Sanford L D, Hunt W K, Ross R J, Morrison A R, Pack A I
Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, USA.
Arch Ital Biol. 1998 Jul;136(3):205-14.
Neurons in the peribrachial region (PB) at the pontine border are implicated in the generation of ponto-geniculo-occipital (PGO) waves, which appear spontaneously during rapid eye movement sleep (REM) and in association with alerting behaviors during waking, as well as in the regulation of REM itself. It has been hypothesized that PGO-related bursting in a subpopulation of these neurons results from low threshold spikes triggered by phasic hyperpolarizations or by excitatory inputs reaching a steadily hyperpolarized neuron. The hyperpolarization necessary for triggering the low threshold spikes may come from local GABA neurons or from GABAergic input into PB. To test the hypothesis that antagonizing GABA would alter PGO wave generation and/or behavioral state, we microinfused, in cats, the GABAA antagonist, bicuculline, locally into PB and monitored behavior, behavioral state and PGO waves recorded in the lateral geniculate bodies. Bicuculline produced no significant alteration in PGO wave activity. In 3 cats, bicuculline produced behaviors ranging from spontaneous orienting and startle (4 cats) to flight behaviors (2 cats) and aggressiveness (2 cats), an effect probably due to diffusion into the central gray region. Thus, the results do not support a GABAA-ergic role in PB in the generation of PGO waves.
脑桥边缘臂周区（PB）的神经元与脑桥-膝状体-枕叶（PGO）波的产生有关，PGO波在快速眼动睡眠（REM）期间自发出现，在清醒时与警觉行为有关，也参与REM睡眠本身的调节。据推测，这些神经元亚群中与PGO相关的爆发是由相位性超极化或兴奋性输入触发的低阈值尖峰引起的，这些输入作用于持续超极化的神经元。触发低阈值尖峰所需的超极化可能来自局部GABA能神经元或来自进入PB的GABA能输入。为了验证拮抗GABA会改变PGO波产生和/或行为状态这一假设，我们在猫身上将GABAA拮抗剂荷包牡丹碱局部微量注入PB，并监测行为、行为状态以及外侧膝状体记录到的PGO波。荷包牡丹碱对PGO波活动没有产生显著改变。在3只猫中，荷包牡丹碱产生了从自发定向和惊吓（4只猫）到逃跑行为（2只猫）和攻击行为（2只猫）等行为，这种效应可能是由于药物扩散到中央灰质区域所致。因此，结果不支持PB中GABAA能在PGO波产生中发挥作用。
