Brenowitz G L, Pubols L M
Brain Res. 1981 Jul 6;216(1):45-59. doi: 10.1016/0006-8993(81)91277-4.
The somatotopic organization of the 17 dorsal horn was studied using extra-cellular recordings in normal cats, and in cats with acute or chronic spinal cord hemisection at T13, sparing the dorsal columns. Based on data concerning recovery of function and collateral sprouting of afferents following hemisections, we predicted that the lesion would result in increases in receptive field size and decreases in the specificity of the somatotopic map. In normal animals, the usual mediolateral, rostrocaudal and dorsoventral somatotopic sequences were found. Following acute hemisections (6 h-5 days), there were changes in spontaneous and evoked activity, but receptive field sizes and somatotopic organization remained unchanged. Following chronic hemisections (88-174 days), proximal hindlimb receptive fields in the lateral dorsal horn ipsilateral to the lesion increased dramatically in size and were significantly larger than similar receptive fields on the contralateral side. The largest of these fields extended from the dorsal midline to the middle of the foot. Receptive field sizes elsewhere in the dorsal horn remained unchanged, as did somatotopic organization in general. These findings indicate that hemisections result in a complex series of changes consisting of an early stage of anatomically generalized changes in excitability and a later stage of highly localized changes in receptive field size. Possible mechanisms for these changes, as well as their relationship to recovery of function, are discussed.
利用细胞外记录技术，在正常猫以及T13水平进行急性或慢性脊髓半切（保留背柱）的猫中，研究了17层背角的躯体定位组织。基于有关半切后传入神经功能恢复和侧支发芽的数据，我们预测该损伤会导致感受野大小增加，躯体定位图的特异性降低。在正常动物中，发现了通常的中外侧、 rostrocaudal和背腹侧躯体定位序列。急性半切（6小时至5天）后，自发和诱发活动发生了变化，但感受野大小和躯体定位组织保持不变。慢性半切（88至174天）后，损伤同侧外侧背角的近端后肢感受野大小显著增加，且明显大于对侧类似的感受野。其中最大的感受野从背中线延伸到足部中部。背角其他部位的感受野大小以及总体的躯体定位组织保持不变。这些发现表明，半切会导致一系列复杂的变化，包括早期兴奋性的解剖学上的全身性变化阶段和后期感受野大小的高度局部化变化阶段。讨论了这些变化的可能机制及其与功能恢复的关系。
