d-Amphetamine-induced behavioral sensitization: implication of a glutamatergic medial prefrontal cortex–ventral tegmental area innervation
Section snippets
Subjects
Male Wistar rats (Iffa–Credo, l'Arbresle, France), weighing 200–220 g upon arrival, were housed five per cage in an animal room maintained at 22±2°C with a 12-h/12-h light–dark cycle (lights on at 06.00). After surgery was performed, animals were kept singly. Food and water were available ad libitum throughout the whole experiments. Behavioral experiments were conducted from 09.00 to 13.00. Experiments were performed in accordance with the declaration of Helsinki, the European Communities
Summary
In the present work, we first investigated the role of the glutamatergic inputs to the VTA in the induction of behavioral sensitization produced by intra-VTA administration of AMPH and, second, the effects of excitotoxic lesions of the structures providing these glutamatergic inputs to the VTA, namely the MPFC and the amygdala, on behavioral sensitization induced by both peripheral and intra-VTA repeated AMPH pretreatment.
The findings and outcome of this work are as follows. (1) Part of the
Conclusions
The data collected in the present experiments led to the conclusions that lesioning the cell bodies of the MPFC completely prevented the induction of behavioral sensitization by either peripheral or intra-VTA injections of AMPH and that this blockade effect is proposed to be the result of removing the glutamate inputs to the VTA arising in the MPFC.
Acknowledgements
This work was supported by the Centre National de la Recherche Scientifique, the Conseil Régional d'Aquitaine and the Institut Fédératif en Neurosciences Cliniques et Experimentales (IFR#8). Y. Bjijou is a recipient of a doctoral fellowship from the Moroccan Government and the Société de Tabacologie (Paris, France). We would like to acknowledge the help of Dr Catherine Le Moine, Servane Lachize and Claude Videauporte in the preparation of histological drawings and photographs.
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