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Parallel and interactive learning processes within the basal ganglia: Relevance for the understanding of addiction
- Source :
-
Behavioural Brain Research . Apr2009, Vol. 199 Issue 1, p89-102. 14p. - Publication Year :
- 2009
-
Abstract
- Abstract: In this review we discuss the evidence that drug addiction, defined as a maladaptive compulsive habit, results from the progressive subversion by addictive drugs of striatum-dependent operant and Pavlovian learning mechanisms that are usually involved in the control over behaviour by stimuli associated with natural reinforcement. Although mainly organized through segregated parallel cortico-striato-pallido-thalamo-cortical loops involved in motor or emotional functions, the basal ganglia, and especially the striatum, are key mediators of the modulation of behavioural responses, under the control of both action-outcome and stimulus-response mechanisms, by incentive motivational processes and Pavlovian associations. Here we suggest that protracted exposure to addictive drugs recruits serial and dopamine-dependent, striato-nigro-striatal ascending spirals from the nucleus accumbens to more dorsal regions of the striatum that underlie a shift from action-outcome to stimulus-response mechanisms in the control over drug seeking. When this progressive ventral to dorsal striatum shift is combined with drug-associated Pavlovian influences from limbic structures such as the amygdala and the orbitofrontal cortex, drug seeking behaviour becomes established as an incentive habit. This instantiation of implicit sub-cortical processing of drug-associated stimuli and instrumental responding might be a key mechanism underlying the development of compulsive drug seeking and the high vulnerability to relapse which are hallmarks of drug addiction. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 01664328
- Volume :
- 199
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Behavioural Brain Research
- Publication Type :
- Academic Journal
- Accession number :
- 36895918
- Full Text :
- https://doi.org/10.1016/j.bbr.2008.09.027