Thalamus and Related Systems最新文献

The role of the thalamic reticular nucleus in visual processing 丘脑网状核在视觉加工中的作用

Thalamus and Related Systems Pub Date : 2008-03-01 DOI: 10.1017/S1472928807000295

A. Sillito, H. Jones

{"title":"The role of the thalamic reticular nucleus in visual processing","authors":"A. Sillito, H. Jones","doi":"10.1017/S1472928807000295","DOIUrl":"https://doi.org/10.1017/S1472928807000295","url":null,"abstract":"The thalamic reticular nucleus (TRN) is an integral part of the thalamic circuitry that mediates the transfer of information to the cortex in the major sensory pathways. Here, we consider its role in visual processing. The TRN provides an inhibitory, GABA-mediated input to relay cells in the thalamus. A key feature of TRN cells is that, because of the extent of their dendritic arborization, they have the capacity to collate visual information from the ascending relay cells and feedback axons from the cortex over a wide retinotopic area, but they feed it back to the thalamus in a narrowly focused retinotopic projection. The corticofugal input to TRN cells is mediated by a higher proportion of AMPA receptors than that to thalamic relay cells and produces sharp EPSCs. We suggest that this might bias the TRN cells to precisely timed, feature-driven feedback from the visual cortex. TRN cells are particularly well driven by either phasic or moving stimuli, so the influence on relay cells provides a strong, transient, inhibitory modulation of relay-cell activity. This might aid image segmentation and highlight responses to moving contours. Although the role of the TRN has been especially linked to selective attention, we suggest that, for vision, its function is linked more closely to the operation of the thalamocortico-thalamic loop as a whole, and that retinotopically selective attentional effects draw on the interaction with the cortical mechanism that influences TRN and relay-cell circuitry equally. © 2007 Cambridge University Press.","PeriodicalId":114195,"journal":{"name":"Thalamus and Related Systems","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131919485","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}

引用次数: 11

Evolution of the thalamus: a morphological and functional review 丘脑的进化:形态学和功能综述

Thalamus and Related Systems Pub Date : 2008-03-01 DOI: 10.1017/S1472928808000356

A. Butler

{"title":"Evolution of the thalamus: a morphological and functional review","authors":"A. Butler","doi":"10.1017/S1472928808000356","DOIUrl":"https://doi.org/10.1017/S1472928808000356","url":null,"abstract":"Enlargement of the forebrain, including elaboration of the thalamus, has occurred independently within different groups of vertebrates. Dorsal and ventral thalamic territories can be identified in most vertebrates, with variations in the presence of GABAergic neuronal components. An inhibitory thalamic reticular nucleus-like input to the dorsal thalamus might be a common feature, as might the organizational plan of two divisions of the dorsal thalamus, the lemnothalamus and collothalamus. Differential, independent elaboration of these divisions occurred in mammals and sauropsids (reptiles and birds), making their evolutionary relationships challenging to discern. Not all of the crucial features identified for mammalian thalamocortical circuitry are present in other vertebrates, but birds share the most features identified to date. These include specific and nonspecific thalamic relay neurons, reciprocal pallial projections, and a GABAergic thalamic reticular nucleus with some but not all hodological features. Because birds share many higher-level cognitive abilities and, thus, possibly higher-level consciousness, with mammals, comparison of the thalamocortical (thalamopallial) circuitry might prove a fruitful resource for testing functional hypotheses. Comparisons with selected other vertebrates that likewise have relatively large brain:body ratios and also exhibit some cognitively sophisticated behaviors, such as cichlid fish, might also prove valuable.","PeriodicalId":114195,"journal":{"name":"Thalamus and Related Systems","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125279854","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}

引用次数: 47

Fast oscillations in activated neocortical brain slices: an in vitro continuation of the pioneering in vivo studies of Mircea Steriade and colleagues 激活的新皮层脑切片中的快速振荡:Mircea Steriade及其同事开创性体内研究的体外延续

Thalamus and Related Systems Pub Date : 2008-03-01 DOI: 10.1017/S1472928808000344

