Gruol D L
Department of Neuropharmacology, Scripps Research Institute, La Jolla, CA 92037.
Brain Res. 1992 Mar 6;574(1-2):271-9. doi: 10.1016/0006-8993(92)90827-v.
The effects of chronic alcohol exposure during development on the responses evoked by glutamate and the selective excitatory amino acid receptor agonists quisqualate (Quis) and kainate were studied in cultured cerebellar Purkinje neurons. The cultures were treated with 22 mM or 44 mM ethanol continuously for one or two weeks during the main period of morphological and physiological development. Extracellular recordings used for most studies characterized the responses to all 3 agonists as initial increase in simple spike firing, usually including a period of burst activity, followed by reduced activity or total inhibition, then return to control firing pattern. Analysis of these responses and background spontaneous activity showed several significant differences between control and ethanol treated Purkinje neurons. Background spontaneous firing, agonist evoked firing, the initial period of activity of the response to Quis, and the inhibitory period of the response to glutamate were all significantly reduced in the chronically treated neurons; the inhibitory period of the response to kainate was significantly increased. In contrast to the effects of chronic ethanol exposure, acutely administered ethanol significantly increased background spontaneous firing and the inhibitory period of the response to Quis. Thus, administering both acute and chronic ethanol altered the responses evoked by excitatory amino acids in the developing Purkinje neurons. The effect of chronic ethanol exposure on some response components was similar for all agonists tested and may be linked to changes in intrinsic membrane properties. However, alterations in the inhibitory component of the agonist responses were agonist specific, indicating that receptor-linked actions of ethanol were involved.(ABSTRACT TRUNCATED AT 250 WORDS)
在培养的小脑浦肯野神经元中,研究了发育过程中慢性酒精暴露对谷氨酸及选择性兴奋性氨基酸受体激动剂quisqualate(喹啉酸,Quis)和海人酸所诱发反应的影响。在形态和生理发育的主要阶段,将培养物分别用22 mM或44 mM乙醇连续处理1周或2周。大多数研究所采用的细胞外记录法将对所有3种激动剂的反应特征描述为:简单锋电位发放最初增加,通常包括一段爆发性活动期,随后活动减少或完全抑制,然后恢复到对照发放模式。对这些反应和背景自发活动的分析显示,对照和乙醇处理的浦肯野神经元之间存在若干显著差异。在慢性处理的神经元中,背景自发发放、激动剂诱发的发放、对喹啉酸反应的初始活动期以及对谷氨酸反应的抑制期均显著降低;对海人酸反应的抑制期则显著延长。与慢性酒精暴露的影响相反,急性给予乙醇可显著增加背景自发发放以及对喹啉酸反应的抑制期。因此,急性和慢性给予乙醇均改变了发育中的浦肯野神经元中兴奋性氨基酸所诱发的反应。对于所有测试的激动剂,慢性酒精暴露对某些反应成分的影响相似,可能与内在膜特性的变化有关。然而,激动剂反应抑制成分的改变具有激动剂特异性,表明乙醇的受体相关作用参与其中。(摘要截短于250词)