Thalamocortical projections to rat auditory cortex from the ventral and dorsal divisions of the medial geniculate nucleus.
Thalamocortical projections to rat auditory cortex from the ventral and dorsal divisions of the medial geniculate nucleus.
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DOI：
10.1002/cne.22682
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发表时间：
2012-01-01
影响因子：
2.5
通讯作者：
Banks, Matthew I.
中科院分区：
文献类型：
--
作者：
Smith, Philip H.;Uhlrich, Daniel J.;Manning, Karen A.;Banks, Matthew I.
腹侧和背侧内侧膝状体(MGV和MGD)构成了丘脑的主要听觉亚区，向听皮质的第IV层和下层III提供丘脑皮质的输入。目前还没有对这一预测的量化评估。使用生物素化葡聚糖胺(BDA)/生物细胞素注射，我们描述了MGV和MGD细胞的皮质投射模式。在初级听皮层，MGV轴突终末主要分布在IV层/III层下层，少量投射到颗粒上层和颗粒下层的中间水平。MGD轴突投射到被指定为背侧(PD)和腹侧(VA)的皮质区域，显示出与MGV到初级皮质的终末分布在数量上相似的板层终末分布。在电子显微镜水平上，MGV和MGD型终末为非γ-氨基丁酸能神经元，MGD型终末在PD和VA略大于MGV终末，但在初级皮质明显大于MGV型终末。MGV/MGD终末主要突触在非GABA能棘突/树突上。GABA能结构上有少量突触，主要接触主要位于丘脑皮质受体层的大树突或细胞体。对于MGV向初级皮质的投射或MGD向PD或VA的投射，无论是颗粒上层、颗粒层还是颗粒下层，每个部位的非GABA能突触后结构的大小都是相同的。然而，VA的MGD终末受体结构的数量明显多于PD的MGD终末受体结构或初级皮质的MGV终末受体结构。因此，如果终末和突触后结构的大小表明兴奋的强度，那么MGD到VA的传入最强，MGD到PD居中，MGV到初级皮质最弱。
The ventral and dorsal medial geniculate (MGV and MGD) constitute the major auditory thalamic subdivisions providing thalamocortical inputs to layer IV and lower layer III of auditory cortex. No quantitative evaluation of this projection is available. Using biotinylated dextran amine (BDA)/biocytin injections, we describe the cortical projection patterns of MGV and MGD cells. In primary auditory cortex the bulk of MGV axon terminals are in layer IV/lower layer III with minor projections to supragranular layers and intermediate levels in infragranular layers. MGD axons project to cortical regions designated posterodorsal (PD) and ventral (VA) showing laminar terminal distributions that are quantitatively similar to the MGV-to-primary cortex terminal distribution. At the electron microscopic level MGV and MGD terminals are non-γ-aminobutyric acid (GABA)ergic with MGD terminals in PD and VA slightly but significantly larger than MGV terminals in primary cortex. MGV/MGD terminals synapse primarily onto non-GABAergic spines/dendrites. A small number synapse on GABAergic structures, contacting large dendrites or cell bodies primarily in the major thalamocortical recipient layers. For MGV projections to primary cortex or MGD projections to PD or VA, the non-GABAergic post-synaptic structures at each site were the same size regardless of whether they were in supragranular, granular, or infragranular layers. However, the population of MGD terminal-recipient structures in VA were significantly larger than the MGD terminal-recipient structures in PD or the MGV terminal-recipient structures in primary cortex. Thus, if terminal and postsynaptic structure size indicate strength of excitation then MGD to VA inputs are strongest, MGD to PD intermediate, and MGV to primary cortex the weakest.
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DOI：
10.1523/jneurosci.2093-08.2008
发表时间：
2008-10-29
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Barbour DL;Callaway EM
通讯作者：
Callaway EM
影响因子：
2.5
作者：
DI, S;BARTH, DS
通讯作者：
BARTH, DS
影响因子：
2.5
作者：
CLERICI, WJ;COLEMAN, JR
通讯作者：
COLEMAN, JR
影响因子：
2.5
作者：
Doron, NN;Ledoux, JE;Semple, MN
通讯作者：
Semple, MN
影响因子：
2.9
作者：
ALLON, N;YESHURUN, Y
通讯作者：
YESHURUN, Y