The ventral tegmental area and nucleus accumbens shell as a distributed brain network for feeding elicited by GABA-B receptor agonists: Modulatory roles of GABA and opioid receptor subtypes in rats
Item
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Title
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The ventral tegmental area and nucleus accumbens shell as a distributed brain network for feeding elicited by GABA-B receptor agonists: Modulatory roles of GABA and opioid receptor subtypes in rats
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Identifier
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d_2009_2013:1a47cdb79bd9:11480
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identifier
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11924
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Creator
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Kavanagh-Miner, Patricia,
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Contributor
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Richard J. Bodnar
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Date
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2012
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Language
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English
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Publisher
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City University of New York.
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Subject
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Neurosciences | food intake | GABA receptors | nucleus accumbens | opioid receptors | ventral tegmental area
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Abstract
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Food intake is significantly increased following administration of GABA and opioid agonists into the nucleus accumbens (NAC) shell and ventral tegmental area (VTA) with receptor-selective antagonist pretreatment capable of blocking these responses within sites. To evaluate whether regional VTA and NAC shell interactions occur for GABA-mediated feeding, specifically meal size of chow intake, the first aim examined whether feeding elicited by the GABA-B agonist, baclofen, microinjected into the NAC shell or VTA dose dependently blocked pretreatment with either the GABA-B antagonist, saclofen, or the GABA-A antagonist, bicuculline, into the alternate site, VTA or NAC shell in rats. VTA and NAC shell saclofen dose-dependently and significantly blocked feeding elicited by baclofen injected into the NAC shell and VTA baclofen, respectively. Whereas VTA bicuculline significantly blocked the increased feeding elicited by NAC shell baclofen, NAC shell bicuculline reduced but did not block feeding elicited by VTA baclofen.;To evaluate whether regional VTA and NACs feeding interactions occur for opioid receptor modulation of GABA agonist-mediated feeding, the second and third aims examined whether feeding elicited by the GABA-B agonist, baclofen microinjected into the NACs or VTA was dose-dependently blocked by pretreatment with general (naltrexone: NTX), mu (beta-funaltrexamine: BFNA), kappa (nor-binaltorphamine: NBNI) or delta (naltrindole: NTI) opioid antagonists into the alternate site, VTA or NAC shell in rats. VTA NTX significantly reduced NACs baclofen-induced feeding. Correspondingly, NACs NTX significantly reduced VTA baclofen-induced feeding. Whereas, the high VTA BFNA dose reduced NACs baclofen-induced feeding, NACs BFNA failed to affect VTA baclofen-induced feeding. Whereas VTA NBNI at both doses reduced NACs baclofen-induced feeding, only the high NACs NBNI dose significantly reduced VTA baclofen-induced feeding. Whereas VTA NTI transiently reduced NACs baclofen induced feeding, NACs NTI failed to affect VTA baclofen-induced feeding. Therefore, the present series of studies suggest that GABA employs a distributed brain network in mediating its ingestive effects that is dependent upon intact GABA and opioid receptor signaling with kappa opioid receptors more involved than mu and delta opioid receptors underlying these regional effects.
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Type
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dissertation
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Source
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2009_2013.csv
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degree
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Ph.D.
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Program
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Psychology
