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|Title:||Glucagon-like peptide-1 receptor activation in the nucleus accumbens core suppresses feeding by increasing glutamatergic AMPA/Kainate signaling|
|Authors:||Mietlicki-Baase, Elizabeth G.|
Ortinski, Pavel I.
Reiner, David J.
Sinon, Christopher G.
McCutcheon, James E.
Pierce, R. Christopher
Roitman, Mitchell F.
Hayes, Matthew R.
|Publisher:||Society for Neuroscience|
|Citation:||Journal of Neuroscience, 2014, 34 (20), pp. 6985-6992|
|Abstract:||Glucagon-like peptide-1 receptor (GLP-1R) activation in the nucleus accumbens (NAc) core is pharmacologically and physiologically relevant for regulating palatable food intake. Here, we assess whether GLP-1R signaling in the NAc core of rats modulates GABAergic medium spiny neurons (MSNs) through presynaptic-glutamatergic and/or presynaptic-dopaminergic signaling to control feeding. First, ex vivo fast-scan cyclic voltammetry showed that the GLP-1R agonist exendin-4 (Ex-4) does not alter dopamine release in the NAc core. Instead, support for a glutamatergic mechanism was provided by ex vivo electrophysiological analyses showing that Ex-4 activates presynaptic GLP-1Rs in the NAc core to increase the activity of MSNs via a glutamatergic, AMPA/kainate receptor-mediated mechanism, indicated by increased mEPSC frequency and decreased paired pulse ratio in core MSNs. Only a small, direct excitatory effect on MSNs by Ex-4 was observed, suggesting that the contribution of postsynaptic GLP-1R to MSN activity is minimal. The behavioral relevance of the electrophysiological data was confirmed by the finding that intracore injection of the AMPA/kainate receptor antagonist CNQX attenuated the ability of NAc core GLP-1R activation by Ex-4 microinjection to suppress food intake and body weight gain; in contrast, intracore NMDA receptor blockade by AP-5 did not inhibit the energy balance effects of NAc core Ex-4. Together, these data provide evidence for a novel glutamatergic, but not dopaminergic, mechanism by which NAc core GLP-1Rs promote negative energy balance.|
|Rights:||Copyright © 2014, The Authors. Deposited with reference to the publisher’s archiving policy available on the SHERPA/RoMEO website.|
|Appears in Collections:||Published Articles, Dept. of Cell Physiology and Pharmacology|
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