R. Traub, M. Cunningham, M. Whittington

引用次数: 0

Pain and temperature encoding in the human thalamic somatic sensory nucleus (ventral caudal): Inhibition-related bursting mediates sensations evoked by somatic stimuli 人丘脑躯体感觉核(腹侧尾侧)的疼痛和温度编码:抑制相关的爆发介导躯体刺激引起的感觉

Thalamus and Related Systems Pub Date : 2005-12-01 DOI: 10.1017/S1472928807000301

J. H. Kim, D. Veldhuijzen, W. Anderson, J. I. Lee, H. T. Lee, S. Ohara, F. Lenz

引用次数: 0

The influence of one, powerful thalamocortical neuron on an inhibitory cortical circuit 一个强大的丘脑皮层神经元对抑制性皮层回路的影响

Thalamus and Related Systems Pub Date : 2005-12-01 DOI: 10.1017/S147292880700026X

H. Swadlow, A. G. Gusev

引用次数: 0

Is the basalo-cortical system simply an extra-thalamic relay of the ascending reticular activating system? A discourse with Mircea Steriade 玄武岩-皮质系统仅仅是上升网状激活系统的丘脑外中继吗?与米尔恰·斯特里亚德的对话

Thalamus and Related Systems Pub Date : 2005-12-01 DOI: 10.1017/S1472928807000271

B. Jones

{"title":"Is the basalo-cortical system simply an extra-thalamic relay of the ascending reticular activating system? A discourse with Mircea Steriade","authors":"B. Jones","doi":"10.1017/S1472928807000271","DOIUrl":"https://doi.org/10.1017/S1472928807000271","url":null,"abstract":"As established in early studies, the basalo-cortical system serves as an extra-thalamic relay from the brainstem reticular activating system to the cerebral cortex. As Mircea Steriade documented, activating impulses are transmitted through either the nonspecific thalamo-cortical projection system or the basalo-cortical projection system to stimulate widespread, fast, cortical activity that is characteristic of the activation that occurs naturally during waking (W) and paradoxical sleep (PS) states. However, basal forebrain (BF) neurons are different from thalamic neurons in several ways. First, many cortically projecting BF neurons utilize acetylcholine (ACh), which has a crucial role in stimulating fast cortical activity. Second, ACh-releasing neurons discharge selectively during W and PS and cease firing during slow-wave sleep (SWS). Third, ACh-releasing neurons discharge rhythmically in bursts during cortical activation and can, thus, modulate the cortex in a slow rhythmic manner to facilitate coherent activity across broad cortical networks. Fourth, the rhythmic discharge by BF neurons that release ACh, GABA or glutamate and project to the cortex occurs at respiratory or theta frequencies of the olfactory and limbic cortices, which reveals the particular importance of these inputs as well as outputs within basalo-cortico-basalo circuits. Fifth, other noncholinergic BF neurons, including GABA-releasing neurons, are active selectively during sleep: some of these potentially promote slow-wave activity during SWS through cortical projections; and others might promote behavioral quiescence during SWS and PS through descending projections. Finally, BF neurons also project to the thalamus and might, thus, either recruit or join thalamic neurons in modulating cortical activity across the sleep–waking cycle.","PeriodicalId":114195,"journal":{"name":"Thalamus and Related Systems","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130134126","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}

引用次数: 0

Modulation of neurons in the paraventricular thalamic nucleus by α 2 adrenoceptor agonists: evidence for physiological and morphological heterogeneity α 2肾上腺素能受体激动剂对室旁丘脑核神经元的调节:生理和形态异质性的证据

Thalamus and Related Systems Pub Date : 2005-12-01 DOI: 10.1017/S1472928807000313

