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Electrical coupling underlies high-frequency oscillations in the hippocampus in vitro

Item Type:Article
Title:Electrical coupling underlies high-frequency oscillations in the hippocampus in vitro
Creators Name:Draguhn, A., Traub, R.D., Schmitz, D. and Jefferys, J.G.R.
Abstract:Coherent oscillations, in which ensembles of neurons fire in a repeated and synchronous manner, are thought to be important in higher brain functions. In the hippocampus, these discharges are categorized according to their frequency as theta (4-10Hz), {gamma} (20-80 Hz) and high-frequency (approximately 200 Hz) discharges, and they occur in relation to different behavioural states. The synaptic bases of theta and {gamma} rhythms have been extensively studied but the cellular bases for high-frequency oscillations are not understood. Here we report that high-frequency network oscillations are present in rat brain slices in vitro, occurring as a brief series of repetitive population spikes at 150-200 Hz in all hippocampal principal cell layers. Moreover, this synchronous activity is not mediated through the more commonly studied modes of chemical synaptic transmission, but is in fact a result of direct electrotonic coupling of neurons, most likely through gap-junctional connections. Thus high-frequency oscillations synchronize the activity of electrically coupled subsets of principal neurons within the well-documented synaptic network of the hippocampus.
Keywords:Action Potentials, Bicuculline, Calcium, Excitatory Amino Acid Antagonists, GABA Antagonists, Gap Junctions, Hippocampus, Neurons, Oscillometry, Animals, Rats
Publisher:Nature Publishing Group
Page Range:189-192
Date:9 July 1998
Official Publication:https://doi.org/10.1038/28184
PubMed:View item in PubMed

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