Holohean A M, Hackman J C, Davidoff R A
Neurophysiology Laboratory, Veteran's Administration Medical Center, Miami, FL.
Neurosci Lett. 1990 May 31;113(2):175-80. doi: 10.1016/0304-3940(90)90299-o.
The effects of serotonin on the membrane potential of primary afferent terminals of isolated hemisected frog spinal cords was investigated by sucrose gap recordings from dorsal root. Serotonin produced two distinctive changes in primary afferent terminal membrane potential: modest (about 0.5 mV) hyperpolarizations in low concentrations (0.01-1.0 microM) and larger (about 1.0 mV) slow depolarizations in higher concentrations (3.0-100 microM). The hyperpolarizations appeared related to a direct activation of 5-HT1A receptors on afferent terminals. The depolarizations were attributed to both direct and indirect actions and appeared to be generated by activation of 5-HT2 and/or 5-HT1C receptors. The results suggest that 5-HT released from terminals in the frog dorsal horn could exert a modulatory action on the afferent input of the spinal cord, but different effects generated by activation of different 5-HT receptor subtypes are dependent upon the concentration of the amine.
通过从背根进行蔗糖间隙记录，研究了血清素对离体半切青蛙脊髓初级传入终末膜电位的影响。血清素在初级传入终末膜电位上产生了两种不同的变化：低浓度（0.01 - 1.0微摩尔）时出现适度（约0.5毫伏）的超极化，高浓度（3.0 - 100微摩尔）时出现较大（约1.0毫伏）的缓慢去极化。超极化似乎与传入终末上5-HT1A受体的直接激活有关。去极化归因于直接和间接作用，似乎是由5-HT2和/或5-HT1C受体的激活产生的。结果表明，青蛙背角终末释放的5-HT可能对脊髓的传入输入发挥调节作用，但不同5-HT受体亚型激活产生的不同效应取决于胺的浓度。
