Armstrong D L, Hay M, Terrian D M
Brain Research Laboratory, University of Texas at San Antonio 78285.
Brain Res Bull. 1987 Dec;19(6):699-704. doi: 10.1016/0361-9230(87)90057-8.
Serotonergic fibers have been identified within the granule cell layer of the cerebellar cortex; however, their functional significance has not been identified. In this study the effect of serotonin on granule cell spontaneous activity was determined in the rat cerebellum. Of the 136 granule cells tested, 44.8% displayed a decrease in firing rate, 21.3% increased firing rate and 33.8% were not affected. The serotonin-induced changes in activity were not blocked by bicuculline or methysergide. The serotonin agonist 1,3 (trifluoromethylphenyl) piperazine mimicked the serotonin-induced suppressive response. Iontophoretically applied serotonin was also found to modulate GABA-induced suppression of granule cell activity. The variable effects of serotonin on spontaneous activity suggests the presence of more than one type of serotonergic receptor in the cerebellar granule cell layer.
5-羟色胺能纤维已在小脑皮质颗粒细胞层中被识别出来；然而，它们的功能意义尚未明确。在本研究中，测定了5-羟色胺对大鼠小脑颗粒细胞自发活动的影响。在测试的136个颗粒细胞中，44.8%的细胞放电频率降低，21.3%的细胞放电频率增加，33.8%的细胞未受影响。5-羟色胺引起的活动变化未被荷包牡丹碱或麦角酰二乙胺阻断。5-羟色胺激动剂1,3-双（三氟甲基苯基）哌嗪模拟了5-羟色胺引起的抑制反应。还发现通过离子导入法施加的5-羟色胺可调节γ-氨基丁酸（GABA）对颗粒细胞活动的抑制作用。5-羟色胺对自发活动的不同影响表明，小脑颗粒细胞层中存在不止一种类型的5-羟色胺能受体。
