Paré D, Gaudreau H
Département de Physiologie, Faculté de Médecine, Université Laval, Québec, Canada.
J Neurosci. 1996 May 15;16(10):3334-50. doi: 10.1523/JNEUROSCI.16-10-03334.1996.
To study relations between the basolateral (BL) amygdaloid complex and major electroencephalogram (EEG) rhythms of the entorhinal cortex (delta and theta), neurons of the lateral and BL nuclei were recorded in conscious cats. An essential task to this end was to obtain criteria allowing the identification of projection cells and interneurons. BL projection cells, identified by their antidromic response to parahippocampal stimuli, generated stereotyped high-frequency bursts (2-4 spikes at 140-250 Hz), which repeated at low rates. Projection cells of the lateral nucleus were virtually silent, but their presence was disclosed by cortical-evoked responses. In both nuclei, the firing rates and/or responsiveness of projection cells increased from waking to slow-wave sleep (S). In contrast with projection cells, presumed interneurons discharged at high rates (approximately 10-15 Hz) and displayed various discharge patterns ranging from tonic to phasic. The bipartite classification of BL neurons on the basis of their discharge patterns and synaptic responses was supported by the differential relation existing between EEG rhythms and the activity of the two cell types. Indeed, fast-firing and bursting cells of the BL nucleus tended to fire on opposite phases of the delta oscillation of S and entorhinal theta oscillation of paradoxical sleep. The unusual state-related changes in activity displayed by lateral and BL neurons point to functional similarities between the amygdala and hippocampus. This idea is supported by the presence of coherent theta oscillations in the amygdala-hippocampal circuit that might favor the emergence of recurring time windows when synaptic interactions will be facilitated in this limbic network.
为了研究基底外侧杏仁核复合体与内嗅皮质主要脑电图（EEG）节律（δ波和θ波）之间的关系，在清醒猫中记录了外侧核和基底外侧核的神经元。为此，一项重要任务是获得能够识别投射细胞和中间神经元的标准。通过对海马旁刺激的逆向反应鉴定出的基底外侧投射细胞产生刻板的高频爆发（140 - 250Hz时2 - 4个尖峰），且以低频率重复出现。外侧核的投射细胞实际上是沉默的，但通过皮层诱发反应可揭示其存在。在这两个核中，投射细胞的放电频率和/或反应性从清醒状态到慢波睡眠（S）均增加。与投射细胞不同，推测的中间神经元以高频率（约10 - 15Hz）放电，并表现出从紧张性到相位性的各种放电模式。基于放电模式和突触反应对基底外侧神经元进行的二分法分类，得到了EEG节律与这两种细胞类型活动之间存在的差异关系的支持。实际上，基底外侧核的快速放电和爆发性细胞倾向于在慢波睡眠的δ振荡和异相睡眠的内嗅θ振荡的相反相位放电。外侧核和基底外侧核神经元所表现出的与状态相关的异常活动变化表明杏仁核与海马体之间存在功能相似性。杏仁核 - 海马体回路中存在相干θ振荡这一现象支持了这一观点，这种振荡可能有利于在这个边缘网络中促进突触相互作用时出现反复出现的时间窗口。
