar rats and the GAERS regarding the counts of interneurons in the LGN, whereas the VPM and VPL showed significantly higher counts in GAERS. Comparison of the mean areas of both relay cells and interneuronal profiles showed no significant differences between Wistar rats and GAERS. These findings show that in the VPL and the VPM there are relatively more GABAergic interneurons in GAERS than in Wistar rats. This may represent a compensatory response of the thalamocortical circuitry to the absence seizures or may be related to the production of absence seizures.

  17. Abnormal functional integration of thalamic low frequency oscillation in the BOLD signal after acute heroin treatment.

    PubMed

    Denier, Niklaus; Schmidt, André; Gerber, Hana; Vogel, Marc; Huber, Christian G; Lang, Undine E; Riecher-Rossler, Anita; Wiesbeck, Gerhard A; Radue, Ernst-Wilhelm; Walter, Marc; Borgwardt, Stefan

    2015-12-01

    Heroin addiction is a severe relapsing brain disorder associated with impaired cognitive control, including deficits in attention allocation. The thalamus has a high density of opiate receptors and is critically involved in orchestrating cortical activity during cognitive control. However, there have been no studies on how acute heroin treatment modulates thalamic activity. In a cross-over, double-blind, vehicle-controlled study, 29 heroin-maintained outpatients were studied after heroin and placebo administration, while 20 healthy controls were included for the placebo condition only. Resting-state functional magnetic resonance imaging was used to analyze functional integration of the thalamus by three different resting state analysis techniques. Thalamocortical functional connectivity (FC) was analyzed by seed-based correlation, while intrinsic thalamic oscillation was assessed by analysis of regional homogeneity (ReHo) and the fractional amplitude of low frequency fluctuations (fALFF). Relative to the placebo treatment and healthy controls, acute heroin administration reduced thalamocortical FC to cortical regions, including the frontal cortex, while the reductions in FC to the mediofrontal cortex, orbitofrontal cortex, and frontal pole were positively correlated with the plasma level of morphine, the main psychoactive metabolite of heroin. Furthermore, heroin treatment was associated with increased thalamic ReHo and fALFF values, whereas fALFF following heroin exposure correlated negatively with scores of attentional control. The heroin-associated increase in fALFF was mainly dominated by slow-4 (0.027-0.073 Hz) oscillations. Our findings show that there are acute effects of heroin within the thalamocortical system and may shed new light on the role of the thalamus in cognitive control in heroin addiction. Future research is needed to determine the underlying physiological mechanisms and their role in heroin addiction.

  18. Thalamic functional connectivity predicts seizure laterality in individual TLE patients: application of a biomarker development strategy.

    PubMed

    Barron, Daniel S; Fox, Peter T; Pardoe, Heath; Lancaster, Jack; Price, Larry R; Blackmon, Karen; Berry, Kristen; Cavazos, Jose E; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas

    2015-01-01

    Noninvasive markers of brain function could yield biomarkers in many neurological disorders. Disease models constrained by coordinate-based meta-analysis are likely to increase this yield. Here, we evaluate a thalamic model of temporal lobe epilepsy that we proposed in a coordinate-based meta-analysis and extended in a diffusion tractography study of an independent patient population. Specifically, we evaluated whether thalamic functional connectivity (resting-state fMRI-BOLD) with temporal lobe areas can predict seizure onset laterality, as established with intracranial EEG. Twenty-four lesional and non-lesional temporal lobe epilepsy patients were studied. No significant differences in functional connection strength in patient and control groups were observed with Mann-Whitney Tests (corrected for multiple comparisons). Notwithstanding the lack of group differences, individual patient difference scores (from control mean connection strength) successfully predicted seizure onset zone as shown in ROC curves: discriminant analysis (two-dimensional) predicted seizure onset zone with 85% sensitivity and 91% specificity; logistic regression (four-dimensional) achieved 86% sensitivity and 100% specificity. The strongest markers in both analyses were left thalamo-hippocampal and right thalamo-entorhinal cortex functional connection strength. Thus, this study shows that thalamic functional connections are sensitive and specific markers of seizure onset laterality in individual temporal lobe epilepsy patients. This study also advances an overall strategy for the programmatic development of neuroimaging biomarkers in clinical and genetic populations: a disease model informed by coordinate-based meta-analysis was used to anatomically constrain individual patient analyses.

  19. Thalamic stimulation largely elicits orthodromic, rather than antidromic, cortical activation in an auditory thalamocortical slice.

    PubMed

    Rose, H J; Metherate, R

    2001-01-01

    Stimulation of the medial geniculate body in an auditory thalamocortical slice elicits a short-latency current sink in the middle cortical layers, as would be expected following activation of thalamocortical relay neurons. However, corticothalamic neurons can have axon collaterals that project to the middle layers, thus, a middle-layer current sink could also result from antidromic activation of corticothalamic neurons and their axon collaterals. The likelihood of thalamic stimulation activating corticothalamic neurons would be reduced substantially if the corticothalamic pathway was not well preserved in the slice, and/or if the threshold for antidromic activation was significantly higher than for orthodromic activation. To determine the prevalence and threshold of antidromic activation, we recorded intracellularly from day 14-17 mouse brain slices containing infragranular cortical neurons while stimulating the medial geniculate or thalamocortical pathway. Antidromic spikes were confirmed by spike collision and characterized according to spike latency "jitter" and the ability to follow a high-frequency (100 Hz) stimulus train. The ability to follow a 100-Hz tetanus was a reliable indicator of antidromic activation, but both antidromic and orthodromic spikes could have low jitter. Thalamic stimulation produced antidromic activation in two of 69 infragranular cortical neurons (<3%), indicating the presence of antidromic activity, but implying a limited corticothalamic connection in the slice. Antidromic spikes in 13 additional neurons were obtained by stimulating axons in the thalamocortical pathway. The antidromic threshold averaged 214+/-40.6 microA (range 6-475 microA), over seven times the orthodromic threshold for medial geniculate-evoked responses in layer IV extracellular (28+/-5.4 microA) or intracellular (27+/-5.6 microA) recordings. We conclude that medial geniculate stimulation activates relatively few corticothalamic neurons. Conversely, low

  20. Cingulate seizure-like activity reveals neuronal avalanche regulated by network excitability and thalamic inputs

    PubMed Central

    2014-01-01

    Background Cortical neurons display network-level dynamics with unique spatiotemporal patterns that construct the backbone of processing information signals and contribute to higher functions. Recent years have seen a wealth of research on the characteristics of neuronal networks that are sufficient conditions to activate or cease network functions. Local field potentials (LFPs) exhibit a scale-free and unique event size distribution (i.e., a neuronal avalanche) that has been proven in the cortex across species, including mice, rats, and humans, and may be used as an index of cortical excitability. In the present study, we induced seizure activity in the anterior cingulate cortex (ACC) with medial thalamic inputs and evaluated the impact of cortical excitability and thalamic inputs on network-level dynamics. We measured LFPs from multi-electrode recordings in mouse cortical slices and isoflurane-anesthetized rats. Results The ACC activity exhibited a neuronal avalanche with regard to avalanche size distribution, and the slope of the power-law distribution of the neuronal avalanche reflected network excitability in vitro and in vivo. We found that the slope of the neuronal avalanche in seizure-like activity significantly correlated with cortical excitability induced by γ-aminobutyric acid system manipulation. The thalamic inputs desynchronized cingulate seizures and affected the level of cortical excitability, the modulation of which could be determined by the slope of the avalanche size. Conclusions We propose that the neuronal avalanche may be a tool for analyzing cortical activity through LFPs to determine alterations in network dynamics. PMID:24387299

  1. Visual input to the mouse lateral posterior and posterior thalamic nuclei: photoreceptive origins and retinotopic order

    PubMed Central

    Allen, Annette E.; Procyk, Christopher A.; Howarth, Michael; Walmsley, Lauren

    2016-01-01

    Key points The lateral posterior and posterior thalamic nuclei have been implicated in aspects of visually guided behaviour and reflex responses to light, including those dependent on melanopsin photoreception.Here we investigated the extent and basic properties of visually evoked activity across the mouse lateral posterior and posterior thalamus.We show that a subset of retinal projections to these regions derive from melanopsin‐expressing retinal ganglion cells and find many cells that exhibit melanopsin‐dependent changes in firing.We also show that subsets of cells across these regions integrate signals from both eyes in various ways and that, within the lateral posterior thalamus, visual responses are retinotopically ordered. Abstract In addition to the primary thalamocortical visual relay in the lateral geniculate nuclei, a number of other thalamic regions contribute to aspects of visual processing. Thus, the lateral posterior thalamic nuclei (LP/pulvinar) appear important for various functions including determining visual saliency, visually guided behaviours and, alongside dorsal portions of the posterior thalamic nuclei (Po), multisensory processing of information related to aversive stimuli. However, despite the growing importance of mice as a model for understanding visual system organisation, at present we know very little about the basic visual response properties of cells in the mouse LP or Po. Prompted by earlier suggestions that melanopsin photoreception might be important for certain functions of these nuclei, we first employ specific viral tracing to show that a subset of retinal projections to the LP derive from melanopsin‐expressing retinal ganglion cells. We next use multielectrode electrophysiology to demonstrate that LP and dorsal Po cells exhibit a variety of responses to simple visual stimuli including two distinct classes that express melanopsin‐dependent changes in firing (together comprising ∼25% of neurons we recorded). We also

  2. Thalamic Massa Intermedia Duplication in a Dysmorphic 14 month-old Toddler

    PubMed Central

    Whitehead, Matthew T

    2015-01-01

    The massa intermedia is an inconstant parenchymal band connecting the medial thalami. It may be thickened in various disease processes such as Chiari II malformation or absent in other disease states. However, the massa intermedia may also be absent in up to 30% of normal human brains. To the best of my knowledge, detailed imaging findings of massa intermedia duplication have only been described in a single case report. An additional case of thalamic massa intermedia duplication discovered on a routine brain MR performed for dysmorphic facial features is reported herein. PMID:26622932

  3. Social cognitive and neurocognitive deficits in inpatients with unilateral thalamic lesions – pilot study

    PubMed Central

    Wilkos, Ewelina; Brown, Timothy JB; Slawinska, Ksenia; Kucharska, Katarzyna A

    2015-01-01

    Background The essential role of the thalamus in neurocognitive processes has been well documented. In contrast, relatively little is known about its involvement in social cognitive processes such as recognition of emotion, mentalizing, or empathy. The aim of the study This study was designed to compare the performance of eight patients (five males, three females, mean age ± SD: 63.7±7.9 years) at early stage of unilateral thalamic lesions and eleven healthy controls (six males, five females, 49.6±12.2 years) in neurocognitive tests (CogState Battery: Groton Maze Learning Test, GML; Groton Maze Learning Test-Delayed Recall, GML-DR; Detection Task, DT; Identification Task, IT; One Card Learning Task, OCLT; One Back Task, OBT; Two Back Task, TBT; Set-Shifting Task, S-ST) and other well-known tests (Benton Visual Retention Test, BVRT; California Verbal Learning Test, CVLT; The Rey-Osterrieth Complex Figure Test, ROCF; Trail Making Test, TMT part A and B; Color – Word Stroop Task, CWST; Verbal Fluency Test, VFT), and social cognitive tasks (The Penn Emotion Recognition Test, ER40; Penn Emotion Discrimination Task, EmoDiff40; The Penn Emotional Acuity Test, PEAT40; Reading the Mind in the Eyes Test, revised version II; Toronto Alexithymia Scale, TAS-20). Methods Thalamic-damaged subjects were included if they experienced a single-episode ischemic stroke localized in right or left thalamus. The patients were examined at 3 weeks after the stroke onset. All were right handed. In addition, the following clinical scales were used: the Mini-Mental State Examination (MMSE), Spielberger State-Trait Anxiety Inventory (STAI), Beck Depression Inventory (BDI II). An inclusion criteria was a minimum score of 23/30 in MMSE. Results Compared with the healthy controls, patients revealed significantly lower scores in CVLT, GML-DR, and VFT. Furthermore, compared to healthy controls, patients showed significantly delayed recognition of “happiness” in EmoDiff40 and significantly

  4. The irregular firing properties of thalamic head direction cells mediate turn-specific modulation of the directional tuning curve

    PubMed Central

    Tsanov, Marian; Chah, Ehsan; Noor, Muhammad S.; Egan, Catriona; Reilly, Richard B.; Aggleton, John P.; Erichsen, Jonathan T.; Vann, Seralynne D.

    2014-01-01

    Head direction cells encode an animal's heading in the horizontal plane. However, it is not clear why the directionality of a cell's mean firing rate differs for clockwise, compared with counterclockwise, head turns (this difference is known as the “separation angle”) in anterior thalamus. Here we investigated in freely behaving rats whether intrinsic neuronal firing properties are linked to this phenomenon. We found a positive correlation between the separation angle and the spiking variability of thalamic head direction cells. To test whether this link is driven by hyperpolarization-inducing currents, we investigated the effect of thalamic reticular inhibition during high-voltage spindles on directional spiking. While the selective directional firing of thalamic neurons was preserved, we found no evidence for entrainment of thalamic head direction cells by high-voltage spindle oscillations. We then examined the role of depolarization-inducing currents in the formation of separation angle. Using a single-compartment Hodgkin-Huxley model, we show that modeled neurons fire with higher frequencies during the ascending phase of sinusoidal current injection (mimicking the head direction tuning curve) when simulated with higher high-threshold calcium channel conductance. These findings demonstrate that the turn-specific encoding of directional signal strongly depends on the ability of thalamic neurons to fire irregularly in response to sinusoidal excitatory activation. Another crucial factor for inducing phase lead to sinusoidal current injection was the presence of spike-frequency adaptation current in the modeled neurons. Our data support a model in which intrinsic biophysical properties of thalamic neurons mediate the physiological encoding of directional information. PMID:25122712

  5. Invariant box-parameterization of neutrino oscillations

    SciTech Connect

    Weiler, Thomas J.; Wagner, DJ

    1998-10-19

    The model-independent 'box' parameterization of neutrino oscillations is examined. The invariant boxes are the classical amplitudes of the individual oscillating terms. Being observables, the boxes are independent of the choice of parameterization of the mixing matrix. Emphasis is placed on the relations among the box parameters due to mixing-matrix unitarity, and on the reduction of the number of boxes to the minimum basis set. Using the box algebra, we show that CP-violation may be inferred from measurements of neutrino flavor mixing even when the oscillatory factors have averaged. General analyses of neutrino oscillations among n{>=}3 flavors can readily determine the boxes, which can then be manipulated to yield magnitudes of mixing matrix elements.

  6. Metabolism of dopamine by the nasal mucosa.

    PubMed

    Chemuturi, Nagendra V; Donovan, Maureen D

    2006-11-01

    The nasal route of administration offers several advantages over oral and intravenous administration, including the ability to avoid hepatic first pass metabolism. Dopamine deficiency has been associated with several neurological disorders; it has been shown to have good systemic bioavailability and significant uptake into the CNS following intranasal administration. The purpose of these studies was to investigate the limiting role of mucosal metabolism of dopamine during nasal absorption. In vitro transport and initial rate studies were carried out using nasal mucosal explants to study dopamine permeability and metabolism. Dihydroxyphenylacetic acid (DOPAC) was the only metabolite detected. Monoamine oxidase (MAO), the enzyme responsible for DOPAC formation, was localized to the submucosal region of the nasal explants. The amount of DOPAC formed during the transport studies was less than 0.5% of the initial amount of dopamine placed into the system. Iproniazid, an MAO inhibitor, blocked DOPAC formation but had no effect on dopamine transport. The limited extent of dopamine metabolism compared to its mucosal transport demonstrates that nasal dopamine transport is not significantly reduced by mucosal metabolism and suggests that the nasal route may be promising for the efficient delivery of dopamine to the CNS.

  7. Synapsins Differentially Control Dopamine and Serotonin Release

    PubMed Central

    Kile, Brian M.; Guillot, Thomas S.; Venton, B. Jill; Wetsel, William C.; Augustine, George J.; Wightman, R. Mark

    2010-01-01

    Synapsins are a family of synaptic vesicle proteins that are important for neurotransmitter release. Here we have used triple knockout (TKO) mice lacking all three synapsin genes to determine the roles of synapsins in the release of two monoamine neurotransmitters, dopamine and serotonin. Serotonin release evoked by electrical stimulation was identical in substantia nigra pars reticulata slices prepared from TKO and wild-type mice. In contrast, release of dopamine in response to electrical stimulation was approximately doubled in striatum of TKO mice, both in vivo and in striatal slices, in comparison to wild-type controls. This was due to loss of synapsin III, because deletion of synapsin III alone was sufficient to increase dopamine release. Deletion of synapsins also increased the sensitivity of dopamine release to extracellular calcium ions. Although cocaine did not affect the release of serotonin from nigral tissue, this drug did enhance dopamine release. Cocaine-induced facilitation of dopamine release was a function of external calcium, an effect that was reduced in TKO mice. We conclude that synapsins play different roles in the control of release of dopamine and serotonin, with release of dopamine being negatively regulated by synapsins, specifically synapsin III, while serotonin release appears to be relatively independent of synapsins. These results provide further support for the concept that synapsin function in presynaptic terminals varies according to the neurotransmitter being released. PMID:20660258

  8. Going for broke: dopamine influences risky choice.

    PubMed

    Moschak, Travis M; Carelli, Regina M

    2014-10-01

    Dopamine neurons track reward by increasing or decreasing their firing rate when a reward is present or absent. In this issue of Neuron, Stopper et al. (2014) demonstrate that artificially eliminating these dopamine bursts or dips can alter risky decision-making.

  9. The functional connectivity of intralaminar thalamic nuclei in the human basal ganglia.

    PubMed

    Rodriguez-Sabate, Clara; Llanos, Catalina; Morales, Ingrid; Garcia-Alvarez, Roberto; Sabate, Magdalena; Rodriguez, Manuel

    2015-04-01

    Projections of the centromedian-parafasicularis neurons of the intralaminar thalamus are major inputs of the striatum. Their functional role in the activity of human basal ganglia (BG) is not well known. The aim of this work was to study the functional connectivity of intralaminar thalamic nuclei with other BG by using the correlations of the BOLD signal recorded during "resting" and a motor task. Intralaminar nuclei showed a marked functional connectivity with all the tested BG, which was observed during "resting" and did not change with the motor task. As regards the intralaminar nuclei, BG connectivity was much lower for the medial dorsal nucleus (a thalamic nucleus bordering the intralaminar nuclei) and for the default mode network (although intralaminar nuclei showed a negative correlation with the default mode network). After the "regression" of intralaminar nuclei activity (partial correlation), the functional connectivity of the caudate and putamen nuclei with other BG decreased (but not with the primary sensorimotor cortex). Present data provide evidence that intralaminar nuclei are not only critical for striatal activity but also for the global performance of human BG, an action involving subcortical BG loops more than cortico-subcortical loops. The high correlation found between BG suggest that, similarly to that reported in other brain centers, the very-slow frequency fluctuations are relevant for the functional activity of these centers.

  10. Thalamic mechanisms underlying alpha-delta sleep with implications for fibromyalgia

    PubMed Central

    Klerman, Elizabeth B.; Adler, Gail K.; Kopell, Nancy J.

    2015-01-01

    Alpha-delta sleep is the abnormal intrusion of alpha activity (8- to 13-Hz oscillations) into the delta activity (1- to 4-Hz oscillations) that defines slow-wave sleep. Alpha-delta sleep is especially prevalent in fibromyalgia patients, and there is evidence suggesting that the irregularities in the sleep of these patients may cause the muscle and tissue pain that characterizes the disorder. We constructed a biophysically realistic mathematical model of alpha-delta sleep. Imaging studies in fibromyalgia patients suggesting altered levels of activity in the thalamus motivated a thalamic model as the source of alpha activity. Since sodium oxybate helps to alleviate the symptoms of fibromyalgia and reduces the amount of alpha-delta sleep in fibromyalgia patients, we examined how changes in the molecular targets of sodium oxybate affected alpha-delta activity in our circuit. Our model shows how alterations in GABAB currents and two thalamic currents, Ih (a hyperpolarization-activated current) and a potassium leak current, transform a circuit that normally produces delta oscillations into one that produces alpha-delta activity. Our findings suggest that drugs that reduce Ih conductances and/or increase potassium conductances, without necessarily increasing GABAB conductances, might be sufficient to restore delta sleep. Furthermore, they suggest that delta sleep might be restored by drugs that preferentially target these currents in the thalamus; such drugs might have fewer side effects than drugs that act systemically. PMID:26245315

  11. Thalamic input to distal apical dendrites in neocortical layer 1 is massive and highly convergent.

    PubMed

    Rubio-Garrido, Pablo; Pérez-de-Manzo, Flor; Porrero, César; Galazo, Maria J; Clascá, Francisco

    2009-10-01

    Input to apical dendritic tufts is now deemed crucial for associative learning, attention, and similar "feedback" interactions in the cerebral cortex. Excitatory input to apical tufts in neocortical layer 1 has been traditionally assumed to be predominantly cortical, as thalamic pathways directed to this layer were regarded relatively scant and diffuse. However, the sensitive tracing methods used in the present study show that, throughout the rat neocortex, large numbers (mean approximately 4500/mm(2)) of thalamocortical neurons converge in layer 1 and that this convergence gives rise to a very high local density of thalamic terminals. Moreover, we show that the layer 1-projecting neurons are present in large numbers in most, but not all, motor, association, limbic, and sensory nuclei of the rodent thalamus. Some layer 1-projecting axons branch to innervate large swaths of the cerebral hemisphere, whereas others arborize within only a single cortical area. Present data imply that realistic modeling of cortical circuitry should factor in a dense axonal canopy carrying highly convergent thalamocortical input to pyramidal cell apical tufts. In addition, they are consistent with the notion that layer 1-projecting axons may be a robust anatomical substrate for extensive "feedback" interactions between cortical areas via the thalamus.

  12. Repetition reveals ups and downs of hippocampal, thalamic, and neocortical engagement during mnemonic decisions.

    PubMed

    Reagh, Zachariah M; Murray, Elizabeth A; Yassa, Michael A

    2017-02-01

    The extent to which current information is consistent with past experiences and our capacity to recognize or discriminate accordingly are key factors in flexible memory-guided behavior. Despite a wealth of evidence linking hippocampal and neocortical computations to these phenomena, many important factors remain poorly understood. One such factor is repeated encoding of learned information. In this experiment, participants completed a task in which study stimuli were incidentally encoded either once or three separate times during high-resolution fMRI scanning. We asked how repetition influenced recognition and discrimination memory judgments, and how this affects engagement of hippocampal and neocortical regions. Repetition revealed shifts in engagement in an anterior (ventral) CA1-thalamic-medial prefrontal network related to true and false recognition. Conversely, repetition revealed shifts in a posterior (dorsal) dentate/CA3-parahippocampal-restrosplenial network related to accurate discrimination. These differences in engagement were accompanied by task-related correlations in respective anterior and posterior networks. In particular, the anterior thalamic region observed during recognition judgments is functionally and anatomically consistent with nucleus reuniens in humans, and was found to mediate correlations between the anterior CA1 and medial prefrontal cortex. These findings offer new insights into how repeated experience affects memory and its neural substrates in hippocampal-neocortical networks. © 2016 Wiley Periodicals, Inc.

  13. Persistence of disturbed thalamic glucose metabolism in a case of Wernicke-Korsakoff syndrome.

    PubMed

    Fellgiebel, Andreas; Scheurich, Armin; Siessmeier, Thomas; Schmidt, Lutz G; Bartenstein, Peter

    2003-10-30

    We report the case of a 40-year-old alcoholic male patient, hospitalized with an acute ataxia of stance and gait, ocular muscle weakness with nystagmus and a global apathetic-confusional state. After admission, an amnestic syndrome with confabulation was also observed and diagnosis of Wernicke-Korsakoff syndrome was made. Under treatment with intravenous thiamine, the patient recovered completely from gaze weakness and ataxia, whereas a severe amnestic syndrome persisted. Fluorodeoxyglucose (FDG) positron emission tomography (PET) showed bilateral thalamic and severe bilateral temporal-parietal hypometabolism resembling a pattern typical for Alzheimer's disease. Longitudinal assessment of the alcohol-abstinent and thiamine-substituted patient revealed improvements of clinical state and neuropsychological performance that were paralleled by recovered cerebral glucose metabolism. In contrast to metabolic rates that increased between 7.1% (anterior cingulate, left) and 23.5% (parietal, left) in cortical areas during a 9-month remission period, thalamic glucose metabolism remained severely disturbed over time (change: left +0.2%, right +0.3%).

  14. Central thalamic deep brain stimulation for support of forebrain arousal regulation in the minimally conscious state.

    PubMed

    Schiff, Nicholas D

    2013-01-01

    This chapter considers the use of central thalamic deep brain stimulation (CT/DBS) to support arousal regulation mechanisms in the minimally conscious state (MCS). CT/DBS for selected patients in a MCS is first placed in the historical context of prior efforts to use thalamic electrical brain stimulation to treat the unconscious clinical conditions of coma and vegetative state. These previous studies and a proof of concept result from a single-subject study of a patient in a MCS are reviewed against the background of new population data providing benchmarks of the natural history of vegetative and MCSs. The conceptual foundations for CT/DBS in selected patients in a MCS are then presented with consideration of both circuit and cellular mechanisms underlying recovery of consciousness identified from empirical studies. Directions for developing future generalizable criteria for CT/DBS that focus on the integrity of necessary brain systems and behavioral profiles in patients in a MCS that may optimally response to support of arousal regulation mechanisms are proposed.

  15. Decoding temporally encoded sensory input by cortical oscillations and thalamic phase comparators.

    PubMed

    Ahissar, E; Haidarliu, S; Zacksenhouse, M

    1997-10-14

    The temporally encoded information obtained by vibrissal touch could be decoded "passively," involving only input-driven elements, or "actively," utilizing intrinsically driven oscillators. A previous study suggested that the trigeminal somatosensory system of rats does not obey the bottom-up order of activation predicted by passive decoding. Thus, we have tested whether this system obeys the predictions of active decoding. We have studied cortical single units in the somatosensory cortices of anesthetized rats and guinea pigs and found that about a quarter of them exhibit clear spontaneous oscillations, many of them around whisking frequencies ( approximately 10 Hz). The frequencies of these oscillations could be controlled locally by glutamate. These oscillations could be forced to track the frequency of induced rhythmic whisker movements at a stable, frequency-dependent, phase difference. During these stimulations, the response intensities of multiunits at the thalamic recipient layers of the cortex decreased, and their latencies increased, with increasing input frequency. These observations are consistent with thalamocortical loops implementing phase-locked loops, circuits that are most efficient in decoding temporally encoded information like that obtained by active vibrissal touch. According to this model, and consistent with our results, populations of thalamic "relay" neurons function as phase "comparators" that compare cortical timing expectations with the actual input timing and represent the difference by their population output rate.

  16. Functional convergence of thalamic and intrinsic projections to cortical layers 4 and 6

    PubMed Central

    Lee, Charles C.; Imaizumi, Kazuo

    2014-01-01

    Ascending sensory information is conveyed from the thalamus to layers 4 and 6 of sensory cortical areas. Interestingly, receptive field properties of cortical layer 6 neurons are different from those in layer 4. Do such differences reflect distinct inheritance patterns from the thalamus or are they derived instead from local cortical circuits? To distinguish between these possibilities, we utilized in vitro slice preparations containing the thalamocortical pathways in the auditory and somatosensory systems. Responses from neurons in layers 4 and 6 that resided in the same column were recorded using whole-cell patch clamp. Laser-scanning photostimulation via uncaging of glutamate in the thalamus and cortex was used to map the functional topography of thalamocortical and intracortical inputs to each layer. In addition, we assessed the functional divergence of thalamocortical inputs by optical imaging of flavoprotein autofluorescence. We found that the thalamocortical inputs to layers 4 and 6 originated from the same thalamic domain, but the intracortical projections to the same neurons differed dramatically. Our results suggest that the intracortical projections, rather than the thalamic inputs, to each layer contribute more to the differences in their receptive field properties. PMID:24563558

  17. Organization of projections of rat retrosplenial cortex to the anterior thalamic nuclei.

    PubMed

    Shibata, H

    1998-10-01

    The organization of the projections from the retrosplenial cortex (Brodmann's area 29) to the anterior thalamic nuclei was examined in the rat with retrograde transport of the cholera toxin B subunit and anterograde transport of biotinylated dextran amine. Areas 29a and 29b project mainly ipsilaterally to the rostral two-thirds of the anteroventral nucleus, with area 29a projecting more rostrodorsally than area 29b. Area 29c projects bilaterally to the ventromedial part of the anteroventral nucleus. The projections from area 29c are organized in a topographic pattern such that the rostral area 29c projects to the caudoventral part of the anteroventral nucleus, whereas the caudal area 29c projects to the more rostrodorsal parts. Caudal area 29d projects mainly ipsilaterally to the rostrodorsal part of the anteromedial nucleus, and the rostral and dorsal parts of the anteroventral nucleus, whereas rostral area 29d projects bilaterally to the caudodorsal part of the anteromedial nucleus and the caudolateral part of the anteroventral nucleus. All the areas of the retrosplenial cortex provide sparse projections, mainly ipsilateral, to the anterodorsal nucleus, with a crude topographic pattern such that the rostrocaudal axis of the retrosplenial cortex corresponds to the caudorostral axis of the anterodorsal nucleus. The results indicate that each area of the retrosplenial cortex has a distinct projection field within the anterior thalamic nuclei. This suggests that each of these projections transmits distinct information that is important for complex memory and learning functions, e.g. discriminative avoidance learning and spatial memory.

  18. T-type calcium channels consolidate tonic action potential output of thalamic neurons to neocortex.

    PubMed

    Deleuze, Charlotte; David, François; Béhuret, Sébastien; Sadoc, Gérard; Shin, Hee-Sup; Uebele, Victor N; Renger, John J; Lambert, Régis C; Leresche, Nathalie; Bal, Thierry

    2012-08-29

    The thalamic output during different behavioral states is strictly controlled by the firing modes of thalamocortical neurons. During sleep, their hyperpolarized membrane potential allows activation of the T-type calcium channels, promoting rhythmic high-frequency burst firing that reduces sensory information transfer. In contrast, in the waking state thalamic neurons mostly exhibit action potentials at low frequency (i.e., tonic firing), enabling the reliable transfer of incoming sensory inputs to cortex. Because of their nearly complete inactivation at the depolarized potentials that are experienced during the wake state, T-channels are not believed to modulate tonic action potential discharges. Here, we demonstrate using mice brain slices that activation of T-channels in thalamocortical neurons maintained in the depolarized/wake-like state is critical for the reliable expression of tonic firing, securing their excitability over changes in membrane potential that occur in the depolarized state. Our results establish a novel mechanism for the integration of sensory information by thalamocortical neurons and point to an unexpected role for T-channels in the early stage of information processing.

  19. Pathways for emotions and attention converge on the thalamic reticular nucleus in primates.

    PubMed

    Zikopoulos, Basilis; Barbas, Helen

    2012-04-11

    How do emotional events readily capture our attention? To address this question we used neural tracers to label pathways linking areas involved in emotional and attentional processes in the primate brain (Macaca mulatta). We report that a novel pathway from the amygdala, the brain's emotional center, targets the inhibitory thalamic reticular nucleus (TRN), a key node in the brain's attentional network. The amygdalar pathway formed unusual synapses close to cell bodies of TRN neurons and had more large and efficient terminals than pathways from the orbitofrontal cortex and the thalamic mediodorsal nucleus, which similarly innervated extensive TRN sites. The robust amygdalar pathway provides a mechanism for rapid shifting of attention to emotional stimuli. Acting synergistically, pathways from the amygdala and orbitofrontal cortex provide a circuit for purposeful assessment of emotional stimuli. The different pathways to TRN suggest distinct mechanisms of attention to external and internal stimuli that may be differentially disrupted in anxiety and mood disorders and may be selectively targeted for therapeutic interventions.

  20. Bilateral Thalamic Stimulation Induces Insomnia in Patients Treated for Intractable Tremor

    PubMed Central

    Bridoux, Agathe; Drouot, Xavier; Sangare, Aude; Al-ani, Tarik; Brignol, Arnaud; Charles-Nelson, Anais; Brugières, Pierre; Gouello, Gaëtane; Hosomi, Koichi; Lepetit, Hélène; Palfi, Stéphane

    2015-01-01

    Study Objectives: To explore the influence of acute bilateral ventral intermediate thalamic nucleus (VIM) stimulation on sleep. Design: Three consecutive full-night polysomnography recordings were made in the laboratory. After the habituation night, a random order for night ON-stim and OFF-stim was applied for the second and third nights. Setting: Sleep disorders unit of a university hospital. Patients: Eleven patients with bilateral stimulation of the ventral intermediate nucleus of the thalamus (VIM) for drug-resistant tremor. Measurements: Sleep measures on polysomnography. Results: Total sleep time was reduced during night ON-stim compared to OFF- stim, as well as rapid eye movement sleep percentage while the percentage of N2 increased. Wakefulness after sleep onset time was increased. Conclusion: Our results show that bilateral stimulation of the VIM nuclei reduces sleep and could be associated with insomnia. Citation: Bridoux A, Drouot X, Sangare A, Al-ani T, Brignol A, Charles-Nelson A, Brugières P, Gouello G, Hosomi K, Lepetit H, Palfi S. Bilateral thalamic stimulation induces insomnia in patients treated for intractable tremor. SLEEP 2015;38(3):473–478. PMID:25515098

  1. Striatum and globus pallidus control the electrical activity of reticular thalamic nuclei.

    PubMed

    Villalobos, Nelson; Oviedo-Chávez, Aldo; Alatorre, Alberto; Ríos, Alain; Barrientos, Rafael; Delgado, Alfonso; Querejeta, Enrique

    2016-08-01

    Through GABAergic fibers, globus pallidus (GP) coordinates basal ganglia global function. Electrical activity of GP neurons depends on their membrane properties and afferent fibers, including GABAergic fibers from striatum. In pathological conditions, abnormal electrical activity of GP neurons is associated with motor deficits. There is a GABAergic pathway from the GP to the reticular thalamic nucleus (RTn) whose contribution to RTn neurons electrical activity has received little attention. This fact called our attention because the RTn controls the overall information flow of thalamic nuclei to cerebral cortex. Here, we study the spontaneous electrical activity of RTn neurons recorded in vivo in anesthetized rats and under pharmacological activation or inhibition of the GP. We found that activation of GP predominantly diminishes the spontaneous RTn neurons firing rate and its inhibition increases their firing rate; however, both activation and inhibition of GP did not modified the burst index (BI) or the coefficient of variation (CV) of RTn neurons. Moreover, stimulation of striatum predominantly diminishes the spiking rate of GP cells and increases the spiking rate in RTn neurons without modifying the BI or CV in reticular neurons. Our data suggest a GP tight control over RTn spiking activity.

