Authors: María José SánchezCatalán Lucía Hipólito Teodoro Zornoza Ana Polache Luis Granero
Publish Date: 2009/02/24
Volume: 204, Issue: 4, Pages: 641-653
Abstract
A recently published study has shown that microinjections of ethanol or its metabolite acetaldehyde into the substantia nigra pars reticulata are able to produce behavioral activation in rats Another brain site that could participate in such effects is the ventral tegmental area VTACannulae were placed into the posterior VTA to perform microinjections of ethanol 75 or 150 nmol or acetaldehyde 25 or 250 nmol in animals not previously microinjected or microinjected with either the nonselective opioid antagonist naltrexone 132 nmol or the irreversible antagonist of the µopioid receptors βfunaltrexamine βFNA 25 nmol After injections spontaneous activity was monitored for 60 minInjections of ethanol or acetaldehyde into the VTA increased the locomotor activity of rats with maximal effects at doses of 150 nmol for ethanol and 250 nmol for acetaldehyde These locomotoractivating effects were reduced by previously administering naltrexone 132 nmol or βFNA 25 nmol into the VTAThe posterior VTA is another brain region involved in the locomotor activation after the intracerebroventricular administration of ethanol or acetaldehyde Our data indicate that opioid receptors particularly the µopioid receptors could be the target of the actions of these compounds in the VTA These results are consistent with the hypothesis that acetaldehyde could be a mediator of some ethanol effectsThis work was supported by Fundación para el Estudio Prevención y Asistencia a las Drogodependencias FEPAD Generalitat Valenciana Spain and the Spanish Ministry of Science and Innovation BFU 200767912C0202 MJSC and LH are recipients of predoctoral fellowships from the Cinc Segles Program Universitat de València
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