Thalamus & related systems最新文献

{"title":"Excitability of cortical neurons depends upon a powerful tonic conductance in inhibitory networks.","authors":"Esther I Krook-Magnuson,&nbsp;Molly M Huntsman","doi":"10.1017/S1472928807000192","DOIUrl":"https://doi.org/10.1017/S1472928807000192","url":null,"abstract":"<p><p>Layer 4 of the mouse somatosensory (barrel) cortex has a diversity of interneuron cell types. Tonic inhibition in other regions is cell type-specific and mediated, in part, by δ-subunit containing, extrasynaptic, GABA(A) receptors. We have investigated tonic inhibition in LTS cells, a major type of inhibitory neuron, and excitatory cells in layer 4 of the mouse barrel cortex using 4,5,6,7-tetrahydroisothiazolo-[5,4-c]pyridine-3-ol (THIP), a superagonist of these receptors. Bath application of 20 µM THIP produced baseline shifts, which indicates activation of tonic inhibition of both excitatory and LTS cells. The baseline shift was significantly larger in LTS cells. This finding of greater induced current in LTS cells was paralleled by a significantly greater increase in conductance with THIP application in LTS cells. The increase in conductance resulted in LTS cells requiring more current to reach threshold. Because of the differential effects of tonic inhibition on LTS cells and excitatory cells, bath application of THIP increased the network excitability, measured by multi-unit recordings. Thus, the network effect of tonic inhibition in horizontal layer 4 circuits is a paradoxical increase in excitation.</p>","PeriodicalId":74923,"journal":{"name":"Thalamus & related systems","volume":" ","pages":"115-120"},"PeriodicalIF":0.0,"publicationDate":"2005-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1472928807000192","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27924803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation of eye-specific retinogeniculate projections occurs prior to the innervation of the dorsal lateral geniculate nucleus by cholinergic fibers.","authors":"Jose M Ballesteros,&nbsp;Deborah A VAN DER List,&nbsp;Leo M Chalupa","doi":"10.1017/S1472928807000167","DOIUrl":"https://doi.org/10.1017/S1472928807000167","url":null,"abstract":"<p><p>We compared the developmental periods in the mouse when projections from the two eyes become segregated in the dorsal lateral geniculate nucleus with the time when this nucleus becomes innervated by cholinergic fibers from the brainstem. Changes in labeling patterns of different tracers injected into each eye revealed that segregation of retinogeniculate inputs commences at postnatal day five (P5) and is largely complete by P8. Immunocytochemical staining showed that cholinergic neurons are present in the parabrachial region of the brain stem on the day of birth. However, cholinergic fibers are not evident in the geniculate until P5, and these are sparse at this age, increasing in density to form well-defined clusters by P12. These results indicate that segregation of eye-specific projections during normal development is unlikely to be regulated by cholinergic inputs from the brainstem.</p>","PeriodicalId":74923,"journal":{"name":"Thalamus & related systems","volume":" ","pages":"157-163"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1472928807000167","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28109212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cellular and network mechanisms of genetically-determined absence seizures.","authors":"Didier Pinault,&nbsp;Terence J O'Brien","doi":"10.1017/S1472928807000209","DOIUrl":"https://doi.org/10.1017/S1472928807000209","url":null,"abstract":"<p><p>The absence epilepsies are characterized by recurrent episodes of loss of consciousness associated with generalized spike-and-wave discharges, with an abrupt onset and offset, in the thalamocortical system. In the absence of detailed neurophysiological studies in humans, many of the concepts regarding the pathophysiological basis of absence seizures are based on studies in animal models. Each of these models has its particular strengths and limitations, and the validity of findings from these models for the human condition cannot be assumed. Consequently, studies in different models have produced some conflicting findings and conclusions. A long-standing concept, based primarily from studies in vivo in cats and in vitro brain slices, is that these paroxysmal electrical events develop suddenly from sleep-related spindle oscillations. More specifically, it is proposed that the initial mechanisms that underlie absence-related spike-and-wave discharges are located in the thalamus, involving especially the thalamic reticular nucleus. By contrast, more recent studies in well-established, genetic