  2. Retinal projections to the thalamic paraventricular nucleus in the rock cavy (Kerodon rupestris).

    PubMed

    Nascimento, Expedito S; Duarte, Renata B; Silva, Sebastião F; Engelberth, Rovena C G J; Toledo, Cláudio A B; Cavalcante, Jeferson S; Costa, Miriam S M O

    2008-11-19

    The thalamic paraventricular nucleus (PVT) receives afferents from numerous brain areas, including the hypothalamic suprachiasmatic nucleus (SCN), considered to be the major circadian pacemaker. The PVT also sends projections to the SCN, limbic system centers and some nuclei involved in the control of the Sleep-Wake cycle. In this study, we report the identification of a hitherto not reported direct retinal projection to the PVT of the rock cavy, a typical rodent species of the northeast region of Brazil. After unilateral intravitreal injections of cholera toxin subunit B (CTb), anterogradely transported CTb-immunoreactive fibers and presumptive terminals were seen in the PVT. Some possible functional correlates of the present data are briefly discussed, including the role of the PVT in the modulation of the circadian rhythms by considering the reciprocal connections between the PVT and the SCN. The present work is the first to show a direct retinal projection to the PVT of a rodent and may contribute to elucidate the anatomical substrate of the functionally demonstrated involvement of this midline thalamic nucleus in the modulation of the circadian timing system.

  3. Thalamic Atrophy Contributes to Low Slow Wave Sleep in Neuromyelitis Optica Spectrum Disorder

    PubMed Central

    Su, Lei; Han, Yujuan; Xue, Rong; Wood, Kristofer; Shi, Fu-Dong; Liu, Yaou; Fu, Ying

    2016-01-01

    Slow wave sleep abnormality has been reported in neuromyelitis optica spectrum disorder (NMOSD), but mechanism for such abnormality is unknown. To determine the structural defects in the brain that account for the decrease of slow wave sleep in NMOSD patients. Thirty-three NMOSD patients and 18 matched healthy controls (HC) were enrolled. Polysomnography was used to monitor slow wave sleep and three-dimensional T1-weighted MRIs were obtained to assess the alterations of grey matter volume. The percentage of deep slow wave sleep decreased in 93% NMOSD patients. Compared to HC, a reduction of grey matter volume was found in the bilateral thalamus of patients with a lower percentage of slow wave sleep (FWE corrected at cluster-level, p < 0.05, cluster size > 400 voxels). Furthermore, the right thalamic fraction was positively correlated with the decrease in the percentage of slow wave sleep in NMOSD patients (p < 0.05, FDR corrected, cluster size > 200 voxels). Our study identified that thalamic atrophy is associated with the decrease of slow wave sleep in NMOSD patients. Further studies should evaluate whether neurotransmitters or hormones which stem from thalamus are involved in the decrease of slow wave sleep. PMID:28053819

  4. Differential effects of petit mal anticonvulsants and convulsants on thalamic neurones: calcium current reduction.

    PubMed Central

    Coulter, D. A.; Huguenard, J. R.; Prince, D. A.

    1990-01-01

    1. Succinimide derivatives can be either convulsant (tetramethylsuccinimide (TMS)), or anticonvulsant (ethosuximide (ES); alpha-methyl-alpha-phenylsuccinimide (MPS)). ES, an anticonvulsant succinimide, has previously been shown to block calcium currents of thalamic neurones, while the convulsant succinimide TMS blocks gamma-aminobutyric acid (GABA) responses in a similar fashion to the convulsant pentylenetetrazol (PTZ). 2. Using voltage-clamp techniques, we analysed the effects of the anticonvulsant succinimides ES and MPS and the convulsants TMS and PTZ on calcium currents of acutely isolated thalamic relay neurones of the rat. 3. MPS and ES reduced low-threshold calcium current (LTCC) in a voltage-dependent manner, without affecting steady-state inactivation. MPS was less potent than ES (IC50 of 1100 vs 200 microM) but greater in efficacy (100% maximal reduction vs 40% for ES). 4. PTZ had no effect on calcium currents, and TMS only reduced LTCC at very high concentrations, and did not occlude MPS effects when applied concurrently. 5. These results, which demonstrate that anticonvulsant, but not convulsant, succinimides block LTCC, provide additional support for the hypothesis that LTCC reduction is a mechanism of action of the anticonvulsant succinimides related to their effects in petit mal epilepsy. PMID:2169941

  5. Thalamic synaptic transmission of sensory information modulated by synergistic interaction of adenosine and serotonin.

    PubMed

    Yang, Ya-Chin; Hu, Chun-Chang; Huang, Chen-Syuan; Chou, Pei-Yu

    2014-03-01

    The thalamic synapses relay peripheral sensory information to the cortex, and constitute an important part of the thalamocortical network that generates oscillatory activities responsible for different vigilance (sleep and wakefulness) states. However, the modulation of thalamic synaptic transmission by potential sleep regulators, especially by combination of regulators in physiological scenarios, is not fully characterized. We found that somnogen adenosine itself acts similar to wake-promoting serotonin, both decreasing synaptic strength as well as short-term depression, at the retinothalamic synapse. We then combined the two modulators considering the coexistence of them in the hypnagogic (sleep-onset) state. Adenosine plus serotonin results in robust synergistic inhibition of synaptic strength and dramatic transformation of short-term synaptic depression to facilitation. These synaptic effects are not achievable with a single modulator, and are consistent with a high signal-to-noise ratio but a low level of signal transmission through the thalamus appropriate for slow-wave sleep. This study for the first time demonstrates that the sleep-regulatory modulators may work differently when present in combination than present singly in terms of shaping information flow in the thalamocortical network. The major synaptic characters such as the strength and short-term plasticity can be profoundly altered by combination of modulators based on physiological considerations.

  6. Fronto-thalamic volumetry markers of somatic delusions and hallucinations in schizophrenia.

    PubMed

    Spalletta, Gianfranco; Piras, Fabrizio; Alex Rubino, Ivo; Caltagirone, Carlo; Fagioli, Sabrina

    2013-04-30

    Although the psychotic phenomena of schizophrenia have been extensively investigated, somatic delusions and hallucinations have seldom been reported and their mechanisms are substantially unexplored. Here, we aimed to identify the brain structural correlates of somatic psychotic phenomena using combined volumetry and diffusivity structural neuroimaging techniques. Seventy-five individuals with a DSM-IV-TR diagnosis of schizophrenia and 75 healthy controls (HC) underwent a comprehensive clinical assessment, a high-resolution T1-weighted magnetic resonance imaging and a diffusion tensor imaging protocol using a 3T MRI scanner. Voxel-based volumetry and mean diffusivity (MD) of gray matter (GM) and fractional anisotropy (FA) of white matter (WM) of the whole brain were calculated for each subject. Reduced left fronto-insular GM volume was found in patients with somatic delusions compared with patients without somatic delusions and HC. Increased GM volume was found in the bilateral thalami, primarily in the right ventral-anterior thalamic nucleus projecting to the prefrontal-temporal cortices and the bilateral pars triangularis of the inferior frontal lobe, of patients with somatic hallucinations and HC compared with patients without somatic hallucinations. No differences emerged in GM MD and in WM FA between patients with and without psychotic somatic phenomena (i.e. delusions or hallucinations). These findings provide the first evidence that a frontal-thalamic structural perturbation mediates somatic psychotic phenomena in schizophrenia.

  7. Metabolic hormones, dopamine circuits, and feeding

    PubMed Central

    Narayanan, Nandakumar S.; Guarnieri, Douglas J.; DiLeone, Ralph J.

    2009-01-01

    Recent evidence has emerged demonstrating that metabolic hormones such as ghrelin and leptin can act on ventral tegmental area (VTA) midbrain dopamine neurons to influence feeding. The VTA is the origin of mesolimbic dopamine neurons that project to the nucleus accumbens (NAc) to influence behavior. While blockade of dopamine via systemic antagonists or targeted gene delete can impair food intake, local NAc dopamine manipulations have little effect on food intake. Notably, non-dopaminergic manipulations in the VTA and NAc produce more consistent effects on feeding and food choice. More recent genetic evidence supports a role for the substantia nigra-striatal dopamine pathways in food intake, while the VTA-NAc circuit is more likely involved in higher-order aspects of food acquisition, such as motivation and cue associations. This rich and complex literature should be considered in models of how peripheral hormones influence feeding behavior via action on the midbrain circuits. PMID:19836414

  8. Dopamine transporter mutant animals: a translational perspective

    PubMed Central

    Efimova, Evgenia V.; Gainetdinov, Raul R.; Budygin, Evgeny A.; Sotnikova, Tatiana D.

    2016-01-01

    The dopamine transporter (DAT) plays an important homeostatic role in the control of both the extracellular and intraneuronal concentrations of dopamine, thereby providing effective control over activity of dopaminergic transmission. Since brain dopamine is known to be involved in numerous neuropsychiatric disorders, investigations using mice with genetically altered DAT function and thus intensity of dopamine-mediated signaling have provided numerous insights into the pathology of these disorders and highlight novel pathological mechanisms that could be targeted to provide new therapeutic approaches for these disorders. In this brief overview we discuss recent investigations involving animals with genetically altered DAT function, particularly focusing on translational studies providing new insights into pathology and pharmacology of dopamine-related disorders. Perspective applications of these and newly developed models of DAT dysfunction are also discussed. PMID:27276191

  9. Dopamine agonist therapy in hyperprolactinemia.

    PubMed

    Webster, J

    1999-12-01

    Introduction of the dopamine agonist bromocriptine heralded a major advance in the management of hyperprolactinemic disorders. Although its side effects of nausea, dizziness and headache and its short elimination half-life are limiting factors, its efficacy established it as a reference compound against the activity of which several dopamine agonists, like pergolide, lysuride, metergoline, terguride and dihydroergocristine, fell by the wayside. More recently, two new agents, cabergoline and quinagolide, have been introduced and appear to offer considerable advantages over bromocriptine. Cabergoline, an ergoline D2 agonist, has a long plasma half-life that enables once- or twice-weekly administration. Quinagolide, in contrast, is a nonergot D2 agonist with an elimination half-life intermediate between those of bromocriptine and cabergoline, allowing the drug to be administered once daily. Comparative studies indicate that cabergoline is clearly superior to bromocriptine in efficacy (prolactin suppression, restoration of gonadal function) and in tolerability. In similar studies, quinagolide appeared to have similar efficacy and superior tolerability to that of bromocriptine. Results of a small crossover study indicate that cabergoline is better tolerated, with a trend toward activity superior to that of quinagolide. In hyperprolactinemic men and in women not seeking to become pregnant, cabergoline may be regarded as the treatment of choice.

  10. Deformity in the "Boxing Boys".

    PubMed

    Ferrence, Susan; Bendersky, Gordon

    2005-01-01

    The late Bronze Age wall painting the Boxing Boys (c. 17th-16th century BCE) was excavated in the ancient town of Akrotiri on the Greek island of Thera. This article considers a medical interpretation for the spinal-pelvic anomaly in the anatomy of one of the boys. The artist has depicted a combination of structural anatomical adjustments diagnostic of spondylolisthesis, a forward slippage of one of the lumbar vertebrae. The accurate portrayal of the surface appearance of this condition suggests that the artist painted directly from a live subject. Thus, the Boxing Boys mural may be the earliest visual record of a sports-induced injury. Although the meaning of the wall paintings is unclear, the wild goats (agrimia) on the adjoining walls simulate swayback as a reflection of the boy's torso deformity and share other features with the boxers, adding to the unifying characteristics of the room. The abnormal morphology appears to be the earliest achievement of transforming disease into aesthetic charm on a monumental scale.

  11. Effect of Spinal Manipulation Thrust Duration on Trunk Mechanical Activation Thresholds of Nociceptive-Specific Lateral Thalamic Neurons

    PubMed Central

    Reed, William R.; Sozio, Randall; Pickar, Joel G.; Onifer, Stephen M.

    2015-01-01

    Objective The objective of this preliminary study was to determine if high-velocity, low-amplitude spinal manipulation (HVLA-SM) thrust duration alters mechanical trunk activation thresholds of nociceptive-specific (NS) lateral thalamic neurons. Methods Extracellular recordings were obtained from 18 NS neurons located in 2 lateral thalamic nuclei (ventrolateral [n = 12] and posterior [n = 6]) in normal anesthetized Wistar rats. Response thresholds to electronic von Frey anesthesiometer (rigid tip) mechanical trunk stimuli applied in 3 lumbar directions (dorsal-ventral, 45° caudal, and 45° cranial) were determined before and immediately after the delivery of 3 HVLA-SM thrust durations (time control 0, 100, and 400 milliseconds). Mean changes in mechanical trunk activation thresholds were compared using a mixed model analysis of variance. Results High-velocity, low-amplitude spinal manipulation duration did not significantly alter NS lateral thalamic neurons’ mechanical trunk responses to any of the 3 directions tested with the anesthesiometer. Conclusions This study is the first to examine the effect of HVLA-SM thrust duration on NS lateral thalamic mechanical response thresholds. High-velocity, low-amplitude spinal manipulation thrust duration did not affect mechanical trunk thresholds. PMID:25220757

  12. MM2-thalamic Creutzfeldt-Jakob disease: neuropathological, biochemical and transmission studies identify a distinctive prion strain.

    PubMed

    Moda, Fabio; Suardi, Silvia; Di Fede, Giuseppe; Indaco, Antonio; Limido, Lucia; Vimercati, Chiara; Ruggerone, Margherita; Campagnani, Ilaria; Langeveld, Jan; Terruzzi, Alessandro; Brambilla, Antonio; Zerbi, Pietro; Fociani, Paolo; Bishop, Matthew T; Will, Robert G; Manson, Jean C; Giaccone, Giorgio; Tagliavini, Fabrizio

    2012-09-01

    In Creutzfeldt-Jakob disease (CJD), molecular typing based on the size of the protease resistant core of the disease-associated prion protein (PrP(Sc) ) and the M/V polymorphism at codon 129 of the PRNP gene correlates with the clinico-pathologic subtypes. Approximately 95% of the sporadic 129MM CJD patients are characterized by cerebral deposition of type 1 PrP(Sc) and correspond to the classic clinical CJD phenotype. The rare 129MM CJD patients with type 2 PrP(Sc) are further subdivided in a cortical and a thalamic form also indicated as sporadic fatal insomnia. We observed two young patients with MM2-thalamic CJD. Main neuropathological features were diffuse, synaptic PrP immunoreactivity in the cerebral cortex and severe neuronal loss and gliosis in the thalamus and olivary nucleus. Western blot analysis showed the presence of type 2A PrP(Sc) . Challenge of transgenic mice expressing 129MM human PrP showed that MM2-thalamic sporadic CJD (sCJD) was able to transmit the disease, at variance with MM2-cortical sCJD. The affected mice showed deposition of type 2A PrP(Sc) , a scenario that is unprecedented in this mouse line. These data indicate that MM2-thalamic sCJD is caused by a prion strain distinct from the other sCJD subtypes including the MM2-cortical form.

  13. The origin of projections from the posterior cingulate and retrosplenial cortices to the anterior, medial dorsal and laterodorsal thalamic nuclei of macaque monkeys.

    PubMed

    Aggleton, John P; Saunders, Richard C; Wright, Nicholas F; Vann, Seralynne D

    2014-01-01

    Interactions between the posterior cingulate cortex (areas 23 and 31) and the retrosplenial cortex (areas 29 and 30) with the anterior, laterodorsal and dorsal medial thalamic nuclei are thought to support various aspects of cognition, including memory and spatial processing. To detail these interactions better, the present study used retrograde tracers to reveal the origins of the corticothalamic projections in two closely related monkey species (Macaca mulatta, Macaca fascicularis). The medial dorsal thalamic nucleus received only light cortical inputs, which predominantly arose from area 23. Efferents to the anterior medial thalamic nucleus also arose principally from area 23, but these projections proved more numerous than those to the medial dorsal nucleus and also involved additional inputs from areas 29 and 30. The anterior ventral and laterodorsal thalamic nuclei had similar sources of inputs from the posterior cingulate and retrosplenial cortices. For both nuclei, the densest projections arose from areas 29 and 30, with numbers of thalamic inputs often decreasing when going dorsal from area 23a to 23c and to area 31. In all cases, the corticothalamic projections almost always arose from the deepest cortical layer. The different profiles of inputs to the anterior medial and anterior ventral thalamic nuclei reinforce other anatomical and electrophysiological findings suggesting that these adjacent thalamic nuclei serve different, but complementary, functions supporting memory. While the lack of retrosplenial connections singled out the medial dorsal nucleus, the very similar connection patterns shown by the anterior ventral and laterodorsal nuclei point to common roles in cognition.

  14. Dopamine-Modulated Recurrent Corticoefferent Feedback in Primary Sensory Cortex Promotes Detection of Behaviorally Relevant Stimuli

    PubMed Central

    Handschuh, Juliane

    2014-01-01

    Dopaminergic neurotransmission in primary auditory cortex (AI) has been shown to be involved in learning and memory functions. Moreover, dopaminergic projections and D1/D5 receptor distributions display a layer-dependent organization, suggesting specific functions in the cortical circuitry. However, the circuit effects of dopaminergic neurotransmission in sensory cortex and their possible roles in perception, learning, and memory are largely unknown. Here, we investigated layer-specific circuit effects of dopaminergic neuromodulation using current source density (CSD) analysis in AI of Mongolian gerbils. Pharmacological stimulation of D1/D5 receptors increased auditory-evoked synaptic currents in infragranular layers, prolonging local thalamocortical input via positive feedback between infragranular output and granular input. Subsequently, dopamine promoted sustained cortical activation by prolonged recruitment of long-range corticocortical networks. A detailed circuit analysis combining layer-specific intracortical microstimulation (ICMS), CSD analysis, and pharmacological cortical silencing revealed that cross-laminar feedback enhanced by dopamine relied on a positive, fast-acting recurrent corticoefferent loop, most likely relayed via local thalamic circuits. Behavioral signal detection analysis further showed that activation of corticoefferent output by infragranular ICMS, which mimicked auditory activation under dopaminergic influence, was most effective in eliciting a behaviorally detectable signal. Our results show that D1/D5-mediated dopaminergic modulation in sensory cortex regulates positive recurrent corticoefferent feedback, which enhances states of high, persistent activity in sensory cortex evoked by behaviorally relevant stimuli. In boosting horizontal network interactions, this potentially promotes the readout of task-related information from cortical synapses and improves behavioral stimulus detection. PMID:24453315

  15. Neuronal Activity in the Subthalamic Nucleus Modulates the Release of Dopamine in the Monkey Striatum

    PubMed Central

    Shimo, Yasushi; Wichmann, Thomas

    2009-01-01

    The primate subthalamic nucleus (STN) is commonly seen as a relay nucleus between the external and internal pallidal segments, and as an input station for cortical and thalamic information into the basal ganglia. In rodents, STN activity is also known to influence neuronal activity in the dopaminergic substantia nigra pars compacta (SNc) through inhibitory and excitatory mono- and polysynaptic pathways. Although the anatomical connections between STN and SNc are not entirely the same in primates as in rodents, the electrophysiologic and microdialysis experiments presented here show directly that this functional interaction can also be demonstrated in primates. In three Rhesus monkeys, extracellular recordings from SNc during microinjections into the STN revealed that transient pharmacologic activation of the subthalamic nucleus by the acetylcholine-receptor agonist carbachol substantially increased burst firing of single nigral neurons. Transient inactivation of the STN with microinjections of the GABA-A-receptor agonist muscimol had the opposite effect. While the firing rates of individual SNc neurons changed in response to the activation or inactivation of the STN, these changes were not consistent across the entire population of SNc cells. Permanent lesions of the STN, produced in two animals with the fiber-sparing neurotoxin ibotenic acid, reduced burst firing and firing rates of SNc neurons, and substantially decreased dopamine levels in the primary recipient area of SNc projections, the striatum, as measured with microdialysis. These results suggest that activity in the primate SNc is prominently influenced by neuronal discharge in the STN, which may thus alter dopamine release in the striatum. PMID:19087163

  16. Dopamine-Secreting Paraganglioma in the Retroperitoneum.

    PubMed

    Matsuda, Yusuke; Kimura, Noriko; Yoshimoto, Takanobu; Sekiguchi, Yoshihiro; Tomoishi, Junzo; Kasahara, Ichiro; Hara, Yoshihito; Ogawa, Yoshihiro

    2017-03-01

    Pheochromocytomas and paragangliomas, which exclusively produce dopamine, are very rare. Herein, we report for the first time a Japanese case of an exclusively dopamine-producing paraganglioma accompanied by detailed immunohistochemical analyses. A 70-year-old Japanese woman was referred to our hospital for functional examination of her left retroperitoneal mass. Her adrenal functions were normal, except for excessive dopamine secretion. After the tumorectomy, her dopamine level normalized. The histopathological diagnosis of the tumor was paraganglioma; this was confirmed by positive immunostaining of chromogranin A (CgA), tyrosine hydroxylase (TH), dopamine β-hydroxylase (DBH), and succinate dehydrogenase gene subunit B (SDHB). However, the immunostaining of CgA in the tumor cells showed peculiar dot-like staining located corresponding to Golgi complex in the perinuclear area, rather than the diffuse cytoplasmic staining usually observed in epinephrine- or norepinephrine-producing functional pheochromocytomas and paragangliomas. The immunohistochemical results suggested that the tumor cells had sparse neuroendocrine granules in the cytoplasm, resulting in inhibition of catecholamine synthesis from dopamine to norepinephrine in neurosecretory granules. This may be the mechanism responsible for exclusive dopamine secretion in the present case.

  17. Dopamine receptors in human gastrointestinal mucosa

    SciTech Connect

    Hernandez, D.E.; Mason, G.A.; Walker, C.H.; Valenzuela, J.E.

    1987-12-21

    Dopamine is a putative enteric neurotransmitter that has been implicated in exocrine secretory and motility functions of the gastrointestinal tract of several mammalian species including man. This study was designed to determine the presence of dopamine binding sites in human gastric and duodenal mucosa and to describe certain biochemical characteristics of these enteric receptor sites. The binding assay was performed in triplicate with tissue homogenates obtained from healthy volunteers of both sexes using /sup 3/H-dopamine as a ligand. The extent of nonspecific binding was determined in the presence of a 100-fold excess of unlabeled dopamine. Scatchard analysis performed with increasing concentrations of /sup 3/H-dopamine (20-500 nM) revealed a single class of saturable dopamine binding sites in gastric and duodenal mucosa. The results of this report demonstrate the presence of specific dopamine receptors in human gastric and duodenal mucosa. These biochemical data suggest that molecular abnormalities of these receptor sites may be operative in the pathogenesis of important gastrointestinal disorders. 33 references, 2 figures.

  18. Dopamine transporter: expression in Xenopus oocytes.

    PubMed

    Uhl, G R; O'Hara, B; Shimada, S; Zaczek, R; DiGiorgianni, J; Nishimori, T

    1991-01-01

    Xenopus oocytes can express biologically relevant transport activity after injection of mRNAs encoding several carrier molecules. mRNA from PC12 cells, as well as transcripts from a rat ventral midbrain library, can be expressed in these oocytes and allow them to display pharmacologically specific dopamine uptake. mRNA-injected oocytes incubated with tritiated dopamine contain tritiated dopamine and metabolites; lower amounts of radiolabeled dopamine and more radiolabeled metabolites are found in oocytes co-incubated with cocaine or in water-injected oocytes. Tritiated dopamine uptake into mRNA-injected oocytes is time, sodium, and temperature dependent. It is blocked by cocaine and mazindol, but not by haloperidol. It is not found after injection of mRNA from other brain regions. A size-selected rat midbrain library constructed in the plasma vector pCDM8 yields mRNA transcripts whose injection into oocytes causes cocaine-blockable [3H]dopamine uptake. These findings provide an assay for purification of the dopamine transporter cDNA by sib selection techniques.

  19. Stereoselectivity of presynaptic autoreceptors modulating dopamine release.

    PubMed

    Arbilla, S; Langer, S Z

    1981-12-17

    The effects of the (R)- and (S)-enantiomers of sulpiride and butaclamol were studied on the spontaneous and field stimulation-evoked release of total radioactivity from slices of rabbit caudate nucleus prelabelled with [3H]dopamine. (S)-Sulpiride in concentrations ranging from 0.01--1 microM enhanced the electrically evoked release of [3H]dopamine while (R)-sulpiride was 10 times less potent than (S)-sulpiride. Exposure to (S)-butaclamol (0.01--1 microM) but not to (R)-butaclamol (0.1--10 microM) enhanced the field-stimulated release of [3H]dopamine. The facilitatory effects of (S)- and (R)-sulpiride and (S)-butaclamol on the stimulated release of the labelled neurotransmitter were observed under conditions in which these drugs did not modify the spontaneous outflow of radioactivity. Only the active enantiomers of sulpiride and butaclamol antagonized the inhibition by apomorphine (1 microM) of the stimulated release of [3H]dopamine. Our results indicate that the presynaptic inhibitory dopamine autoreceptors modulating the stimulation-evoked release of [3H]dopamine in the caudate nucleus are, like the classical postsynaptic dopamine receptors, chemically stereoselective.

  20. Interchangeable breech lock for glove boxes

    DOEpatents

    Lemonds, David Preston

    2015-11-24

    A breech lock for a glove box is provided that may be used to transfer one or more items into the glove box. The breech lock can be interchangeably installed in place of a plug, glove, or other device in a port or opening of a glove box. Features are provided to aid the removal of items from the breech lock by a gloved operator. The breech lock can be reused or, if needed, can be replaced with a plug, glove, or other device at the port or opening of the glove box.

  1. Duplex unwinding with DEAD-box proteins.

    PubMed

    Jankowsky, Eckhard; Putnam, Andrea

    2010-01-01

    DEAD-box proteins, which comprise the largest helicase family, are involved in virtually all aspects of RNA metabolism. DEAD-box proteins catalyze diverse ATP-driven functions including the unwinding of RNA secondary structures. In contrast to many well-studied DNA and viral RNA helicases, DEAD-box proteins do not rely on translocation on one of the nucleic acid strands for duplex unwinding, but directly load onto helical regions and then locally pry the strands apart in an ATP-dependent fashion. In this chapter, we outline substrate design and unwinding protocols for DEAD-box proteins and focus on the quantitative evaluation of their unwinding activity.

  2. Repackaging SRS Black Box TRU Waste

    SciTech Connect

    Swale, D. J.; Stone, K.A.; Milner, T. N.

    2006-01-09

    Historically, large items of TRU Waste, which were too large to be packaged in drums for disposal have been packaged in various sizes of custom made plywood boxes at the Savannah River Site (SRS), for many years. These boxes were subsequently packaged into large steel ''Black Boxes'' for storage at SRS, pending availability of Characterization and Certification capability, to facilitate disposal of larger items of TRU Waste. There are approximately 107 Black Boxes in inventory at SRS, each measuring some 18' x 12' x 7', and weighing up to 45,000 lbs. These Black Boxes have been stored since the early 1980s. The project to repackage this waste into Standard Large Boxes (SLBs), Standard Waste Boxes (SWB) and Ten Drum Overpacks (TDOP), for subsequent characterization and WIPP disposal, commenced in FY04. To date, 10 Black Boxes have been repackaged, resulting in 40 SLB-2's, and 37 B25 overpack boxes, these B25's will be overpacked in SLB-2's prior to shipping to WIPP. This paper will describe experience to date from this project.

  3. Robust thalamic nuclei segmentation method based on local diffusion magnetic resonance properties.

    PubMed

    Battistella, Giovanni; Najdenovska, Elena; Maeder, Philippe; Ghazaleh, Naghmeh; Daducci, Alessandro; Thiran, Jean-Philippe; Jacquemont, Sébastien; Tuleasca, Constantin; Levivier, Marc; Bach Cuadra, Meritxell; Fornari, Eleonora

    2016-11-25

    The thalamus is an essential relay station in the cortical-subcortical connections. It is characterized by a complex anatomical architecture composed of numerous small nuclei, which mediate the involvement of the thalamus in a wide range of neurological functions. We present a novel framework for segmenting the thalamic nuclei, which explores the orientation distribution functions (ODFs) from diffusion magnetic resonance images at 3 T. The differentiation of the complex intra-thalamic microstructure is improved by using the spherical harmonic (SH) representation of the ODFs, which provides full angular characterization of the diffusion process in each voxel. The clustering was performed using the k-means algorithm initialized in a data-driven manner. The method was tested on 35 healthy volunteers and our results show a robust, reproducible and accurate segmentation of the thalamus in seven nuclei groups. Six of them closely matched the anatomy and were labeled as anterior, ventral anterior, medio-dorsal, ventral latero-ventral, ventral latero-dorsal and pulvinar, while the seventh cluster included the centro-lateral and the latero-posterior nuclei. Results were evaluated both qualitatively, by comparing the segmented nuclei to the histological atlas of Morel, and quantitatively, by measuring the clusters' extent and the clusters' spatial distribution across subjects and hemispheres. We also showed the robustness of our approach across different sequences and scanners, as well as intra-subject reproducibility of the segmented clusters using additional two scan-rescan datasets. We also observed an overlap between the path of the main long-connection tracts passing through the thalamus and the spatial distribution of the nuclei identified with our clustering algorithm. Our approach, based on SH representations of the ODFs, outperforms the one based on angular differences between the principle diffusion directions, which is considered so far as state

  4. Medial thalamic 18-FDG uptake following inescapable shock correlates with subsequent learned helpless behavior

    SciTech Connect

    Mirrione,M.M.; Mirrione, M.M.; Schulz, D.; Dewey, S.L.; Henn, F.A.

    2009-12-06

    The learned helplessness paradigm has been repeatedly shown to correlate with neurobiological aspects of depression in humans. In this model, rodents are exposed inescapable foot-shock in order to reveal susceptibility to escape deficit, defined as 'learned helplessness' (LH). Few methods are available to probe the neurobiological aspects underlying the differences in susceptibility in the living animal, thus far being limited to studies examining regional neurochemical changes with microdialysis. With the widespread implementation of small animal neuroimaging methods, including positron emission tomography (PET), it is now possible to explore the living brain on a systems level to define regional changes that may correlate with vulnerability to stress. In this study, 12 wild type Sprague-Dawley rats were exposed to 40 minutes of inescapable foot-shock followed by metabolic imaging using 2-deoxy-2[{sup 18}F]fluoro-D-glucose (18-FDG) 1 hour later. The escape test was performed on these rats 48 hours later (to accommodate radiotracer decay), where they were given the opportunity to press a lever to shut off the shock. A region of interest (ROI) analysis was used to investigate potential correlations (Pearson Regression Coefficients) between regional 18-FDG uptake following inescapable shock and subsequent learned helpless behavior (time to finish the test; number of successful lever presses within 20 seconds of shock onset). ROI analysis revealed a significant positive correlation between time to finish and 18-FDG uptake, and a negative correlation between lever presses and uptake, in the medial thalamic area (p=0.033, p=0.036). This ROI included the paraventricular thalamus, mediodorsal thalamus, and the habenula. In an effort to account for possible spillover artifact, the posterior thalamic area (including ventral medial and lateral portions) was also evaluated but did not reveal significant correlations (p=0.870, p=0.897). No other significant correlations were

  5. Functional correlates of the therapeutic and adverse effects evoked by thalamic stimulation for essential tremor

    PubMed Central

    Gibson, William S.; Jo, Hang Joon; Testini, Paola; Cho, Shinho; Felmlee, Joel P.; Welker, Kirk M.; Klassen, Bryan T.; Min, Hoon-Ki

    2016-01-01

    Deep brain stimulation is an established neurosurgical therapy for movement disorders including essential tremor and Parkinson’s disease. While typically highly effective, deep brain stimulation can sometimes yield suboptimal therapeutic benefit and can cause adverse effects. In this study, we tested the hypothesis that intraoperative functional magnetic resonance imaging could be used to detect deep brain stimulation-evoked changes in functional and effective connectivity that would correlate with the therapeutic and adverse effects of stimulation. Ten patients receiving deep brain stimulation of the ventralis intermedius thalamic nucleus for essential tremor underwent functional magnetic resonance imaging during stimulation applied at a series of stimulation localizations, followed by evaluation of deep brain stimulation-evoked therapeutic and adverse effects. Correlations between the therapeutic effectiveness of deep brain stimulation (3 months postoperatively) and deep brain stimulation-evoked changes in functional and effective connectivity were assessed using region of interest-based correlation analysis and dynamic causal modelling, respectively. Further, we investigated whether brain regions might exist in which activation resulting from deep brain stimulation might correlate with the presence of paraesthesias, the most common deep brain stimulation-evoked adverse effect. Thalamic deep brain stimulation resulted in activation within established nodes of the tremor circuit: sensorimotor cortex, thalamus, contralateral cerebellar cortex and deep cerebellar nuclei (FDR q < 0.05). Stimulation-evoked activation in all these regions of interest, as well as activation within the supplementary motor area, brainstem, and inferior frontal gyrus, exhibited significant correlations with the long-term therapeutic effectiveness of deep brain stimulation (P < 0.05), with the strongest correlation (P < 0.001) observed within the contralateral cerebellum. Dynamic causal

  6. Effects of 17β-Estradiol on Responses of Viscerosomatic Convergent Thalamic Neurons in the Ovariectomized Female Rat

    PubMed Central

    Reed, William R.; Chadha, Harpreet K.; Hubscher, Charles H.

