Gubellini P, Ben-Ari Y, Gaïarsa J L
Institut de Neurobiologie de la Mediterranée (INMED), Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 29, Avenue de Luminy, BP 13, 13273 Marseille Cedex 09, France.
Eur J Neurosci. 2001 Dec;14(12):1937-46. doi: 10.1046/j.0953-816x.2001.01823.x.
Activity-dependent plasticity of GABAergic synaptic transmission was investigated in rat hippocampal slices obtained between postnatal day (P) 0-15 using the whole-cell patch-clamp recording technique. Spontaneous GABA(A) receptor-mediated postsynaptic currents (sGABA(A)-PSCs) were isolated in the presence of ionotropic glutamate receptor antagonists. A conditioning protocol relevant to the physiological condition, consisting of repetitive depolarizing pulses (DPs) at 0.1 Hz, was able to induce long-lasting changes in both frequency and amplitude of sGABA(A)-PSCs between P0 and P8. Starting from P12, DPs were unable to induce any form of synaptic plasticity. The effects of DPs were tightly keyed to the frequency at which they were delivered. When delivered at a lower (0.05 Hz) or higher (1 Hz) frequency, DPs failed to induce any long-lasting change in the frequency or amplitude of sGABA(A)-PSCs. In two cases, DPs were able to activate sGABA(A)-PSCs in previously synaptically silent cells at P0-1. These results show that long-term changes in GABAergic synaptic activity can be induced during a restricted period of development by a conditioning protocol relevant to the physiological condition. It is suggested that such activity-induced modifications may represent a physiological mechanism for the functional maturation of GABAergic synaptic transmission.
采用全细胞膜片钳记录技术，在出生后0至15天（P0 - P15）的大鼠海马切片中研究了GABA能突触传递的活动依赖性可塑性。在离子型谷氨酸受体拮抗剂存在的情况下，分离出自发性GABA(A)受体介导的突触后电流（sGABA(A)-PSCs）。一种与生理条件相关的条件方案，由0.1 Hz的重复去极化脉冲（DPs）组成，能够在P0至P8期间诱导sGABA(A)-PSCs的频率和幅度发生长期变化。从P12开始，DPs无法诱导任何形式的突触可塑性。DPs的作用与它们的发放频率紧密相关。当以较低（0.05 Hz）或较高（1 Hz）的频率发放时，DPs无法诱导sGABA(A)-PSCs的频率或幅度发生任何长期变化。在两个案例中，DPs能够在P0 - 1时激活先前突触沉默细胞中的sGABA(A)-PSCs。这些结果表明，与生理条件相关的条件方案可以在发育的受限时期诱导GABA能突触活动的长期变化。有人认为，这种活动诱导的修饰可能代表了GABA能突触传递功能成熟的一种生理机制。