models of absence epilepsy in rats demonstrate that spike-and-wave discharges originate in a cortical focus and develop from a wake-related natural corticothalamic sensorimotor rhythm. In this review we integrate recent findings showing that, in both the thalamus and the neocortex, genetically-determined, absence-related spike-and-wave discharges are the manifestation of hypersynchronized, cellular, rhythmic excitations and inhibitions that result from a combination of complex, intrinsic, synaptic mechanisms. Arguments are put forward supporting the hypothesis that layer VI corticothalamic neurons act as 'drivers' in the generation of spike-and-wave discharges in the somatosensory thalamocortical system that result in corticothalamic resonances particularly initially involving the thalamic reticular nucleus. However an important unresolved question is: what are the cellular and network mechanisms responsible for the switch from physiological, wake-related, natural oscillations into pathological spike-and-wave discharges? We speculate on possible answers to this, building particularly on recent findings from genetic models in rats.</p>","PeriodicalId":74923,"journal":{"name":"Thalamus & related systems","volume":"3 3","pages":"181-203"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1472928807000209","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30134766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pallidothalamocortical pathway to the medial agranular cortex in the rat: a double labeling light and electron microscopic study","authors":"Sharleen T Sakai,&nbsp;Kathy Bruce","doi":"10.1016/j.tharel.2003.12.002","DOIUrl":"10.1016/j.tharel.2003.12.002","url":null,"abstract":"<div><p><span><span>The goal of the present study was to determine if the medial agranular cortex (AGm) that is thought to contain the </span>supplementary motor area<span> in the rat receives the pallidothalamocortical pathway. A double labeling paradigm was employed whereby injections of the anterograde tracer </span></span><em>Phaseolus vulgaris-</em><span><span>leucoagglutinin<span><span> (PHA-L) into the entopeduncular nucleus (EN) were combined with injections of the retrograde tracer </span>cholera toxin<span> subunit B into either the rostral or caudal part AGm in the rat. We found that the pallidothalamic projections occupied a crescent shaped arc within the thalamic ventral anterior-ventral lateral nuclear complex (VAL) and ventral medial nucleus (VM). Additional efferents projected to LD/LP, MD, Pf and CL. Dense projections were also found to LHb. In addition, we found that a wide band of cells extending from rostral </span></span></span>thalamus<span> including VAL and VM through caudal thalamus including MD, Po, LD/LP, Pf and CL projected to either the rostral or caudal parts of the AGm. The greatest coincidence of the pallidothalamic efferents and AGm thalamocortical cells was found in VAL and VM where numerous PHA-L varicosities were found in close apposition to CTB labeled cells. Synaptic contacts between VAL thalamocortical neurons and pallidal terminals were verified in the electron microscope. These results demonstrate for the first time the pallidothalamocortical pathway by way of VAL to the AGm in the rat.</span></span></p></div>","PeriodicalId":74923,"journal":{"name":"Thalamus & related systems","volume":"2 4","pages":"Pages 273-286"},"PeriodicalIF":0.0,"publicationDate":"2004-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tharel.2003.12.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116901092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum to “Neural basis of alertness and cognitive performance impairments during sleepiness II. Effects of 48 and 72 h of sleep deprivation on waking human regional brain activity”","authors":"Maria L. Thomas ,&nbsp;Helen C. Sing ,&nbsp;Gregory Belenky ,&nbsp;Henry H. Holcomb ,&nbsp;Helen S. Mayberg ,&nbsp;Robert F. Dannals ,&nbsp;Henry N. Wagner Jr. ,&nbsp;David R. Thorne ,&nbsp;Kathryn A. Popp ,&nbsp;Laura M. Rowland ,&nbsp;Amy B. Welsh ,&nbsp;Sharon M. Balwinski ,&nbsp;Daniel P. Redmond","doi":"10.1016/j.tharel.2004.05.001","DOIUrl":"10.1016/j.tharel.2004.05.001","url":null,"abstract":"","PeriodicalId":74923,"journal":{"name":"Thalamus & related systems","volume":"2 4","pages":"Page 345"},"PeriodicalIF":0.0,"publicationDate":"2004-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tharel.2004.05.