    2009-01-01

    Ovarian hormones have been shown to exert multiple effects on CNS function and viscerosomatic convergent activity. Ovariectomized (OVX) female rats were used in the present study to examine the long-term effects of proestrus levels of 17β-estradiol (EB) delivered by a 60-day time-released subcutaneous pellet on the response properties of viscerosomatic convergent thalamic neurons. In addition, avoidance thresholds to mechanical stimulation for one of the convergent somatic territories, the trunk, was assessed using an electro–von Frey anesthesiometer before and at the end of the 6-wk post-OVX/implant period prior to the terminal electrophysiological experiments, which were done under urethane anesthesia. Rats implanted with an EB-containing pellet, relative to placebo controls, demonstrated 1) altered thalamic response frequencies and thresholds for cervix and vaginal but not colon stimulation; 2) some response variations for just the lateral group of thalamic subnuclei; and 3) altered thalamic response frequencies and thresholds for trunk stimulation. Thalamic response thresholds for trunk pressure in EB versus placebo rats were consistent with the avoidance thresholds obtained from the same groups. In addition, EB replacement affected visceral and somatic thresholds in opposite ways (i.e., reproductive-related structures were less sensitive to pressure, whereas somatic regions showed increased sensitivity). These results have obvious reproductive advantages (i.e., decreased reproductive organ sensitivity for copulation and increased trunk sensitivity for lordosis posturing), as well as possible clinical implications in women suffering from chronic pelvic pain syndromes and/or neuropathic pain. PMID:19553492

  7. The mediodorsal thalamus as a higher order thalamic relay nucleus important for learning and decision-making.

    PubMed

    Mitchell, Anna S

    2015-07-01

    Recent evidence from monkey models of cognition shows that the magnocellular subdivision of the mediodorsal thalamus (MDmc) is more critical for learning new information than for retention of previously acquired information. Further, consistent evidence in animal models shows the mediodorsal thalamus (MD) contributes to adaptive decision-making. It is assumed that prefrontal cortex (PFC) and medial temporal lobes govern these cognitive processes so this evidence suggests that MD contributes a role in these cognitive processes too. Anatomically, the MD has extensive excitatory cortico-thalamo-cortical connections, especially with the PFC. MD also receives modulatory inputs from forebrain, midbrain and brainstem regions. It is suggested that the MD is a higher order thalamic relay of the PFC due to the dual cortico-thalamic inputs from layer V ('driver' inputs capable of transmitting a message) and layer VI ('modulator' inputs) of the PFC. Thus, the MD thalamic relay may support the transfer of information across the PFC via this indirect thalamic route. This review summarizes the current knowledge about the anatomy of MD as a higher order thalamic relay. It also reviews behavioral and electrophysiological studies in animals to consider how MD might support the transfer of information across the cortex during learning and decision-making. Current evidence suggests the MD is particularly important during rapid trial-by-trial associative learning and decision-making paradigms that involve multiple cognitive processes. Further studies need to consider the influence of the MD higher order relay to advance our knowledge about how the cortex processes higher order cognition.

  8. Dopamine receptor-interacting proteins: the Ca(2+) connection in dopamine signaling.

    PubMed

    Bergson, Clare; Levenson, Robert; Goldman-Rakic, Patricia S; Lidow, Michael S

    2003-09-01

    Abnormal activity of the dopamine system has been implicated in several psychiatric and neurological illnesses; however, lack of knowledge about the precise sites of dopamine dysfunction has compromised our ability to improve the efficacy and safety of dopamine-related drugs used in treatment modalities. Recent work suggests that dopamine transmission is regulated via the concerted efforts of a cohort of cytoskeletal, adaptor and signaling proteins called dopamine receptor-interacting proteins (DRIPs). The discovery that two DRIPs, calcyon and neuronal Ca(2+) sensor 1 (NCS-1), are upregulated in schizophrenia highlights the possibility that altered protein interactions and defects in Ca(2+) homeostasis might contribute to abnormalities in the brain dopamine system in neuropsychiatric diseases.

  9. Human dopamine receptor and its uses

    DOEpatents

    Civelli, Olivier; Van Tol, Hubert Henri-Marie

    1999-01-01

    The present invention is directed toward the isolation, characterization and pharmacological use of the human D4 dopamine receptor. The nucleotide sequence of the gene corresponding to this receptor and alleleic variant thereof are provided by the invention. The invention also includes recombinant eukaryotic expression constructs capable of expressing the human D4 dopamine receptor in cultures of transformed eukaryotic cells. The invention provides cultures of transformed eukaryotic cells which synthesize the human D4 dopamine receptor, and methods for characterizing novel psychotropic compounds using such cultures.

  10. Phasic dopamine release in appetitive behaviors and drug abuse

    PubMed Central

    Wanat, Matthew J.; Willuhn, Ingo; Clark, Jeremy J.; Phillips, Paul E. M.

    2010-01-01

    Short phasic bursts of neuronal activity in dopamine neurons produce rapid and transient increases in extracellular dopamine concentrations throughout the mesocorticolimbic system, which are associated with the initiation of goal-directed behaviors. It is well established that acute exposure to many addictive drugs produce increases in tonic dopamine levels that occur on the order of minutes. However, recent studies suggest that abused drugs similarly enhance phasic dopamine release events that occur on a subsecond time scale. Furthermore, drug experience modulates the synaptic and intrinsic properties of dopamine neurons, which could affect dopamine burst firing and phasic dopamine release. This review will provide a general introduction to the mesolimbic dopamine system, as well as the primary methods used to detect dopamine neurons and dopamine release. We present the role of phasic dopamine release in appetitive behaviors in the context of contemporary theories regarding the function of dopamine. Next we discuss the known drug-induced changes to dopamine neurons and phasic release in both in vitro and in vivo preparations. Finally, we offer a simple model that chronic drug experience attenuates tonic/basal dopamine levels but promotes phasic dopamine release, which may result in aberrant goal-directed behaviors contributing to the development of addiction. PMID:19630749

  11. Boxing and chronic brain damage.

    PubMed

    Stiller, J W; Weinberger, D R

    1985-06-01

    A chronic, and at times, progressive neurologic syndrome associated with boxing has been recognized for some time by boxing fans and people involved with the sport. Since Martland's first description of the syndrome in 1929, there has been only one randomly selected study of ex-boxers, that of Roberts, which showed a 17 per cent prevalence of this syndrome among boxers who fought between 1929 and 1955. This syndrome can be progressive but often is not. Furthermore, the extent of occupational exposure is probably a significant risk factor. Because of this, it would be expected that the prevalance of the syndrome in the modern boxer, as well as the amateur, would be significantly less than during the first half of the century, and, indeed, several studies appear to support this. Recent studies provide evidence that brain damage does exist in modern boxers and suggests that "subclinical" brain damage is likely to be more prevalent than obvious clinical dysfunction. There is clearly a discrepancy between subclinical evidence of neurologic involvement (for example, an abnormal CT scan) and signs of clinical neurologic dysfunction (for example, clinical exam and neuropsychological testing). The latter tend to show less frequent and consistent evidence of brain damage in boxers than does the CT scan. Although it is tempting to assume that an abnormal CT scan presages the development of neurologic dysfunction, it is not clear that this is the case. The prevalence of the syndrome, risk for progression to functional deficit, warning signs, and the natural history cannot be defined at this time. The only way to better define these parameters would be a controlled prospective study, which has yet to be undertaken.

  12. Thalamic neglect. Possible role of the medial thalamus and nucleus reticularis in behavior.

    PubMed

    Watson, R T; Valenstein, E; Heilman, K M

    1981-08-01

    A patient had an ischemic infarction of the right medial thalamus, with a resultant contralateral neglect syndrome. We propose that the medial thalamic nuclei, particularly centromedian and parafascicularis (CMPF), are normally involved in the arousal-activation process by which an organism can be aroused by and respond to novel or important stimuli. Specifically, we propose that (1) the mesencephalic reticular formation subserves tonic arousal to novel or painful stimuli by inhibiting the nucleus reticularis thalami (NR) and (2) that selective attention is mediated by cortical input to NR. The CMPF is closely associated with motor systems (basal ganglia, ventrolateral nucleus of the thalamus [VL], and frontal lobes). A pathway involving CMPF, the frontal cortex, and the portion of NR associated with VL may be important in preparing the tonically aroused organism for action. Unilateral lesions of CMPF therefore induce an asymmetric hypokinesia, and bilateral lesions may induce akinetic mutism.

  13. [Persistent psychotic disorder following bilateral mesencephalo-thalamic ischaemia: case report].

    PubMed

    Predescu, A; Damsa, C; Riegert, M; Bumb, A; Pull, C

    2004-01-01

    A 38-year old male patient with no history of psychiatric illness developed a progressive psychotic disorder after bilateral (predominantly left) mesencephalo-thalamic cerebral ischaemia. The reason of the emergency hospitalization was the sudden onset of a confusional state, culminating in a fluctuating comatose status. The neurological examination found mild right hemiparesia, praxic disorders and reactive left mydriasis with paresia of the downward vertical stare, leading to the hospitalisation in the neurology department for suspicion of a cerebral vascular ischaemic accident. The psychiatric symptoms started with acoustic-verbal hallucinations, poorly structured paranoid delusions, progressively developed over two weeks, followed by behavioural disorders with psychomotor agitation and heteroaggressivity. The patient was transferred to the psychiatric department, because of the heteroaggressive risk and lack of morbid consciousness, in spite of recovering from the confusional status. An intensive psychiatric management was proposed, combining a psychotherapeutic approach with 4 mg of risperidone and adjustable doses of benzodiazepine according to the psychomotor agitation. During the next days, there was a net recovery of the behavioural disorders, in spite of the persistence of the ideas of persecution. All the neurological symptoms also decreased. An anomaly of the polygon of Willis was found on a cerebral arteriography (the posterior cerebral arteries had a foetal origin, dependent on carotidal axes and not on the vertebro-basilar system). The main emboligen risk factor was the presence of a permeable foramen ovale, discovered during a transoesophageal echography. The patient underwent a surgical correction of the permeable foramen ovale. The psychiatric hospitalization for three months was continued by ambulatory follow-up. The initial positive symptoms (delusions, acoustic-verbal hallucinations) progressively diminished while negative symptoms became

  14. Selectively driving cholinergic fibers optically in the thalamic reticular nucleus promotes sleep.

    PubMed

    Ni, Kun-Ming; Hou, Xiao-Jun; Yang, Ci-Hang; Dong, Ping; Li, Yue; Zhang, Ying; Jiang, Ping; Berg, Darwin K; Duan, Shumin; Li, Xiao-Ming

    2016-02-11

    Cholinergic projections from the basal forebrain and brainstem are thought to play important roles in rapid eye movement (REM) sleep and arousal. Using transgenic mice in which channelrhdopsin-2 is selectively expressed in cholinergic neurons, we show that optical stimulation of cholinergic inputs to the thalamic reticular nucleus (TRN) activates local GABAergic neurons to promote sleep and protect non-rapid eye movement (NREM) sleep. It does not affect REM sleep. Instead, direct activation of cholinergic input to the TRN shortens the time to sleep onset and generates spindle oscillations that correlate with NREM sleep. It does so by evoking excitatory postsynaptic currents via α7-containing nicotinic acetylcholine receptors and inducing bursts of action potentials in local GABAergic neurons. These findings stand in sharp contrast to previous reports of cholinergic activity driving arousal. Our results provide new insight into the mechanisms controlling sleep.

  15. Selectively driving cholinergic fibers optically in the thalamic reticular nucleus promotes sleep

    PubMed Central

    Ni, Kun-Ming; Hou, Xiao-Jun; Yang, Ci-Hang; Dong, Ping; Li, Yue; Zhang, Ying; Jiang, Ping; Berg, Darwin K; Duan, Shumin; Li, Xiao-Ming

    2016-01-01

    Cholinergic projections from the basal forebrain and brainstem are thought to play important roles in rapid eye movement (REM) sleep and arousal. Using transgenic mice in which channelrhdopsin-2 is selectively expressed in cholinergic neurons, we show that optical stimulation of cholinergic inputs to the thalamic reticular nucleus (TRN) activates local GABAergic neurons to promote sleep and protect non-rapid eye movement (NREM) sleep. It does not affect REM sleep. Instead, direct activation of cholinergic input to the TRN shortens the time to sleep onset and generates spindle oscillations that correlate with NREM sleep. It does so by evoking excitatory postsynaptic currents via α7-containing nicotinic acetylcholine receptors and inducing bursts of action potentials in local GABAergic neurons. These findings stand in sharp contrast to previous reports of cholinergic activity driving arousal. Our results provide new insight into the mechanisms controlling sleep. DOI: http://dx.doi.org/10.7554/eLife.10382.001 PMID:26880556

  16. Human anterior thalamic nuclei are involved in emotion-attention interaction.

    PubMed

    Sun, Lihua; Peräkylä, Jari; Polvivaara, Markus; Öhman, Juha; Peltola, Jukka; Lehtimäki, Kai; Huhtala, Heini; Hartikainen, Kaisa M

    2015-11-01

    Patients treated with deep brain stimulation (DBS) provide an opportunity to study affective processes in humans with "lesion on demand" at key nodes in the limbic circuitries, such as at the anterior thalamic nuclei (ANT). ANT has been suggested to play a role in emotional control with its connection to the orbitofrontal cortex and the anterior cingulate cortex. However, direct evidence for its role in emotional function in human subjects is lacking. Reported side effects of ANT-DBS in the treatment of refractory epilepsy include depression related symptoms. In line with these mood-related clinical side effects, we have previously reported that stimulating the anterior thalamus increased emotional interference in a visual attention task as indicated by prolonged reaction times due to threat-related emotional distractors. We used event-related potentials to investigate potential attentional mechanism behind this behavioural observation. We hypothesized that ANT-DBS leads to greater attention capture by threat-related distractors. We tested this hypothesis using centro-parietal N2-P3 peak-to-peak amplitude as a measure of allocated attentional resources. Six epileptic patients treated with deep brain stimulation at ANT participated in the study. Electroencephalography was recorded while the patients performed a computer based Executive-Reaction Time test with threat-related emotional distractors. During the task, either ANT or a thalamic control location was stimulated, or the stimulation was turned off. Stimulation of ANT was associated with increased centro-parietal N2-P3 amplitude and increased reaction time in the context of threat-related emotional distractors. We conclude that high frequency electric stimulation of ANT leads to greater attentional capture by emotional stimuli. This is the first study to provide direct evidence from human subjects with on-line electric manipulation of ANT for its role in emotion-attention interaction.

  17. Early thalamic lesions in patients with sleep-potentiated epileptiform activity

    PubMed Central

    Sánchez Fernández, I.; Takeoka, M.; Tas, E.; Peters, J.M.; Prabhu, S.P.; Stannard, K.M.; Gregas, M.; Eksioglu, Y.; Rotenberg, A.; Riviello, J.J.; Kothare, S.V.

    2012-01-01

    Objective: To compare the prevalence and type of early developmental lesions in patients with a clinical presentation consistent with electrical status epilepticus in sleep either with or without prominent sleep-potentiated epileptiform activity (PSPEA). Methods: We performed a case-control study and enrolled patients with 1) clinical features consistent with electrical status epilepticus in sleep, 2) ≥1 brain MRI scan, and 3) ≥1 overnight EEG recording. We quantified epileptiform activity using spike percentage, the percentage of 1-second bins in the EEG tracing containing at least 1 spike. PSPEA was present when spike percentage during non-REM sleep was ≥50% than spike percentage during wakefulness. Results: One hundred patients with PSPEA (cases) and 47 patients without PSPEA (controls) met the inclusion criteria during a 14-year period. Both groups were comparable in terms of clinical and epidemiologic features. Early developmental lesions were more frequent in cases (48% vs 19.2%, p = 0.002). Thalamic lesions were more frequent in cases (14% vs 2.1%, p = 0.037). The main types of early developmental lesions found in cases were vascular lesions (14%), periventricular leukomalacia (9%), and malformation of cortical development (5%). Vascular lesions were the only type of early developmental lesions that were more frequent in cases (14% vs 0%, p = 0.005). Conclusions: Patients with PSPEA have a higher frequency of early developmental lesions and thalamic lesions than a comparable population of patients without PSPEA. Vascular lesions were the type of early developmental lesions most related to PSPEA. PMID:22539569

  18. [The thalamic syndrome of Déjérine-Roussy. Prolegomenon].

    PubMed

    De Smet, Y

    1986-01-01

    Predicted by Dejerine and Long in 1898 and formally described by Dejerine and Roussy in 1906, the "thalamic syndrome" corrected the wrong hypothesis of a capsular "sensory cross roads" suggested by Charcot after 1873 and supported in France during 25 years. Both established the "persistent frank organic hemianesthesia" (sensory-sensitive for Charcot, pure sensitive for Dejerine), namely that a sensory deficit, still severe after regression of the early hemiplegia, could be due to focal brain damage. At that time such a clinical concept was hardly acceptable because it opposed the classic greek philosophical idea that sensation and movement should not be separated. Moreover, intelligence was at that time looked as a four-stage process including sensation, imagination, intellect and memory. The very first step began with the "sensus communis", an anteroom-like where all the sensations simultaneously perceived were coordinated to ensure mind unity. This "sensus communis" was given many subcortical seats during the following centuries, such as the trigone (Herophilus), the ventricles (Founders of the Church, Soemmering), the pineal body (Descartes), the striate bodies (Willis) and, finally, the thalamus (Todd and Carpenter's "English theory"). The description by Meynert in 1871 of a transcapsular direct "sensory bundle" and the cases reported by Türck in 1859 of a sensory-sensitive hemianesthesia after a posterior capsular lesion (in fact, thalamo-capsulostriate) led Charcot to develop his theory after 1873. Owing to the new staining methods of Weigert and Marchi introduced around 1885, Dejerine showed in 1895 the route of the medial lemniscus and his arrival in the thalamus, which led him to postulate in 1898 a "thalamic syndrome" and later to demonstrate it.

  19. Modulation of sensitivity to alcohol by cortical and thalamic brain regions

    PubMed Central

    Jaramillo, Anel A.; Randall, Patrick A.; Frisbee, Suzanne; Besheer, Joyce

    2017-01-01

    The nucleus accumbens core (AcbC) is a key brain region known to regulate the discriminative stimulus/interoceptive effects of alcohol. As such, the goal of the present work was to identify AcbC projection regions that may also modulate sensitivity to alcohol. Accordingly, AcbC afferent projections were identified in behaviorally naïve rats using a retrograde tracer which led to the focus on the medial prefrontal cortex (mPFC), insular cortex (IC) and rhomboid thalamic nucleus (Rh). Next, to examine the possible role of these brain regions in modulating sensitivity to alcohol, neuronal response to alcohol in rats trained to discriminate alcohol (1 g/kg, intragastric [IG]) vs. water was examined using a two-lever drug discrimination task. As such, rats were administered water or alcohol (1g/kg, IG) and brain tissue was processed for c-Fos immunoreactivity (IR), a marker of neuronal activity. Alcohol decreased c-Fos IR in the mPFC, IC, Rh, and AcbC. Lastly, site-specific pharmacological inactivation with muscimol+baclofen (GABAA agonist+GABAB agonist) was used to determine the functional role of the mPFC, IC and Rh in modulating the interoceptive effects of alcohol in rats trained to discriminate alcohol (1 g/kg, IG) vs. water. mPFC inactivation resulted in full substitution for the alcohol training dose, and IC and Rh inactivation produced partial alcohol-like effects, demonstrating the importance of these regions, with known projections to the AcbC, in modulating sensitivity to alcohol. Together, these data demonstrate a site of action of alcohol and the recruitment of cortical/thalamic regions in modulating sensitivity to the interoceptive effects of alcohol. PMID:27543844

  20. Two classes of excitatory synaptic responses in rat thalamic reticular neurons.

    PubMed

    Deleuze, Charlotte; Huguenard, John R

    2016-09-01

    The thalamic reticular nucleus (nRt), composed of GABAergic cells providing inhibition of relay neurons in the dorsal thalamus, receives excitation from the neocortex and thalamus. The two excitatory pathways promoting feedback or feedforward inhibition of thalamocortical neurons contribute to sensory processing and rhythm generation. While synaptic inhibition within the nRt has been carefully characterized, little is known regarding the biophysics of synaptic excitation. To characterize the functional properties of thalamocortical and corticothalamic connections to the nRt, we recorded minimal electrically evoked excitatory postsynaptic currents from nRt cells in vitro. A hierarchical clustering algorithm distinguished two types of events. Type 1 events had larger amplitudes and faster kinetics, largely mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, whereas type 2 responses had more prominent N-methyl-d-aspartate (NMDA) receptor contribution. Type 1 responses showed subnormal axonal propagation and paired pulse depression, consistent with thalamocortical inputs. Furthermore, responses kinetically similar to type 1 events were evoked by glutamate-mediated activation of thalamic neurons. Type 2 responses, in contrast, likely arise from corticothalamic inputs, with larger NMDA conductance and weak Mg(2+)-dependent block, suggesting that NMDA receptors are critical for the cortical excitation of reticular neurons. The long-lasting action of NMDA receptors would promote reticular cell burst firing and produce powerful inhibitory output to relay neurons proposed to be important in triggering epilepsy. This work provides the first complete voltage-clamp analysis of the kinetics and voltage dependence of AMPA and NMDA responses of thalamocortical and corticothalamic synapses in the nRt and will be critical in optimizing biologically realistic neural network models of thalamocortical circuits relevant to sensory processing and

  1. Thalamic involvement in paroxysmal kinesigenic dyskinesia: a combined structural and diffusion tensor MRI analysis.

    PubMed

    Kim, Ji Hyun; Kim, Dong-Wook; Kim, Jung Bin; Suh, Sang-Il; Koh, Seong-Beom

    2015-04-01

    Alteration of basal ganglia-thalamocortical circuit has been hypothesized to play a role in the pathophysiology underlying paroxysmal kinesigenic dyskinesia (PKD). We investigated macrostructural and microstructural changes in PKD patients using structural and diffusion tensor magnetic resonance imaging (MRI) analyses. Twenty-five patients with idiopathic PKD and 25 control subjects were prospectively studied on a 3T magnetic resonance (MR) scanner. Cortical thickness analysis was used to evaluate cortical gray matter (GM) changes, and automated volumetry and shape analysis were used to assess volume changes and shape deformation of the subcortical GM structures, respectively. Tract-based spatial statistics (TBSS) was used to evaluate white matter integrity changes in a whole-brain manner, and region-of-interest (ROI) analysis of diffusion tensor metrics was performed in subcortical GM structures. Compared to controls, PKD patients exhibited a reduction in volume of bilateral thalami and regional shape deformation mainly localized to the anterior and medial aspects of bilateral thalami. TBSS revealed an increase in fractional anisotropy (FA) of bilateral thalami and right anterior thalamic radiation in patients relative to controls. ROI analysis also showed an increase in FA of bilateral thalami in patients compared to controls. We have shown evidence for thalamic abnormalities of volume reduction, regional shape deformation, and increased FA in patients with PKD. Our novel findings of concomitant macrostructural and microstructural abnormalities in the thalamus lend further support to previous observations indicating causal relationship between a preferential lesion in the thalamus and development of PKD, thus providing neuroanatomical basis for the involvement of thalamus within the basal ganglia-thalamocortical pathway in PKD.

  2. Central sensitization in thalamic nociceptive neurons induced by mustard oil application to rat molar tooth pulp.

    PubMed

    Zhang, S; Chiang, C Y; Xie, Y F; Park, S J; Lu, Y; Hu, J W; Dostrovsky, J O; Sessle, B J

    2006-10-27

    We have recently demonstrated that application of mustard oil (MO), a small-fiber excitant and inflammatory irritant, to the rat maxillary molar tooth pulp induces central sensitization that is reflected in changes in spontaneous activity, mechanoreceptive field (RF) size, mechanical activation threshold, and responses to graded mechanical stimuli applied to the neuronal RF in trigeminal brainstem subnucleus caudalis and subnucleus oralis. The aim of this study was to test whether central sensitization can be induced in nociceptive neurons of the posterior thalamus by MO application to the pulp. Single unit neuronal activity was recorded in the ventroposterior medial nucleus (VPM) or posterior nuclear group (PO) of the thalamus in anesthetized rats, and nociceptive neurons were classified as wide dynamic range (WDR) or nociceptive-specific (NS). MO application to the pulp was studied in 47 thalamic nociceptive neurons and found to excite over 50% of the 35 VPM neurons tested and to produce significant long-lasting (over 40 min) increases in spontaneous activity, cutaneous pinch RF size and responses to graded mechanical stimuli, and a decrease in threshold in the 29 NS neurons tested; a smaller but statistically significant increase in mean spontaneous firing rate and decrease in activation threshold occurred following MO in the six WDR neurons tested. Vehicle application to the pulp did not produce any significant changes in six VPM NS neurons tested. MO application to the pulp produced pronounced increases in spontaneous activity, pinch RF size, and responses to mechanical stimuli, and a decrease in threshold in three of the six PO neurons. In conclusion, application of the inflammatory irritant MO to the tooth pulp results in central sensitization of thalamic nociceptive neurons and this neuronal hyperexcitability likely contributes to the behavioral consequences of peripheral inflammation manifesting as pain referral, hyperalgesia and allodynia.

  3. Prognostic Factors of Clinical Outcomes in Patients with Spontaneous Thalamic Hemorrhage

    PubMed Central

    Lee, Sang-Hoon; Park, Kyung-Jae; Kang, Shin-Hyuk; Jung, Yong-Gu; Park, Jung-Yul; Park, Dong-Hyuk

    2015-01-01

    Background Intracerebral hemorrhage (ICH) is a well-known condition, but ICH restricted to the thalamus is less widely studied. We investigated the prognostic factors of thalamic ICHs. Material/Methods Seventy patients from January 2009 to November 2014 were retrospectively reviewed. Patients who demonstrated spontaneous ICH primarily affecting the thalamus on initial brain computed tomography (CT) were enrolled. Patients were categorized into 2 groups based on their Glasgow Outcome Scale (GOS) scores. Various presumptive prognostic factors were analyzed to investigate relationships between various clinical characteristics and outcomes. Results Of the enrolled patients, 39 showed a GOS of 4–5, and were categorized as the good outcome group, while another 31 patients showed a GOS of 1–3 and were categorized as the poor outcome group. Initial GCS score, calculated volume of hematoma, presence of intraventricular hemorrhage (IVH), coexisting complications, hydrocephalus, performance of external ventricular drainage, and modified Graeb’s scores of patients with IVH were significantly different between the 2 groups. In multivariate analysis, among the factors above, initial GCS score (P=0.002, Odds ratio [OR]=1.761, Confidence interval [CI]=1.223–2.536) and the existence of systemic complications (P=0.015, OR=0.059, CI=0.006–0.573) were independently associated with clinical outcomes. Calculated hematoma volume showed a borderline relationship with outcomes (P=0.079, OR=0.920, CI=0.839–1.010). Conclusions Initial GCS score and the existence of systemic complications were strong predictive factors for prognosis of thalamic ICH. Calculated hematoma volume also had predictive value for clinical outcomes. PMID:26343784

  4. Modulation of sensitivity to alcohol by cortical and thalamic brain regions.

    PubMed

    Jaramillo, Anel A; Randall, Patrick A; Frisbee, Suzanne; Besheer, Joyce

    2016-10-01

    The nucleus accumbens core (AcbC) is a key brain region known to regulate the discriminative stimulus/interoceptive effects of alcohol. As such, the goal of the present work was to identify AcbC projection regions that may also modulate sensitivity to alcohol. Accordingly, AcbC afferent projections were identified in behaviorally naïve rats using a retrograde tracer which led to the focus on the medial prefrontal cortex (mPFC), insular cortex (IC) and rhomboid thalamic nucleus (Rh). Next, to examine the possible role of these brain regions in modulating sensitivity to alcohol, neuronal response to alcohol in rats trained to discriminate alcohol (1 g/kg, intragastric [IG]) vs. water was examined using a two-lever drug discrimination task. As such, rats were administered water or alcohol (1 g/kg, IG) and brain tissue was processed for c-Fos immunoreactivity (IR), a marker of neuronal activity. Alcohol decreased c-Fos IR in the mPFC, IC, Rh and AcbC. Lastly, site-specific pharmacological inactivation with muscimol + baclofen (GABAA agonist + GABAB agonist) was used to determine the functional role of the mPFC, IC and Rh in modulating the interoceptive effects of alcohol in rats trained to discriminate alcohol (1 g/kg, IG) vs. water. mPFC inactivation resulted in full substitution for the alcohol training dose, and IC and Rh inactivation produced partial alcohol-like effects, demonstrating the importance of these regions, with known projections to the AcbC, in modulating sensitivity to alcohol. Together, these data demonstrate a site of action of alcohol and the recruitment of cortical/thalamic regions in modulating sensitivity to the interoceptive effects of alcohol.

  5. Prolonged hyperpolarizing potentials precede spindle oscillations in the thalamic reticular nucleus

    PubMed Central

    Fuentealba, Pablo; Timofeev, Igor; Steriade, Mircea

    2004-01-01

    The thalamic reticular (RE) nucleus is a key structure in the generation of spindles, a hallmark bioelectrical oscillation during early stages of sleep. Intracellular recordings of RE neurons in vivo revealed the presence of prolonged hyperpolarizing potentials preceding spindles in a subgroup (30%) of neurons. These hyperpolarizations (6-10 mV) lasted for 200-300 ms and were present just before the onset of spontaneously occurring spindle waves. Corticothalamic volleys also were effective in generating such hyperpolarizations followed by spindles in RE neurons. A drop of up to 40% in the apparent input resistance (Rin) was associated with these hyperpolarizing potentials, suggesting an active process rather than disfacilitation. Accordingly, the reversal potential was approximately -100 mV for both spontaneous and cortically elicited hyperpolarizations, consistent with the activation of slow K+ conductances. QX-314 in the recording pipettes decreased both the amplitude and incidence of prolonged hyperpolarizations, suggesting the participation of G protein-dependent K+ currents in the generation of hyperpolarizations. Simultaneous extracellular and intracellular recordings in the RE nucleus demonstrated that some RE neurons discharged during the hyperpolarizations and, thus, may be implicated in their generation. The prolonged hyperpolarizations preceding spindles may play a role in the transition from tonic to bursting firing of RE neurons within a range of membrane potential (-60 to -65 mV) at which they set favorable conditions for the generation of low-threshold spike bursts that initiate spindle sequences. These data are further arguments for the generation of spindles within the thalamic RE nucleus. PMID:15210981

  6. Delusions, superstitious conditioning and chaotic dopamine neurodynamics.

    PubMed

    Shaner, A

    1999-02-01

    Excessive mesolimbic dopaminergic neurotransmission is closely related to the psychotic symptoms of schizophrenia. A mathematical model of dopamine neuron firing rates, developed by King and others, suggests a mechanism by which excessive dopaminergic transmission could produce psychotic symptoms, especially delusions. In this model, firing rates varied chaotically when the efficacy of dopaminergic transmission was enhanced. Such non-contingent changes in firing rates in mesolimbic reward pathways could produce delusions by distorting thinking in the same way that non-contingent reinforcement produces superstitious conditioning. Though difficult to test in humans, the hypothesis is testable as an explanation for a common animal model of psychosis--amphetamine stereotypy in rats. The hypothesis predicts that: (1) amphetamine will cause chaotic firing rates in mesolimbic dopamine neurons; (2) non-contingent brain stimulation reward will produce stereotypy; (3) non-contingent microdialysis of dopamine into reward areas will produce stereotypy; and (4) dopamine antagonists will block all three effects.

  7. Detection of Dopamine Dynamics in the Brain.

    ERIC Educational Resources Information Center

    Wightman, R. Mark; And Others

    1988-01-01

    Explores neurochemical events in the extra cellular space of the brain by use of in vivo voltammetric microelectrodes. Reports dopamine concentrations and pathways, and discusses techniques used for analysis. Recognizes current problems and future directions for research. (ML)

  8. 36 CFR 1192.33 - Fare box.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Fare box. 1192.33 Section 1192.33 Parks, Forests, and Public Property ARCHITECTURAL AND TRANSPORTATION BARRIERS COMPLIANCE BOARD... Systems § 1192.33 Fare box. Where provided, the farebox shall be located as far forward as practicable...

  9. 49 CFR 38.33 - Fare box.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Fare box. 38.33 Section 38.33 Transportation Office of the Secretary of Transportation AMERICANS WITH DISABILITIES ACT (ADA) ACCESSIBILITY SPECIFICATIONS FOR TRANSPORTATION VEHICLES Buses, Vans and Systems § 38.33 Fare box. Where provided, the...

  10. 49 CFR 38.33 - Fare box.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false Fare box. 38.33 Section 38.33 Transportation Office of the Secretary of Transportation AMERICANS WITH DISABILITIES ACT (ADA) ACCESSIBILITY SPECIFICATIONS FOR TRANSPORTATION VEHICLES Buses, Vans and Systems § 38.33 Fare box. Where provided, the...

  11. 49 CFR 38.33 - Fare box.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Fare box. 38.33 Section 38.33 Transportation Office of the Secretary of Transportation AMERICANS WITH DISABILITIES ACT (ADA) ACCESSIBILITY SPECIFICATIONS FOR TRANSPORTATION VEHICLES Buses, Vans and Systems § 38.33 Fare box. Where provided, the...

  12. BLS: Box-fitting Least Squares

    NASA Astrophysics Data System (ADS)

    Kovács, G.; Zucker, S.; Mazeh, T.

    2016-07-01

    BLS (Box-fitting Least Squares) is a box-fitting algorithm that analyzes stellar photometric time series to search for periodic transits of extrasolar planets. It searches for signals characterized by a periodic alternation between two discrete levels, with much less time spent at the lower level.

  13. Box Plots in the Australian Curriculum

    ERIC Educational Resources Information Center

    Watson, Jane M.

