摘要
本文报道用损毁溃变结合电镜观察的方法,研究了猫丘脑腹外侧核(VL)神经纤维束梢在运动皮层的分布。根据猫的大脑皮层4区与十字沟的关系,将此区分为沟前、沟旁及沟后亚区。对各亚区的电镜观察结果表明,VL核的神经末梢主要分布在沟前和沟旁区。在沟前亚区观察到的112个溃变末梢中,78.6％分布在第Ⅲ层,19.6％在第Ⅰ层,第Ⅴ层仅占1.8％。在沟旁亚区也观察到112个溃变末梢,62.％分布在第Ⅲ层,31.2％分布在第Ⅰ层,第Ⅴ层仅6.3％。溃变末梢在沟后亚区分布较少,只观察到33个,第Ⅰ层占51.6％,第Ⅲ层为42.4％,第Ⅴ层为6.0％。3个亚区的溃变末梢有75％分布在树突棘上,25％在树突梗(shaft)上,均为非对称型突触。6区内溃变末梢大多分布在第Ⅲ层内,均与树突棘形成非对称型突触,在3a区内未见溃变末梢。
The distribution of afferent terminals from VL nucleus to cruciate cortex was studied by using nerve fibers degeneration and electron microscopic technigues. Cortical area 4 could be further divided into three subdivisions according to their geographical relations to the eruciate sulcus: an anterior, a posterior and a lateral zone, respectively. It was demonstrated that the degenerating axon terminals were mainly distributed in anterior and lateral zones. Much less terminals were observed in the posterior zone. Totally 112 terminals were observed in the anterior zone. Among them, 78.6％ were seen in layer Ⅲ, 19.6％ in layer Ⅰ, 1.8％ in layer Ⅴ. Of the 112 terminals found in the lateral zone, 62.5％ were distributed in layer Ⅲ, 31.2％ in layer Ⅰ and 6.3％ in layer Ⅴ. On the other hand, only 33 degenerating terminals were found in posterior zone. their distributions were: 51.6％ in layer Ⅰ, 42.4％ in layer Ⅲ and 6.0％ in layer V. Approximately 75％ of the degenerating axon terminals examined in these three zones made synaptie contacts with dendritic spines, and 25％ with dendritic shafts. The vast majority of these synapses could be classified as asymmetrical type synapse.
In area 6, most of the degenerating terminals were encountered in layer Ⅰ and Ⅲ. All of them formed asymmetrical type synapses with dendritic spines. No degenerating terminals could be found in area 3a.
出处
《解剖学报》
CAS
CSCD
北大核心
1990年第2期144-149,共6页
Acta Anatomica Sinica
关键词
丘脑
运动皮层
突触联系
溃变法
VL nucleus, Projecting fibers
Motor cortex
Synaptic relationship
Lesioning combined with electronmicroscopy