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128857741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Instruction to author","authors":"","doi":"10.1016/S1472-9288(04)00014-7","DOIUrl":"https://doi.org/10.1016/S1472-9288(04)00014-7","url":null,"abstract":"","PeriodicalId":74923,"journal":{"name":"Thalamus & related systems","volume":"2 4","pages":"Pages 347-349"},"PeriodicalIF":0.0,"publicationDate":"2004-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1472-9288(04)00014-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137157130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparison of M1 and M4 muscarinic receptors in the thalamus from control subjects and subjects with schizophrenia","authors":"B. Dean ,&nbsp;L. Gray ,&nbsp;D. Keriakous ,&nbsp;E. Scarr","doi":"10.1016/j.tharel.2003.12.001","DOIUrl":"10.1016/j.tharel.2003.12.001","url":null,"abstract":"<div><p><span><span>Having shown a decrease in muscarinic M1 receptors in Brodmann’s area (BA) 9 from subjects with </span>schizophrenia<span> we have extended our studies to determine if this receptor is decreased in the thalamus from the same cohort of subjects. Levels of </span></span><span><math><mtext>[</mtext><msup><mi></mi><mn>3</mn></msup><mtext>H</mtext><mtext>]</mtext></math></span><span>pirenzepine<span> binding to and mRNA encoding for M1 and M4 receptors were measured throughout the thalamus. Levels of M1 and M4 receptor proteins were measured in the mediodorsal nucleus. Two-way ANOVA revealed a variance in </span></span><span><math><mtext>[</mtext><msup><mi></mi><mn>3</mn></msup><mtext>H</mtext><mtext>]</mtext></math></span>pirenzepine binding (<em>F</em>=4.69, d.f. = 1.190, <em>P</em><span><span>=0.03), but there was no significant change in radioligand binding in any thalamic region in schizophrenia. Neither levels of mRNA encoding the thalamic M1 or M4 receptor nor levels of M1 or M4 receptor protein in the mediodorsal nucleus differed between the schizophrenic and control subjects. We therefore conclude that the M1 and M4 receptor are not altered in the thalamus from subjects with schizophrenia. These data add weight to the hypothesis that changes in M1 receptors in selective regions of the CNS are associated with the </span>pathology of schizophrenia.</span></p></div>","PeriodicalId":74923,"journal":{"name":"Thalamus & related systems","volume":"2 4","pages":"Pages 287-295"},"PeriodicalIF":0.0,"publicationDate":"2004-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tharel.2003.12.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131835277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developmental decrease in REM sleep: the shift to kainate receptor regulation","authors":"T. Kobayashi,&nbsp;R.D. Skinner,&nbsp;E. Garcia-Rill","doi":"10.1016/j.tharel.2004.01.002","DOIUrl":"10.1016/j.tharel.2004.01.002","url":null,"abstract":"<div><p>We found a shift in the responsiveness of pedunculopontine neurons from <em>N</em>-methyl-<span>d</span><span><span><span>-aspartic acid (NMDA) to kainic acid (KA) regulation around 15 days of age. While rapid eye movement (REM) sleep in humans decreases from 50 to 15% of sleep time between birth and the end of puberty, a similar decrease in the rat occurs from 10 to 30 days postnatally. Intracellularly recorded type II cholinergic </span>PPN<span> neurons, known to modulate waking and REM sleep, showed a gradual decrease in responsiveness to NMDA, and an increase in responsiveness to KA, during this period. Non-cholinergic PPN neurons did not show a developmental-dependent change in responsiveness. These results do not help explain if KA and NMDA control the developmental decrease in REM sleep, however, the data indicate that the shift at ∼15 days suggests that REM sleep becomes selectively modulated by KA receptors in the adult. Therefore, given development of appropriate compounds, KA receptor antagonism may become an effective treatment for disorders that manifest increased REM sleep drive and produce frequent nocturnal arousals and awakenings, e.g. </span></span>schizophrenia, anxiety, insomnia, etc.</span></p></div>","PeriodicalId":74923,"journal":{"name":"Thalamus & related systems","volume":"2 4","pages":"Pages 315-324"},"PeriodicalIF":0.0,"publicationDate":"2004-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tharel.2004.01.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121840964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circuits through prefrontal cortex, basal ganglia, and ventral anterior nucleus map pathways beyond motor control","authors":"Danqing Xiao ,&nbsp;Helen Barbas","doi":"10.1016/j.tharel.2004.03.001","DOIUrl":"10.1016/j.tharel.2004.03.001","url":null,"abstract":"<div><p><span>The ventral anterior (VA) nucleus of the thalamus<span><span><span> is connected with prefrontal and premotor cortices and with the </span>basal ganglia<span>. Although classically associated with motor functions, recent evidence implicates the basal ganglia in cognition and emotion as well. Here, we used two complementary approaches to