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Protein kinase signalling requirements for metabotropic action of kainate receptors in rat CA1 pyramidal neurones
Author(s) -
Grabauskas Gintautas,
Lancaster Barrie,
O'Connor Vincent,
Wheal Howard V.
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.2006.122051
Subject(s) - kainate receptor , protein kinase c , metabotropic receptor , protein kinase a , microbiology and biotechnology , neuroscience , biology , receptor , chemistry , signal transduction , kinase , biochemistry , glutamate receptor , ampa receptor
Hippocampal pyramidal neurones display a Ca 2+ ‐dependent K + current responsible for the slow afterhyperpolarization ( I sAHP ), a prominent regulator of excitability. There is considerable transmitter convergence onto I sAHP but little information about the interplay between the kinase‐based transduction mechanisms underlying transmitter action. We have added to existing information about the role of protein kinase C (PKC) in kainate receptor actions by demonstrating that direct postsynaptic activation of PKC with either 1‐oleoyl‐2‐acethylsn‐glycerol (OAG) or indolactam is sufficient to inhibit I sAHP . The physiological correlate of this action – activation of PKC by kainate receptors – requires Gα i/o proteins. The cAMP/PKA system is well documented to subserve the actions of monoamine transmitters. We have found an additional role for the cAMP/PKA system as a requirement for kainate receptor‐mediated inhibition of I sAHP . Inhibition of adenylyl cyclase with dideoxyadenosine or PKA with either H89 or RpcAMPs blocked kainate receptor‐mediated actions but did not prevent the actions of direct PKC activation with either OAG or indolactam. We therefore propose that the PKA requirement is upstream from the actions of PKC. We additionally report a downstream link in the form of increased mitogen‐activated protein (MAP) kinase activity, which may explain the long duration of metabotropic actions of kainate receptors on I sAHP .