Mednikova Y S, Karnup S V, Loseva E V
Institute of Higher Nervous Activity and Neurophysiology, Moscow, Russia.
Neuroscience. 1998 Dec;87(4):783-96. doi: 10.1016/s0306-4522(98)00166-3.
Discharge patterns were studied in response to iontophoretic application of acetylcholine to the soma and dendrites of 128 neocortical pyramidal neurons of layer V. Extracellular recordings were obtained from slices of the guinea-pig parietal cortex. All responses found were excitatory and were better expressed in spontaneously firing cells than in silent ones. Sensitivity to acetylcholine was approximately the same at somatic and dendritic sites in all the cells. Activation of muscarinic receptors gave rise to firing patterns with equal latencies and intensities when applied to both soma and dendrites. The latter suggests that membrane excitation elicited in dendrites by binding of acetylcholine to muscarinic cholinoreceptors is likely to propagate towards the soma through intracellular biochemical processes. Modulating effect of acetylcholine on output firing patterns, elicited by dendritic application of excitatory amino acids, included shortening of the somatic response latency and increase of response intensity and duration. We propose that, in contrast to glutamatergic excitation, the spread of cholinergic excitation along dendrites involves intra-cellular chemical signalling and results in changing the electrical properties of dendrites all over their length.
研究了向128个豚鼠顶叶皮层V层新皮层锥体神经元的胞体和树突进行离子电渗法施加乙酰胆碱后的放电模式。从豚鼠顶叶皮层切片获取细胞外记录。所有发现的反应都是兴奋性的，并且在自发放电细胞中比在静息细胞中表现得更好。在所有细胞中，胞体和树突部位对乙酰胆碱的敏感性大致相同。当向胞体和树突都施加毒蕈碱受体激动剂时，会产生潜伏期和强度相等的放电模式。后者表明，乙酰胆碱与毒蕈碱胆碱能受体结合在树突中引发的膜兴奋可能通过细胞内生化过程向胞体传播。乙酰胆碱对由树突施加兴奋性氨基酸引发的输出放电模式的调节作用包括缩短胞体反应潜伏期以及增加反应强度和持续时间。我们提出，与谷氨酸能兴奋相反，胆碱能兴奋沿树突的传播涉及细胞内化学信号传导，并导致树突全长的电特性发生变化。
