Valeyev A Y, Cruciani R A, Lange G D, Smallwood V S, Barker J L
Laboratory of Neurophysiology, NINDS, National Institutes of Health, Bethesda, MD 20892.
Neurosci Lett. 1993 Jun 11;155(2):199-203. doi: 10.1016/0304-3940(93)90707-r.
Throughout the adult vertebrate central nervous system (CNS) gamma-aminobutyric acid (GABA) mediates transient Cl- conductances commonly identified as fast, Cl(-)-dependent inhibitory synaptic signals [Prog. Neurobiol., 36 (1991) 35-92]. In the rat hippocampus Cl(-)-dependent excitatory transients mediated by GABA emerge during the first postnatal week superimposed on a steady-state baseline that is also Cl(-)- and GABA-dependent [Int. J. Dev. Neurosci., 8 (1990) 481-490]. Here we report that many embryonic rat hippocampal neurons cultured for hours to days exhibit random fluctuations in Cl- channel activity that are mediated by continuous secretion of GABA in the absence of transients. Thus, GABA is broadcast tonically before it is released transiently.
在整个成年脊椎动物中枢神经系统(CNS)中,γ-氨基丁酸(GABA)介导短暂的氯离子电导,通常被认为是快速的、氯离子依赖性抑制性突触信号[《神经生物学进展》,36(1991)35 - 92]。在大鼠海马体中,由GABA介导的氯离子依赖性兴奋性瞬变在出生后的第一周出现,叠加在同样依赖氯离子和GABA的稳态基线之上[《国际发育神经科学杂志》,8(1990)481 - 490]。在此我们报告,许多培养数小时至数天的胚胎大鼠海马神经元在氯离子通道活性上表现出随机波动,这是由在无瞬变情况下GABA的持续分泌所介导的。因此,GABA在短暂释放之前会持续进行张力性释放。