    2012-01-01

    This article compares the definition of "box plot" as used in the "Australian Curriculum: Mathematics" with other definitions used in the education community; describes the difficulties students experience when dealing with box plots; and discusses the elaboration that is necessary to enable teachers to develop the knowledge…

  14. PINE Discovery Box, 101 Stimulating Ideas.

    ERIC Educational Resources Information Center

    Busch, Phyllis S.

    This manual is intended for use with the PINE (Projects in Imaginative Nature Education) discovery box in elementary school conservation education. The box contains 21 natural specimens which can serve as the starting point for simple student investigations. Specimens and activities are keyed for grade level. For each item, background information…

  15. Cereal Box Design: An Interdisciplinary Graphics Activity

    ERIC Educational Resources Information Center

    Fitzgerald, Mike; Tsosie, Teri

    2004-01-01

    This article describes cereal box design, an interdisciplinary graphics activity. The cereal box design activity is intriguing both for its simplicity and the resourcefulness that it can generate in young people. It lends itself to a variety of curriculums. It covers both consumerism and Design for the Environment (DfE) concepts broadly and in…

  16. 46 CFR 111.81-3 - Cables entering boxes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Cables entering boxes. 111.81-3 Section 111.81-3...-GENERAL REQUIREMENTS Outlet Boxes and Junction Boxes § 111.81-3 Cables entering boxes. Each cable entering a box or fitting must be protected from abrasion and must meet the following: (a) Each...

  17. Dopamine-oxytocin interactions in penile erection.

    PubMed

    Baskerville, T A; Allard, J; Wayman, C; Douglas, A J

    2009-12-03

    Dopamine and oxytocin have established roles in the central regulation of penile erection in rats; however, the neural circuitries involved in a specific erectile context and the interaction between dopamine and oxytocin mechanisms remain to be elucidated. The medial preoptic area (MPOA), supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus may serve as candidate sites because they contain oxytocin cells, receive dopaminergic inputs and have been implicated in mediating masculine sexual behavior. Double immunofluorescence revealed that substantial numbers of oxytocin cells in the MPOA, SON and PVN possess dopamine D(2), D(3) and D(4) receptors. In anaesthetized rats, using intracavernous pressure as a physiological indicator of erection, blockade of lumbosacral oxytocin receptors (UK, 427843) reduced erectile responses to a nonselective dopamine agonist (apomorphine), suggesting that dopamine recruits a paraventriculospinal oxytocin pathway. In conscious males in the absence of a female, penile erection elicited by a D(2)/D(3) (Quinelorane) but not D(4) (PD168077) agonist was associated with activation of medial parvocellular PVN oxytocin cells. In another experiment where males were given full access to a receptive female, a D(4) (L-745870) but not D(2) or D(3) antagonist (L-741626; nafadotride) inhibited penile erection (intromission), and this was correlated with SON magnocellular oxytocin neuron activation. Together, the data suggest dopamine's effects on hypothalamic oxytocin cells during penile erection are context-specific. Dopamine may act via different parvocellular and magnocellular oxytocin subpopulations to elicit erectile responses, depending upon whether intromission is performed. This study demonstrates the potential existence of interaction between central dopamine and oxytocin pathways during penile erection, with the SON and PVN serving as integrative sites.

  18. A model of dopamine modulated glutamatergic synapse.

    PubMed

    Di Maio, Vito; Ventriglia, Francesco; Santillo, Silvia

    2015-10-01

    The dopamine neurotransmitter regulates important neural pathways and its action in the brain is very complex. When dopaminergic neurons make synapses on spiny neurons of the striatum nucleus, they tune the responsiveness of glutamatergic synapses by means of the dopamine D1 and D2 receptors. We studied the effect of dopamine D1 receptors on glutamatergic synapse of GABAergic spiny neurons in striatum nucleus where they are located on the neck of the same spine. The action of dopamine consists essentially in promoting the phosphorylation of AMPA and NMDA receptors thus increasing the Excitatory Post Synaptic Current peak amplitude. The consequence is a cooperative effect of glutamatergic and dopaminergic synapses for the regulation of the GABAergic neuronal code. The mechanisms by which the phosphorylation induces the increase of the EPSC amplitude still remain unclear although the lack of this regulation can be involved in several pathologies as, for example, the Parkinson's disease. We tested, by computational experiments based on our model of glutamatergic synapse, three parameters of the synaptic function that could be involved in dopamine action: (a) time binding of glutamate to receptors; (b) open probability of the receptors; and (c) single receptor conductance. For different reasons, any of the three parameters could be responsible of the increased EPSC-dopamine-dependent. Our computational results were compared and discussed with experimental results found in literature. Although for our model both the open probability and the single receptor conductance can reproduce the phosphorylation effect of dopamine, we argue that the dopamine effect consists essentially in an increase of the single receptor conductance due to a 3D rearrangement of the phosphorylated receptors.

  19. North American box turtles: A natural history

    USGS Publications Warehouse

    Dodd, C. Kenneth

    2002-01-01

    Once a familiar backyard visitor in many parts of the United States and Mexico, the box turtle is losing the battle against extinction. In North American Box Turtles, C. Kenneth Dodd, Jr., has written the first book-length natural history of the twelve species and subspecies of this endangered animal. This volume includes comprehensive information on the species’ evolution, behavior, courtship and reproduction, habitat use, diet, population structure, systematics, and disease. Special features include color photos of all species, subspecies, and their habitats; a simple identification guide to both living and fossil species; and a summary of information on fossil Terrapene and Native uses of box turtles. End-of-chapter sections highlight future research directions, including the need for long-term monitoring and observation of box turtles within their natural habitat and conservation applications. A glossary and a bibliography of literature on box turtles accompany the text.

  20. Feasibility of Diffusion Tractography for the Reconstruction of Intra-Thalamic and Cerebello-Thalamic Targets for Functional Neurosurgery: A Multi-Vendor Pilot Study in Four Subjects

    PubMed Central

    Jakab, András; Werner, Beat; Piccirelli, Marco; Kovács, Kázmér; Martin, Ernst; Thornton, John S.; Yousry, Tarek; Szekely, Gabor; O‘Gorman Tuura, Ruth

    2016-01-01

    Functional stereotactic neurosurgery by means of deep brain stimulation or ablation provides an effective treatment for movement disorders, but the outcome of surgical interventions depends on the accuracy by which the target structures are reached. The purpose of this pilot study was to evaluate the feasibility of diffusion tensor imaging (DTI) based probabilistic tractography of deep brain structures that are commonly used for pre- and perioperative targeting for functional neurosurgery. Three targets were reconstructed based on their significance as intervention sites or as a no-go area to avoid adverse side effects: the connections propagating from the thalamus to (1) primary and supplementary motor areas, (2) to somatosensory areas and the cerebello-thalamic tract (CTT). We evaluated the overlap of the reconstructed connectivity based targets with corresponding atlas based data, and tested the inter-subject and inter-scanner variability by acquiring repeated DTI from four volunteers, and on three MRI scanners with similar sequence parameters. Compared to a 3D histological atlas of the human thalamus, moderate overlaps of 35-50% were measured between connectivity- and atlas based volumes, while the minimal distance between the centerpoints of atlas and connectivity targets was 2.5 mm. The variability caused by the MRI scanner was similar to the inter-subject variability, except for connections with the postcentral gyrus where it was higher. While CTT resolved the anatomically correct trajectory of the tract individually, high volumetric variability was found across subjects and between scanners. DTI can be applied in the clinical, preoperative setting to reconstruct the CTT and to localize subdivisions within the lateral thalamus. In our pilot study, such subdivisions moderately matched the borders of the ventrolateral-posteroventral (VLpv) nucleus and the ventral-posterolateral (VPL) nucleus. Limitations of the currently used standard DTI protocols were

  1. Long-term studies of dopamine agonists.

    PubMed

    Hubble, Jean P

    2002-02-26

    Dopamine agonists have long been used as adjunctive therapy for the treatment of Parkinson's disease (PD). In more recent years these drugs have also been proved safe and effective as initial therapy in lieu of levodopa in the treatment of PD. Long-term levodopa therapy is associated with motor complications, including fluctuating response patterns and dyskinesia. By initially introducing a dopamine agonist as symptomatic drug therapy, it may be possible to postpone the use of levodopa and delay or prevent the development of motor complications. Recently, four clinical trials have explored this hypothesis by comparing the long-term response and side effects of levodopa with dopamine agonist therapy. The drugs studied have included ropinirole, pramipexole, cabergoline, and pergolide. In each of these projects, the occurrence of motor complications, such as wearing off and dyskinesia, was significantly less in the subjects assigned to initiation of therapy with a dopamine agonist. The addition of levodopa could be postponed by many months or even several years. Therefore, these long-term studies of dopamine agonists support the initiation of a dopamine agonist instead of levodopa in an effort to postpone levodopa-related motor complications. This therapeutic approach may be particularly appropriate in PD patients with a long treatment horizon on the basis of age and general good health. The extension phase of the long-term study comparing pramipexole with levodopa is ongoing, and follow-up information may help to establish the value of this treatment strategy.

  2. Pharmacological characterization of renal vascular dopamine receptors.

    PubMed

    Schmidt, M; Imbs, J L

    1980-01-01

    We present an in vitro method for studying the renal effects of dopamine in the isolated rat kidney. The organ is perfused in an open circuit and can be maintained satisfactorily for up to 180 min. The responses to dopamine were studied in the presence of phenoxybenzamine (10(-5) M) and sotalol (10(-5) M) while stable renal vasoconstriction was maintained by perfusion with prostaglandine F2 alpha. Dopamine induced dose-dependent renal vasodilation with an ED50 of 2.53 X 10(-6) moles/liter, which was not modified by reserpine pretreatment. (+) Butaclamol but not (-) butaclamol shifted the dopamine dose-response curve to the right in a parallel fashion, indicating competitive antagonism. Haloperidol and sulpiride at concentrations without intrinsic effect on vascular resistance also acted as competitive inhibitors for dopamine. Calculation of empirical pA2 values yielded the following relative potencies for these antagonists: (+) butaclamol greater than haloperidol greater than sulpiride. The renal vascular dopamine receptors are tentatively classified as being of the D1 type.

  3. Boxing injuries: neurologic, radiologic, and neuropsychologic evaluation.

    PubMed

    Ross, R J; Casson, I R; Siegel, O; Cole, M

    1987-01-01

    Boxing is an endeavor that may have to be re-evaluated in the coming years as to whether it should be designated as a sport. It is the only "sport" in which victory is determined by the amount of physical damage done to the opponent. We have presented the largest number of professional and amateur boxers (58) evaluated by various modern diagnostic modalities and have unequivocally demonstrated the deleterious effects of boxing upon the brain. There have been few, if any, meaningful actions taken by the promoters of boxing to correct the conditions under which boxers are subjected to physical abuse. Recommendations regarding the creation of a National Board of Boxing to supervise this "sport" have not been heeded. Suggested safeguards for the boxer, including mandatory medical and boxing history records (passports), use of headgear and approved safe boxing gloves, avoiding blows to the head, improved boxing ring floors, mandatory neurologic examinations, and more competent physicians at ringsides making medical decisions, have essentially not been implemented. The suggestions that mandatory computed tomograms at various stages in a boxer's career be used to determine possible changes of atrophy have not been followed, even when the CT scans have been made available at no cost to the boxers. The effective use of neuropsychologic evaluation, even when offered at no cost, has also been denied. The established medical injuries due to boxing and the lack of any sustained and significant efforts on the part of organized boxing create an atmosphere that is conducive to following the call for the consideration of a ban of boxing.

  4. [123I]beta-CIT SPECT demonstrates decreased brain dopamine and serotonin transporter levels in untreated parkinsonian patients.

    PubMed

    Haapaniemi, T H; Ahonen, A; Torniainen, P; Sotaniemi, K A; Myllylä, V V

    2001-01-01

    Striatal dopamine transporters (DATs) and serotonin transporters (SERTs) were evaluated in untreated patients with Parkinson's disease (PD) and controls using single-photon emission computed tomography (SPECT) with 2beta-carboxymethoxy-3beta-(4-iodophenyl)tropane ([123I]beta-CIT). The striatal DAT specific to non-displaceable uptake ratios of 29, and the SERT uptake measurements of 27, PD patients were compared with those of 21 and 16 controls, respectively. The results were correlated with Unified Parkinson's Disease Rating Scale (UPDRS) scores, the Hoehn & Yahr stage, age, duration of the disease, and the major PD signs. The specific DAT binding in the caudate, the putamen and the caudate/putamen ratio were measured. In all of the PD patients the striatal uptake values were bilaterally reduced, being 36.9% (P < 0.001) lower than those of the controls. In the hemiparkinsonian patients the reduction was greater on the side contralateral to the initial symptoms (33.3% vs. 27.8%) and the uptake ratios indicated a more pronounced deficit in the putamen (39.1%) than in the caudate (27.9%). The DAT uptake correlated with the UPDRS total score and activities of daily living (ADL) and motor subscores, the Hoehn & Yahr stage, and rigidity score. PD patients had significantly higher caudate to putamen ratios than the controls. In the PD patients the SERT values were lower in the thalamic and frontal regions. The SERT uptake ratio of the frontal area correlated with the UPDRS subscore I. [123I]beta-CIT SPECT provides a useful method for confirming the clinical diagnosis of PD with correlation to disease severity. Additionally, this technique allows the simultaneous measurement of SERT uptake and shows that PD patients, interestingly, seem to have decreased SERT availability in the thalamic and frontal areas.

  5. 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.

  6. 6. VIEW OF SPILLWAY TIMBERS AND WATER CONTROL BOX, SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF SPILLWAY TIMBERS AND WATER CONTROL BOX, SHOWING WATER CONTROL BOX WITH LOWERED LAKE LEVEL - Three Bears Lake & Dams, Water Control Box, North of Marias Pass, East Glacier Park, Glacier County, MT

  7. The ocular complications of boxing.

    PubMed

    Giovinazzo, V J; Yannuzzi, L A; Sorenson, J A; Delrowe, D J; Cambell, E A

    1987-06-01

    In cooperation with the New York State Athletic Commission, 74 boxers applying for a new or yearly renewal license were sequentially referred over a 2-year period for a complete dilated ocular examination at the Sports Vision Institute of the Manhattan Eye, Ear and Throat Hospital. At least one ocular injury was found in 66% of boxers. Vision-threatening injuries, defined as significant damage to the angle, lens, macula, or peripheral retina occurred in 58% of boxers. Nineteen percent of boxers had angle abnormalities. Nineteen percent of boxers had pathologic cataracts, over 70% of these were posterior subcapsular. Six boxers had macular lesions. A total of 24% of boxers had retinal tears. Standardized photographs were used to distinguish pathologic cataracts from congenital opacities and pathologic retinal tears from atrophic holes. Attempts were made to identify risk factors in boxing that might be predictive for ocular injury. Variables included age, weight division, left- or right-handedness, total number of losses, and total number of bouts. Significant correlations were found between the total number of bouts and the total number of losses, and the presence of retinal tears. College varsity athletes were selected as controls. Significant differences were found between boxers and controls for the total number of injuries, total vision-threatening injuries, and the number of retinal tears. A series of recommendations are proposed to aide in the early detection and prevention of serious ocular injuries.

  8. Anterior thalamic lesions produce chronic and profuse transcriptional de-regulation in retrosplenial cortex: A model of retrosplenial hypoactivity and covert pathology

    PubMed Central

    Poirier, G.L.; Shires, K.L.; Sugden, D.; Amin, E.; Thomas, K.L.; Carter, D.A.; Aggleton, J.P.

    2010-01-01

    Anterior thalamic lesions are thought to produce ‘covert pathology’ in retrosplenial cortex, but the causes are unknown. Microarray analyses tested the hypothesis that thalamic damage causes a chronic, hypo-function of metabolic and plasticity-related pathways (Experiment 1). Rats with unilateral, anterior thalamic lesions were exposed to a novel environment for 20 minutes, and granular retrosplenial tissue sampled from both hemispheres 30 minutes, 2h, or 8h later. Complementary statistical approaches (analyses of variance, predictive patterning and gene set enrichment analysis) revealed pervasive gene expression differences between retrosplenial cortex ipsilateral to the thalamic lesion and contralateral to the lesion. Selected gene differences were validated by QPCR, immunohistochemistry (Experiment 1), and in situ hybridisation (Experiment 2). Following thalamic lesions, the retrosplenial cortex undergoes profuse cellular transcriptome changes including lower relative levels of specific mRNAs involved in energy metabolism and neuronal plasticity. These changes in functional gene expression may be largely driven by decreases in the expression of multiple transcription factors, including brd8, c-fos, fra-2, klf5, nfix, nr4a1, smad3, smarcc2, and zfp9, with a much smaller number (nfat5, neuroD1, RXRγ) showing increases. These findings have implications for conditions such as diencephalic amnesia and Alzheimer’s disease, where both anterior thalamic pathology and retrosplenial cortex hypometabolism are prominent. PMID:21289865

  9. Hydro-Balanced Stuffing Box field test

    SciTech Connect

    Giangiacomo, L.A.

    1999-05-28

    The Hydro-Balanced Stuffing Box is a seal assembly for polished rod pumping installations commonly used in oil and gas pumping well installations to contain produced well fluids. The improved stuffing box was developed and patented by Harold H. Palmour of The Palmour Group of Livingston, TX. The stuffing box is designed to reduce the incidence of seal leakage and to utilize an environmentally safe fluid, so that if there is any leakage, environmental damage is reduced or eliminated. The unit was tested on two wells at the Rocky Mountain Oilfield Testing Center. During the test period, the performance of the stuffing box was measured by monitoring the pressure on the tubing and the inner chamber with a Barton Two-pen recorder. The amount of safe fluid consumed, fluid leakage at the top of the stuffing box, pressure supplied from the nitrogen bottle, ambient temperature, and polish rod temperature was recorded. The stuffing box is capable of providing a better seal between well fluids an d the environment than conventional stuffing boxes. It allows the polished rod to operate cooler and with lubrication, extending the life of the packing elements, and reducing the amount of attention required to prevent leakage.

  10. High-Density Terminal Box for Testing Wire Harness

    NASA Technical Reports Server (NTRS)

    Pierce, W. B.; Collins, W. G.

    1982-01-01

    Compact terminal box provides access to complex wiring harnesses for testing. Box accommodates more than twice as many wires as previous boxes. Box takes in wires via cable connectors and distributes them to contacts on box face. Instead of separate insulated jacks in metal face panel, box uses pairs of small military-standard metal sockets in precision-drilled plastic panel. Shorting plug provides continuity for wires when not being tested.

  11. Immunomodulatory Effects Mediated by Dopamine.

    PubMed

    Arreola, Rodrigo; Alvarez-Herrera, Samantha; Pérez-Sánchez, Gilberto; Becerril-Villanueva, Enrique; Cruz-Fuentes, Carlos; Flores-Gutierrez, Enrique Octavio; Garcés-Alvarez, María Eugenia; de la Cruz-Aguilera, Dora Luz; Medina-Rivero, Emilio; Hurtado-Alvarado, Gabriela; Quintero-Fabián, Saray; Pavón, Lenin

    2016-01-01

    Dopamine (DA), a neurotransmitter in the central nervous system (CNS), has modulatory functions at the systemic level. The peripheral and central nervous systems have independent dopaminergic system (DAS) that share mechanisms and molecular machinery. In the past century, experimental evidence has accumulated on the proteins knowledge that is involved in the synthesis, reuptake, and transportation of DA in leukocytes and the differential expression of the D1-like (D1R and D5R) and D2-like receptors (D2R, D3R, and D4R). The expression of these components depends on the state of cellular activation and the concentration and time of exposure to DA. Receptors that are expressed in leukocytes are linked to signaling pathways that are mediated by changes in cAMP concentration, which in turn triggers changes in phenotype and cellular function. According to the leukocyte lineage, the effects of DA are associated with such processes as respiratory burst, cytokine and antibody secretion, chemotaxis, apoptosis, and cytotoxicity. In clinical conditions such as schizophrenia, Parkinson disease, Tourette syndrome, and multiple sclerosis (MS), there are evident alterations during immune responses in leukocytes, in which changes in DA receptor density have been observed. Several groups have proposed that these findings are useful in establishing clinical status and clinical markers.

  12. Addiction: Beyond dopamine reward circuitry

    SciTech Connect

    Volkow, N.D.; Wang, G.; Volkow, N.D.; Wang, G.-J.; Fowler, J.S.; Tomasi, D.; Telang, F.

    2011-09-13

    Dopamine (DA) is considered crucial for the rewarding effects of drugs of abuse, but its role in addiction is much less clear. This review focuses on studies that used PET to characterize the brain DA system in addicted subjects. These studies have corroborated in humans the relevance of drug-induced fast DA increases in striatum [including nucleus accumbens (NAc)] in their rewarding effects but have unexpectedly shown that in addicted subjects, drug-induced DA increases (as well as their subjective reinforcing effects) are markedly blunted compared with controls. In contrast, addicted subjects show significant DA increases in striatum in response to drug-conditioned cues that are associated with self-reports of drug craving and appear to be of a greater magnitude than the DA responses to the drug. We postulate that the discrepancy between the expectation for the drug effects (conditioned responses) and the blunted pharmacological effects maintains drug taking in an attempt to achieve the expected reward. Also, whether tested during early or protracted withdrawal, addicted subjects show lower levels of D2 receptors in striatum (including NAc), which are associated with decreases in baseline activity in frontal brain regions implicated in salience attribution (orbitofrontal cortex) and inhibitory control (anterior cingulate gyrus), whose disruption results in compulsivity and impulsivity. These results point to an imbalance between dopaminergic circuits that underlie reward and conditioning and those that underlie executive function (emotional control and decision making), which we postulate contributes to the compulsive drug use and loss of control in addiction.

  13. Dopamine, behavioral economics, and effort.

    PubMed

    Salamone, John D; Correa, Merce; Farrar, Andrew M; Nunes, Eric J; Pardo, Marta

    2009-01-01

    There are numerous problems with the hypothesis that brain dopamine (DA) systems, particularly in the nucleus accumbens, directly mediate the rewarding or primary motivational characteristics of natural stimuli such as food. Research and theory related to the functions of mesolimbic DA are undergoing a substantial conceptual restructuring, with the traditional emphasis on hedonia and primary reward yielding to other concepts and lines of inquiry. The present review is focused upon the involvement of nucleus accumbens DA in behavioral activation and effort-related processes. Viewed from the framework of behavioral economics, the effects of accumbens DA depletions and antagonism on food-reinforced behavior are highly dependent upon the work requirements of the instrumental task, and DA depleted rats are more sensitive to increases in response costs (i.e., ratio requirements). Moreover, interference with accumbens DA transmission exerts a powerful influence over effort-related choice behavior. Rats with accumbens DA depletions or antagonism reallocate their instrumental behavior away from food-reinforced tasks that have high response requirements, and instead these rats select a less-effortful type of food-seeking behavior. Nucleus accumbens DA and adenosine interact in the regulation of effort-related functions, and other brain structures (anterior cingulate cortex, amygdala, ventral pallidum) also are involved. Studies of the brain systems regulating effort-based processes may have implications for understanding drug abuse, as well as energy-related disorders such as psychomotor slowing, fatigue or anergia in depression and other neurological disorders.

  14. Immunomodulatory Effects Mediated by Dopamine

    PubMed Central

    Alvarez-Herrera, Samantha; Pérez-Sánchez, Gilberto; Becerril-Villanueva, Enrique; Cruz-Fuentes, Carlos; Flores-Gutierrez, Enrique Octavio; Quintero-Fabián, Saray

    2016-01-01

    Dopamine (DA), a neurotransmitter in the central nervous system (CNS), has modulatory functions at the systemic level. The peripheral and central nervous systems have independent dopaminergic system (DAS) that share mechanisms and molecular machinery. In the past century, experimental evidence has accumulated on the proteins knowledge that is involved in the synthesis, reuptake, and transportation of DA in leukocytes and the differential expression of the D1-like (D1R and D5R) and D2-like receptors (D2R, D3R, and D4R). The expression of these components depends on the state of cellular activation and the concentration and time of exposure to DA. Receptors that are expressed in leukocytes are linked to signaling pathways that are mediated by changes in cAMP concentration, which in turn triggers changes in phenotype and cellular function. According to the leukocyte lineage, the effects of DA are associated with such processes as respiratory burst, cytokine and antibody secretion, chemotaxis, apoptosis, and cytotoxicity. In clinical conditions such as schizophrenia, Parkinson disease, Tourette syndrome, and multiple sclerosis (MS), there are evident alterations during immune responses in leukocytes, in which changes in DA receptor density have been observed. Several groups have proposed that these findings are useful in establishing clinical status and clinical markers. PMID:27795960

  15. Dopamine, Behavioral Economics, and Effort

    PubMed Central

    Salamone, John D.; Correa, Merce; Farrar, Andrew M.; Nunes, Eric J.; Pardo, Marta

    2009-01-01

    There are numerous problems with the hypothesis that brain dopamine (DA) systems, particularly in the nucleus accumbens, directly mediate the rewarding or primary motivational characteristics of natural stimuli such as food. Research and theory related to the functions of mesolimbic DA are undergoing a substantial conceptual restructuring, with the traditional emphasis on hedonia and primary reward yielding to other concepts and lines of inquiry. The present review is focused upon the involvement of nucleus accumbens DA in behavioral activation and effort-related processes. Viewed from the framework of behavioral economics, the effects of accumbens DA depletions and antagonism on food-reinforced behavior are highly dependent upon the work requirements of the instrumental task, and DA depleted rats are more sensitive to increases in response costs (i.e., ratio requirements). Moreover, interference with accumbens DA transmission exerts a powerful influence over effort-related choice behavior. Rats with accumbens DA depletions or antagonism reallocate their instrumental behavior away from food-reinforced tasks that have high response requirements, and instead these rats select a less-effortful type of food-seeking behavior. Nucleus accumbens DA and adenosine interact in the regulation of effort-related functions, and other brain structures (anterior cingulate cortex, amygdala, ventral pallidum) also are involved. Studies of the brain systems regulating effort-based processes may have implications for understanding drug abuse, as well as energy-related disorders such as psychomotor slowing, fatigue or anergia in depression and other neurological disorders. PMID:19826615

  16. Thalamic atrophy in antero-medial and dorsal nuclei correlates with six-month outcome after severe brain injury☆

    PubMed Central

    Lutkenhoff, Evan S.; McArthur, David L.; Hua, Xue; Thompson, Paul M.; Vespa, Paul M.; Monti, Martin M.

    2013-01-01

    The primary and secondary damage to neural tissue inflicted by traumatic brain injury is a leading cause of death and disability. The secondary processes, in particular, are of great clinical interest because of their potential susceptibility to intervention. We address the dynamics of tissue degeneration in cortico-subcortical circuits after severe brain injury by assessing volume change in individual thalamic nuclei over the first six-months post-injury in a sample of 25 moderate to severe traumatic brain injury patients. Using tensor-based morphometry, we observed significant localized thalamic atrophy over the six-month period in antero-dorsal limbic nuclei as well as in medio-dorsal association nuclei. Importantly, the degree of atrophy in these nuclei was predictive, even after controlling for full-brain volume change, of behavioral outcome at six-months post-injury. Furthermore, employing a data-driven decision tree model, we found that physiological measures, namely the extent of atrophy in the anterior thalamic nucleus, were the most predictive variables of whether patients had regained consciousness by six-months, followed by behavioral measures. Overall, these findings suggest that the secondary non-mechanical degenerative processes triggered by severe brain injury are still ongoing after the first week post-trauma and target specifically antero-medial and dorsal thalamic nuclei. This result therefore offers a potential window of intervention, and a specific target region, in agreement with the view that specific cortico-thalamo-cortical circuits are crucial to the maintenance of large-scale network neural activity and thereby the restoration of cognitive function after severe brain injury. PMID:24273723

  17. Roles of GABAA and GABAB receptors in regulating thalamic activity by the zona incerta: a computational study

    PubMed Central

    Park, Anthony; Hoffman, Kathleen

    2014-01-01

    The posterior thalamic nucleus (PO) is a higher order nucleus heavily implicated in the processing of somatosensory information. We have previously shown in rodent models that activity in PO is tightly regulated by inhibitory inputs from a GABAergic nucleus known as the zona incerta (ZI). The level of incertal inhibition varies under both physiological and pathological conditions, leading to concomitant changes in PO activity. These changes are causally linked to variety of phenomena from altered sensory perception to pathological pain. ZI regulation of PO is mediated by GABAA and GABAB receptors (GABAAR and GABABR) that differ in their binding kinetics and their electrophysiological properties, suggesting that each may have distinct roles in incerto-thalamic regulation. We developed a computational model to test this hypothesis. We created a two-cell Hodgkin-Huxley model representing PO and ZI with kinetically realistic GABAAR- and GABABR-mediated synapses. We simulated spontaneous and evoked firing in PO and observed how these activities were affected by inhibition mediated by each receptor type. Our model predicts that spontaneous PO activity is preferentially regulated by GABABR-mediated mechanisms, while evoked activity is preferentially regulated by GABAAR. Our model also predicts that modulation of ZI firing rate and synaptic GABA concentrations is an effective means to regulate the incerto-thalamic circuit. The coupling of distinct functions to GABAAR and GABABR presents an opportunity for the development of therapeutics, as particular aspects of incerto-thalamic regulation can be targeted by manipulating the corresponding receptor class. Thus these findings may provide interventions for pathologies of sensory processing. PMID:25143541

  18. Thalamic nuclei segmentation in clinical 3T T1-weighted Images using high-resolution 7T shape models

    NASA Astrophysics Data System (ADS)

    Liu, Yuan; D'Haese, Pierre-François; Newton, Allen T.; Dawant, Benoit M.

    2015-03-01

    Accurate and reliable identification of thalamic nuclei is important for surgical interventions and neuroanatomical studies. This is a challenging task due to their small sizes and low intra-thalamic contrast in standard T1-weighted or T2- weighted images. Previously proposed techniques rely on diffusion imaging or functional imaging. These require additional scanning and suffer from the low resolution and signal-to-noise ratio in these images. In this paper, we aim to directly segment the thalamic nuclei in standard 3T T1-weighted images using shape models. We manually delineate the structures in high-field MR images and build high resolution shape models from a group of subjects. We then investigate if the nuclei locations can be inferred from the whole thalamus. To do this, we hierarchically fit joint models. We start from the entire thalamus and fit a model that captures the relation between the thalamus and large nuclei groups. This allows us to infer the boundaries of these nuclei groups and we repeat the process until all nuclei are segmented. We validate our method in a leave-one-out fashion with seven subjects by comparing the shape-based segmentations on 3T images to the manual contours. Results we have obtained for major nuclei (dice coefficients ranging from 0.57 to 0.88 and mean surface errors from 0.29mm to 0.72mm) suggest the feasibility of using such joint shape models for localization. This may have a direct impact on surgeries such as Deep Brain Stimulation procedures that require the implantation of stimulating electrodes in specific thalamic nuclei.

  19. Complementary subicular pathways to the anterior thalamic nuclei and mammillary bodies in the rat and macaque monkey brain.

    PubMed

    Christiansen, Kat; Dillingham, Christopher M; Wright, Nicholas F; Saunders, Richard C; Vann, Seralynne D; Aggleton, John P

    2016-04-01

    The origins of the hippocampal (subicular) projections to the anterior thalamic nuclei and mammillary bodies were compared in rats and macaque monkeys using retrograde tracers. These projections form core components of the Papez circuit, which is vital for normal memory. The study revealed a complex pattern of subicular efferents, consistent with the presence of different, parallel information streams, whose segregation appears more marked in the rat brain. In both species, the cells projecting to the mammillary bodies and anterior thalamic nuclei showed laminar separation but also differed along other hippocampal axes. In the rat, these diencephalic inputs showed complementary topographies in the proximal-distal (columnar) plane, consistent with differential involvement in object-based (proximal subiculum) and context-based (distal subiculum) information. The medial mammillary inputs, which arose along the anterior-posterior extent of the rat subiculum, favoured the central subiculum (septal hippocampus) and the more proximal subiculum (temporal hippocampus). In contrast, anterior thalamic inputs were largely confined to the dorsal (i.e. septal and intermediate) subiculum, where projections to the anteromedial nucleus favoured the proximal subiculum while those to the anteroventral nucleus predominantly arose in the distal subiculum. In the macaque, the corresponding diencephalic inputs were again distinguished by anterior-posterior topographies, as subicular inputs to the medial mammillary bodies predominantly arose from the posterior hippocampus while subicular inputs to the anteromedial thalamic nucleus predominantly arose from the anterior hippocampus. Unlike the rat, there was no clear evidence of proximal-distal separation as all of these medial diencephalic projections preferentially arose from the more distal subiculum.

  20. The impact of fornix lesions in rats on spatial learning tasks sensitive to anterior thalamic and hippocampal damage

    PubMed Central

    Dumont, Julie R.; Amin, Eman; Wright, Nicholas F.; Dillingham, Christopher M.; Aggleton, John P.

    2015-01-01

    The present study sought to understand how the hippocampus and anterior thalamic nuclei are conjointly required for spatial learning by examining the impact of cutting a major tract (the fornix) that interconnects these two sites. The initial experiments examined the consequences of fornix lesions in rats on spatial biconditional discrimination learning. The rationale arose from previous findings showing that fornix lesions spare the learning of spatial biconditional tasks, despite the same task being highly sensitive to both hippocampal and anterior thalamic nuclei lesions. In the present study, fornix lesions only delayed acquisition of the spatial biconditional task, pointing to additional contributions from non-fornical routes linking the hippocampus with the anterior thalamic nuclei. The same fornix lesions spared the learning of an analogous nonspatial biconditional task that used local contextual cues. Subsequent tests, including T-maze place alternation, place learning in a cross-maze, and a go/no-go place discrimination, highlighted the impact of fornix lesions when distal spatial information is used flexibly to guide behaviour. The final experiment examined the ability to learn incidentally the spatial features of a square water-maze that had differently patterned walls. Fornix lesions disrupted performance but did not stop the rats from distinguishing the various corners of the maze. Overall, the results indicate that interconnections between the hippocampus and anterior thalamus, via the fornix, help to resolve problems with flexible spatial and temporal cues, but the results also signal the importance of additional, non-fornical contributions to hippocampal-anterior thalamic spatial processing, particularly for problems with more stable spatial solutions. PMID:25453745

  1. Thalamic superoxide and peroxide handling capacity (SPHC): An experimental study with aluminum, ethanol and tocopherol in rats.

