Biagini Giuseppe, D'Antuono Margherita, Inaba Yuji, Kano Toshiyuki, Ragsdale David, Avoli Massimo
Montreal Neurological Institute, McGill University, 3801 Rue University, Montreal, QC, H3A 2B4, Canada.
Pflugers Arch. 2015 Apr;467(4):805-16. doi: 10.1007/s00424-014-1545-8. Epub 2014 Jun 7.
Rat brain slices comprising the perirhinal cortex (PC) and a portion of the lateral nucleus of the amygdala (LA), in standard medium, can generate synchronous oscillatory activity that is associated with action potential discharge and reflects the activation of glutamatergic and GABAergic receptors. We report here that similar synchronous oscillatory events are recorded in the PC in response to single-shock, electrical stimuli delivered in LA. In addition, we found that the latency of these responses progressively increased when the stimulus interval was varied from 10 to 1 s; for example, the response latency during stimuli delivered at 1 Hz was more than twofold longer than that seen during stimulation at 0.1 Hz. This prolongation in latency occurred after approximately 5 stimuli, attained a steady value after 24-35 stimuli, and recovered to control values 30 s after stimulation arrest. These frequency-dependent changes in latency continued to occur during NMDA receptor antagonism but weakened following application of GABAA and/or GABAB receptor blockers. Our findings identify a new type of short-term plasticity that is mediated by GABA receptor function and may play a role in decreasing neuronal network synchronization during repeated activation. We propose that this frequency-dependent adaptive mechanism influences the excitability of limbic networks, thus potentially controlling epileptiform synchronization.
包含内嗅皮质（PC）和杏仁核外侧核（LA）一部分的大鼠脑片，在标准培养基中能够产生与动作电位发放相关的同步振荡活动，并反映谷氨酸能和γ-氨基丁酸能受体的激活。我们在此报告，在LA中施加单次电击电刺激时，PC中会记录到类似的同步振荡事件。此外，我们发现当刺激间隔从10秒变化到1秒时，这些反应的潜伏期会逐渐增加；例如，在1赫兹刺激时的反应潜伏期比在0.1赫兹刺激时观察到的长两倍多。这种潜伏期的延长在大约5次刺激后出现，在24 - 35次刺激后达到稳定值，并在刺激停止后30秒恢复到对照值。这些潜伏期的频率依赖性变化在NMDA受体拮抗期间持续发生，但在应用GABAA和/或GABAB受体阻滞剂后减弱。我们的研究结果确定了一种由GABA受体功能介导的新型短期可塑性，可能在重复激活期间降低神经元网络同步性方面发挥作用。我们提出这种频率依赖性适应机制影响边缘网络的兴奋性，从而潜在地控制癫痫样同步。
