DIFFERENTIAL FORMATION OF TOPOGRAPHIC MAPS IN THE CEREBRAL-CORTEX AND SUPERIOR COLLICULUS OF THE MOUSE BY TEMPORALLY CORRELATED TACTILE TACTILE AND TACTILE VISUAL INPUTS
DIFFERENTIAL FORMATION OF TOPOGRAPHIC MAPS IN THE CEREBRAL-CORTEX AND SUPERIOR COLLICULUS OF THE MOUSE BY TEMPORALLY CORRELATED TACTILE TACTILE AND TACTILE VISUAL INPUTS
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DOI：
10.1111/j.1460-9568.1995.tb00717.x
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发表时间：
1995-09-01
影响因子：
3.4
通讯作者：
BENEDETTI, F
中科院分区：
文献类型：
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作者：
BENEDETTI, F
神经纤维的一致电活动似乎在中枢神经系统有序联系的发展中起着重要作用。为了验证这个关于地形图形成的假说，我们通过植入一座人造猪毛桥，将新生小鼠身体的两个皮肤区域连接起来。通过这个过程，我们产生了耳朵与肩膀或鼻子的机械融合。在这些情况下，耳朵不仅与肩膀或鼻子相连，而且还与鼻腔或视觉空间的下部相连。因此，时间相关的触觉-触觉输入(耳-肩或耳-鼻)以及触觉-视觉输入(耳-下或耳-鼻视觉空间)的概率增加。通过对初级体感皮层和上丘的记录，我们发现地形图的形成是基于不同的原理。根据触觉-触觉相关的输入，躯体感觉皮质发育，显示躯体感觉神经元的感受野延伸到身体的融合部分。相反，上丘处理与触觉-视觉相关的输入；我们发现体感-视觉双峰神经元的视觉感受野延伸到人工桥所指向的视觉空间部分。这些结果表明，两个身体部分的融合是通过皮质的皮肤坐标和上丘的外部世界(视觉)坐标来表示的。因此，不同的触觉-触觉和触觉-视觉重合活动似乎与这两个大脑区域信息处理的不同意义有关。
Coincident electrical activity of nerve fibres seems to play a fundamental role in the development of ordered connections in the CNS. To test this hypothesis on the formation of topographic maps we connected two cutaneous regions of the body of newborn mice by implanting an artificial bridge of pig hair. Through this procedure we produced the mechanical fusion of the ear with either the shoulder or the nose. In these conditions the ear not only was connected with shoulder or nose, but was also in relation with the nasal or the inferior portion of visual space. Therefore the probability of temporally correlated tactile-tactile inputs (ear-shoulder or ear-nose) as well as tactile-visual inputs (ear-inferior or ear-nasal visual space) increased. By recording from the primary somatosensory cortex and superior colliculus, we found that the formation of topographic maps was based on different principles. The somatosensory cortex developed in terms of tactile-tactile correlated inputs, showing somatosensory neurons with receptive fields extending through the fused parts of the body. Conversely, the superior colliculus processed tactile-visual correlated inputs; we found somatosensory-visual bimodal neurons with visual receptive fields extending into the portion of visual space where the artificial bridge was directed. These results suggest that the fusion of two body parts is represented in terms of cutaneous coordinates in the cortex and external world (visual) coordinates in the superior colliculus. Therefore the differential tactile-tactile and tactile-visual coincident activity seems to be correlated to the different meaning of information processing of these two brain regions.