    PubMed

    Nayak, Prasunpriya; Sharma, S B; Chowdary, N V S

    2015-09-01

    Superoxide and peroxide handling capacity (SPHC) is an important determinant of oxidative stress. Neurotoxic impacts of aluminum are associated with oxidant imbalance. Here, we studied the influence of aluminum on oxidative stress parameters, antioxidative enzymes and SPHC of thalamic area on pro-oxidant (ethanol) and antioxidant (α-tocopherol) exposure. Two sets of male Wistar rats were divided into 8 groups (6 each) and exposed to aluminum (10 mg/Kg body wt.), ethanol (0.6 g/Kg body wt.) and α-tocopherol (5 IU/day) for 4 wk, each having respective control group. Levels of reduced glutathione (GSH), lipid peroxidation (TBARS) along with activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) of thalamic area were estimated for each group. Glutathione-independent superoxide peroxide handling capacity (GI-SPHC) and glutathione-dependent superoxide peroxide handling capacity (GD-SPHC) were calculated from the GPx, CAT and SOD values. Concomitant exposure to aluminum and ethanol demonstrated significant increase in SOD activity and significant decrease in GPx activity compared to the control group, while lone aluminum-exposed rats showed raised GR activity, without alterations in GPx and SOD activities. However, significant reduction of both GI- and GD- SPHC were found in ethanol-exposed groups. α-Tocopherol supplementation could resist most of the alterations. In addition, current antioxidant exposure reduced the inherent GD-SPHC, and thus, made thalamic area more vulnerable to oxidant threat. The present study corroborates the thalamic susceptibility to aluminum-augmented oxidant imbalance and suggests cautious use of antioxidant supplementation against neurodegenerative disorders.

  2. Thalamic pathology and memory loss in early Alzheimer's disease: moving the focus from the medial temporal lobe to Papez circuit.

    PubMed

    Aggleton, John P; Pralus, Agathe; Nelson, Andrew J D; Hornberger, Michael

    2016-07-01

    It is widely assumed that incipient protein pathology in the medial temporal lobe instigates the loss of episodic memory in Alzheimer's disease, one of the earliest cognitive deficits in this type of dementia. Within this region, the hippocampus is seen as the most vital for episodic memory. Consequently, research into the causes of memory loss in Alzheimer's disease continues to centre on hippocampal dysfunction and how disease-modifying therapies in this region can potentially alleviate memory symptomology. The present review questions this entrenched notion by bringing together findings from post-mortem studies, non-invasive imaging (including studies of presymptomatic, at-risk cases) and genetically modified animal models. The combined evidence indicates that the loss of episodic memory in early Alzheimer's disease reflects much wider neurodegeneration in an extended mnemonic system (Papez circuit), which critically involves the limbic thalamus. Within this system, the anterior thalamic nuclei are prominent, both for their vital contributions to episodic memory and for how these same nuclei appear vulnerable in prodromal Alzheimer's disease. As thalamic abnormalities occur in some of the earliest stages of the disease, the idea that such changes are merely secondary to medial temporal lobe dysfunctions is challenged. This alternate view is further strengthened by the interdependent relationship between the anterior thalamic nuclei and retrosplenial cortex, given how dysfunctions in the latter cortical area provide some of the earliest in vivo imaging evidence of prodromal Alzheimer's disease. Appreciating the importance of the anterior thalamic nuclei for memory and attention provides a more balanced understanding of Alzheimer's disease. Furthermore, this refocus on the limbic thalamus, as well as the rest of Papez circuit, would have significant implications for the diagnostics, modelling, and experimental treatment of cognitive symptoms in Alzheimer's disease.

  3. Genetic disruption of dopamine production results in pituitary adenomas and severe prolactinemia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dopamine release from tuberoinfundibular dopamine neurons into the median eminence activates dopamine-D2 receptors in the pituitary gland where it inhibits lactotroph function. We have previously described genetic dopamine-deficient mouse models which lack the ability to synthesize dopamine. Because...

  4. Newly observed thalamic involvement and mutations of the HEXA gene in a Korean patient with juvenile GM2 gangliosidosis.

    PubMed

    Lee, Soon Min; Lee, Min Jung; Lee, Joon Soo; Kim, Heung Dong; Lee, Jin Sung; Kim, Jinna; Lee, Seung Koo; Lee, Young Mock

    2008-09-01

    Neuroimaging studies of patients with GM2 gangliosidosis are rare. The thalamus and basal ganglia are principally involved in patients affected by the infantile form of GM2 gangliosidosis. Unlike in the infantile form, in juvenile or adult type GM2 gangliosidosis, progressive cortical and cerebellar atrophy is the main abnormality seen on conventional magnetic resonance imaging (MRI); no basal ganglial or thalamic impairment were observed. This report is of a Korean girl with subacute onset, severe deficiency of hexosaminidase A activity and mutations (Arg137Term, Ala246Thr) of the HEXA gene. A 3.5-year-old girl who was previously in good health was evaluated for hypotonia and ataxia 3 months ago and showed progressive developmental deterioration, including cognitive decline. Serial brain MRI showed progressive overall volume decrease of the entire brain and thalamic atrophy. Fluorine-18 FDG PET scan showed severe decreased uptake in bilateral thalamus and diffuse cerebral cortex. We suggest, through our experience, that the thalamic involvement in MR imaging and FDG-PET can be observed in the juvenile form of GM2 gangliosidosis, and we suspect the association of mutations in the HEXA gene.

  5. Childhood Maltreatment Is Associated with Larger Left Thalamic Gray Matter Volume in Adolescents with Generalized Anxiety Disorder

    PubMed Central

    Liao, Mei; Yang, Fan; Zhang, Yan; He, Zhong; Song, Ming; Jiang, Tianzi; Li, Zexuan; Lu, Shaojia; Wu, Weiwei; Su, Linyan; Li, Lingjiang

    2013-01-01

    Background Generalized anxiety disorder (GAD) is a common anxiety disorder that usually begins in adolescence. Childhood maltreatment is highly prevalent and increases the possibility for developing a variety of mental disorders including anxiety disorders. An earlier age at onset of GAD is significantly related to maltreatment in childhood. Exploring the underpinnings of the relationship between childhood maltreatment and adolescent onset GAD would be helpful in identifying the potential risk markers of this condition. Methods Twenty-six adolescents with GAD and 25 healthy controls participated in this study. A childhood trauma questionnaire (CTQ) was introduced to assess childhood maltreatment. All subjects underwent high-resolution structural magnetic resonance scans. Voxel-based morphometry (VBM) was used to investigate gray matter alterations. Results Significantly larger gray matter volumes of the right putamen were observed in GAD patients compared to healthy controls. In addition, a significant diagnosis-by-maltreatment interaction effect for the left thalamic gray matter volume was revealed, as shown by larger volumes of the left thalamic gray matter in GAD patients with childhood maltreatment compared with GAD patients without childhood maltreatment as well as with healthy controls with/without childhood maltreatment. A significant positive association between childhood maltreatment and left thalamic gray matter volume was only seen in GAD patients. Conclusions These findings revealed an increased volume in the subcortical regions in adolescent GAD, and the alterations in the left thalamus might be involved in the association between childhood maltreatment and the occurrence of GAD. PMID:23951265

  6. Delayed thalamic astrocytosis and disrupted sleep-wake patterns in a preclinical model of traumatic brain injury.

    PubMed

    Hazra, Anupam; Macolino, Christine; Elliott, Melanie B; Chin, Jeannie

    2014-11-01

    Traumatic brain injury (TBI) involves diffuse axonal injury and induces subtle but persistent changes in brain tissue and function and poses challenges for early detection of neurological injury. The present study uses an automated behavioral analysis system to assess alterations in rodent behavior in the subacute phase in a preclinical mouse model of TBI, controlled cortical impact (CCI) injury. In the first few weeks following CCI, mice demonstrated normal exploratory behaviors and other typical home-cage behaviors. However, beginning 4 weeks post-injury, CCI mice developed disruptions in sleep-wake patterns, including an increased number of awakenings from sleep. Such impaired sleep maintenance was accompanied by an increased latency to reach peak sleep in CCI mice. These sleep disruptions implicate involvement of the thalamocortical network, the activity of which must be tightly regulated to control sleep maintenance. After injury, there was an increase in reactive microglia in thalamic regions as well as delayed reactive astrocytosis that was evident in the thalamic reticular nucleus, which preceded the development of sleep disruptions. These data suggest that cortical injury may trigger inflammatory responses in deeper neuroanatomical structures, including the thalamic reticular nucleus. Such engagement of the thalamus may perturb the thalamocortical network that regulates sleep/awake patterns and contribute to sleep disruptions observed in this model as well as those documented in patients with TBI.

  7. Spikes and bursts in two types of thalamic projection neurons differentially shape sleep patterns and auditory responses in a songbird.

    PubMed

    Hahnloser, Richard H R; Wang, Claude Z-H; Nager, Aymeric; Naie, Katja

    2008-05-07

    In mammals, the thalamus plays important roles for cortical processing, such as relay of sensory information and induction of rhythmical firing during sleep. In neurons of the avian cerebrum, in analogy with cortical up and down states, complex patterns of regular-spiking and dense-bursting modes are frequently observed during sleep. However, the roles of thalamic inputs for shaping these firing modes are largely unknown. A suspected key player is the avian thalamic nucleus uvaeformis (Uva). Uva is innervated by polysensory input, receives indirect cerebral feedback via the midbrain, and projects to the cerebrum via two distinct pathways. Using pharmacological manipulation, electrical stimulation, and extracellular recordings of Uva projection neurons, we study the involvement of Uva in zebra finches for the generation of spontaneous activity and auditory responses in premotor area HVC (used as a proper name) and the downstream robust nucleus of the arcopallium (RA). In awake and sleeping birds, we find that single Uva spikes suppress and spike bursts enhance spontaneous and auditory-evoked bursts in HVC and RA neurons. Strong burst suppression is mediated mainly via tonically firing HVC-projecting Uva neurons, whereas a fast burst drive is mediated indirectly via Uva neurons projecting to the nucleus interface of the nidopallium. Our results reveal that cerebral sleep-burst epochs and arousal-related burst suppression are both shaped by sophisticated polysynaptic thalamic mechanisms.

  8. Evidence for Thalamic Involvement in the Thermal Grill Illusion: An fMRI Study

    PubMed Central

    Lindstedt, Fredrik; Johansson, Bo; Martinsen, Sofia; Kosek, Eva; Fransson, Peter; Ingvar, Martin

    2011-01-01

    Background Perceptual illusions play an important role in untangling neural mechanisms underlying conscious phenomena. The thermal grill illusion (TGI) has been suggested as a promising model for exploring percepts involved in neuropathic pain, such as cold-allodynia (pain arising from contact with innocuous cold). The TGI is an unpleasant/painful sensation from touching juxtapositioned bars of cold and warm innocuous temperatures. Aim To develop an MRI-compatible TGI-unit and explore the supraspinal correlates of the illusion, using fMRI, in a group of healthy volunteers. Methods We constructed a TGI-thermode allowing the rapid presentation of warm(41°C), cold(18°C) and interleaved(41°C+18°C = TGI) temperatures in an fMRI-environment. Twenty volunteers were tested. The affective-motivational (“unpleasantness”) and sensory-disciminatory (“pain-intensity”) dimensions of each respective stimulus were rated. Functional images were analyzed at a corrected α-level <0.05. Results The TGI was rated as significantly more unpleasant and painful than stimulation with each of its constituent temperatures. Also, the TGI was rated as significantly more unpleasant than painful. Thermal stimulation versus neutral baseline revealed bilateral activations of the anterior insulae and fronto-parietal regions. Unlike its constituent temperatures the TGI displayed a strong activation of the right (contralateral) thalamus. Exploratory contrasts at a slightly more liberal threshold-level also revealed a TGI-activation of the right mid/anterior insula, correlating with ratings of unpleasantness(rho = 0.31). Conclusion/Significance To the best of our knowledge, this is the first fMRI-study of the TGI. The activation of the anterior insula is consistent with this region's putative role in processing of homeostatically relevant feeling-states. Our results constitute the first neurophysiologic evidence of thalamic involvement in the TGI. Similar thalamic activity has

  9. Direct projections from the anterior thalamic nuclei to the retrohippocampal region in the rat.

    PubMed

    Shibata, H

    1993-11-15

    The present study examined the areal and laminar distribution of direct projections from the anterior thalamic nuclei to the retrohippocampal region in the rat, with anterograde transport of Phaseolus vulgaris-leucoagglutinin. The anteromedial nucleus (AM) projects to the temporal subiculum, medial entorhinal area, perirhinal area, and caudomedial part of the lateral entorhinal area. The interanteromedial nucleus (IAM) projects to the perirhinal area and the caudolateral part of the lateral entorhinal area. Furthermore, both the AM and IAM project to the temporal area 2, occipital area 1, and lateral occipital area 2. The projections from the AM and IAM to these retrohippocampal and neocortical regions terminate mainly in deep layers. The anteroventral nucleus (AV) projects to the subicular complex with a complex topographic organization. The most rostral part of the AV projects to layers I and III of the ventral presubiculum, the pyramidal cell layer of the temporal subiculum, and deep layers of the parasubiculum and medial entorhinal area. At the midrostrocaudal level of the AV, the lateral and the dorsal quadrants of the AV project, respectively, to layers I and III and to layers I and IV-VI of the ventral presubiculum, whereas the ventral and the medial quadrants project, respectively, to layers I and III and to layers I and IV-VI of the dorsal presubiculum. Furthermore, the lateral and dorsal quadrants project to the pyramidal cell layer of the temporal subiculum, whereas the ventral and medial quadrants project more septally. At the caudal third level of the AV, the dorsolateral part projects to layers I and III of the presubiculum with a patchy pattern and to the pyramidal cell layer of the septal subiculum. The anterodorsal nucleus projects mainly to deep layers of the presubiculum, parasubiculum, and entorhinal area. The results show that each subdivision of the anterior thalamic nuclei projects to a distinct field in the retrohippocampal region. This

  10. Role of dopamine in distal retina.

    PubMed

    Popova, E

    2014-05-01

    Dopamine is the most abundant catecholamine in the vertebrate retina. Despite the description of retinal dopaminergic cells three decades ago, many aspects of their function in the retina remain unclear. There is no consensus among the authors about the stimulus conditions for dopamine release (darkness, steady or flickering light) as well as about its action upon the various types of retinal cells. Many contradictory results exist concerning the dopamine effect on the gross electrical activity of the retina [reflected in electroretinogram (ERG)] and the receptors involved in its action. This review summarized current knowledge about the types of the dopaminergic neurons and receptors in the retina as well as the effects of dopamine receptor agonists and antagonists on the light responses of photoreceptors, horizontal and bipolar cells in both nonmammalian and mammalian retina. Special focus of interest concerns their effects upon the diffuse ERG as a useful tool for assessment of the overall function of the distal retina. An attempt is made to reveal some differences between the dopamine actions upon the activity of the ON versus OFF channel in the distal retina. The author has included her own results demonstrating such differences.

  11. Effect of "enriched environment" during development on adult rat behavior and response to the dopamine receptor agonist apomorphine.

    PubMed

    Hoffmann, L C; Schütte, S R M; Koch, M; Schwabe, K

    2009-02-18

    Enriched housing conditions (enriched environment, EE) during development has been shown to influence adult rat behavior and transmitter systems, especially dopamine function. We were interested in how different degrees of enrichment during development would affect adult rats' behavior and response to dopamine receptor challenge. Two groups of male Wistar rats (n=11-12) were raised under two different degrees of EE, i.e. "high enriched" and "low enriched" groups. A third group was kept under standard conditions and served as "non-enriched" control. As adults, rats were tested for anxiety (elevated plus-maze), for spatial learning (four-arm-baited eight-arm radial maze), and for motivation (breakpoint of the progressive ratio test). Finally, locomotor activity (activity box) and sensorimotor gating (prepulse inhibition (PPI) of the acoustic startle response (ASR)) were tested with and without challenge with the dopamine receptor agonist apomorphine. The time spent on the open or enclosed arms of the elevated plus-maze did not differ between groups, but the high enriched group showed higher rearing activity on the open arms. The breakpoint did not differ between groups. Learning and memory in the radial maze task only differed on the first few trials, but high enriched rats run faster compared with the other groups. In contrast, in the activity box enriched groups were less active, but apomorphine had the highest effect. Between groups, no difference in PPI and startle amplitude was found, but in the high and low EE group startle amplitude was enhanced after administration of apomorphine, while the PPI deficit induced by this drug was not different between groups. Altogether, we found no evidence that different amounts of environmental enrichment without differences in social EE affect rats' cognitive, emotional or motivational behavior. However, motor activity seems to be enhanced when rats are behaviorally or pharmacologically challenged by dopamine receptor

  12. [Present views on boxing--Henner's legacy].

    PubMed

    Tichý, J

    1997-05-29

    Fifty years ago academician Henner formulated clearly the negative view of neurologists on boxing as practised in his time. It was his merit that a protective helmet was introduced, many of his demands concerning the regime after a KO and the importance of medical examinations were no yet adequately appreciated. At the opportunity of the 100th anniversary of Henner's birth and the fiftieth anniversary of the Clinic he founded in the premises of saint Catherine the author discusses contemporary views on boxing, the risk of repeated injuries for the development of encephalopathia pugilistica and their relationship to Alzheimer's disease. Contemporary boxing is a spectacle which is a continuation of historical fights of gladiators. If the main objective is to hurt the adversary, this activity does not deserve the name of "sport" Sport should promote and maintain physical and mental health which is not the case in professional boxing.

  13. Mystery Boxes, X Rays, and Radiology.

    ERIC Educational Resources Information Center

    Thomson, Norman

    2000-01-01

    Indicates the difficulties of teaching concepts beyond light and color and creating memorable learning experiences. Recommends sequential activities using the mystery box approach to explain how scientists and doctors use photon applications. (YDS)

  14. EPA ExpoBox Toolbox Search

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant assessment data bases,

  15. Black Box Theatres: Cheyenne Mountain High School.

    ERIC Educational Resources Information Center

    Binder, Robert D.

    2002-01-01

    Describes the design of the academic arts building at Cheyenne Mountain High School in Colorado Springs, Colorado, including its black box theater, art classroom, computer graphics lab, gallery, video production area, and chorus classroom. (EV)

  16. Light Therapy Boxes for Seasonal Affective Disorder

    MedlinePlus

    Diseases and Conditions Seasonal affective disorder (SAD) Light therapy boxes can offer an effective treatment for seasonal affective disorder. Features such as light intensity, safety, cost and style are important considerations. ...

  17. Dopamine transporter deficiency syndrome: phenotypic spectrum from infancy to adulthood

    PubMed Central

    Ng, Joanne; Zhen, Juan; Meyer, Esther; Erreger, Kevin; Li, Yan; Kakar, Naseebullah; Ahmad, Jamil; Thiele, Holger; Kubisch, Christian; Rider, Nicholas L.; Holmes Morton, D.; Strauss, Kevin A.; Puffenberger, Erik G.; D’Agnano, Daniela; Anikster, Yair; Carducci, Claudia; Hyland, Keith; Rotstein, Michael; Leuzzi, Vincenzo; Borck, Guntram; Reith, Maarten E. A.

    2014-01-01

    Dopamine transporter deficiency syndrome due to SLC6A3 mutations is the first inherited dopamine ‘transportopathy’ to be described, with a classical presentation of early infantile-onset progressive parkinsonism dystonia. In this study we have identified a new cohort of patients with dopamine transporter deficiency syndrome, including, most significantly, atypical presentation later in childhood with a milder disease course. We report the detailed clinical features, molecular genetic findings and in vitro functional investigations undertaken for adult and paediatric cases. Patients presenting with parkinsonism dystonia or a neurotransmitter profile characteristic of dopamine transporter deficiency syndrome were recruited for study. SLC6A3 mutational analysis was undertaken in all patients. The functional consequences of missense variants on the dopamine transporter were evaluated by determining the effect of mutant dopamine transporter on dopamine uptake, protein expression and amphetamine-mediated dopamine efflux using an in vitro cellular heterologous expression system. We identified eight new patients from five unrelated families with dopamine transporter deficiency syndrome. The median age at diagnosis was 13 years (range 1.5–34 years). Most significantly, the case series included three adolescent males with atypical dopamine transporter deficiency syndrome of juvenile onset (outside infancy) and progressive parkinsonism dystonia. The other five patients in the cohort presented with classical infantile-onset parkinsonism dystonia, with one surviving into adulthood (currently aged 34 years) and labelled as having ‘juvenile parkinsonism’. All eight patients harboured homozygous or compound heterozygous mutations in SLC6A3, of which the majority are previously unreported variants. In vitro studies of mutant dopamine transporter demonstrated multifaceted loss of dopamine transporter function. Impaired dopamine uptake was universally present, and more

  18. Glove box on vehicular instrument panel

    DOEpatents

    Atarashi, Kazuya

    1985-01-01

    A glove box for the upper surface of an automobile dashboard whereby it may be positioned close to the driver. The glove box lid is pivotally supported by arms extending down either side to swing forwardly for opening. A hook is pivotally support adjacent an arm and weighted to swing into engagement with the arm to prevent opening of the lid during abrupt deceleration. A toggle spring assists in maintaining the lid in either the open or closed position.

  19. BOX-DEATH HOLLOW ROADLESS AREA, UTAH.

    USGS Publications Warehouse

    Weir, Gordon W.; Lane, Michael

    1984-01-01

    Geologic mapping, geochemical sampling, and a search for prospects and mineralized rock in the Box-Death Hollow Roadless Area, Utah indicate that there is little promise for the occurrence of mineral or energy resources in the area. Additional exploratory drilling by industry seems warranted if wells elsewhere in the region find oil or gas in strata as yet untested in the Box-Death Hollow Roadless Area.

  20. A look inside the actuarial black box.

    PubMed

    Math, S E; Youngerman, H

    1992-12-01

    Hospital executives often rely on actuaries (and their "black boxes") to determine self-insurance program liabilities and funding contributions. Typically, the hospital supplies the actuary with a myriad of statistics, and eventually the hospital receives a liability estimate and recommended funding level. The mysterious actuarial calculations that occur in between data reporting and receipt of the actuary's report are akin to a black box--a complicated device whose internal mechanism is hidden from or mysterious to the user.

  1. Autoantibodies to box A of high mobility group box 1 in systemic lupus erythematosus.

    PubMed

    Schaper, F; de Leeuw, K; Horst, G; Maas, F; Bootsma, H; Heeringa, P; Limburg, P C; Westra, J

    2017-02-28

    Autoantibodies to nuclear structures are a hallmark of systemic lupus erythematosus (SLE), including autoantibodies to nuclear protein high mobility group box 1 (HMGB1). HMGB1 consists of three separate domains: box A, box B and an acidic tail. Recombinant box A acts as a competitive antagonist for HMGB1 and might be an interesting treatment option in SLE. However, antibodies to box A might interfere. Therefore, levels of anti-box A were examined in SLE patients in association with disease activity and clinical parameters. Serum anti-box A was measured in 86 SLE patients and 44 age- and sex-matched healthy controls (HC). Serum samples of 28 patients with primary Sjögren's syndrome and 32 patients with rheumatoid arthritis were included as disease controls. Anti-HMGB1 and anti-box B levels were also measured by enzyme-linked immunosorbent assay during quiescent disease [SLE Disease Activity Index (SLEDAI) ≤ 4, n = 47] and active disease (SLEDAI ≥ 5, n = 39). Anti-box A levels in active SLE patients were higher compared to quiescent patients, and were increased significantly compared to HC and disease controls. Anti-box A levels correlated positively with SLEDAI and anti-dsDNA levels and negatively with complement C3 levels. Increased levels of anti-box A antibodies were present in the majority of patients with nephritic (73%) and non-nephritic exacerbations (71%). Antibodies to the box A domain of HMGB1 might be an interesting new biomarker, as these had a high specificity for SLE and were associated with disease activity. Longitudinal studies should be performed to evaluate whether these antibodies perform better in predicting an exacerbation, especially non-nephritic exacerbations.

  2. Dopamine Uptake in the Somatic Cell Hybrid NX31

    DTIC Science & Technology

    1975-08-01

    AFRRI SR75-21 AUGUST 1975 AFRRI SCIENTIFIC REPORT CM CO DOPAMINE UPTAKE IN THE SOMATIC CELL HYBRID NX31 P. R. Myers W. G. Shaln, Jr...Sciences - National Research Council. AFRRI SR75-21 August 1975 DOPAMINE UPTAKE IN THE SOMATIC CELL HYBRID NX31 P. R. MYERS W. G. SHAIN...Introduction 1 II. Experimental Methods 2 Materials 2 Cell lines 2 Dopamine uptake experiments 3 Metabolism of accumulated dopamine 5

  3. HYDROGEN AND VOC RETENTION IN WASTE BOXES

    SciTech Connect

    PACE ME; MARUSICH RM

    2008-11-21

    The Hanford Waste Management Project Master Documented Safety Analysis (MDSA) (HNF-14741, 2003) identifies derived safety controls to prevent or mitigate the risks of a single-container deflagration during operations requiring moving, venting or opening transuranic (TRU)-waste containers. The issue is whether these safety controls are necessary for operations involving TRU-waste boxes that are being retrieved from burial at the Hanford Site. This paper investigates the potential for a deflagration hazard within these boxes and whether safety controls identified for drum deflagration hazards should be applied to operations involving these boxes. The study evaluates the accumulation of hydrogen and VOCs within the waste box and the transport of these gases and vapors out of the waste box. To perform the analysis, there were numerous and major assumptions made regarding the generation rate and the transport pathway dimensions and their number. Since there is little actual data with regards to these assumptions, analyses of three potential configurations were performed to obtain some indication of the bounds of the issue (the concentration of hydrogen or flammable VOCs within a waste box). A brief description of each of the three cases along with the results of the analysis is summarized.

  4. Neuronal Source of Plasma Dopamine

    PubMed Central

    Goldstein, David S.; Holmes, Courtney

    2008-01-01

    BACKGROUND Determinants of plasma norepinephrine (NE) and epinephrine concentrations are well known; those of the third endogenous catecholamine, dopamine (DA), remain poorly understood. We tested in humans whether DA enters the plasma after corelease with NE during exocytosis from sympathetic noradrenergic nerves. METHODS We reviewed plasma catecholamine data from patients referred for autonomic testing and control subjects under the following experimental conditions: during supine rest and in response to orthostasis; intravenous yohimbine (YOH), isoproterenol (ISO), or glucagon (GLU), which augment exocytotic release of NE from sympathetic nerves; intravenous tri-methaphan (TRI) or pentolinium (PEN), which decrease exocytotic NE release; or intravenous tyramine (TYR), which releases NE by nonexocytotic means. We included groups of patients with pure autonomic failure (PAF), bilateral thoracic sympathectomies (SNS-x), or multiple system atrophy (MSA), since PAF and SNS-x are associated with noradrenergic denervation and MSA is not. RESULTS Orthostasis, YOH, ISO, and TYR increased and TRI/PEN decreased plasma DA concentrations. Individual values for changes in plasma DA concentrations correlated positively with changes in NE in response to orthostasis (r =0.72, P <0.0001), YOH (r = 0.75, P < 0.0001), ISO (r = 0.71, P < 0.0001), GLU (r = 0.47, P = 0.01), and TYR (r = 0.67, P < 0.0001). PAF and SNS-x patients had low plasma DA concentrations. We estimated that DA constitutes 2%– 4% of the catecholamine released by exocytosis from sympathetic nerves and that 50%–90% of plasma DA has a sympathoneural source. CONCLUSIONS Plasma DA is derived substantially from sympathetic noradrenergic nerves. PMID:18801936

  5. Imaging of Brain Dopamine Pathways

    PubMed Central

    Wang, Gene-Jack; Volkow, Nora D.; Thanos, Panayotis K.; Fowler, Joanna S.

    2011-01-01

    Obesity is typically associated with abnormal eating behaviors. Brain imaging studies in humans implicate the involvement of dopamine (DA)-modulated circuits in pathologic eating behavior(s). Food cues increase striatal extracellular DA, providing evidence for the involvement of DA in the nonhedonic motivational properties of food. Food cues also increase metabolism in the orbitofrontal cortex indicating the association of this region with the motivation for food consumption. Similar to drug-addicted subjects, striatal DA D2 receptor availability is reduced in obese subjects, which may predispose obese subjects to seek food as a means to temporarily compensate for understimulated reward circuits. Decreased DA D2 receptors in the obese subjects are also associated with decreased metabolism in prefrontal regions involved in inhibitory control, which may underlie their inability to control food intake. Gastric stimulation in obese subjects activates cortical and limbic regions involved with self-control, motivation, and memory. These brain regions are also activated during drug craving in drug-addicted subjects. Obese subjects have increased metabolism in the somatosensory cortex, which suggests an enhanced sensitivity to the sensory properties of food. The reduction in DA D2 receptors in obese subjects coupled with the enhanced sensitivity to food palatability could make food their most salient reinforcer putting them at risk for compulsive eating and obesity. The results from these studies suggest that multiple but similar brain circuits are disrupted in obesity and drug addiction and suggest that strategies aimed at improving DA function might be beneficial in the treatment and prevention of obesity. PMID:21603099

  6. Recovery of dopamine transporters with methamphetamine detoxification is not linked to changes in dopamine release.

    PubMed

    Volkow, Nora D; Wang, Gene-Jack; Smith, Lisa; Fowler, Joanna S; Telang, Frank; Logan, Jean; Tomasi, Dardo

    2015-11-01

    Methamphetamine's widepread abuse and concerns that it might increase Parkinson's disease led us to assess if the reported loss of dopamine transporters (DAT) in methamphetamine abusers (MA) reflected damage to dopamine neurons. Using PET with [(11)C]cocaine to measure DAT, and with [(11)C]raclopride to measure dopamine release (assessed as changes in specific binding of [(11)C]raclopride between placebo and methylphenidate), which was used as a marker of dopamine neuronal function, we show that MA (n=16), tested during early detoxification, had lower DAT (20-30%) but overall normal DA release in striatum (except for a small decrease in left putamen), when compared to controls (n=15). In controls, DAT were positively correlated with DA release (higher DAT associated with larger DA increases), consistent with DAT serving as markers of DA terminals. In contrast, MA showed a trend for a negative correlation (p=0.07) (higher DAT associated with lower DA increases), consistent with reduced DA re-uptake following DAT downregulation. MA who remained abstinent nine-months later (n=9) showed significant increases in DAT (20%) but methylphenidate-induced dopamine increases did not change. In contrast, in controls, DAT did not change when retested 9 months later but methylphenidate-induced dopamine increases in ventral striatum were reduced (p=0.05). Baseline D2/D3 receptors in caudate were lower in MA than in controls and did not change with detoxification, nor did they change in the controls upon retest. The loss of DAT in the MA, which was not associated with a concomitant reduction in dopamine release as would have been expected if DAT loss reflected DA terminal degneration; as well as the recovery of DAT after protracted detoxification, which was not associated with increased dopamine release as would have been expected if DAT increases reflected terminal regeneration, indicate that the loss of DAT in these MA does not reflect degeneration of dopamine terminals.

  7. Detection of cell surface dopamine receptors.

    PubMed

    Xiao, Jiping; Bergson, Clare

    2013-01-01

    Dopamine receptors are a class of metabotropic G protein-coupled receptors. Plasma membrane expression is a key determinant of receptor signaling, and one that is regulated both by extra and intracellular cues. Abnormal dopamine receptor signaling is implicated in several neuropsychiatric disorders, including schizophrenia and attention deficit hyperactivity disorder, as well as drug abuse. Here, we describe in detail the application of two complementary applications of protein biotinylation and enzyme-linked immunoabsorbent assay (ELISA) for detecting and quantifying levels of dopamine receptors expressed on the cell surface. In the biotinylation method, cell surface receptors are labeled with Sulfo-NHS-biotin. The charge on the sulfonyl facilitates water solubility of the reactive biotin compound and prevents its diffusion across the plasma membrane. In the ELISA method, surface labeling is achieved with antibodies specific to extracellular epitopes on the receptors, and by fixing the cells without detergent such that the plasma membrane remains intact.

