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The amygdala is concerned with the emotional memory consolidation, and is known as a stress-vulnerable region of the brain. Slow network oscillation is considered to play roles in memory consolidation during sleep. We investigated the relationship between the sleep and oscillation in the basolateral nucleus (BL) of the amygdala, in which burst firing is preferentially observed during sleep and the slow inhibitory oscillation is recorded from projection neuron. We examined whether sleep deprivation (SD) alters the properties of the network inhibition by whole-cell recordings from BL projection neurons and interneurons of the slice preparation of the juvenile rats. The level of the oscillatory network inhibition, measured as summed power of the spectral density between 0.1 and 3 Hz of the synaptic currents in the projection neurons, was significantly attenuated by acute (3 h) SD in older (P20–24) but not in younger (P15–19) animals. This reduction was mainly derived from the reduced peak amplitude of periodic IPSC bursts. In inhibitory interneurons in BL, spontaneous firings were reduced in older SD rats. The spike threshold of interneurons was increased and the power of the periodic excitatory transmission was reduced in the SD rats. Moreover, a reduction in input resistance in projection neurons was observed in SD rats without significant difference in the excitability which was measured by the spike number induced by depolarizing currents. These results suggest that SD stress affects the network oscillatory property accompanied by changes of individual neuronal excitability and synaptic communications.

Anterior cingulate cortex (ACC) plays a pivotal role in higher order processing of cognition, attention and emotion. The network oscillation is considered an essential means for integration of these CNS functions. The oscillation power and coherence among related areas are often dis-regulated in several psychiatric and pathological conditions with a hemispheric asymmetric manner. Here we describe the network-based activity of field potentials recorded from the superficial layer of the mouse ACC in vitro using submerged type recordings. A short activation by kainic acid administration to the preparation induced populational activities ranging over several frequency bands including theta (3-8Hz), alpha (8-12Hz), beta (13-30Hz), low gamma (30-50Hz) and high gamma (50-80Hz). These responses were repeatable and totally abolished by tetrodotoxin, and greatly diminished by inhibitors of ionotropic and metabotropic glutamate receptors, GABAA receptor or gap-junctions. These observations suggest that the kainate-induced network activity can be a useful model of the network oscillation in the ACC circuit.