Pearson P P, Oladehin A, Li C X, Johnson E F, Weeden A M, Daniel C H, Waters R S
Department of Anatomy and Neurobiology, University of Tennessee, Memphis 38163, USA.
Neuroreport. 1996 Oct 2;7(14):2317-23. doi: 10.1097/00001756-199610020-00009.
We describe the organization of the hindpaw barrel subfield (HBS) in layer IV of rat somatosensory cortex (SI) and relate this organization to the representation of the hindpaw. The ovoid-shaped, HBS is oriented anterior to posterior and comprises barrels and barrel-like structures, the most prominent of which consist of at least five anteriorly-located elongated barrel bands. Posterior to these elongated bands is a cluster of four barrels. Two additional barrels are found, one lateral, the other medial. The lateral border is formed by a nearly continuous band that overlaps portions of the anterior elongated bands and posterior barrels. The HBS shows considerable variability in size and shape; nevertheless, the overall pattern reflects a common plan of organization. Electrophysiological mapping confirmed that hindpaw representation is somatotopically organized. The glabrous toes are represented anteriorly, the pads posteriorly, and the dorsal hairy skin of the toes and hindpaw laterally. By aligning physiological and morphological (HBS) maps according to lesion sites, our data suggest that the elongated anteriorly-located barrel bands represent the hindpaw toes, the four toe pads are represented immediately posterior followed by barrels representing the plantar pads. The representations of dorsal hairy skin of toe and dorsal hindpaw form the lateral border; the heel and ankle are represented most posterior. We interpret our findings as support that individual barrels in the HBS are associated with discrete regions of the hindpaw; however, the precise relationship of structure and function reported between the vibrissae and posteromedial barrel subfield (PMBSF) and between the forepaw and the forepaw barrel subfield (FBS) were not observed.
我们描述了大鼠躯体感觉皮层（SI）IV层中后爪桶状亚区（HBS）的组织结构，并将该组织结构与后爪的表征联系起来。卵形的HBS从前向后定向，由桶状结构和桶状样结构组成，其中最突出的是至少五条位于前方的细长桶状带。在这些细长带的后方是一组四个桶状结构。另外还发现了两个桶状结构，一个在外侧，另一个在内侧。外侧边界由一条几乎连续的带形成，该带与前方细长带和后方桶状结构的部分重叠。HBS在大小和形状上表现出相当大的变异性；然而，整体模式反映了一种共同的组织结构。电生理图谱证实后爪的表征是按躯体定位组织的。无毛的脚趾在前部表征，肉垫在后部表征，脚趾和后爪的背部多毛皮肤在外侧表征。通过根据损伤部位对齐生理图谱和形态学（HBS）图谱，我们的数据表明，位于前方的细长桶状带代表后爪脚趾，紧接着是代表四个趾垫的桶状结构，随后是代表跖垫的桶状结构。脚趾背部多毛皮肤和后爪背部的表征形成外侧边界；脚跟和脚踝在最后部表征。我们将我们的发现解释为支持HBS中的单个桶状结构与后爪的离散区域相关；然而，未观察到在触须与后内侧桶状亚区（PMBSF）之间以及前爪与前爪桶状亚区（FBS）之间所报道的结构与功能的精确关系。
