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Titolo:
Modulation of latent inhibition in the rat by altered dopamine transmission in the nucleus accumbens at the time of conditioning
Autore:
Joseph, MH; Peters, SL; Moran, PM; Grigoryan, GA; Young, AMJ; Gray, JA;
Indirizzi:
Inst Psychiat, MRC, Behav Neurochem Grp, London SE5 8AF, England Inst Psychiat London England SE5 8AF rochem Grp, London SE5 8AF, England Inst Psychiat, Dept Psychol, London SE5 8AF, England Inst Psychiat London England SE5 8AF pt Psychol, London SE5 8AF, England
Titolo Testata:
NEUROSCIENCE
fascicolo: 4, volume: 101, anno: 2000,
pagine: 921 - 930
SICI:
0306-4522(2000)101:4<921:MOLIIT>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
VENTRAL TEGMENTAL AREA; CHRONIC AMPHETAMINE; SYSTEMIC AMPHETAMINE; PREPULSE INHIBITION; NICOTINE; SCHIZOPHRENIA; HALOPERIDOL; LESIONS; RELEASE; EXPRESSION;
Keywords:
nucleus accumbens; dopamine; latent inhibition; learned association; amphetamine; haloperidol;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
51
Recensione:
Indirizzi per estratti:
Indirizzo: Joseph, MH Univ Leicester, Sch Psychol, Behav Neurosci Grp, Univ Rd, Leicester LE1 7RH, Leics, England Univ Leicester Univ Rd Leicester Leics EnglandLE1 7RH England
Citazione:
M.H. Joseph et al., "Modulation of latent inhibition in the rat by altered dopamine transmission in the nucleus accumbens at the time of conditioning", NEUROSCIENC, 101(4), 2000, pp. 921-930

Abstract

Latent inhibition describes a process by which pre-exposure of a stimulus without consequence retards the learning of subsequent conditioned associations with that stimulus. It is well established that latent inhibition in rats is impaired by increased dopamine function and potentiated by reduced dopamine function. Previous evidence has suggested that these effects are modulated via the meso-accumbens dopamine projections. We have now undertakenthree experiments to examine this issue directly, especially in the light of one study in which latent inhibition was reported to be unaffected by direct injection of amphetamine into the accumbens. Latent inhibition was studied using the effect of pre-exposure of a tone stimulus on the subsequent formation of a conditioned emotional response to the tone. 6-Hydroxydopamine-induced lesions of dopamine terminals in the nucleus accumbens resulted in potentiation of latent inhibition. Bilateral local injections of the dopamine antagonist haloperidol into the nucleus accumbens (0.5 mug/side) before conditioning also potentiated latent inhibition. Moreover, such injections were able to reverse the disruptive effect of systemic amphetamine (1 mg/kg, i.p.) on latent inhibition. Bilateral local injection of amphetamine (5mug/side) into the nucleus accumbens before conditioning was able to disrupt latent inhibition, provided that it was preceded by a systemic injectionof amphetamine (1 mg/kg) 24 h earlier. We conclude that the attenuation of latent inhibition by increased dopamine function in the nucleus accumbens is brought about by impulse-dependent release of the neurotransmitter ocurring at the time of conditioning. The previously reported failure to disrupt latent inhibition with intra-accumbensamphetamine is probably due to impulse-independent release of dopamine. The implications of these conclusions for theories linking disrupted latent inhibition to the attentional deficits in schizophrenia, and to the dopaminetheory of this disorder, are discussed. (C) 2000 IBRO. Published by Elsevier Science Ltd. All rights reserved.

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Documento generato il 22/01/20 alle ore 12:24:58