Liu X B, Jones E G
Department of Anatomy and Neurobiology, University of California, Irvine 92717.
Exp Brain Res. 1991;85(3):507-18. doi: 10.1007/BF00231734.
Immunocytochemical methods have been combined with serial thin section analysis to study the synaptic organization of serotonin (5-HT) and tyrosine hydroxylase (TH) immunoreactive terminals in the ventral posterior nucleus of the cat and monkey thalamus. One hundred 5-HT immunoreactive terminals from the cat and approximately forty 5-HT and TH immunoreactive terminals from the monkey were selected for analysis in serial thin sections. Only 7-10% of the immunoreactive terminals could be revealed to form conventional synaptic contacts. Most of these could be identified as the asymmetrical type. Dendritic shafts belonging to relay neurons were the major targets of these monoamine immunoreactive terminals. The remainder made intimate membrane associations with relay cell dendrites and somata or with presynaptic dendrites of interneurons, but no overt membrane specializations could be detected. The present results suggest that the modulation of thalamocortical relay function by brainstem monoamine pathways in the somatosensory thalamus may occur by release of transmitters at atypical contact sites.
免疫细胞化学方法已与连续超薄切片分析相结合，以研究猫和猴丘脑腹后核中5-羟色胺（5-HT）和酪氨酸羟化酶（TH）免疫反应性终末的突触组织。从猫的100个5-HT免疫反应性终末和猴的约40个5-HT及TH免疫反应性终末中选取用于连续超薄切片分析。仅7-10%的免疫反应性终末可显示形成传统突触联系。其中大多数可鉴定为不对称型。属于中继神经元的树突干是这些单胺免疫反应性终末的主要靶点。其余的与中继细胞的树突和胞体或中间神经元的突触前树突形成紧密的膜联系，但未检测到明显的膜特化。目前的结果表明，脑干单胺能通路对体感丘脑丘脑皮质中继功能的调节可能通过在非典型接触位点释放递质来实现。
