Pre-trial cocaine biases choice toward cocaine through suppression of the nondrug option
Pharmacology Biochemistry and Behavior. 2018-07-01; :
DOI: 10.1016/j.pbb.2018.07.010
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1. Pharmacol Biochem Behav. 2018 Jul 26. pii: S0091-3057(18)30302-2. doi:
10.1016/j.pbb.2018.07.010. [Epub ahead of print]
Pre-trial cocaine biases choice toward cocaine through suppression of the nondrug
option.
Freese L(1), Durand A(2), Guillem K(2), Ahmed SH(3).
Author information:
(1)Laboratory of Neuropsychopharmacology, Federal University of Health Sciences
of Porto Alegre (UFCSPA), Porto Alegre, Rio Grande do Sul, Brazil.
(2)Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293,
146 rue Léo-Saignat, F-33000 Bordeaux, France; CNRS, Institut des Maladies
Neurodégénératives, UMR 5293, 146 rue Léo-Saignat, F-33000 Bordeaux, France.
(3)Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293,
146 rue Léo-Saignat, F-33000 Bordeaux, France; CNRS, Institut des Maladies
Neurodégénératives, UMR 5293, 146 rue Léo-Saignat, F-33000 Bordeaux, France.
Electronic address: .
Being under the influence during choice between drug and nondrug options can have
a dramatic effect on choice outcomes. When rats face a choice between cocaine and
sweet water and are not under the influence, they prefer sweet water. In
contrast, when they are under the influence of cocaine, this causes them to shift
their choice to cocaine nearly exclusively. Here we sought to characterize the
behavioral mechanisms underlying the influence of cocaine on choice. In theory,
rats under the influence of cocaine should be in a mixed motivational state, at
least temporarily, with both their motivation for cocaine and their motivation
for the nondrug option suppressed by the drug satiating and anorexic effects of
cocaine, respectively. For this mixed state to shift choice to cocaine, the
satiated motivation for cocaine should recover before the suppressed motivation
for the preferred nondrug option. The goal of the present study was to test this
prediction in rats that expressed a preference for sweet water after extended
access to cocaine self-administration. We measured their choice and response
latencies to each option after pre-trial, passive administration of cocaine to
estimate the duration of its drug satiating and anorexic effects. As expected,
pre-trial cocaine caused most rats to shift their choice to cocaine. Though this
shift was not simply due to a longer latency to respond for sweet water than for
cocaine after pre-trial cocaine, it nevertheless occurred while rats’ motivation
for the nondrug option was still partially suppressed. Thus, cocaine seems to
bias choice toward more cocaine mainly via suppression of the nondrug option.
Copyright © 2018. Published by Elsevier Inc.
DOI: 10.1016/j.pbb.2018.07.010
PMID: 30056175