Thiriet G, Kempf J, Ebel A
Centre de Neurochimie du CNRS, Strasbourg, France.
Int J Dev Neurosci. 1986;4(5):451-63. doi: 10.1016/0736-5748(86)90027-4.
The expression of cholinergic neurotransmission in the developing spinal cord was followed with pre- and postsynaptic cholinergic markers and histoautoradiographic determinations of cholinergic receptors and ultrastructural studies. Two distinct steps in the development of cholinergic markers were evident. The first step of cholinergic expression occurs early in development and its characterized by a sudden and large increase in choline acetyltransferase activity, whereas the high affinity choline uptake mechanism remains undetectable and few muscarinic receptors are detectable. This phenomenon possibly reflects the expression of high choline acetyltransferase gene activity in developing neurons which are still not synaptically connected. The second step is also characterized by a sharp rise of choline acetyltransferase activity. This rise parallels an active development of high affinity choline uptake and big increase in both number and density of muscarinic receptors. Also nicotine receptors increase, as revealed by histoautoradiography. Specific morphogenetic events, such as the increase of synaptic junctions with postsynaptic thickenings and numerous presynaptic clear vesicles, occur at the same time. Such interactions may contribute to the full maturity of cholinergic neurotransmission of the spinal cord.
利用突触前和突触后胆碱能标志物、胆碱能受体的组织放射自显影测定以及超微结构研究，对发育中的脊髓中胆碱能神经传递的表达进行了跟踪。胆碱能标志物的发育明显有两个不同阶段。胆碱能表达的第一步发生在发育早期，其特征是胆碱乙酰转移酶活性突然大幅增加，而高亲和力胆碱摄取机制仍无法检测到，且几乎检测不到毒蕈碱受体。这种现象可能反映了发育中尚未形成突触连接的神经元中胆碱乙酰转移酶基因活性的表达。第二步同样以胆碱乙酰转移酶活性的急剧上升为特征。这种上升与高亲和力胆碱摄取的活跃发育以及毒蕈碱受体数量和密度的大幅增加同时出现。组织放射自显影显示，烟碱受体也增加。特定的形态发生事件，如具有突触后增厚和大量突触前清亮小泡的突触连接增加，也同时发生。这些相互作用可能有助于脊髓胆碱能神经传递的完全成熟。