  8. Detection of Cell Surface Dopamine Receptors

    PubMed Central

    Xiao, Jiping; Bergson, Clare

    2014-01-01

    Dopamine receptors are a class of metabotropic G protein-coupled receptors. Plasma membrane expression is a key determinant of receptor signaling, and one that is regulated both by extra and intracellular cues. Abnormal dopamine receptor signaling is implicated in several neuropsychiatric disorders, including schizophrenia and attention deficit hyperactivity disorder, as well as drug abuse. Here, we describe in detail the application of two complementary applications of protein biotinylation and enzyme-linked immunoabsorbant assay (ELISA) for detecting and quantifying levels of dopamine receptors expressed on the cell surface. In the biotinylation method, cell surface receptors are labeled with Sulfo-NHS-biotin. The charge on the sulfonyl facilitates water solubility of the reactive biotin compound and prevents its diffusion across the plasma membrane. In the ELISA method, cells surface labeling is achieved with antibodies specific to extracellular epitopes on the receptors, and by fixing the cells without detergent such that the plasma membrane remains intact. PMID:23296774

  9. Dopamine, T cells and multiple sclerosis (MS).

    PubMed

    Levite, Mia; Marino, Franca; Cosentino, Marco

    2017-03-10

    Dopamine is a key neurotransmitter that induces critical effects in the nervous system and in many peripheral organs, via 5 dopamine receptors (DRs): D1R-D5R. Dopamine also induces many direct and very potent effects on many DR-expressing immune cells, primarily T cells and dendritic cells. In this review, we focus only on dopamine receptors, effects and production in T cells. Dopamine by itself (at an optimal concentration of~0.1 nM) induces multiple function of resting normal human T cells, among them: T cell adhesion, chemotactic migration, homing, cytokine secretion and others. Interestingly, dopamine activates resting effector T cells (Teffs), but suppresses regulatory T cells (Tregs), and both effects lead eventually to Teff activation. Dopamine-induced effects on T cells are dynamic, context-sensitive and determined by the: T cell activation state, T cell type, DR type, and dopamine concentration. Dopamine itself, and also few dopaminergic molecules/ drugs that are in clinical use for cardiac, neurological and other non-immune indications, have direct effects on human T cells (summarized in this review). These dopaminergic drugs include: dopamine = intropin, L-DOPA, bromocriptine, pramipexole, pergolide, haloperidol, pimozide, and amantadine. Other dopaminergic drugs were not yet tested for their direct effects on T cells. Extensive evidence in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) show dopaminergic dysregulations in T cells in these diseases: D1-like DRs are decreased in Teffs of MS patients, and dopamine does not affect these cells. In contrast, D1-like DRs are increased in Tregs of MS patients, possibly causing functional Treg impairment in MS. Treatment of MS patients with interferon β (IFN-β) increases D1-like DRs and decreases D2-like DRs in Teffs, decreases D1-like DRs in Tregs, and most important: restores responsiveness of patient's Teffs to dopamine. DR agonists and antagonists confer some benefits in

  10. How Addictive Drugs Disrupt Presynaptic Dopamine Neurotransmission

    PubMed Central

    Sulzer, David

    2011-01-01

    The fundamental principle that unites addictive drugs appears to be that each enhances synaptic dopamine by means that dissociate it from normal behavioral control, so that they act to reinforce their own acquisition. This occurs via the modulation of synaptic mechanisms involved in learning, including enhanced excitation or disinhibition of dopamine neuron activity, blockade of dopamine reuptake, and altering the state of the presynaptic terminal to enhance evoked over basal transmission. Amphetamines offer an exception to such modulation in that they combine multiple effects to produce non-exocytic stimulation-independent release of neurotransmitter via reverse transport independent from normal presynaptic function. Questions on the molecular actions of addictive drugs, prominently including the actions of alcohol and solvents, remain unresolved, but their ability to co-opt normal presynaptic functions helps to explain why treatment for addiction has been challenging. PMID:21338876

  11. Vascular dopamine receptors: Demonstration and characterization by in vitro studies.

    PubMed

    Brodde, O E

    1982-07-26

    Substantial evidence has accumulated that in certain vascular beds dopamine produces its relaxant effect through stimulation of specific dopamine receptors. The goal of this review is to describe several in vitro models (perfused mesenteric vessels of the dog; renal, mesenteric, splenic, coronary and cerebral arterial strips of rabbits, dogs and cats; perfused kidney of the rat) recently developed to demonstrate such specific relaxations induced by dopamine and dopaminomimetics. On these models studies on structure-activity relationship for activation of the dopamine receptor resulted in the following order of potency for agonists: SK&F 38393 (partial agonist) greater than epinine greater than A-6, 7-DTN greater than or equal to dopamine greater than N, N-di-n-propyl-dopamine (partial agonist) greater than apomorphine (partial agonist). The dopamine receptor antagonists (+)-butaclamol, cis-alpha-flupenthixol, metoclopramide, droperidol and bulbocapnine were found to competitively antagonize dopamine induced relaxation. In addition, in two isolated organ systems (rabbit mesenteric artery, rat perfused kidney) stereospecificity of the vascular dopamine receptor was demonstrated with the isomers of butaclamol. With the development of several in vitro models demonstrating a specific antagonism against dopamine induced relaxation an important requirement for definition of a specific dopamine receptor if fulfilled according to classical pharmacological criteria. Thus, there can be do doubt on the existence of post-synaptic dopamine receptors mediating vasodilation in certain vascular tissues.

  12. Dopamine receptors in a songbird brain

    PubMed Central

    Kubikova, Lubica; Wada, Kazuhiro; Jarvis, Erich D

    2010-01-01

    Dopamine is a key neuromodulatory transmitter in the brain. It acts through dopamine receptors to affect changes in neural activity, gene expression, and behavior. In songbirds, dopamine is released into the striatal song nucleus Area X, and the levels depend on social contexts of undirected and directed singing. This differential release is associated with differential expression of activity-dependent genes, such as egr1 (avian zenk), which in mammalian brain are modulated by dopamine receptors. Here we cloned from zebra finch brain cDNAs of all avian dopamine receptors: the D1 (D1A, D1B, D1D) and D2 (D2, D3, D4) families. Comparative sequence analyses of predicted proteins revealed expected phylogenetic relationships, in which the D1 family exists as single exon and the D2 family exists as spliced exon genes. In both zebra finch and chicken, the D1A, D1B, and D2 receptors were highly expressed in the striatum, the D1D and D3 throughout the pallium and within the mesopallium, respectively, and the D4 mainly in the cerebellum. Furthermore, within the zebra finch, all receptors, except for D4, showed differential expression in song nuclei relative to the surrounding regions and developmentally regulated expression that decreased for most receptors during the sensory acquisition and sensorimotor phases of song learning. Within Area X, half of the cells expressed both D1A and D2 receptors, and a higher proportion of the D1A-only-containing neurons expressed egr1 during undirected but not during directed singing. Our findings are consistent with hypotheses that dopamine receptors may be involved in song development and social context-dependent behaviors. J. Comp. Neurol. 518:741–769, 2010. © 2009 Wiley-Liss, Inc. PMID:20058221

  13. Mediodorsal thalamic stimulation is not protective against seizures induced by amygdaloid kindling in rats.

    PubMed

    Wang, Shuang; Wu, Deng-Chang; Fan, Xiao-Ning; Zhu, Mei-Zhen; Hu, Qiong-Yao; Zhou, Dong; Ding, Mei-Ping; Chen, Zhong

    2010-09-06

    Deep brain stimulation (DBS) is now emerging as a new option for treating intractable epilepsy. Cumulative studies suggest that the mediodorsal thalamic nucleus (MD) is involved in limbic seizure activity. This study aims to investigate whether DBS of the MD can protect against seizures induced by amygdaloid kindling. We studied the effect of low-frequency stimulation (LFS, 1 Hz) or high-frequency stimulation (HFS, 100 Hz) in the MD on amygdaloid kindling seizures. During the kindling acquisition, DBS in the MD was daily administered immediately after the kindling stimulus or before the kindling stimulus (preemptive DBS). The effects of both post-treatment of DBS and preemptive DBS in the MD on the expression of amygdaloid kindling seizures were evaluated. We found the DBS or preemptive DBS in the MD, either LFS or HFS, did not significantly change the rate of amygdaloid kindling. Similarly, DBS or preemptive DBS in the MD did not significantly change any parameters representing the expression of amygdaloid kindling. Our study suggests that DBS in the MD may have no significant effect on limbic seizures.

  14. The Slow Oscillation in Cortical and Thalamic Networks: Mechanisms and Functions

    PubMed Central

    Neske, Garrett T.

    2016-01-01

    During even the most quiescent behavioral periods, the cortex and thalamus express rich spontaneous activity in the form of slow (<1 Hz), synchronous network state transitions. Throughout this so-called slow oscillation, cortical and thalamic neurons fluctuate between periods of intense synaptic activity (Up states) and almost complete silence (Down states). The two decades since the original characterization of the slow oscillation in the cortex and thalamus have seen considerable advances in deciphering the cellular and network mechanisms associated with this pervasive phenomenon. There are, nevertheless, many questions regarding the slow oscillation that await more thorough illumination, particularly the mechanisms by which Up states initiate and terminate, the functional role of the rhythmic activity cycles in unconscious or minimally conscious states, and the precise relation between Up states and the activated states associated with waking behavior. Given the substantial advances in multineuronal recording and imaging methods in both in vivo and in vitro preparations, the time is ripe to take stock of our current understanding of the slow oscillation and pave the way for future investigations of its mechanisms and functions. My aim in this Review is to provide a comprehensive account of the mechanisms and functions of the slow oscillation, and to suggest avenues for further exploration. PMID:26834569

  15. Differential Responses of Thalamic Reticular Neurons to Nociception in Freely Behaving Mice

    PubMed Central

    Huh, Yeowool; Cho, Jeiwon

    2016-01-01

    Pain serves an important protective role. However, it can also have debilitating adverse effects if dysfunctional, such as in pathological pain conditions. As part of the thalamocortical circuit, the thalamic reticular nucleus (TRN) has been implicated to have important roles in controlling nociceptive signal transmission. However studies on how TRN neurons, especially how TRN neuronal subtypes categorized by temporal bursting firing patterns—typical bursting, atypical bursting and non-bursting TRN neurons—contribute to nociceptive signal modulation is not known. To reveal the relationship between TRN neuronal subtypes and modulation of nociception, we simultaneously recorded behavioral responses and TRN neuronal activity to formalin induced nociception in freely moving mice. We found that typical bursting TRN neurons had the most robust response to nociception; changes in tonic firing rate of typical TRN neurons exactly matched changes in behavioral nociceptive responses, and burst firing rate of these neurons increased significantly when behavioral nociceptive responses were reduced. This implies that typical TRN neurons could critically modulate ascending nociceptive signals. The role of other TRN neuronal subtypes was less clear; atypical bursting TRN neurons decreased tonic firing rate after the second peak of behavioral nociception and the firing rate of non-bursting TRN neurons mostly remained at baseline level. Overall, our results suggest that different TRN neuronal subtypes contribute differentially to processing formalin induced sustained nociception in freely moving mice. PMID:27917114

  16. The thalamic projection to the sensory neocortex of the porpoise, Phocoena phocoena.

    PubMed Central

    Revishchin, A V; Garey, L J

    1990-01-01

    Retrograde tracers were injected in various parts of the neocortex of the porpoise (Phocoena phocoena). Labelled thalamic neurons were plotted in three-dimensional reconstructions. The lateral geniculate nucleus projects to the visually excitable part of the lateral gyrus. Ventral parts of the medial geniculate nucleus project to the auditory area of the suprasylvian gyrus, while dorsal medial geniculate projects to the 'secondary' auditory area of the ectosylvian gyrus and to the temporal operculum. The ventrobasal and ventropostero-inferior complex projects to cortex anterior to the suprasylvian auditory area, corresponding to somatosensory function. The main projection of the inferior pulvinar is to the suprasylvian gyrus, that of the medial pulvinar to the ectosylvian gyrus, and of the lateral pulvinar to the border of the lateral and suprasylvian gyri. The lateral and posterior complexes project to perisylvian cortex. Throughout the thalamus there is a rough topographic organisation. Lateral to medial through the thalamus represents progression from medial to lateral over the cortex from lateral gyrus to perisylvian cortex. Anterior in cortex is represented by anteroventral in thalamus, and posterior in cortex by posterodorsal in thalamus. Images Fig. 1 Fig. 2 Fig. 4 Fig. 5 Fig. 6 PMID:2384340

  17. Simple Cortical and Thalamic Neuron Models for Digital Arithmetic Circuit Implementation.

    PubMed

    Nanami, Takuya; Kohno, Takashi

    2016-01-01

    Trade-off between reproducibility of neuronal activities and computational efficiency is one of crucial subjects in computational neuroscience and neuromorphic engineering. A wide variety of neuronal models have been studied from different viewpoints. The digital spiking silicon neuron (DSSN) model is a qualitative model that focuses on efficient implementation by digital arithmetic circuits. We expanded the DSSN model and found appropriate parameter sets with which it reproduces the dynamical behaviors of the ionic-conductance models of four classes of cortical and thalamic neurons. We first developed a four-variable model by reducing the number of variables in the ionic-conductance models and elucidated its mathematical structures using bifurcation analysis. Then, expanded DSSN models were constructed that reproduce these mathematical structures and capture the characteristic behavior of each neuron class. We confirmed that statistics of the neuronal spike sequences are similar in the DSSN and the ionic-conductance models. Computational cost of the DSSN model is larger than that of the recent sophisticated Integrate-and-Fire-based models, but smaller than the ionic-conductance models. This model is intended to provide another meeting point for above trade-off that satisfies the demand for large-scale neuronal network simulation with closer-to-biology models.

  18. Corticothalamic Synaptic Noise as a Mechanism for Selective Attention in Thalamic Neurons

    PubMed Central

    Béhuret, Sébastien; Deleuze, Charlotte; Bal, Thierry

    2015-01-01

    A reason why the thalamus is more than a passive gateway for sensory signals is that two-third of the synapses of thalamocortical neurons are directly or indirectly related to the activity of corticothalamic axons. While the responses of thalamocortical neurons evoked by sensory stimuli are well characterized, with ON- and OFF-center receptive field structures, the prevalence of synaptic noise resulting from neocortical feedback in intracellularly recorded thalamocortical neurons in vivo has attracted little attention. However, in vitro and modeling experiments point to its critical role for the integration of sensory signals. Here we combine our recent findings in a unified framework suggesting the hypothesis that corticothalamic synaptic activity is adapted to modulate the transfer efficiency of thalamocortical neurons during selective attention at three different levels: First, on ionic channels by interacting with intrinsic membrane properties, second at the neuron level by impacting on the input-output gain, and third even more effectively at the cell assembly level by boosting the information transfer of sensory features encoded in thalamic subnetworks. This top-down population control is achieved by tuning the correlations in subthreshold membrane potential fluctuations and is adapted to modulate the transfer of sensory features encoded by assemblies of thalamocortical relay neurons. We thus propose that cortically-controlled (de-)correlation of subthreshold noise is an efficient and swift dynamic mechanism for selective attention in the thalamus. PMID:26733818

  19. Bilateral Lesions of the Thalamic Trigeminal Orosensory Area Dissociate Natural from Drug Reward in Contrast Paradigms

    PubMed Central

    Nyland, Jennifer E.; Alexander, Danielle N.; Liang, Nu-Chu; Grigson, Patricia S.

    2012-01-01

    Substance abuse and addiction are associated with an apparent devaluation of, and inattention to, natural rewards. This consequence of addiction can be modeled using a reward comparison paradigm where rats avoid intake of a palatable taste cue that comes to predict access to a drug of abuse. Evidence suggests rats avoid intake following such pairings, at least in part, because the taste cue pales in comparison to the highly rewarding drug expected in the near future. In accordance, lesions of the gustatory thalamus or cortex eliminate avoidance of a taste cue when paired with either a drug of abuse or a rewarding sucrose solution, but not when paired with the aversive agent, LiCl. The present study used bilateral ibotenic acid lesions to evaluate the role of a neighboring thalamic structure, the trigeminal orosensory area (TOA), in avoidance of a gustatory cue when paired with sucrose (Experiment 1), morphine (Experiment 2), cocaine (Experiment 3), or LiCl (Experiment 4). The results show that the TOA lesion disrupts, but does not eliminate avoidance of a taste cue that predicts access to a preferred sucrose solution and leaves intact the development of a LiCl-induced conditioned taste aversion. The lesion does, however, eliminate the suppression of intake of a taste cue when paired with experimenter administered morphine or cocaine using our standard parameters. As such, this is the first manipulation found to dissociate avoidance of a taste cue when mediated by a sweet or by a drug of abuse. PMID:22687147

  20. Central thalamic deep brain stimulation for cognitive neuromodulation: a review of proposed mechanisms and investigational studies

    PubMed Central

    Shah, Sudhin A.; Schiff, Nicholas D.

    2010-01-01

    We review the history of efforts to apply central thalamic deep brain stimulation (CT/DBS) to restore consciousness in patients in coma and vegetative state by changing the arousal state. Early experimental and clinical studies and the results of a recent single-subject human study that demonstrated both immediate behavioral facilitation and carry-over effects of CT/DBS are reviewed. We consider possible mechanisms underlying CT/DBS effects on cognitively-mediated behaviors in conscious patients in light of the anatomical connectivity and physiological specializations of the central thalamus. Immediate and carry-over effects of CT/DBS are discussed within the context of possible effects on neuronal plasticity and gene expression. We conclude that CT/DBS be studied as a therapeutic intervention to improve impaired cognitive function in severely brain-injured patients who in addition to demonstrating clinical evidence of consciousness and goal-directed behavior, retain sufficient preservation of large-scale cerebral networks within the anterior forebrain. Although available data provide evidence for proof-of-concept, very significant challenges for study design and development of CT/DBS for clinical use are identified. PMID:21039953

  1. Modulation of Temporal Precision in Thalamic Population Responses to Natural Visual Stimuli

    PubMed Central

    Desbordes, Gaëlle; Jin, Jianzhong; Alonso, Jose-Manuel; Stanley, Garrett B.

    2010-01-01

    Natural visual stimuli have highly structured spatial and temporal properties which influence the way visual information is encoded in the visual pathway. In response to natural scene stimuli, neurons in the lateral geniculate nucleus (LGN) are temporally precise – on a time scale of 10–25 ms – both within single cells and across cells within a population. This time scale, established by non stimulus-driven elements of neuronal firing, is significantly shorter than that of natural scenes, yet is critical for the neural representation of the spatial and temporal structure of the scene. Here, a generalized linear model (GLM) that combines stimulus-driven elements with spike-history dependence associated with intrinsic cellular dynamics is shown to predict the fine timing precision of LGN responses to natural scene stimuli, the corresponding correlation structure across nearby neurons in the population, and the continuous modulation of spike timing precision and latency across neurons. A single model captured the experimentally observed neural response, across different levels of contrasts and different classes of visual stimuli, through interactions between the stimulus correlation structure and the nonlinearity in spike generation and spike history dependence. Given the sensitivity of the thalamocortical synapse to closely timed spikes and the importance of fine timing precision for the faithful representation of natural scenes, the modulation of thalamic population timing over these time scales is likely important for cortical representations of the dynamic natural visual environment. PMID:21151356

  2. Transneuronal Degeneration of Thalamic Nuclei following Middle Cerebral Artery Occlusion in Rats

    PubMed Central

    2016-01-01

    Objective. Postinfarction transneuronal degeneration refers to secondary neuronal death that occurs within a few days to weeks following the disruption of input or output to synapsed neurons sustaining ischemic insults. The thalamus receives its blood supply from the posterior circulation; however, infarctions of the middle cerebral arterial may cause secondary transneuronal degeneration in the thalamus. In this study, we presented the areas of ischemia and associated transneuronal degeneration following MCAo in a rat model. Materials and Methods. Eighteen 12-week-old male Sprague-Dawley rats were randomly assigned to receive middle cerebral artery occlusion surgery for 1, 7, and 14 days. Cerebral atrophy was assessed by 2,3,5-triphenyltetrazolium hydrochloride staining. Postural reflex and open field tests were performed prior to animal sacrifice to assess the effects of occlusion on behavior. Results. Myelin loss was observed at the lesion site following ischemia. Gliosis was also observed in thalamic regions 14 days following occlusion. Differential degrees of increased vascular endothelial growth factor expression were observed at each stage of infarction. Increases in myelin basic protein levels were also observed in the 14-day group. Conclusion. The present rat model of ischemia provides evidence of transneuronal degeneration within the first 14 days of occlusion. The observed changes in protein expression may be associated with self-repair mechanisms in the damaged brain. PMID:27597962

  3. Emergent spindle oscillations and intermittent burst firing in a thalamic model: specific neuronal mechanisms.

    PubMed Central

    Wang, X J; Golomb, D; Rinzel, J

    1995-01-01

    The rhythmogenesis of 10-Hz sleep spindles is studied in a large-scale thalamic network model with two cell populations: the excitatory thalamocortical (TC) relay neurons and the inhibitory nucleus reticularis thalami (RE) neurons. Spindle-like bursting oscillations emerge naturally from reciprocal interactions between TC and RE neurons. We find that the network oscillations can be synchronized coherently, even though the RE-TC connections are random and sparse, and even though individual neurons fire rebound bursts intermittently in time. When the fast gamma-aminobutyrate type A synaptic inhibition is blocked, synchronous slow oscillations resembling absence seizures are observed. Near-maximal network synchrony is established with even modest convergence in the RE-to-TC projection (as few as 5-10 RE inputs per TC cell suffice). The hyperpolarization-activated cation current (Ih) is found to provide a cellular basis for the intermittency of rebound bursting that is commonly observed in TC neurons during spindles. Such synchronous oscillations with intermittency can be maintained only with a significant degree of convergence for the TC-to-RE projection. PMID:7777551

  4. Topographic relationship between anteromedial thalamic nucleus neurons and their cortical terminal fields in the rat.

    PubMed

    Shibata, H; Kato, A

    1993-06-01

    The present study has examined the topographic relationship between cells in the anteromedial thalamic nucleus (AM) and their cortical terminal fields, with retrograde transport of Fluoro Gold in the rat. Projections to the frontal area 2 originate from the ventrolateral part of the AM and the entire interanteromedial nucleus (IAM). Projections to the anterior cingulate area originate from the peripheral part of the rostral AM and the entire IAM. Fibers to the rostral retrosplenial area arise from the caudodorsal part of the AM, whereas those to the caudal retrosplenial area arise from the rostralmost and the rostrodorsomedial parts. Fibers to the rostral area 29D originate from the rostrocentral part of the AM, whereas those to the caudal area 29D originate from the rostroventrolateral and the ventromedial parts. Projections to the medial half of the entorhinal area originate from the rostrodorsomedial part of the AM. In contrast, projections to the lateral half of the entorhinal area originate from the IAM and the central part of the AM. The results show a complex topographic relationship between cells of origin of the AM and their cortical terminal fields, suggesting complex functional roles played by the AM in learning behavior such as discriminative avoidance behavior.

  5. Locomotion and Task Demands Differentially Modulate Thalamic Audiovisual Processing during Active Search.

    PubMed

    Williamson, Ross S; Hancock, Kenneth E; Shinn-Cunningham, Barbara G; Polley, Daniel B

    2015-07-20

    Active search is a ubiquitous goal-driven behavior wherein organisms purposefully investigate the sensory environment to locate a target object. During active search, brain circuits analyze a stream of sensory information from the external environment, adjusting for internal signals related to self-generated movement or "top-down" weighting of anticipated target and distractor properties. Sensory responses in the cortex can be modulated by internal state, though the extent and form of modulation arising in the cortex de novo versus an inheritance from subcortical stations is not clear. We addressed this question by simultaneously recording from auditory and visual regions of the thalamus (MG and LG, respectively) while mice used dynamic auditory or visual feedback to search for a hidden target within an annular track. Locomotion was associated with strongly suppressed responses and reduced decoding accuracy in MG but a subtle increase in LG spiking. Because stimuli in one modality provided critical information about target location while the other served as a distractor, we could also estimate the importance of task relevance in both thalamic subdivisions. In contrast to the effects of locomotion, we found that LG responses were reduced overall yet decoded stimuli more accurately when vision was behaviorally relevant, whereas task relevance had little effect on MG responses. This double dissociation between the influences of task relevance and movement in MG and LG highlights a role for extrasensory modulation in the thalamus but also suggests key differences in the organization of modulatory circuitry between the auditory and visual pathways.

  6. DCC functions as an accelerator of thalamocortical axonal growth downstream of spontaneous thalamic activity

    PubMed Central

    Castillo-Paterna, Mar; Moreno-Juan, Verónica; Filipchuk, Anton; Rodríguez-Malmierca, Luis; Susín, Rafael; López-Bendito, Guillermina

    2015-01-01

    Controlling the axon growth rate is fundamental when establishing brain connections. Using the thalamocortical system as a model, we previously showed that spontaneous calcium activity influences the growth rate of thalamocortical axons by regulating the transcription of Robo1 through an NF-κB-binding site in its promoter. Robo1 acts as a brake on the growth of thalamocortical axons in vivo. Here, we have identified the Netrin-1 receptor DCC as an accelerator for thalamic axon growth. Dcc transcription is regulated by spontaneous calcium activity in thalamocortical neurons and activating DCC signaling restores normal axon growth in electrically silenced neurons. Moreover, we identified an AP-1-binding site in the Dcc promoter that is crucial for the activity-dependent regulation of this gene. In summary, we have identified the Dcc gene as a novel downstream target of spontaneous calcium activity involved in axon growth. Together with our previous data, we demonstrate a mechanism to control axon growth that relies on the activity-dependent regulation of two functionally opposed receptors, Robo1 and DCC. These two proteins establish a tight and efficient means to regulate activity-guided axon growth in order to correctly establish neuronal connections during development. PMID:25947198

  7. Corticothalamic Synaptic Noise as a Mechanism for Selective Attention in Thalamic Neurons.

    PubMed

    Béhuret, Sébastien; Deleuze, Charlotte; Bal, Thierry

    2015-01-01

    A reason why the thalamus is more than a passive gateway for sensory signals is that two-third of the synapses of thalamocortical neurons are directly or indirectly related to the activity of corticothalamic axons. While the responses of thalamocortical neurons evoked by sensory stimuli are well characterized, with ON- and OFF-center receptive field structures, the prevalence of synaptic noise resulting from neocortical feedback in intracellularly recorded thalamocortical neurons in vivo has attracted little attention. However, in vitro and modeling experiments point to its critical role for the integration of sensory signals. Here we combine our recent findings in a unified framework suggesting the hypothesis that corticothalamic synaptic activity is adapted to modulate the transfer efficiency of thalamocortical neurons during selective attention at three different levels: First, on ionic channels by interacting with intrinsic membrane properties, second at the neuron level by impacting on the input-output gain, and third even more effectively at the cell assembly level by boosting the information transfer of sensory features encoded in thalamic subnetworks. This top-down population control is achieved by tuning the correlations in subthreshold membrane potential fluctuations and is adapted to modulate the transfer of sensory features encoded by assemblies of thalamocortical relay neurons. We thus propose that cortically-controlled (de-)correlation of subthreshold noise is an efficient and swift dynamic mechanism for selective attention in the thalamus.

  8. Thalamic reticular nucleus induces fast and local modulation of arousal state

    PubMed Central

    Lewis, Laura D; Voigts, Jakob; Flores, Francisco J; Schmitt, L Ian; Wilson, Matthew A

    2015-01-01

    During low arousal states such as drowsiness and sleep, cortical neurons exhibit rhythmic slow wave activity associated with periods of neuronal silence. Slow waves are locally regulated, and local slow wave dynamics are important for memory, cognition, and behaviour. While several brainstem structures for controlling global sleep states have now been well characterized, a mechanism underlying fast and local modulation of cortical slow waves has not been identified. Here, using optogenetics and whole cortex electrophysiology, we show that local tonic activation of thalamic reticular nucleus (TRN) rapidly induces slow wave activity in a spatially restricted region of cortex. These slow waves resemble those seen in sleep, as cortical units undergo periods of silence phase-locked to the slow wave. Furthermore, animals exhibit behavioural changes consistent with a decrease in arousal state during TRN stimulation. We conclude that TRN can induce rapid modulation of local cortical state. DOI: http://dx.doi.org/10.7554/eLife.08760.001 PMID:26460547

  9. Entrainment of slow oscillations of auditory thalamic neurons by repetitive sound stimuli.

    PubMed

    Gao, Lixia; Meng, Xiankai; Ye, Changquan; Zhang, Haitian; Liu, Chunhua; Dan, Yang; Poo, Mu-Ming; He, Jufang; Zhang, Xiaohui

    2009-05-06

    Slow oscillations at frequencies <1 Hz manifest in many brain regions as discrete transitions between a depolarized up state and a hyperpolarized down state of the neuronal membrane potential. Although up and down states are known to differentially affect sensory-evoked responses, whether and how they are modulated by sensory stimuli are not well understood. In the present study, intracellular recording in anesthetized guinea pigs showed that membrane potentials of nonlemniscal auditory thalamic neurons exhibited spontaneous up/down transitions at random intervals in the range of 2-30 s, which could be entrained to a regular interval by repetitive sound stimuli. After termination of the entraining stimulation (ES), regular up/down transitions persisted for several cycles at the ES interval. Furthermore, the efficacy of weak sound stimuli in triggering the up-to-down transition was potentiated specifically at the ES interval for at least 10 min. Extracellular recordings in the auditory thalamus of unanesthetized guinea pigs also showed entrainment of slow oscillations by rhythmic sound stimuli during slow wave sleep. These results demonstrate a novel form of network plasticity, which could help to retain the information of stimulus interval on the order of seconds.

  10. Simple Cortical and Thalamic Neuron Models for Digital Arithmetic Circuit Implementation

    PubMed Central

    Nanami, Takuya; Kohno, Takashi

    2016-01-01

    Trade-off between reproducibility of neuronal activities and computational efficiency is one of crucial subjects in computational neuroscience and neuromorphic engineering. A wide variety of neuronal models have been studied from different viewpoints. The digital spiking silicon neuron (DSSN) model is a qualitative model that focuses on efficient implementation by digital arithmetic circuits. We expanded the DSSN model and found appropriate parameter sets with which it reproduces the dynamical behaviors of the ionic-conductance models of four classes of cortical and thalamic neurons. We first developed a four-variable model by reducing the number of variables in the ionic-conductance models and elucidated its mathematical structures using bifurcation analysis. Then, expanded DSSN models were constructed that reproduce these mathematical structures and capture the characteristic behavior of each neuron class. We confirmed that statistics of the neuronal spike sequences are similar in the DSSN and the ionic-conductance models. Computational cost of the DSSN model is larger than that of the recent sophisticated Integrate-and-Fire-based models, but smaller than the ionic-conductance models. This model is intended to provide another meeting point for above trade-off that satisfies the demand for large-scale neuronal network simulation with closer-to-biology models. PMID:27242397

  11. Detection of low salience whisker stimuli requires synergy of tectal and thalamic sensory relays

    PubMed Central

    Cohen, Jeremy D.; Castro-Alamancos, Manuel A.

    2010-01-01

    Detection of a sensory stimulus depends on its psychophysical saliency; the higher the saliency, the easier the detection. But it is not known if sensory relay nuclei differ in their ability to detect low salient whisker stimuli. We found that reversible lesions of either the somatosensory thalamus or superior colliculus blocked detection of a low salience whisker conditioned stimulus (WCS) in an active avoidance task, without affecting detection of a high salience WCS. Thus, thalamic and tectal sensory relays work synergistically to detect low salient stimuli during avoidance behavior, but are redundant during detection of highly salient stimuli. We also recorded electrophysiological responses evoked by high and low salience stimuli in the superior colliculus and barrel cortex of freely behaving animals during active exploration, awake immobility and sensory detection in the active avoidance task. Field potential (FP) responses evoked in barrel cortex and superior colliculus by high intensity stimuli are larger and adapt more to frequency than those evoked by low intensity stimuli. FP responses are also more suppressed and adapt less during active exploration, and become further suppressed in barrel cortex during successful detection of either high or low salient stimuli in the active avoidance task. In addition, unit recordings revealed that firing rate increases in superior colliculus during active exploration, and especially during successful detection of either high or low salient stimuli in the active avoidance task. We conclude that detection of low salient stimuli is achieved by a sparse neural code distributed through multiple sensory relays. PMID:20147551

  12. [Neuronal mechanisms of motor signal transmission in thalamic Voi nucleus in spasmodic torticollis patients].

    PubMed

    Sedov, A S; Raeva, S N; Pavlenko, V B

    2014-01-01

    Neural mechanisms of motor signal transmission in ventrooral (Voi) nucleus of motor thalamus during the realization-of voluntary and involuntary abnormal (dystonic) movements in patients with spasmodic torticollis were investigated by means of microelectrode technique. The high reactivity of the cellular Voi elements to various functional (mainly motor) tests was proved. Analysis of neuronal activity showed: (1) the difference of neural mechanisms of motor signal transmission in the realization of voluntary movement with and without the involvement of the pathological axial neck muscles, as well as passive and abnormal involuntary dystonic movements; (2) significance of sensory component in the mechanisms of sensorimotor interactions during realization of voluntary and involuntary dystonic head and neck movements, causing the activation of the axial neck muscles; (3) important role of the rhythmic and synchronized neuronal activity in motor signal transmission during the realization of active and passive movements. Participation of Voi nucleus in pathological mechanisms of spasmodic torticollis was shown. The data obtained can be used for identificatiori of Voi thalamic nucleus during stereotactic neurosurgical operations in patients with spasmodic torticollis for selection the optimum destruction (stimulation) target and reduction of postoperative effects.

  13. Pontine and thalamic influences on fluid rewards: I. Operant responding for sucrose and corn oil.

    PubMed

    Liang, Nu-Chu; Freet, Christopher S; Grigson, Patricia S; Norgren, Ralph

    2012-01-18

    The reward strength of orosensory sucrose and corn oil was measured using fixed and progressive ratio operant schedules. Because the orosensory effects of the stimuli were of interest, Experiment 1 compared operant responses for sucrose in sham and real feeding rats. The results demonstrated that rats would work for sucrose solutions without the accompanying postingestive effects. Furthermore, the break points for high concentrations of sucrose (1.0 M or 2.0 M) were significantly higher in sham feeding rats than in real feeding controls. Experiment 2 investigated the role of the parabrachial nucleus (PBN) and of the thalamic orosensory area (TOA) in sucrose and corn oil reward. During free access, rats with PBN lesions (PBNx) licked significantly less sucrose solution than their controls, but both groups ingested a similar volume of corn oil emulsion. When an operant was imposed, these same PBNx rats failed to respond for sucrose and continued only modestly for corn oil. In contrast, the TOA lesioned rats (TOAx) showed no impairment in responding for sucrose or corn oil during either the free access or operant sessions. Furthermore, rats with TOA lesions demonstrated significantly higher break points for sucrose than did their controls. Together, the data imply that the PBN but not the TOA is critical for the perception of, or responding to the reward value of sucrose and corn oil.

  14. Distinctions in burst spiking between thalamic reticular nucleus cells projecting to the dorsal lateral geniculate and lateral posterior nuclei in the anesthetized rat.

