Negishi K, Kato S, Teranishi T, Laufer M
Brain Res. 1978 Jun 9;148(1):85-93. doi: 10.1016/0006-8993(78)90379-7.
The effects on spike discharges of acetylcholine chloride (ACh), applied electrophoretically at the inner plexiform layer, were examined in air-exposed and superfused preparations of the isolated carp retina. Most of spike-generating units examined (147 of 204 units; 72%) were sensitive to electrophoretically applied ACh. Among the ACh-sensitive ones, 125 units (85%), including all ON-center, most ON-OFF and two-thirds of OFF-center units, were activated, whereas 22 units (15%), including mainly OFF-center units, were suppressed by the agent. In retinas superfused with a medium containing 20 mM M2+ and 0.5 mM Ca2+, units ceased in their spontaneous and light-induced discharges, but they were activated by electrophoretically applied ACh. The ACh-induced activation was reduced in magnitude or abolished during an exposure of the retina to a medium containing hexamethonium chloride (25 micrometer), whereas the ACh-induced suppression was reduced by atropine sulfate (25 micrometer) more effectively than by hexamethonium. Therefore, the results suggest that nicotinic receptors are involved in the ACh-activation, whereas both, but predominantly muscarinic, receptors may participate in the ACh-suppression of spike discharges in the carp retina.
在离体鲤鱼视网膜的空气暴露和灌流标本中，研究了在内网状层电泳施加氯化乙酰胆碱（ACh）对锋电位发放的影响。所检查的大多数锋电位产生单位（204个单位中的147个；72%）对电泳施加的ACh敏感。在对ACh敏感的单位中，125个单位（85%），包括所有的ON中心、大多数ON-OFF中心以及三分之二的OFF中心单位，被该药物激活，而22个单位（15%），主要包括OFF中心单位，被该药物抑制。在灌流含有20 mM M2+和0.5 mM Ca2+的培养基的视网膜中，单位停止其自发和光诱导的放电，但它们被电泳施加的ACh激活。在视网膜暴露于含有氯化六甲铵（25微米）的培养基期间，ACh诱导的激活幅度降低或消失，而ACh诱导的抑制被硫酸阿托品（25微米）比被六甲铵更有效地降低。因此，结果表明烟碱样受体参与ACh激活，而两种受体，主要是毒蕈碱样受体，可能参与鲤鱼视网膜中ACh对锋电位发放的抑制。
