Sun L, Miller R J
Department of Pharmacological and Physiological Sciences, The University of Chicago, Chicago, Illinois 60637, USA.
J Neurophysiol. 1999 Mar;81(3):1391-403. doi: 10.1152/jn.1999.81.3.1391.
We examined the effects of neuropeptide Y (NPY) and related peptides on Ca2+ and K+ currents in acutely isolated neurons from the arcuate nucleus of the rat. NPY analogues that activated all of the known NPY receptors (Y1-Y5), produced voltage-dependent inhibition of Ca2+ currents and activation of inwardly rectifying K+ currents in arcuate neurons. Both of these effects could occur simultaneously in the same cells. In some cells, activation of Y4 NPY receptors also caused oscillations in [Ca2+]i. NPY hyperpolarized arcuate neurons through the activation of a K+ conductance and increased the spike threshold. Molecular biological studies indicated that arcuate neurons possessed all of the previously cloned NPY receptor types (Y1, Y2, Y4, and Y5). Thus activation of multiple types NPY receptors on arcuate neurons can regulate both Ca2+ and K+ conductances leading to a reduction in neuronal excitability and a suppression of neurotransmitter release.
我们研究了神经肽Y（NPY）及相关肽对大鼠弓状核急性分离神经元中Ca2+和K+电流的影响。激活所有已知NPY受体（Y1 - Y5）的NPY类似物，可使弓状神经元中的Ca2+电流产生电压依赖性抑制，并激活内向整流K+电流。这两种效应可在同一细胞中同时发生。在某些细胞中，Y4 NPY受体的激活还会引起细胞内Ca2+浓度（[Ca2+]i）的振荡。NPY通过激活K+电导使弓状神经元超极化，并提高动作电位阈值。分子生物学研究表明，弓状神经元拥有所有先前克隆的NPY受体类型（Y1、Y2、Y4和Y5）。因此，弓状神经元上多种类型NPY受体的激活可调节Ca2+和K+电导，导致神经元兴奋性降低和神经递质释放受到抑制。
