Ko C P, Burton H, Bunge R P
Brain Res. 1976 Dec 3;117(3):437-60. doi: 10.1016/0006-8993(76)90752-6.
Physiological properties of the synapses formed between explants of spinal cord and dissociated autonomic ganglion neurons in tissue culture were studied using intracellular and extracellular stimulation and recording techniques (as well as iontophoresis) with a culture perfusion system allowing continuous microscopic observation during repeated changes of the bathing medium. The principal neurons of the superior cervical ganglion (SCGN) were dissociated from perinatal rats and the spinal cord explants were obtained from 15-day rat fetuses; these were allowed to mature for 3-10 weeks in co-culture. Recordings from over 1000 SCGN established that: (a) spontaneous small depolarizations and action potentials occurred in 20% of the SCGN studied, (b) the EPSPs observed in SCGN after spinal cord stimulation were sensitive to decreased Ca2+ and increased Mg2+, as well as to D-tubocurare, hexamethonium and mecamylamine, but not to atropine (at 10(-6) M concentration) or to the alpha-adrenergic blocking agents phentolamine or phenoxybenzamine; no potentiation of the EPSPs was seen with neostigmate or eserine, (c) acetylcholine directly applied to the SCGN was seen to mimic the responses seen after spinal cord stimulation; tetrodotoxin blocked both direct and iontophoretically fired action potentials, with only a suprathreshold acetylcholine potential remaining. These synapses were not sensitive to alpha-bungarotoxin. It is concluded that the synapses formed by spinal cord neurites on principal SCGN in tissue culture are nicotinic cholinergic, and that the evoked EPSPs recorded in this study are thus similar to the orthodromic fast EPSPs observed in vivo. No slow synaptic responses were observed and no demonstrable effects were noted that could be attributed to adrenergic transmission.
利用细胞内和细胞外刺激及记录技术（以及离子电泳），借助培养灌注系统，在反复更换浴液介质的过程中进行连续显微镜观察，研究了组织培养中脊髓外植体与解离的自主神经节神经元之间形成的突触的生理特性。从围产期大鼠分离出颈上神经节（SCGN）的主要神经元，从15日龄大鼠胚胎获取脊髓外植体；将它们共同培养3至10周使其成熟。对1000多个SCGN的记录表明：（a）在研究的SCGN中，20%出现自发的小去极化和动作电位；（b）脊髓刺激后在SCGN中观察到的兴奋性突触后电位（EPSP）对Ca2+浓度降低、Mg2+浓度升高以及对筒箭毒碱、六甲铵和美加明敏感，但对阿托品（浓度为10(-6) M）或α-肾上腺素能阻断剂酚妥拉明或酚苄明不敏感；新斯的明或毒扁豆碱未使EPSP增强；（c）直接施加于SCGN的乙酰胆碱可模拟脊髓刺激后所见的反应；河豚毒素阻断直接和离子电泳激发的动作电位，仅留下阈上乙酰胆碱电位。这些突触对α-银环蛇毒素不敏感。得出的结论是，在组织培养中脊髓神经突与主要SCGN形成的突触是烟碱型胆碱能突触，因此本研究中记录的诱发EPSP与体内观察到的顺向快速EPSP相似。未观察到缓慢的突触反应，也未发现可归因于肾上腺素能传递的明显效应。
