Vibrissal responses of thalamic cells that project to the septal columns of the barrel cortex and to the second somatosensory area.
Vibrissal responses of thalamic cells that project to the septal columns of the barrel cortex and to the second somatosensory area.
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DOI：
10.1523/jneurosci.0490-08.2008
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发表时间：
2008-05-14
影响因子：
5.3
通讯作者：
Deschenes, Martin
中科院分区：
文献类型：
--
作者：
Bokor, Hajnalka;Acsady, Laszlo;Deschenes, Martin
关键词：
啮齿动物的体感觉皮层包含与桶相关的和与隔相关的回路，它们代表了两种不同的振动信息处理流，它们的反应模式和解剖联系不同。脑管相关回路处理通过丘脑小桶状体传递的颅神经输入，而隔膜相关回路处理通过腹侧后内侧核（VPMvl）的腹侧外侧部分传递的平行神经输入和输入。隔突出的丘脑传入事件也以第二体感觉皮层为目标。虽然许多研究已经检查了小桶状体通路的反应特性，并证明小桶状体从特定的皮质丘脑和网状丘脑神经元组接收反馈，但目前缺乏关于VPMvl的此类信息。在本研究中，我们发现VPMvl神经元表现出独立于三叉主核输入的大的多须接受野，VPMvl的响应特性依赖于三叉主核内插神经元的收敛输入。示踪剂注射和单细胞标记进一步揭示了VPMvl接收来自丘脑网状神经元和丘脑皮质神经元特定群体的输入。这些结果证实了VPMvl作为振动信息处理平行通路的中继的地位。他们进一步指出，感觉通路不仅包括连接触须和大脑皮层的3个神经元链，而且还包括与地形相关的皮质丘脑和网状丘脑投影的特定集合。
The rodent somatosensory cortex contains barrel-related and septa-related circuits that represent two separate streams of vibrissa information processing that differ in their response patterns and anatomical connections. Whereas barrel-related circuits process lemniscal inputs that transit through the thalamic barreloids, septa-related circuits process paralemniscal inputs and inputs that are relayed through the ventral lateral part of the ventral posterior medial nucleus (VPMvl). Septa-projecting thalamic afferents also target the second somatosensory cortical area. While a number of studies have examined response properties in the lemniscal pathway, and demonstrated that barreloids receive feedback from specific sets of corticothalamic and reticular thalamic neurons, such information is currently lacking for the VPMvl. In the present study we show that VPMvl neurons exhibit large multiwhisker receptive fields that are independent of input from the principal trigeminal nucleus, and that response properties in VPMvl rely on converging input from neurons of the interpolaris trigeminal nucleus. Tracer injection and single-cell labeling further reveal that the VPMvl receives input from specific populations of reticular thalamic and corticothalamic neurons. These results confirm the status of the VPMvl as a relay of a parallel pathway of vibrissa information processing. They further indicate that a sensory pathway does not merely consist on a 3-neuron chain that links the vibrissae to the cerebral cortex, but that it also involves specific sets of topographically related corticothalamic and reticular thalamic projections.