AREAL DISTRIBUTIONS OF CORTICAL-NEURONS PROJECTING TO DIFFERENT LEVELS OF THE CAUDAL BRAIN-STEM AND SPINAL-CORD IN RATS
AREAL DISTRIBUTIONS OF CORTICAL-NEURONS PROJECTING TO DIFFERENT LEVELS OF THE CAUDAL BRAIN-STEM AND SPINAL-CORD IN RATS
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DOI：
10.3109/08990229009144711
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发表时间：
1990-01-01
影响因子：
0.9
通讯作者：
KAAS, JH
中科院分区：
文献类型：
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作者：
LI, XG;FLORENCE, SL;KAAS, JH
将与辣根过氧化物酶缀合的麦芽凝集素 (WGA:HRP) 注射到脊髓的颈椎或腰椎增大部分，或者脑干的髓质或脑桥水平后，通过四甲基联苯胺 (TMB) 处理揭示皮质脊髓和皮质延髓神经元的分布。对细胞色素氧化酶 (CO) 进行反应的切片允许标记神经元的模式与第一体感皮层区域 (SI) 中体表图的细节相关。结果表明，许多皮质区域投射到这些皮质下水平：（1）颗粒SI中的投射神经元形成了清晰的生长激素模式。后爪区域投射到腰部增大，前爪区域投射到颈部增大，胡须垫区域投射到下髓质，而更多的面部区域投射到更多的脑干头部水平。 (2) SI中标记神经元的每个区域延伸到相邻的颗粒异常体感皮层，形成投射神经元的第二体位模式。 (3)初级运动皮层(MI)中投射神经元的体位模式与对应于后肢、前肢和面部的中外侧序列中的SI平行。 (4) 在内侧无颗粒皮层 (Agm) 中提出了弱的投射神经元体位模式，表明前运动场具有后肢、前肢和面部的从鼻内侧到尾外侧的表征。 (5) 在位于 SI 和区域 17 之间的内侧顶叶皮层 (PM) 中观察到代表脚到脸的中外侧序列的体位投射模式。 (6) 在第二体感皮层区 (SII)，投射到脑干的神经元紧邻 SI 桶状区的尾外侧，而投射到上脊髓的神经元则更外侧。下脊髓中的注射没有标记该区域的投射神经元。 (7) 面部和前肢的投射神经元的其他焦点位于 SII 的吻侧，为 SI 外侧的鼻周皮层 (PR) 以及 SII 和 PM 之间的皮层中的顶叶腹侧区 (PV) 提供了证据。这些可能是高级体感区域的区域在注射到下脊髓后均不包含标记的神经元。因此，与后肢相比，更多的皮质区域直接影响与面部和前爪的感觉和运动功能相关的脑干和脊髓水平。
Distributions of corticospinal and corticobulbar neurons were revealed by tetramethylbenzidine (TMB) processing after injections of wheatgerm agglutinin conjugated to horseradish peroxidase (WGA:HRP) into the cervical or lumbar enlargements of the spinal cord, or medullary or pontine levels of the brain stem. Sections reacted for ctyochrome oxidase (CO) allowed patterns of labeled neurons to be related to the details of the body surface map in the first somatosensory cortical area (SI). The results indicate that a number of cortical areas project to these subcortical levels: (1) Projection neurons in granular SI formed a clear somatotrophic pattern. The hindpaw region projected to the lumbar enlargement, the forepaw region to the cervical enlargement, the whisker pad field to the lower medulla, and the more rostral face region to more rostral brain stem levels. (2) Each zone of labeled neurons in SI extended into adjacent dysgranular somatosensory cortex, forming a second somatotopic pattern of projection neurons. (3) A somatotopic pattern of projection neurons in primary motor cortex (MI) paralleled SI in mediolateral sequence corresponding to the hindlimb, forelimb, and face. (4) A weak somatotopic pattern of projection neurons was suggested in medial agranular cortex (Agm), indicating a premotor field with a rostromedial-to-caudolateral representation of hindlimb, forelimb, and face. (5) A somatotopic pattern of projection representing the foot to face in a mediolateral sequence was observed in medial parietal cortex (PM) located between SI and area 17. (6) In the second somatosensory cortical area (SII), neurons projecting to the brain stem were immediately adjacent caudolaterally to the barrel field of SI, whereas neurons projecting to the upper spinal cord were more lateral. No projection neurons in this region were labeled by the injections in the lower spinal cord. (7) Other foci of projection neurons for the face and forelimb were located rostral to SII, providing evidence for a parietal ventral area (PV) in perirhinal cortex (PR) lateral to SI, and in cortex between SII and PM. None of these regions, which may be higher-order somatosensory areas, contained labeled neurons after injections in the lower spinal cord. Thus, more cortical fields directly influence brainstem and spinal cord levels related to sensory and motor functions of the face and forepaw than the hindlimb.