Increase in medial frontal cortex ERK activation following the induction of apomorphine sensitization

Date
2014-03-01Author
Sanguedo, Frederico Velasco Costa
Dias, Flavia Regina Cruz
Bloise, Enrrico
Céspedes, Isabel Cristina [UNIFESP]
Giraldi-Guimaraes, Arthur
Samuels, Richard Ian
Carey, Robert J.
Carrera, Marinete Pinheiro
Type
ArtigoISSN
0091-3057Is part of
Pharmacology Biochemistry and BehaviorDOI
10.1016/j.pbb.2013.12.020Metadata
Show full item recordAbstract
Repeated high dose injections of the direct acting D1/D2 agonist apomorphine (APO) induces context specific behavioral sensitization. We assessed the effects of 2.0 mg/kg APO on open-field locomotor responses of rats over a 30 min period following either single or five daily APO injections. Acute injections increased locomotor activity, which was markedly increased in rats given 5 daily APO injections. This progressive increase in locomotion during the repeated APO treatments is indicative of behavioral sensitization. Immediately following the open-field test for the acute and the fifth apomorphine injection, the animals were euthanized and their brain tissue was prepared for immunohistochemistry. ERK immunoreactive nuclei in the medial prefrontal cortex (PFC), nucleus accumbens (NAcc), amygdala (AMYG) and lateral hypothalamus (LH) were quantified. the acute apomorphine injections increased ERK in all brain areas as compared to vehicle. Following the fifth apomorphine injection, ERK significantly increased in the PFC, decreased in the amygdala but was unchanged in the LH and NAcc the selective increase in ERK activity in the PFC associated with behavioral sensitization, points to a possible pivotal role of the dopamine projection to the medial frontal cortex in the mediation of neural plasticity, considered to underlie the sensitization processes induced by dopaminergic drugs. (C) 2013 Published by Elsevier Inc.
Citation
Pharmacology Biochemistry and Behavior. Oxford: Pergamon-Elsevier B.V., v. 118, p. 60-68, 2014.Sponsorship
UENFFundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
UENF-Brazil
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