    PubMed

    Kimura, A; Yokoi, I; Imbe, H; Donishi, T; Kaneoke, Y

    2012-12-13

    Thalamic cell activity is under a significant influence of inhibition from the thalamic reticular nucleus (TRN) that is composed of domains connected with first and higher order thalamic nuclei, which are thought to subserve transmission of sensory inputs to the cortex and cortico-thalamo-cortical transmission of cortical outputs, respectively. Provided that TRN cells have distinct activities along with their projections to first and higher order thalamic nuclei, TRN cells could shape cell activities of the two thalamic nuclei in different manners for the distinct functions. In anesthetized rats, visual response and spontaneous activity were recorded from TRN cells projecting to the dorsal lateral geniculate (first order) and lateral posterior (higher order) nuclei (TRN-DLG and TRN-LP cells), using juxta-cellular recording and labeling techniques. TRN-DLG cells had a higher propensity for burst spiking and exhibited bursts of larger numbers of spikes with shorter inter-spike intervals as compared to TRN-LP cells in both visual response and spontaneous activity. Sustained effects of visual input on burst spiking were recognized in recurrent activation of TRN-DLG but not of TRN-LP cells. Further, the features of burst spiking were related with the locations of topographically connected cell bodies and terminal fields. The difference in burst spiking contrasts with the difference between thalamic cells in the DLG and LP, which show low and high levels of burst spiking, respectively. The synergy between thalamic and TRN cell activities with their contrasting features of burst spiking may compose distinctive sensory processing and attentional gating functions of geniculate and extra-geniculate systems.

  15. 31 CFR 500.326 - Custody of safe deposit boxes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Custody of safe deposit boxes. 500... Definitions § 500.326 Custody of safe deposit boxes. Safe deposit boxes shall be deemed to be in the custody not only of all persons having access thereto but also of the lessors of such boxes whether or...

  16. 46 CFR 78.47-10 - Manual alarm boxes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Manual alarm boxes. 78.47-10 Section 78.47-10 Shipping... and Emergency Equipment, Etc. § 78.47-10 Manual alarm boxes. (a) In all new installations, manual alarm boxes shall be clearly and permanently marked “IN CASE OF FIRE BREAK GLASS.” Existing boxes not...

  17. 48 CFR 908.7118 - Rental of post office boxes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... boxes. 908.7118 Section 908.7118 Federal Acquisition Regulations System DEPARTMENT OF ENERGY COMPETITION... post office boxes. DOE offices and authorized contractors may rent post office boxes on an annual basis... the whole period or at the beginning of each quarter in which the box is to be used....

  18. 49 CFR 230.101 - Steam locomotive driving journal boxes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Steam locomotive driving journal boxes. 230.101... Locomotives and Tenders Running Gear § 230.101 Steam locomotive driving journal boxes. (a) Driving journal boxes. Driving journal boxes shall be maintained in a safe and suitable condition for service. Not...

  19. 31 CFR 515.326 - Custody of safe deposit boxes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Custody of safe deposit boxes. 515... Definitions § 515.326 Custody of safe deposit boxes. Safe deposit boxes shall be deemed to be in the custody not only of all persons having access thereto but also of the lessors of such boxes whether or...

  20. 49 CFR 230.101 - Steam locomotive driving journal boxes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Steam locomotive driving journal boxes. 230.101... Locomotives and Tenders Running Gear § 230.101 Steam locomotive driving journal boxes. (a) Driving journal boxes. Driving journal boxes shall be maintained in a safe and suitable condition for service. Not...

  1. 49 CFR 230.101 - Steam locomotive driving journal boxes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Steam locomotive driving journal boxes. 230.101... Locomotives and Tenders Running Gear § 230.101 Steam locomotive driving journal boxes. (a) Driving journal boxes. Driving journal boxes shall be maintained in a safe and suitable condition for service. Not...

  2. 49 CFR 230.101 - Steam locomotive driving journal boxes.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Steam locomotive driving journal boxes. 230.101... Locomotives and Tenders Running Gear § 230.101 Steam locomotive driving journal boxes. (a) Driving journal boxes. Driving journal boxes shall be maintained in a safe and suitable condition for service. Not...

  3. 49 CFR 230.101 - Steam locomotive driving journal boxes.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Steam locomotive driving journal boxes. 230.101... Locomotives and Tenders Running Gear § 230.101 Steam locomotive driving journal boxes. (a) Driving journal boxes. Driving journal boxes shall be maintained in a safe and suitable condition for service. Not...

  4. 49 CFR 178.517 - Standards for plastic boxes.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Standards for plastic boxes. 178.517 Section 178...-bulk Performance-Oriented Packaging Standards § 178.517 Standards for plastic boxes. (a) The following are identification codes for plastic boxes: (1) 4H1 for an expanded plastic box; and (2) 4H2 for...

  5. 49 CFR 178.517 - Standards for plastic boxes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Standards for plastic boxes. 178.517 Section 178...-bulk Performance-Oriented Packaging Standards § 178.517 Standards for plastic boxes. (a) The following are identification codes for plastic boxes: (1) 4H1 for an expanded plastic box; and (2) 4H2 for...

  6. 49 CFR 178.517 - Standards for plastic boxes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Standards for plastic boxes. 178.517 Section 178...-bulk Performance-Oriented Packaging Standards § 178.517 Standards for plastic boxes. (a) The following are identification codes for plastic boxes: (1) 4H1 for an expanded plastic box; and (2) 4H2 for...

  7. PET evaluation of the dopamine system of the human brain

    SciTech Connect

    Volkow, N.D.; Fowler, J.S.; Gatley, S. |

    1996-07-01

    Dopamine plays a pivotal role in the regulation and control of movement, motivation and cognition. It also is closely linked to reward, reinforcement and addiction. Abnormalities in brain dopamine are associated with many neurological and psychiatric disorders including Parkinson`s disease, schizophrenia and substance abuse. This close association between dopamine and neurological and psychiatric diseases and with substance abuse make it an important topic in research in the neurosciences and an important molecular target in drug development. PET enables the direct measurement of components of the dopamine system in the living human brain. It relies on radiotracers which label dopamine receptors, dopamine transporters, precursors of dopamine or compounds which have specificity for the enzymes which degrade dopamine. Additionally, by using tracers that provide information on regional brain metabolism or blood flow as well as neurochemically specific pharmacological interventions, PET can be used to assess the functional consequences of change in brain dopamine activity. PET dopamine measurements have been used to investigate the normal human brain and its involvement in psychiatric and neurological diseases. It has also been used in psychopharmacological research to investigate dopamine drugs used in the treatment of Parkinson`s disease and of schizophrenia as well as to investigate the effects of drugs of abuse on the dopamine system. Since various functional and neurochemical parameters can be studied in the same subject, PET enables investigation of the functional integrity of the dopamine system in the human brain and investigation of the interactions of dopamine with other neurotransmitters. This paper summarizes the different tracers and experimental strategies developed to evaluate the various elements of the dopamine system in the human brain with PET and their applications to clinical research. 254 refs., 7 figs., 3 tabs.

  8. Quadruplex Integrated DNA (QuID) Nanosensors for Monitoring Dopamine

    PubMed Central

    Morales, Jennifer M.; Skipwith, Christopher G.; Clark, Heather A.

    2015-01-01

    Dopamine is widely innervated throughout the brain and critical for many cognitive and motor functions. Imbalances or loss in dopamine transmission underlie various psychiatric disorders and degenerative diseases. Research involving cellular studies and disease states would benefit from a tool for measuring dopamine transmission. Here we show a Quadruplex Integrated DNA (QuID) nanosensor platform for selective and dynamic detection of dopamine. This nanosensor exploits DNA technology and enzyme recognition systems to optically image dopamine levels. The DNA quadruplex architecture is designed to be compatible in physically constrained environments (110 nm) with high flexibility, homogeneity, and a lower detection limit of 110 µM. PMID:26287196

  9. Slat Heater Boxes for Thermal Vacuum Testing

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene

    2003-01-01

    Slat heater boxes have been invented for controlling the sink temperatures of objects under test in a thermal vacuum chamber, the walls of which are cooled to the temperature of liquid nitrogen. A slat heater box (see Figure 1) includes a framework of struts that support electrically heated slats that are coated with a high-emissivity optically gray paint. The slats can be grouped together into heater zones for the purpose of maintaining an even temperature within each side. The sink temperature of an object under test is defined as the steady-state temperature of the object in the vacuum/ radiative environment during the absence of any internal heat source or sink. The slat heater box makes it possible to closely control the radiation environment to obtain a desired sink temperature. The slat heater box is placed inside the cold thermal vacuum chamber, and the object under test is placed inside (but not in contact with) the slat heater box. The slat heaters occupy about a third of the field of view from any point on the surface of the object under test, the remainder of the field of view being occupied by the cold chamber wall. Thus, the radiation environment is established by the combined effects of the slat heater box and the cold chamber wall. Given (1) the temperature of the chamber wall, (2) the fractions of the field of view occupied by the chamber wall and the slat heater box, and (3) the emissivities of the slats, chamber wall, and the surface of object under test, the slat temperature required to maintain a desired sink temperature can be calculated by solving the equations of gray-body radiation for the steady-state adiabatic case (equal absorption and emission by the object under test). Slat heater boxes offer an important advantage over the infrared lamps that have been previously used to obtain desired sink temperatures: In comparison with an infrared lamp, a slat heater box provides a greater degree of sink temperature uniformity for a test

  10. BMI Sandwich Wing Box Analysis and Test

    NASA Technical Reports Server (NTRS)

    Palm, Tod; Mahler, Mary; Shah, Chandu; Rouse, Marshall; Bush, Harold; Wu, Chauncey; Small, William J.

    2000-01-01

    A composite sandwich single bay wing box test article was developed by Northrop Grumman and tested recently at NASA Langley Research Center. The objectives for the wing box development effort were to provide a demonstration article for manufacturing scale up of structural concepts related to a high speed transport wing, and to validate the structural performance of the design. The box concept consisted of highly loaded composite sandwich wing skins, with moderately loaded composite sandwich spars. The dimensions of the box were chosen to represent a single bay of the main wing box, with a spar spacing of 30 inches, height of 20 inches constant depth, and length of 64 inches. The bismaleimide facesheet laminates and titanium honeycomb core chosen for this task are high temperature materials able to sustain a 300F service temperature. The completed test article is shown in Figure 1. The tests at NASA Langley demonstrated the structures ability to sustain axial tension and compression loads in excess of 20,000 lb/in, and to maintain integrity in the thermal environment. Test procedures, analysis failure predictions, and test results are presented.

  11. Invariance of the density of dopamine uptake sites and dopamine metabolism in the rat brain after a chronic treatment with the dopamine uptake inhibitor GBR 12783.

    PubMed

    Boulay, D; Leroux-Nicollet, I; Duterte-Boucher, D; Naudon, L; Costentin, J

    1994-01-01

    A chronic treatment (10 mg/kg, twice daily during 9 days) with the dopamine uptake inhibitor GBR 12783 was performed in rats at a dose increasing their locomotor activity. Forty-eight hours after the last administration, animals were sacrificed and 3H mazindol binding was performed on brain slices. Autoradiographic analysis revealed no change in this binding relatively to control animals in regions with high dopamine contents: striatum, nucleus accumbens, olfactory tubercle, substantia nigra and ventral tegmentum area. The treatment did not either modify the levels of dopamine (DA) and metabolites (HVA, DOPAC) both in the striatum and the nucleus accumbens. Thus, early after the end of the treatment, the chronic blockade of the dopamine uptake complex regulates neither the dopamine uptake complex nor the dopamine metabolism.

  12. Dopamine-melanin nanofilms for biomimetic structural coloration.

    PubMed

    Wu, Tong-Fei; Hong, Jong-Dal

    2015-02-09

    This article describes the formation of dopamine-melanin thin films (50-200 nm thick) at an air/dopamine solution interface under static conditions. Beneath these films, spherical melanin granules formed in bulk liquid phase. The thickness of dopamine-melanin films at the interface relied mainly on the concentration of dopamine solution and the reaction time. A plausible mechanism underlining dopamine-melanin thin film formation was proposed based on the hydrophobicity of dopamine-melanin aggregates and the mass transport of the aggregates to the air/solution interface as a result of convective flow. The thickness of the interfacial films increased linearly with the dopamine concentration and the reaction time. The dopamine-melanin thin film and granules (formed in bulk liquid phase) with a double-layered structure were transferred onto a solid substrate to mimic the (keratin layer)/(melanin granules) structure present in bird plumage, thereby preparing full dopamine-melanin thin-film reflectors. The reflected color of the thin-film reflectors depended on the film thickness, which could be adjusted according to the dopamine concentration. The reflectance of the resulted reflectors exhibited a maximal reflectance value of 8-11%, comparable to that of bird plumage (∼11%). This study provides a useful, simple, and low-cost approach to the fabrication of biomimetic thin-film reflectors using full dopamine-melanin materials.

  13. Regulation of Dopamine Uptake by Vasoactive Peptides in the Kidney

    PubMed Central

    Gironacci, M. M.

    2016-01-01

    Considering the key role of renal dopamine in tubular sodium handling, we hypothesized that c-type natriuretic peptide (CNP) and Ang-(1-7) may regulate renal dopamine availability in tubular cells, contributing to Na+, K+-ATPase inhibition. Present results show that CNP did not affect either 3H-dopamine uptake in renal tissue or Na+, K+-ATPase activity; meanwhile, Ang-(1-7) was able to increase 3H-dopamine uptake and decreased Na+, K+-ATPase activity in renal cortex. Ang-(1-7) and dopamine together decreased further Na+, K+-ATPase activity showing an additive effect on the sodium pump. In addition, hydrocortisone reversed Ang-(1-7)-dopamine overinhibition on the enzyme, suggesting that this inhibition is closely related to Ang-(1-7) stimulation on renal dopamine uptake. Both anantin and cANP (4-23-amide) did not modify CNP effects on 3H-dopamine uptake by tubular cells. The Mas receptor antagonist, A-779, blocked the increase elicited by Ang-(1-7) on 3H-dopamine uptake. The stimulatory uptake induced by Ang-(1-7) was even more pronounced in the presence of losartan, suggesting an inhibitory effect of Ang-(1-7) on AT1 receptors on 3H-dopamine uptake. By increasing dopamine bioavailability in tubular cells, Ang-(1-7) enhances Na+, K+-ATPase activity inhibition, contributing to its natriuretic and diuretic effects. PMID:27635280

  14. Regulation of Dopamine Uptake by Vasoactive Peptides in the Kidney.

    PubMed

    Rukavina Mikusic, N L; Kouyoumdzian, N M; Rouvier, E; Gironacci, M M; Toblli, J E; Fernández, B E; Choi, M R

    2016-01-01

    Considering the key role of renal dopamine in tubular sodium handling, we hypothesized that c-type natriuretic peptide (CNP) and Ang-(1-7) may regulate renal dopamine availability in tubular cells, contributing to Na(+), K(+)-ATPase inhibition. Present results show that CNP did not affect either (3)H-dopamine uptake in renal tissue or Na(+), K(+)-ATPase activity; meanwhile, Ang-(1-7) was able to increase (3)H-dopamine uptake and decreased Na(+), K(+)-ATPase activity in renal cortex. Ang-(1-7) and dopamine together decreased further Na(+), K(+)-ATPase activity showing an additive effect on the sodium pump. In addition, hydrocortisone reversed Ang-(1-7)-dopamine overinhibition on the enzyme, suggesting that this inhibition is closely related to Ang-(1-7) stimulation on renal dopamine uptake. Both anantin and cANP (4-23-amide) did not modify CNP effects on (3)H-dopamine uptake by tubular cells. The Mas receptor antagonist, A-779, blocked the increase elicited by Ang-(1-7) on (3)H-dopamine uptake. The stimulatory uptake induced by Ang-(1-7) was even more pronounced in the presence of losartan, suggesting an inhibitory effect of Ang-(1-7) on AT1 receptors on (3)H-dopamine uptake. By increasing dopamine bioavailability in tubular cells, Ang-(1-7) enhances Na(+), K(+)-ATPase activity inhibition, contributing to its natriuretic and diuretic effects.

  15. Extracellular dopamine and alterations on dopamine transporter are related to reserpine toxicity in Caenorhabditis elegans.

    PubMed

    Reckziegel, Patrícia; Chen, Pan; Caito, Sam; Gubert, Priscila; Soares, Félix Alexandre Antunes; Fachinetto, Roselei; Aschner, Michael

    2016-03-01

    Reserpine is used as an animal model of parkinsonism. We hypothesized that the involuntary movements induced by reserpine in rodents are induced by dopaminergic toxicity caused by extracellular dopamine accumulation. The present study tested the effects of reserpine on the dopaminergic system in Caenorhabditis elegans. Reserpine was toxic to worms (decreased the survival, food intake, development and changed egg laying and defecation cycles). In addition, reserpine increased the worms' locomotor rate on food and decreased dopamine levels. Morphological evaluations of dopaminergic CEP neurons confirmed neurodegeneration characterized by decreased fluorescence intensity and the number of worms with intact CEP neurons, and increased number of shrunken somas per worm. These effects were unrelated to reserpine's effect on decreased expression of the dopamine transporter, dat-1. Interestingly, the locomotor rate on food and the neurodegenerative parameters fully recovered to basal conditions upon reserpine withdrawal. Furthermore, reserpine decreased survival in vesicular monoamine transporter and dat-1 loss-of-function mutant worms. In addition, worms pre-exposed to dopamine followed by exposure to reserpine had decreased survival. Reserpine activated gst-4, which controls a phase II detoxification enzymes downstream of nuclear factor (erythroid-derived-2)-like 2. Our findings establish that the dopamine transporter, dat-1, plays an important role in reserpine toxicity, likely by increasing extracellular dopamine concentrations.

  16. Impulse control disorders and dopamine dysregulation syndrome associated with dopamine agonist therapy in Parkinson's disease.

    PubMed

    Fenu, Sandro; Wardas, Jadwiga; Morelli, Micaela

    2009-09-01

    Over the last decade, evidence has emerged linking disorders in the impulsive-compulsive spectrum in Parkinson's disease to dopamine receptor agonist treatment. These disorders include hypersexuality, gambling and, to a minor extent, compulsive shopping and eating, as well as dopamine dysregulation syndrome, characterized by an addictive pattern toward dopamine replacement therapy and stereotyped behaviors, such as punding. These syndromes, which have only recently been recognized and are still underdiagnosed, have deleterious social consequences that warrant interventions at the clinical level and promotion of research at the preclinical level. In this review, we first provide a summary of features of Parkinson's disease and current pharmacological therapies associated with the development of dopamine dysregulation syndrome and impulsive-compulsive disorders. We also examine the dopamine receptors and brain areas important in reward and compulsive behaviors. We then critically examine the neuroadaptations in dopaminergic circuitries and the literature concerning gambling, hypersexuality, and other addictive behaviors in parkinsonian patients. Finally, we focus on suggestions pointing to a role for dopamine D(3) receptors and sensitization phenomena as the main factors which may be the origin of these disorders.

  17. Molecular model of the neural dopamine transporter

    NASA Astrophysics Data System (ADS)

    Ravna, Aina Westrheim; Sylte, Ingebrigt; Dahl, Svein G.

    2003-05-01

    The dopamine transporter (DAT) regulates the action of dopamine by reuptake of the neurotransmitter into presynaptic neurons, and is the main molecular target of amphetamines and cocaine. DAT and the Na+/H+ antiporter (NhaA) are secondary transporter proteins that carry small molecules across a cell membrane against a concentration gradient, using ion gradients as energy source. A 3-dimensional projection map of the E. coli NhaA has confirmed a topology of 12 membrane spanning domains, and was previously used to construct a 3-dimensional NhaA model with 12 trans-membrane α-helices (TMHs). The NhaA model, and site directed mutagenesis data on DAT, were used to construct a detailed 3-dimensional DAT model using interactive molecular graphics and empiric force field calculations. The model proposes a dopamine transport mechanism involving TMHs 1, 3, 4, 5, 7 and 11. Asp79, Tyr252 and Tyr274 were the primary cocaine binding residues. Binding of cocaine or its analogue, (-)-2β-carbomethoxy-3β-(4-fluorophenyl)tropane (CFT), seemed to lock the transporter in an inactive state, and thus inhibit dopamine transport. The present model may be used to design further experimental studies of the molecular structure and mechanisms of DAT and other secondary transporter proteins.

  18. Dopamine receptor in anterior byssus retractor muscle of Mytilus edulis.

    PubMed

    Takayanagi, I; Murakami, H; Iwayama, Y; Yoshida, Y; Miki, S

    1981-04-01

    Effects of dopamine, N-methyl-, ethyl- and propyl-derivatives of dopamine, and alpha- and beta-adrenoceptor stimulants on catch contraction of anterior byssus retractor muscle of Mytilus edulis were tested. The test drugs except the beta-adrenoceptor stimulants relaxed catch contraction. Dopamine was most active and substitution of amino group in dopamine with ethyl and propyl decreased activity considerably. The concentration-curves of dopamine, its derivatives and norepinephrine shifted in parallel with application of haloperidol but were not influenced by the alpha- and beta-adrenoceptor antagonists. These results suggest that relaxation of catch contraction by catecholamines is mediated through a dopamine receptor. This muscle is considered to be suitable for a study of the dopamine receptor.

  19. Nearly Seamless Vacuum-Insulated Boxes

    NASA Technical Reports Server (NTRS)

    Stepanian, Christopher J.; Ou, Danny; Hu, Xiangjun

    2010-01-01

    A design concept, and a fabrication process that would implement the design concept, have been proposed for nearly seamless vacuum-insulated boxes that could be the main structural components of a variety of controlled-temperature containers, including common household refrigerators and insulating containers for shipping foods. In a typical case, a vacuum-insulated box would be shaped like a rectangular parallelepiped conventional refrigerator box having five fully closed sides and a hinged door on the sixth side. Although it is possible to construct the five-closed-side portion of the box as an assembly of five unitary vacuum-insulated panels, it is not desirable to do so because the relatively high thermal conductances of the seams between the panels would contribute significant amounts of heat leakage, relative to the leakage through the panels themselves. In contrast, the proposal would make it possible to reduce heat leakage by constructing the five-closed-side portion of the box plus the stationary portion (if any) of the sixth side as a single, seamless unit; the only remaining seam would be the edge seal around the door. The basic cross-sectional configuration of each side of a vacuum-insulated box according to the proposal would be that of a conventional vacuum-insulated panel: a low-density, porous core material filling a partially evacuated space between face sheets. However, neither the face sheets nor the core would be conventional. The face sheets would be opposite sides of a vacuum bag. The core material would be a flexible polymer-modified silica aerogel of the type described in Silica/Polymer and Silica/Polymer/Fiber Composite Aero - gels (MSC-23736) in this issue of NASA Tech Briefs. As noted in that article, the stiffness of this core material against compression is greater than that of prior aerogels. This is an important advantage because it translates to greater retention of thickness and, hence, of insulation performance when pressure is

  20. Advances in the theory of box integrals

    SciTech Connect

    Bailey, David H.; Borwein, J.M.; Crandall, R.E.

    2009-06-25

    Box integrals - expectations <|{rvec r}|{sup s}> or <|{rvec r}-{rvec q}|{sup s}> over the unit n-cube (or n-box) - have over three decades been occasionally given closed forms for isolated n,s. By employing experimental mathematics together with a new, global analytic strategy, we prove that for n {le} 4 dimensions the box integrals are for any integer s hypergeometrically closed in a sense we clarify herein. For n = 5 dimensions, we show that a single unresolved integral we call K{sub 5} stands in the way of such hyperclosure proofs. We supply a compendium of exemplary closed forms that naturally arise algorithmically from this theory.

  1. Pharmacological characterization of the dopamine-sensitive adenylate cyclase in cockroach brain: evidence for a distinct dopamine receptor

    SciTech Connect

    Orr, G.L.; Gole, J.W.D.; Notman, H.J.; Downer, R.G.H.

    1987-12-21

    Dopamine increases cyclic AMP production in crude membrane preparations of cockroach brain with plateaus in cyclic AMP production occurring between 1-10 ..mu..M and 10 mM. Maximal production of cyclic AMP is 2.25 fold greater than that of control values. Octopamine also increases cyclic AMP production with a Ka of 1.4 ..mu..M and maximal production 3.5 fold greater than that of control. 5-Hydroxytryptamine does not increase cyclic AMP production. The effects of octopamine and dopamine are fully additive. The vertebrate dopamine agonists ADTN and epinine stimulate the dopamine-sensitive adenylate cyclase (AC) with Ka values of 4.5 and 0.6 ..mu..M respectively and with maximal effectiveness 1.7 fold greater than that of control. The selective D/sub 2/-dopamine agonist LY-171555 stimulates cyclic AMP production to a similar extent with a Ka of 50 ..mu..M. Other dopamine agonists have no stimulatory effects. With the exception of mianserin, /sup 3/H-piflutixol is displaced from brain membranes by dopamine antagonists with an order of potency similar to that observed for the inhibition of dopamine-sensitive AC. The results indicate that the octopamine- and dopamine-sensitive AC in cockroach brain can be distinguished pharmacologically and the dopamine receptors coupled to AC have pharmacological characteristics distinct from vertebrate D/sup 1/- and D/sup 2/-dopamine receptors. 33 references, 3 figures, 2 tables.

  2. Locomotion and task demands differentially modulate thalamic audiovisual processing during active search

    PubMed Central

    Williamson, Ross S.; Hancock, Kenneth E.; Shinn-Cunningham, Barbara G.; Polley, Daniel B.

    2015-01-01

    SUMMARY Active search is a ubiquitous goal-driven behavior wherein organisms purposefully investigate the sensory environment to locate a target object. During active search, brain circuits analyze a stream of sensory information from the external environment, adjusting for internal signals related to self-generated movement or “top-down” weighting of anticipated target and distractor properties. Sensory responses in the cortex can be modulated by internal state [1–9], though the extent and form of modulation arising in the cortex de novo versus an inheritance from subcortical stations is not clear [4, 8–12]. We addressed this question by simultaneously recording from auditory and visual regions of the thalamus (MG and LG, respectively) while mice used dynamic auditory or visual feedback to search for a hidden target within an annular track. Locomotion was associated with strongly suppressed responses and reduced decoding accuracy in MG but a subtle increase in LG spiking. Because stimuli in one modality provided critical information about target location while the other served as a distractor, we could also estimate the importance of task relevance in both thalamic subdivisions. In contrast to the effects of locomotion, we found that LG responses were reduced overall yet decoded stimuli more accurately when vision was behaviorally relevant, whereas task relevance had little effect on MG responses. This double dissociation between the influences of task relevance and movement in MG and LG highlights a role for extrasensory modulation in the thalamus but also suggests key differences in the organization of modulatory circuitry between the auditory and visual pathways. PMID:26119749

  3. MDMA (Ecstasy) association with impaired fMRI BOLD thalamic coherence and functional connectivity*

    PubMed Central

    Salomon, Ronald M.; Karageorgiou, John; Dietrich, Mary S.; McLellan, Jessica Y.; Charboneau, Evonne J.; Blackford, Jennifer U.; Cowan, Ronald L.

    2011-01-01

    Background MDMA exposure is associated with chronic serotonergic dysfunction in preclinical and clinical studies. A recent functional magnetic resonance imaging (fMRI) comparison of past MDMA users to non-MDMA-using controls revealed increased spatial extent and amplitude of activation in the supplementary motor area during motor tasks (Karageorgiou et al., 2009). Blood oxygenation level dependent (BOLD) data from that study were reanalyzed for intraregional coherence and for inter-regional temporal correlations between time series, as functional connectivity. Methods Fourteen MDMA users and ten controls reporting similar non-MDMA abuse performed finger taps during fMRI. Fourteen motor pathway regions plus a pontine raphé region were examined. Coherence was expressed as percent of voxels positively correlated with an intraregional index voxel. Functional connectivity was determined using wavelet correlations. Results Intraregional thalamic coherence was significantly diminished at low frequencies in MDMA users compared to controls (p=0.009). Inter-regional functional connectivity was significantly weaker for right thalamo - left caudate (p=0.002), right thalamo - left thalamus (p=0.007), right caudate - right postcentral (p=0.007) and right supplementary motor area - right precentral gyrus (p=0.011) region pairs compared to controls. When stratified by lifetime exposure, significant negative associations were observed between cumulative MDMA use and functional connectivity in seven other region-pairs, while only one region-pair showed a positive association. Conclusions Reported prior MDMA use was associated with deficits in BOLD intraregional coherence and inter-regional functional connectivity, even among functionally robust pathways involving motor regions. This suggests that MDMA use is associated with long-lasting effects on brain neurophysiology beyond the cognitive domain. PMID:21807471

  4. Lesions of mediodorsal thalamus and anterior thalamic nuclei produce dissociable effects on instrumental conditioning in rats.

    PubMed

    Corbit, Laura H; Muir, Janice L; Balleine, Bernard W

    2003-09-01

    Two experiments examined the effects of bilateral excitotoxic lesions of either the mediodorsal (MD) or anterior (ANT) thalamic nuclei on instrumental acquisition and performance, sensitivity to changes in the value of the instrumental outcome, and sensitivity to changes in the instrumental contingency. Rats were food deprived and trained to press two levers, each earning a unique food outcome (pellets or sucrose). All rats acquired the instrumental response although ANT lesions appear slightly to increase and MD lesions slightly to suppress instrumental performance. After training, specific satiety-induced devaluation of one of the two instrumental outcomes produced a selective reduction in responding on the lever that in training had earned the now devalued outcome but only in the SHAM and ANT groups. In contrast, MD animals failed to show evidence of a selective devaluation effect when tested in extinction. Additionally, SHAM and ANT animals selectively decreased responding when one action-outcome contingency was degraded, whereas MD animals reduced responding nonselectively on the two levers. Subsequent tests established that an inability to discriminate between either the two actions or the two outcomes cannot account for the lack of selective responding observed in the MD animals. Together these data suggest that MD lesions produce a profound deficit in the ability of rats to utilize specific action-outcome associations and appear to render rats relatively insensitive to the causal consequences of their instrumental actions. In contrast, far from producing a deficit, ANT lesioned rats were as sensitive to the effects of these behavioural manipulations as the sham lesioned controls.

  5. Thalamic olfaction: characterizing odor processing in the mediodorsal thalamus of the rat

    PubMed Central

    Wilson, Donald A.

    2013-01-01

    Thalamus is a key crossroad structure involved in various functions relative to visual, auditory, gustatory, and somatosensory senses. Because of the specific organization of the olfactory pathway (i.e., no direct thalamic relay between sensory neurons and primary cortex), relatively little attention has been directed toward the thalamus in olfaction. However, an olfactory thalamus exists: the mediodorsal nucleus of the thalamus (MDT) receives input from various olfactory structures including the piriform cortex. How the MDT contributes to olfactory perception remains unanswered. The present study is a first step to gain insight into the function of the MDT in olfactory processing. Spontaneous and odor-evoked activities were recorded in both the MDT (single unit and local field potential) and the piriform cortex (local field potential) of urethane-anesthetized rats. We demonstrate that: 1) odorant presentation induces a conjoint, coherent emergence of beta-frequency-band oscillations in both the MDT and the piriform cortex; 2) 51% of MDT single units were odor-responsive with narrow-tuning characteristics across an odorant set, which included biological, monomolecular, and mixture stimuli. In fact, a majority of MDT units responded to only one odor within the set; 3) the MDT and the piriform cortex showed tightly related activities with, for example, nearly 20% of MDT firing in phase with piriform cortical beta-frequency oscillations; and 4) MDT-piriform cortex coherence was state-dependent with enhanced coupling during slow-wave activity. These data are discussed in the context of the hypothesized role of MDT in olfactory perception and attention. PMID:24353302

  6. Thalamic Kv7 channels: pharmacological properties and activity control during noxious signal processing

    PubMed Central

    Cerina, Manuela; Szkudlarek, Hanna J; Coulon, Philippe; Meuth, Patrick; Kanyshkova, Tatyana; Nguyen, Xuan Vinh; Göbel, Kerstin; Seidenbecher, Thomas; Meuth, Sven G; Pape, Hans-Christian; Budde, Thomas

    2015-01-01

    Background and Purpose The existence of functional Kv7 channels in thalamocortical (TC) relay neurons and the effects of the K+-current termed M-current (IM) on thalamic signal processing have long been debated. Immunocytochemical evidence suggests their presence in this brain region. Therefore, we aimed to verify their existence, pharmacological properties and function in regulating activity in neurons of the ventrobasal thalamus (VB). Experimental Approach Characterization of Kv7 channels was performed by combining in vitro, in vivo and in silico techniques with a pharmacological approach. Retigabine (30 μM) and XE991 (20 μM), a specific Kv7 channel enhancer and blocker, respectively, were applied in acute brain slices during electrophysiological recordings. The effects of intrathalamic injection of retigabine (3 mM, 300 nL) and/or XE991 (2 mM, 300 nL) were investigated in freely moving animals during hot-plate tests by recording behaviour and neuronal activity. Key Results Kv7.2 and Kv7.3 subunits were found to be abundantly expressed in TC neurons of mouse VB. A slow K+-current with properties of IM was activated by retigabine and inhibited by XE991. Kv7 channel activation evoked membrane hyperpolarization, a reduction in tonic action potential firing, and increased burst firing in vitro and in computational models. Single-unit recordings and pharmacological intervention demonstrated a specific burst-firing increase upon IM activation in vivo. A Kv7 channel-mediated increase in pain threshold was associated with fewer VB units responding to noxious stimuli, and increased burst firing in responsive neurons. Conclusions and Implications Kv7 channel enhancement alters somatosensory activity and may reflect an anti-nociceptive mechanism during acute pain processing. PMID:25684311

  7. Functional interactions between dentate gyrus, striatum and anterior thalamic nuclei on spatial memory retrieval.

    PubMed

    Méndez-Couz, M; Conejo, N M; González-Pardo, H; Arias, J L

    2015-04-24

    The standard model of memory system consolidation supports the temporal reorganization of brain circuits underlying long-term memory storage, including interactions between the dorsal hippocampus and extra-hippocampal structures. In addition, several brain regions have been suggested to be involved in the retrieval of spatial memory. In particular, several authors reported a possible role of the ventral portion of the hippocampus together with the thalamus or the striatum in the persistence of this type of memory. Accordingly, the present study aimed to evaluate the contribution of different cortical and subcortical brain regions, and neural networks involved in spatial memory retrieval. For this purpose, we used cytochrome c oxidase quantitative histochemistry as a reliable method to measure brain oxidative metabolism. Animals were trained in a hidden platform task and tested for memory retention immediately after the last training session; one week after completing the task, they were also tested in a memory retrieval probe. Results showed that retrieval of the previously learned task was associated with increased levels of oxidative metabolism in the prefrontal cortex, the dorsal and ventral striatum, the anterodorsal thalamic nucleus and the dentate gyrus of the dorsal and ventral hippocampus. The analysis of functional interactions between brain regions suggest that the dorsal and ventral dentate gyrus could be involved in spatial memory retrieval. In addition, the results highlight the key role of the extended hippocampal system, thalamus and striatum in this process. Our study agrees with previous ones reporting interactions between the dorsal hippocampus and the prefrontal cortex during spatial memory retrieval. Furthermore, novel activation patterns of brain networks involving the aforementioned regions were found. These functional brain networks could underlie spatial memory retrieval evaluated in the Morris water maze task.

