Academia.eduAcademia.edu

Neurobiología de la adicción a opiáceos

2005

Abstract

Opiate drugs are highly addictive substances. Opiates produce acute and long-term adaptive changes at celular and molecular level in the central nervous system that are responsible for the addictive disorder. Reinforcing effects of opiates (euphoria, well being) are involved in the initiation of the opiate use, while negative effects (dysphoria during the abstinence) are responsible for the maintenance of the addictive behaviour. Biochemical, pharmacological, electrophysiological and molecular studies have identified several neurochemical pathways within the mesolimbic system as a common neurobiological substrate for the reinforcing effects of all the drugs of abuse, including opiates. The mesolimic dopaminergic system and the neural pathways involved in the physiological responses to stress mediate the motivational negative effects associated to opiate withdrawal. Finally, opiates produce long-term adaptive changes at the level of several transcription factors that could participate in the increased vulnerability to relapse in the addictive behaviour observed even after long periods of drug abstinence..