Abstract
Repeated exposure to addictive drugs results in long-lasting neuroadaptations in the brain, especially in the mesocorticolimbic system. Within this system, the nucleus accumbens (NAc) plays a major integrative role. As such, the NAc has been shown to be a target of short- and long-lasting drug-induced neuro adaptations at the levels of neurotransmission and cellular morphology. The long-lasting neuroadaptations might depend critically on alterations in gene expression. Recently, we obtained a set of transcripts by means of subtractive hybridization, of which the expression was decreased in the rat NAc shell after long-term extinction of intravenous heroin self-administration. Interestingly, the majority of these transcripts were also down-regulated upon long-term extinction of cocaine self-administration. Using the yoked-control operant paradigm, it was shown that non-contingent administration of these drugs resulted in a totally different gene expression profile. However, in the rat NAc core, both self-administration and non-contingent heroin administration induced a qualitatively similar expression profile. Hence, cognitive processes associated with drug self-administration seem to direct the long-term genomic responses in the NAc shell, whereas the NAc core might primarily mediate the persistent pharmacological effects of addictive drugs (including Pavlovian conditioning).
Original language | English |
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Pages (from-to) | 91-100 |
Number of pages | 10 |
Journal | Addiction Biology |
Volume | 10 |
Issue number | 1 |
DOIs | |
Publication status | Published - Mar 2005 |
Keywords
- Adaptation, Physiological
- DNA, Complementary
- Drug Administration Routes
- Gene Expression
- Gene Expression Profiling
- Gene Expression Regulation
- Heroin
- Heroin Dependence
- Humans
- Hybridization, Genetic
- Journal Article
- Nerve Tissue Proteins
- Nucleus Accumbens
- Review
- Synaptic Transmission
- Time Factors