U. Heilbronner, G. Flügge

{"title":"Modulation of neurons in the paraventricular thalamic nucleus by α 2 adrenoceptor agonists: evidence for physiological and morphological heterogeneity","authors":"U. Heilbronner, G. Flügge","doi":"10.1017/S1472928807000313","DOIUrl":"https://doi.org/10.1017/S1472928807000313","url":null,"abstract":"The paraventricular thalamic nucleus (PVT) receives dense noradrenergic input, but little is known about α 2 adrenoceptors (ARs) in this nucleus. We have investigated effects of the agonist α-methyl-norepinephrine (m-NE) on PVT neurons in vitro. Based on their physiological and morphological characteristics, three distinct classes of PVT neurons have been identified. The first class exhibits membrane hyperpolarization on stimulation with m-NE (0.05–25 µM). This hyperpolarizing effect is observed in the presence of tetrodotoxin (TTX; 0.5–1 µM), blocked by yohimbine (1 µM) and mimicked by clonidine (10 µM), which indicates that it is mediated by postsynaptic α 2 ARs. Further experiments indicate that it is mediated through an increase in G protein-coupled K + conductance. In a second class of neurons, m-NE (0.05–25 µM) induces a slow membrane depolarization that is mimicked by phenylephrine (5 µM) and blocked by prazosin (75 nM), which indicates the involvement of α 1 ARs. The third class of neurons is insensitive to m-NE (5–25 µM), and has a lower input resistance and a larger dendritic tree compared to the two other classes. The three types of neurons differ in their resting properties, and their firing patterns are changed by m-NE. These findings indicate anatomical and functional specialization of PVT neurons.","PeriodicalId":114195,"journal":{"name":"Thalamus and Related Systems","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122921107","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}

引用次数: 3

Biophysical mechanisms underlying the paradoxical potentiation of the low-voltage activated calcium current in thalamocortical neurons: a modeling study 低电压激活钙电流在丘脑皮质神经元中矛盾增强的生物物理机制:一项模型研究

Thalamus and Related Systems Pub Date : 2005-09-01 DOI: 10.1017/S1472928807000179

R. Lambert, T. Bessaïh, N. Leresche

{"title":"Biophysical mechanisms underlying the paradoxical potentiation of the low-voltage activated calcium current in thalamocortical neurons: a modeling study","authors":"R. Lambert, T. Bessaïh, N. Leresche","doi":"10.1017/S1472928807000179","DOIUrl":"https://doi.org/10.1017/S1472928807000179","url":null,"abstract":"In thalamocortical neurons relaying sensory information, we recently described a phosphorylation mechanism that induces a marked increase in the amplitude of the low-voltage activated Ca 2þ current (T-type). Surprisingly, potentiation of the T-current closely depends on the state of the channel and is, therefore, both voltage-and ATP-dependent. Further analysis of the modification of channel activity induced by this regulation, and underlying the increase in the macroscopic current amplitude, requires a detailed study of the T-current biophysical properties that, unfortunately, might be constrained by the technical limitations of whole-cell recordings. Therefore, in the present study we have developed an alternative approach that is based on computational models of T-channel activity using Markov gating schemes. We show that both modifications in the activation kinetics of the channels and/or the existence of a second channel population with a conducting state conditioned by a phosphorylation step can explain the specific properties of T-currents that have been observed in thalamocortical neurons as a result of their ATP/voltage-dependent regulation. The flexibility in the T-type current behavior that is incorporated in these models might also help to unravel new roles for T-channels in shaping the different firing properties of thalamocortical neurons.","PeriodicalId":114195,"journal":{"name":"Thalamus and Related Systems","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129639985","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}

引用次数: 1

Local circuit connections in thalamo-recipient layers 丘脑-受体层的局部电路连接

Thalamus and Related Systems Pub Date : 2005-09-01 DOI: 10.1017/S1472928807000246

A. Thomson

引用次数: 1

Developmental and functional profile of the thalamic hyperpolarization-activated cation current, I h , in absence epilepsy 缺席癫痫时丘脑超极化激活阳离子电流的发育和功能特征

Thalamus and Related Systems Pub Date : 2005-09-01 DOI: 10.1017/S1472928807000180

H. Pape, T. Kanyshkova, T. Broicher, T. Budde

引用次数: 6