investigate whether the VA is a key link for pathways underlying cognitive and emotional processes through prefrontal cortices<span> and the basal ganglia. After application of bidirectional tracers in functionally distinct lateral, medial, and orbitofrontal cortices, we found that projection neurons were embedded in much larger patches of axonal terminations found in the magnocellular part of VA (VAmc), and in the principal part of VA. Connections from </span></span></span>medial prefrontal cortices<span> occupied the dorsomedial and ventromedial VA, and orbitofrontal connections were found in ventrolateral VAmc. Moreover, about half of all projection neurons in orbitofrontal areas directed to the VA or VAmc were positive for calbindin<span> but not parvalbumin, even though comparable populations of neurons were positive for each marker in the VA. We then applied tracers in VA and investigated simultaneously projections from all prefrontal areas, the internal segment of the </span></span></span></span>globus pallidus<span><span><span> (GPi), the substantia nigra reticulata (SNr), and the </span>thalamic reticular nucleus. Projection neurons were most densely distributed in anterior cingulate areas 24 and 32, and dorsolateral areas 9 and 8, innervating the same VA sites that received projections from a large part of GPi and dorsal SNr. Nearly as many projection neurons originated from </span>cortical layer<span> V as from layer VI. There is evidence that cortical layer VI neurons innervate thalamic neurons that project focally to the middle cortical layers, whereas layer V neurons synapse with thalamic neurons projecting widely to cortical layer I. Projections from layer V to the VA may facilitate cortical recruitment for executive functions within a cognitive context through lateral prefrontal areas, and autonomic responses within an emotional context through anterior cingulate areas.</span></span></p></div>","PeriodicalId":74923,"journal":{"name":"Thalamus & related systems","volume":"2 4","pages":"Pages 325-343"},"PeriodicalIF":0.0,"publicationDate":"2004-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tharel.2004.03.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125599802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neurofilament subunit protein abnormalities in the thalamus in schizophrenia","authors":"Sarah M. Clinton ,&nbsp;Sara Abelson ,&nbsp;Vahram Haroutunian ,&nbsp;Kenneth Davis ,&nbsp;James H. Meador-Woodruff","doi":"10.1016/j.tharel.2003.11.001","DOIUrl":"10.1016/j.tharel.2003.11.001","url":null,"abstract":"<div><p><span>Postmortem and in vivo imaging studies have revealed structural and functional pathology in the thalamus<span> in schizophrenia. We have reported a series neurochemical changes in the thalamus in schizophrenia, including decreased expression of </span></span>NMDA receptor<span><span><span><span><span> subunit transcripts and increased levels of NMDA receptor-associated intracellular </span>proteins<span> like postsynaptic density protein 95 (PSD95) and neurofilament-light (NF-L) chain that link the NMDA receptor to downstream </span></span>signal transduction pathways. NF-L, along with the </span>neurofilament<span> subunit proteins NF-medium (NF-M) chain and NF-heavy (NF-H) chain, assemble to form neurofilaments, one of the most abundant cytoskeletal elements. While the neurofilament subunits play a crucial role in sustaining the neuronal </span></span>cytoskeleton<span><span>, two subunits, NF-L and NF-M, also participate in neurotransmission, interacting with the NMDA and the </span>dopamine D1 receptors<span>, respectively. In the present study, using in situ hybridization, we determined whether all of the neurofilament subunits (NF-L, NF-M, and NF-H) are abnormally expressed in the thalamus in schizophrenia, or whether the abnormality is specific to NF-L. We found that NF-L and NF-M transcripts are both increased in schizophrenia, but the expression of NF-H is unchanged. Both NF-L and NF-M play an important role in maintaining the neuronal cytoskeleton, so abnormal transcript expression may be associated with structural thalamic pathology. Alternatively, since these proteins are also known to interact with the NMDA and D1 dopamine receptors, abnormal transcript levels may be associated with abnormalities of neurotransmission in the thalamus in schizophrenia.</span></span></span></p></div>","PeriodicalId":74923,"journal":{"name":"Thalamus & related systems","volume":"2 4","pages":"Pages 265-272"},"PeriodicalIF":0.0,"publicationDate":"2004-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.tharel.2003.11.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122673524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}