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Synaptic kainate currents reset interneuron firing phase
Author(s) -
Yang Ellen J.,
Harris Alexander Z.,
Pettit Diana L.
Publication year - 2007
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2006.118448
Subject(s) - interneuron , kainate receptor , neuroscience , reset (finance) , chemistry , biology , glutamate receptor , receptor , ampa receptor , inhibitory postsynaptic potential , biochemistry , economics , financial economics
Hippocampal interneuron activity has been linked to epileptogenesis, seizures and the oscillatory synaptic activity detected in behaving rats. Interneurons fire at specific times in the rhythmic cycles that comprise these oscillations; however, the mechanisms controlling these firing patterns remain unclear. We have examined the role of synaptic input in modulating the firing of spontaneously active rat hippocampal interneurons. We find that synaptic glutamate receptor currents of 20–30 pA increase instantaneous firing frequency and reset the phase of spontaneously firing CA1 stratum oriens interneurons. Kainate receptor (KAR)‐mediated currents are particularly effective at producing this phase reset, while AMPA receptor currents are relatively ineffective. The efficacy of KAR‐mediated currents is probably due to their 3‐fold longer decay. Given the small amplitude of the currents needed for this phase reset, coincident activation of only a few KAR‐containing synapses could synchronize firing in groups of interneurons. These data suggest that KARs are potent modulators of circuit behaviour and their activation alters hippocampal interneuron output.