  8. Effects of Anterior Thalamic Nucleus Deep Brain Stimulation in Chronic Epileptic Rats

    PubMed Central

    Amorim, Beatriz; Cavarsan, Clarissa; Miranda, Maisa Ferreira; Aarão, Mayra C.; Madureira, Ana Paula; Rodrigues, Antônio M.; Nobrega, José N.; Mello, Luiz E.; Hamani, Clement

    2014-01-01

    Deep brain stimulation (DBS) has been investigated for the treatment of epilepsy. In rodents, an increase in the latency for the development of seizures and status epilepticus (SE) has been reported in different animal models but the consequences of delivering stimulation to chronic epileptic animals have not been extensively addressed. We study the effects of anterior thalamic nucleus (AN) stimulation at different current intensities in rats rendered epileptic following pilocarpine (Pilo) administration. Four months after Pilo-induced SE, chronic epileptic rats were bilaterally implanted with AN electrodes or had sham-surgery. Stimulation was delivered for 6 h/day, 5 days/week at 130 Hz, 90 µsec. and either 100 µA or 500 µA. The frequency of spontaneous recurrent seizures in animals receiving stimulation was compared to that recorded in the preoperative period and in rats given sham treatment. To investigate the effects of DBS on hippocampal excitability, brain slices from animals receiving AN DBS or sham surgery were studied with electrophysiology. We found that rats treated with AN DBS at 100 µA had a 52% non-significant reduction in the frequency of seizures as compared to sham-treated controls and 61% less seizures than at baseline. Animals given DBS at 500 µA had 5.1 times more seizures than controls and a 2.8 fold increase in seizure rate as compared to preoperative values. In non-stimulated controls, the average frequency of seizures before and after surgery remained unaltered. In vitro recordings have shown that slices from animals previously given DBS at 100 µA had a longer latency for the development of epileptiform activity, shorter and smaller DC shifts, and a smaller spike amplitude compared to non-stimulated controls. In contrast, a higher spike amplitude was recorded in slices from animals given AN DBS at 500 µA. PMID:24892420

  9. Oscillatory synchrony between head direction cells recorded bilaterally in the anterodorsal thalamic nuclei.

    PubMed

    Butler, William N; Taube, Jeffrey Steven

    2017-03-01

    The head direction (HD) circuit is a complex, interconnected network of brain regions ranging from the brainstem to the cortex. Recent work found that HD cells co-recorded ipsilaterally in the anterodorsal nucleus (ADN) of the thalamus displayed coordinated firing patterns. A high frequency oscillation pattern (130-160 Hz) was visible in the cross-correlograms of these HD cell pairs. Spectral analysis further found that the power of this oscillation was greatest at 0 ms and decreased at greater lags, and demonstrated that there was greater synchrony between HD cells with similar tunings. Here, we demonstrate that the same high frequency synchrony exists in HD cell pairs recorded contralaterally from one another in the bilateral ADN. When we examined the cross-correlograms of HD cells that were co-recorded bilaterally we observed the same high frequency (~150-200 Hz) oscillatory relationship. The strength of this synchrony was similar to the synchrony seen in ipsilateral HD cell pairs, and the degree of synchrony in each cross-correlogram was dependent on the difference in tuning between the two cells. Additionally, the frequency rate of this oscillation appeared to be independent of the firing rates of the two cross-correlated cells. Taken together, these results imply that the left and right thalamic HD network are functionally related, despite an absence of direct anatomical projections. However, anatomical tracing has found that each of the lateral mammillary nuclei (LMN) project bilaterally to both of the ADN, suggesting the LMN may be responsible for the functional connectivity observed between the two ADN.

  10. Somatosensory phenotype is associated with thalamic metabolites and pain intensity after spinal cord injury

    PubMed Central

    Widerström-Noga, Eva; Cruz-Almeida, Yenisel; Felix, Elizabeth R.; Pattany, Pradip M.

    2015-01-01

    Neuropathic pain is one of the most difficult consequences of spinal cord injury (SCI). The clinical correlates of the underlying mechanisms responsible for neuropathic pain are not well understood, although methods such as quantitative somatosensory testing (QST) or brain imaging have been used to further a mechanism-based understanding of pain. Our previous SCI study demonstrated a significantly lower glutamate-glutamine/myo-inositol ratio (Glx/Ins) in the anterior cingulate cortex in persons with severe neuropathic pain compared with those with less severe neuropathic pain or pain-free, able-bodied controls, suggesting that a combination of decreased glutamatergic metabolism and glial activation may contribute to the development of severe neuropathic pain after SCI. The present study aimed to determine the relationships between somatosensory function below the level of injury and low thalamic Glx/Ins in persons with intense neuropathic pain after SCI. Participants underwent QST and a 3 Tesla proton magnetic resonance spectroscopy. A cluster analysis including SCI participants resulted in 1 group (n = 19) with significantly (P < 0.001) greater pain intensity (6.43 ± 1.63; high neuropathic pain [HNP], and lower Glx/Ins [1.22 ± 0.16]) and another group (n = 35) with lower pain intensity ratings (1.59 ± 1.52, low neuropathic pain [LNP], and higher Glx/Ins [1.47 ± 0.26]). After correcting for age, QST indicated significantly greater somatosensory function in the HNP group compared with the LNP group. Our results are consistent with research suggesting that damage to, but not abolition of, the spinothalamic tract contributes to development of neuropathic pain after SCI and that secondary inflammatory processes may amplify residual spinothalamic tract signals by facilitation, disinhibition, or sensitization. PMID:25599312

  11. Tactile responses of hindpaw, forepaw and whisker neurons in the thalamic ventrobasal complex of anesthetized rats.

    PubMed

    Aguilar, J; Morales-Botello, M L; Foffani, G

    2008-01-01

    The majority of studies investigating responses of thalamocortical neurons to tactile stimuli have focused on the whisker representation of the rat thalamus: the ventral-posterior-medial nucleus (VPM). To test whether the basic properties of thalamocortical responses to tactile stimuli could be extended to the entire ventrobasal complex, we recorded single neurons from the whisker, forepaw and hindpaw thalamic representations. We performed a systematic analysis of responses to stereotyped tactile stimuli--500 ms pulses (i.e. ON-OFF stimuli) or 1 ms pulses (i.e. impulsive stimuli)--under two different anesthetics (pentobarbital or urethane). We obtained the following main results: (i) the tuning of cells to ON vs. OFF stimuli displayed a gradient across neurons, so that two-thirds of cells responded more to ON stimuli and one-third responded more to OFF stimuli; (ii) on average, response magnitudes did not differ between ON and OFF stimuli, whereas latencies of response to OFF stimuli were a few milliseconds longer; (iii) latencies of response to ON and OFF stimuli were highly correlated; (iv) responses to impulsive stimuli and ON stimuli showed a strong correlation, whereas the relationship between the responses to impulsive stimuli and OFF stimuli was subtler; (v) unlike ON responses, OFF responses did not decrease when stimuli were moved from the receptive field center to a close location in the excitatory surround. We obtained the same results for hindpaw, forepaw and whisker neurons. Our results support the view of a neurophysiologically homogeneous ventrobasal complex, in which OFF responses participate in the structure of the spatiotemporal receptive field of thalamocortical neurons for tactile stimuli.

  12. Tactile responses of hindpaw, forepaw and whisker neurons in the thalamic ventrobasal complex of anesthetized rats

    PubMed Central

    Aguilar, J; Morales-Botello, M L; Foffani, G

    2008-01-01

    The majority of studies investigating responses of thalamocortical neurons to tactile stimuli have focused on the whisker representation of the rat thalamus: the ventral–posterior–medial nucleus (VPM). To test whether the basic properties of thalamocortical responses to tactile stimuli could be extended to the entire ventrobasal complex, we recorded single neurons from the whisker, forepaw and hindpaw thalamic representations. We performed a systematic analysis of responses to stereotyped tactile stimuli − 500 ms pulses (i.e. ON–OFF stimuli) or 1 ms pulses (i.e. impulsive stimuli) − under two different anesthetics (pentobarbital or urethane). We obtained the following main results: (i) the tuning of cells to ON vs. OFF stimuli displayed a gradient across neurons, so that two-thirds of cells responded more to ON stimuli and one-third responded more to OFF stimuli; (ii) on average, response magnitudes did not differ between ON and OFF stimuli, whereas latencies of response to OFF stimuli were a few milliseconds longer; (iii) latencies of response to ON and OFF stimuli were highly correlated; (iv) responses to impulsive stimuli and ON stimuli showed a strong correlation, whereas the relationship between the responses to impulsive stimuli and OFF stimuli was subtler; (v) unlike ON responses, OFF responses did not decrease when stimuli were moved from the receptive field center to a close location in the excitatory surround. We obtained the same results for hindpaw, forepaw and whisker neurons. Our results support the view of a neurophysiologically homogeneous ventrobasal complex, in which OFF responses participate in the structure of the spatiotemporal receptive field of thalamocortical neurons for tactile stimuli. PMID:18190520

  13. Thalamic connections of architectonic subdivisions of temporal cortex in grey squirrels (Sciurus carolinenesis)

    PubMed Central

    Wong, Peiyan; Gharbawie, Omar A.; Luethke, Lynn E.; Kaas, Jon H.

    2008-01-01

    The temporal cortex of grey squirrels contains three architectonically distinct regions. One of these regions, the temporal anterior (Ta) region has been identified in previous physiological and anatomical studies as containing several areas that are largely auditory in function. Consistent with this evidence, Ta has architectonic features that are internally somewhat variable, but overall sensory in nature. In contrast, the caudally adjoining temporal intermediate region (Ti) has architectonic features that suggest higher order and possibly multisensory processing. Finally, the most caudal region, composed of previously defined temporal medial (Tm) and temporal posterior (Tp) fields, again has more of the appearance of sensory cortex. To better understand their functional roles, we injected anatomical tracers into these regions to reveal their thalamic connections. As expected, the dorsal portion of Ta, containing two primary or primary-like auditory areas, received inputs from the ventral and magnocellular divisions of the auditory medial geniculate complex, MGv and MGm. The most caudal region, Tm plus Tp, received inputs from the large visual pulvinar of squirrels, possibly accounting for the sensory architectonic characteristics of this region. However, Tp additionally receives inputs from the magnocellular (MGm) and dorsal (MGd) divisions of the medial geniculate complex, implicating Tp in bisensory processing. Finally, the middle region, Ti, had auditory inputs from MGd and MGm, but not from the visual pulvinar, providing evidence that Ti has higher-order auditory functions. The results indicate that the architectonically distinct regions of temporal cortex of squirrels are also functionally distinct. Understanding how temporal cortex is functionally organized in squirrels can guide interpretations of temporal cortex organization in other rodents where architectonic subdivisions are not as obvious. PMID:18666125

  14. Thalamic mediodorsal nucleus and its participation in spatial working memory processes: comparison with the prefrontal cortex.

    PubMed

    Funahashi, Shintaro

    2013-01-01

    Working memory is a dynamic neural system that includes processes for temporarily maintaining and processing information. Working memory plays a significant role in a variety of cognitive functions, such as thinking, reasoning, decision-making, and language comprehension. Although the prefrontal cortex (PFC) is known to play an important role in working memory, several lines of evidence indicate that the thalamic mediodorsal nucleus (MD) also participates in this process. While monkeys perform spatial working memory tasks, MD neurons exhibit directionally selective delay-period activity, which is considered to be a neural correlate for the temporary maintenance of information in PFC neurons. Studies have also shown that, while most MD neurons maintain prospective motor information, some maintain retrospective sensory information. Thus, the MD plays a greater role in prospective motor aspects of working memory processes than the PFC, which participates more in retrospective aspects. For the performance of spatial working memory tasks, the information provided by a sensory cue needs to be transformed into motor information to give an appropriate response. A population vector analysis using neural activities revealed that, although the transformation of sensory-to-motor information occurred during the delay period in both the PFC and the MD, PFC activities maintained sensory information until the late phase of the delay period, while MD activities initially represented sensory information but then started to represent motor information in the earlier phase of the delay period. These results indicate that long-range neural interactions supported by reciprocal connections between the MD and the PFC could play an important role in the transformation of maintained information in working memory processes.

  15. Long-term efficacy and safety of thalamic stimulation for drug-resistant partial epilepsy

    PubMed Central

    Witt, Thomas; Worth, Robert; Henry, Thomas R.; Gross, Robert E.; Nazzaro, Jules M.; Labar, Douglas; Sperling, Michael R.; Sharan, Ashwini; Sandok, Evan; Handforth, Adrian; Stern, John M.; Chung, Steve; Henderson, Jaimie M.; French, Jacqueline; Baltuch, Gordon; Rosenfeld, William E.; Garcia, Paul; Barbaro, Nicholas M.; Fountain, Nathan B.; Elias, W. Jeffrey; Goodman, Robert R.; Pollard, John R.; Tröster, Alexander I.; Irwin, Christopher P.; Lambrecht, Kristin; Graves, Nina; Fisher, Robert

    2015-01-01

    Objective: To report long-term efficacy and safety results of the SANTE trial investigating deep brain stimulation of the anterior nucleus of the thalamus (ANT) for treatment of localization-related epilepsy. Methods: This long-term follow-up is a continuation of a previously reported trial of 5- vs 0-V ANT stimulation. Long-term follow-up began 13 months after device implantation with stimulation parameters adjusted at the investigators' discretion. Seizure frequency was determined using daily seizure diaries. Results: The median percent seizure reduction from baseline at 1 year was 41%, and 69% at 5 years. The responder rate (≥50% reduction in seizure frequency) at 1 year was 43%, and 68% at 5 years. In the 5 years of follow-up, 16% of subjects were seizure-free for at least 6 months. There were no reported unanticipated adverse device effects or symptomatic intracranial hemorrhages. The Liverpool Seizure Severity Scale and 31-item Quality of Life in Epilepsy measure showed statistically significant improvement over baseline by 1 year and at 5 years (p < 0.001). Conclusion: Long-term follow-up of ANT deep brain stimulation showed sustained efficacy and safety in a treatment-resistant population. Classification of evidence: This long-term follow-up provides Class IV evidence that for patients with drug-resistant partial epilepsy, anterior thalamic stimulation is associated with a 69% reduction in seizure frequency and a 34% serious device-related adverse event rate at 5 years. PMID:25663221

  16. Synaptic responsiveness of cortical and thalamic neurones during various phases of slow sleep oscillation in cat.

    PubMed Central

    Timofeev, I; Contreras, D; Steriade, M

    1996-01-01

    1. The fluctuations during various phases of the slow sleep oscillation (< 1 Hz) in synaptic responsiveness of motor cortical (Cx), thalamic reticular (RE) and thalamocortical (TC) neurones were investigated intracellularly in cats under ketamine-xylazine anaesthesia. Orthodromic responses to stimuli applied to brachium conjunctivum (BC) axons and corticothalamic pathways were studied. The phases of slow oscillation consist of a long-hyperpolarized, followed by a sharp depth-negative EEG deflection and a series of faster waves that are associated with the depolarization of Cx and RE neurones, while TC cells display a sequence of IPSPs within the spindle frequency. 2. BC-evoked bisynaptic excitatory postsynaptic potentials (EPSPs) in Cx and RE neurones were drastically reduced in amplitude during the long-lasting hyperpolarization and the early part of the depolarizing phase. By contrast, the BC-evoked monosynaptic EPSPs of TC cells were not diminished during the depth-positive EEG wave, but the hyperpolarization during this phase of the slow oscillation prevented TC neurones transferring prethalamic signals to the cortex. 3. At variance with the diminished bisynaptic EPSPs evoked in response to BC stimuli during the long-lasting hyperpolarization, Cx-evoked monosynaptic EPSPs in Cx cells increased linearly with hyperpolarization during this phase of the slow oscillation. Similarly, the amplitudes of Cx-evoked EPSPs in RE and TC cells were not diminished during the long-lasting hyperpolarization. 4. The diminished responsiveness of Cx and RE neurones to prethalamic volleys during the long-lasting hyperpolarization is attributed to gating processes at the level of TC cells that, because of their hyperpolarization, do not transfer prethalamic information to further relays. PMID:8814620

  17. Active action potential propagation but not initiation in thalamic interneuron dendrites

    PubMed Central

    Casale, Amanda E.; McCormick, David A.

    2012-01-01

    Inhibitory interneurons of the dorsal lateral geniculate nucleus of the thalamus modulate the activity of thalamocortical cells in response to excitatory input through the release of inhibitory neurotransmitter from both axons and dendrites. The exact mechanisms by which release can occur from dendrites are, however, not well understood. Recent experiments using calcium imaging have suggested that Na/K based action potentials can evoke calcium transients in dendrites via local active conductances, making the back-propagating action potential a candidate for dendritic neurotransmitter release. In this study, we employed high temporal and spatial resolution voltage-sensitive dye imaging to assess the characteristics of dendritic voltage deflections in response to Na/K action potentials in interneurons of the mouse dorsal lateral geniculate nucleus. We found that trains or single action potentials elicited by somatic current injection or local synaptic stimulation led to action potentials that rapidly and actively back-propagated throughout the entire dendritic arbor and into the fine filiform dendritic appendages known to release GABAergic vesicles. Action potentials always appeared first in the soma or proximal dendrite in response to somatic current injection or local synaptic stimulation, and the rapid back-propagation into the dendritic arbor depended upon voltage-gated sodium and TEA-sensitive potassium channels. Our results indicate that thalamic interneuron dendrites integrate synaptic inputs that initiate action potentials, most likely in the axon initial segment, that then back-propagate with high-fidelity into the dendrites, resulting in a nearly synchronous release of GABA from both axonal and dendritic compartments. PMID:22171033

  18. CASAS: A Smart Home in a Box.

    PubMed

    Cook, Diane J; Crandall, Aaron S; Thomas, Brian L; Krishnan, Narayanan C

    2013-07-01

    While the potential benefits of smart home technology are widely recognized, a lightweight design is needed for the benefits to be realized at a large scale. We introduce the CASAS "smart home in a box", a lightweight smart home design that is easy to install and provides smart home capabilities out of the box with no customization or training. We discuss types of data analysis that have been performed by the CASAS group and can be pursued in the future by using this approach to designing and implementing smart home technologies.

  19. FRAC-IN-THE-BOX utilization

    SciTech Connect

    Collins, D.G.; West, J.T.

    1989-06-01

    FRAC-IN-THE-BOX is a computer code developed to calculate the fractions of rectangular parallelepiped mesh cell volumes that are intersected by combinatorial geometry type zones. The geometry description used in the code is a subset of the combinatorial geometry used in SABRINA. The input file may be read into SABRINA and three dimensional plots made of the input geometry. The volume fractions for those portions of the geometry that are too complicated to describe with the geometry routines provided in FRAC-IN-THE-BOX may be calculated in SABRINA and merged with the volume fractions computed for the remainder of the geometry. 21 figs., 1 tab.

  20. Differential changes in thalamic and cortical excitatory synapses onto striatal spiny projection neurons in a Huntington disease mouse model.

    PubMed

    Kolodziejczyk, Karolina; Raymond, Lynn A

    2016-02-01

    Huntington disease (HD), a neurodegenerative disorder caused by CAG repeat expansion in the gene encoding huntingtin, predominantly affects the striatum, especially the spiny projection neurons (SPN). The striatum receives excitatory input from cortex and thalamus, and the role of the former has been well-studied in HD. Here, we report that mutated huntingtin alters function of thalamostriatal connections. We used a novel thalamostriatal (T-S) coculture and an established corticostriatal (C-S) coculture, generated from YAC128 HD and WT (FVB/NJ background strain) mice, to investigate excitatory neurotransmission onto striatal SPN. SPN in T-S coculture from WT mice showed similar mini-excitatory postsynaptic current (mEPSC) frequency and amplitude as in C-S coculture; however, both the frequency and amplitude were significantly reduced in YAC128 T-S coculture. Further investigation in T-S coculture showed similar excitatory synapse density in WT and YAC128 SPN dendrites by immunostaining, suggesting changes in total dendritic length or probability of release as possible explanations for mEPSC frequency changes. Synaptic N-methyl-D-aspartate receptor (NMDAR) current was similar, but extrasynaptic current, associated with cell death signaling, was enhanced in YAC128 SPN in T-S coculture. Employing optical stimulation of cortical versus thalamic afferents and recording from striatal SPN in brain slice, we found increased glutamate release probability and reduced AMPAR/NMDAR current ratios in thalamostriatal synapses, most prominently in YAC128. Enhanced extrasynaptic NMDAR current in YAC128 SPN was apparent with both cortical and thalamic stimulation. We conclude that thalamic afferents to the striatum are affected early, prior to an overt HD phenotype; however, changes in NMDAR localization in SPN are independent of the source of glutamatergic input.

  1. Synchronization of Isolated Downstates (K-Complexes) May Be Caused by Cortically-Induced Disruption of Thalamic Spindling

    PubMed Central

    Mak-McCully, Rachel A.; Deiss, Stephen R.; Rosen, Burke Q.; Jung, Ki-Young; Sejnowski, Terrence J.; Bastuji, Hélène; Rey, Marc

    2014-01-01

    Sleep spindles and K-complexes (KCs) define stage 2 NREM sleep (N2) in humans. We recently showed that KCs are isolated downstates characterized by widespread cortical silence. We demonstrate here that KCs can be quasi-synchronous across scalp EEG and across much of the cortex using electrocorticography (ECOG) and localized transcortical recordings (bipolar SEEG). We examine the mechanism of synchronous KC production by creating the first conductance based thalamocortical network model of N2 sleep to generate both spontaneous spindles and KCs. Spontaneous KCs are only observed when the model includes diffuse projections from restricted prefrontal areas to the thalamic reticular nucleus (RE), consistent with recent anatomical findings in rhesus monkeys. Modeled KCs begin with a spontaneous focal depolarization of the prefrontal neurons, followed by depolarization of the RE. Surprisingly, the RE depolarization leads to decreased firing due to disrupted spindling, which in turn is due to depolarization-induced inactivation of the low-threshold Ca2+ current (IT). Further, although the RE inhibits thalamocortical (TC) neurons, decreased RE firing causes decreased TC cell firing, again because of disrupted spindling. The resulting abrupt removal of excitatory input to cortical pyramidal neurons then leads to the downstate. Empirically, KCs may also be evoked by sensory stimuli while maintaining sleep. We reproduce this phenomenon in the model by depolarization of either the RE or the widely-projecting prefrontal neurons. Again, disruption of thalamic spindling plays a key role. Higher levels of RE stimulation also cause downstates, but by directly inhibiting the TC neurons. SEEG recordings from the thalamus and cortex in a single patient demonstrated the model prediction that thalamic spindling significantly decreases before KC onset. In conclusion, we show empirically that KCs can be widespread quasi-synchronous cortical downstates, and demonstrate with the first model

  2. Connectivity-Based Parcellation of the Thalamus Explains Specific Cognitive and Behavioural Symptoms in Patients with Bilateral Thalamic Infarct

    PubMed Central

    Serra, Laura; Cercignani, Mara; Carlesimo, Giovanni A.; Fadda, Lucia; Tini, Nadia; Giulietti, Giovanni; Caltagirone, Carlo; Bozzali, Marco

    2013-01-01

    A novel approach based on diffusion tractography was used here to characterise the cortico-thalamic connectivity in two patients, both presenting with an isolated bilateral infarct in the thalamus, but exhibiting partially different cognitive and behavioural profiles. Both patients (G.P. and R.F.) had a pervasive deficit in episodic memory, but only one of them (R.F.) suffered also from a dysexecutive syndrome. Both patients had an MRI scan at 3T, including a T1-weighted volume. Their lesions were manually segmented. T1-volumes were normalised to standard space, and the same transformations were applied to the lesion masks. Nineteen healthy controls underwent a diffusion-tensor imaging (DTI) scan. Their DTI data were normalised to standard space and averaged. An atlas of Brodmann areas was used to parcellate the prefrontal cortex. Probabilistic tractography was used to assess the probability of connection between each voxel of the thalamus and a set of prefrontal areas. The resulting map of corticothalamic connections was superimposed onto the patients’ lesion masks, to assess whether the location of the thalamic lesions in R.F. (but not in G. P.) implied connections with prefrontal areas involved in dysexecutive syndromes. In G.P., the lesion fell within areas of the thalamus poorly connected with prefrontal areas, showing only a modest probability of connection with the anterior cingulate cortex (ACC). Conversely, R.F.’s lesion fell within thalamic areas extensively connected with the ACC bilaterally, with the right dorsolateral prefrontal cortex, and with the left supplementary motor area. Despite a similar, bilateral involvement of the thalamus, the use of connectivity-based segmentation clarified that R.F.’s lesions only were located within nuclei highly connected with the prefrontal cortical areas, thus explaining the patient’s frontal syndrome. This study confirms that DTI tractography is a useful tool to examine in vivo the effect of focal lesions

  3. Bilateral thalamic infarct caused by spontaneous vertebral artery dissection in pre-eclampsia with HELLP syndrome: a previously unreported association.

    PubMed

    Borelli, Paolo; Baldacci, Filippo; Vergallo, Andrea; Del Dotto, Paolo; Lucetti, Claudio; Nuti, Angelo; Bonuccelli, Ubaldo

    2012-11-01

    Cerebrovascular accidents are not rare during pregnancy and the postpartum period. Pre-eclampsia is a common condition that is characterized by proteinuria and de novo hypertension that may be complicated by hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome. Spontaneous cervical artery dissection has been rarely reported in the postpartum period but never in association with HELLP syndrome. We describe a case of pre-eclampsia and HELLP syndrome complicated in the postpartum period by bilateral thalamic infarct as result of left vertebral artery dissection. We speculated about the possible common etiopathologic mechanisms involved in this previously unreported association.

  4. Subcellular domain-restricted GABAergic innervation in primary visual cortex in the absence of sensory and thalamic inputs.

    PubMed

    Di Cristo, Graziella; Wu, Caizhi; Chattopadhyaya, Bidisha; Ango, Fabrice; Knott, Graham; Welker, Egbert; Svoboda, Karel; Huang, Z Josh

    2004-11-01

    Distinct classes of GABAergic synapses target restricted subcellular domains, thereby differentially regulating the input, integration and output of principal neurons, but the underlying mechanism for such synapse segregation is unclear. Here we show that the distributions of two major classes of GABAergic synapses along the perisomatic and dendritic domains of pyramidal neurons were indistinguishable between primary visual cortex in vivo and cortical organotypic cultures. Therefore, subcellular synapse targeting is independent of thalamic input and probably involves molecular labels and experience-independent forms of activity.

  5. Participation of thalamic nuclei in the elaboration of conditioned avoidance reflexes of rats. VIII. Lesions of the nucleus posterior.

    PubMed

    Klingberg, F; Klingberg, H

    1982-01-01

    Bilateral symmetric lesions of the posterior thalamic nucleus reduced the preoperatively learnt avoidance responses in Long-Evans hooded rats strongly. Postoperative acquisition of conditioned avoidance reflexes was rather low in each rat in a simple runway and impossible in an alternation task. Thresholds of reactions to pain (withdrawal of paws from the grid floor) were significantly increased. The lesioned rats had trouble to find the way out, as if they had difficulties to localize the source of punishment or to associate pain information with any other cues.

  6. Steroid-responsive thalamic lesions accompanying microbleeds in a case of Hashimoto's encephalopathy with autoantibodies against α-enolase.

    PubMed

    Yamaguchi, Yoshitaka; Wada, Manabu; Tanji, Haruko; Kurokawa, Katsuro; Kawanami, Toru; Tanji, Kazuyo; Yoneda, Makoto; Kato, Takeo

    2013-01-01

    A 67-year-old man receiving antithrombotic therapy developed rapidly progressive amnesia. T2-weighted images of brain MRI revealed hyperintense lesions in the bilateral thalami accompanied by microbleeds. Antithyroglobulin antibodies and autoantibodies against the N-terminal of α-enolase (NAE) were identified in the patient's serum; therefore, Hashimoto's encephalopathy (HE) was suspected. Although the patient's radiological findings improved following steroid therapy, his symptoms did not improve, possibly due to increased thalamic microbleeds. Because anti-NAE antibodies are possibly associated with vasculitis, HE accompanied by anti-NAE antibodies may be exacerbated by microbleeds in patients receiving antithrombotic therapy.

  7. Dopamine Receptor Activation Increases HIV Entry into Primary Human Macrophages

    PubMed Central

    Gaskill, Peter J.; Yano, Hideaki H.; Kalpana, Ganjam V.; Javitch, Jonathan A.; Berman, Joan W.

    2014-01-01

    Macrophages are the primary cell type infected with HIV in the central nervous system, and infection of these cells is a major component in the development of neuropathogenesis and HIV-associated neurocognitive disorders. Within the brains of drug abusers, macrophages are exposed to increased levels of dopamine, a neurotransmitter that mediates the addictive and reinforcing effects of drugs of abuse such as cocaine and methamphetamine. In this study we examined the effects of dopamine on HIV entry into primary human macrophages. Exposure to dopamine during infection increased the entry of R5 tropic HIV into macrophages, irrespective of the concentration of the viral inoculum. The entry pathway affected was CCR5 dependent, as antagonizing CCR5 with the small molecule inhibitor TAK779 completely blocked entry. The effect was dose-dependent and had a steep threshold, only occurring above 108 M dopamine. The dopamine-mediated increase in entry required dopamine receptor activation, as it was abrogated by the pan-dopamine receptor antagonist flupenthixol, and could be mediated through both subtypes of dopamine receptors. These findings indicate that the effects of dopamine on macrophages may have a significant impact on HIV pathogenesis. They also suggest that drug-induced increases in CNS dopamine may be a common mechanism by which drugs of abuse with distinct modes of action exacerbate neuroinflammation and contribute to HIV-associated neurocognitive disorders in infected drug abusers. PMID:25268786

  8. Expo-Box: Submit Tool Information

    EPA Pesticide Factsheets

    EPA-Expo-Box is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases, mode

  9. EPA ExpoBox Related Links

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases,

  10. Mystery Boxes: Helping Children Improve Their Reasoning

    ERIC Educational Resources Information Center

    Rule, Audrey C.

    2007-01-01

    This guest editorial describes ways teachers can use guessing games about an unknown item in a "mystery box" to help children improve their abilities to listen to others, recall information, ask purposeful questions, classify items by class, make inferences, synthesize information, and draw conclusions. The author presents information…

  11. Hazard Analysis of Japanese Boxed Lunches (Bento).

    ERIC Educational Resources Information Center

    Bryan, Frank L.; And Others

    1991-01-01

    For the purposes of identifying contaminants, of assessing risks, and of determining critical food processing control points, hazard analyses were conducted at two "bento" (oriental boxed meals) catering operations. Time and temperature abuses during the holding period, after cooking and prior to consumption, were found to be the primary…

  12. Fast box-counting algorithm on GPU.

    PubMed

    Jiménez, J; Ruiz de Miras, J

    2012-12-01

    The box-counting algorithm is one of the most widely used methods for calculating the fractal dimension (FD). The FD has many image analysis applications in the biomedical field, where it has been used extensively to characterize a wide range of medical signals. However, computing the FD for large images, especially in 3D, is a time consuming process. In this paper we present a fast parallel version of the box-counting algorithm, which has been coded in CUDA for execution on the Graphic Processing Unit (GPU). The optimized GPU implementation achieved an average speedup of 28 times (28×) compared to a mono-threaded CPU implementation, and an average speedup of 7 times (7×) compared to a multi-threaded CPU implementation. The performance of our improved box-counting algorithm has been tested with 3D models with different complexity, features and sizes. The validity and accuracy of the algorithm has been confirmed using models with well-known FD values. As a case study, a 3D FD analysis of several brain tissues has been performed using our GPU box-counting algorithm.

  13. One-Dimensional Oscillator in a Box

    ERIC Educational Resources Information Center

    Amore, Paolo; Fernandez, Francisco M.

    2010-01-01

    We discuss a quantum-mechanical model of two particles that interact by means of a harmonic potential and are confined to a one-dimensional box with impenetrable walls. We apply perturbation theory to the cases of different and equal masses and analyse the symmetry of the states in the latter case. We compare the approximate perturbation results…

  14. 30 CFR 56.12006 - Distribution boxes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Distribution boxes. 56.12006 Section 56.12006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity §...

  15. 30 CFR 57.12006 - Distribution boxes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Distribution boxes. 57.12006 Section 57.12006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Electricity...

  16. 30 CFR 57.12006 - Distribution boxes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Distribution boxes. 57.12006 Section 57.12006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Electricity...

  17. 30 CFR 56.12006 - Distribution boxes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Distribution boxes. 56.12006 Section 56.12006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity §...

  18. 30 CFR 56.12006 - Distribution boxes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distribution boxes. 56.12006 Section 56.12006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity §...

  19. 30 CFR 56.12006 - Distribution boxes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Distribution boxes. 56.12006 Section 56.12006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity §...

  20. 30 CFR 56.12006 - Distribution boxes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Distribution boxes. 56.12006 Section 56.12006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity §...