Cocaine-induced dendritic remodeling occurs in both D1 and D2 dopamine receptor-expressing neurons in the nucleus accumbens.
Neurosci Lett
; 517(2): 118-22, 2012 May 31.
Article
in En
| MEDLINE
| ID: mdl-22561554
ABSTRACT
Repeated exposure to cocaine can induce persistent alterations in the brain's reward system, including increases in the number of dendrites and spine density on medium-sized spiny neurons (MSNs) in the nucleus accumbens (NAc). The structural remodeling of dendrites and spines in the NAc is thought to play a critical role in cocaine addiction. MSNs in the NAc can be classified by expression of either D1 or D2 dopamine receptors, which are localized to the direct and indirect pathway, respectively. It is unknown whether the dendritic changes induced by repeated cocaine treatment occur in MSNs of the direct or indirect pathway. Because the traditional Golgi-Cox impregnation of neurons precludes identifying particular subpopulations of MSNs, we performed dendritic morphology analysis after biocytin-labeling and Golgi-Cox impregnation. We found that the biocytin staining MSNs showed higher dendritic spine density and higher number of dendrites than that in Golgi impregnation group. In addition, we found that the increasing spine density induced by repeated cocaine treatment in female mice was higher than that in male mice. Next we used biocytin staining and dynorphin/D2 receptor colocalization to determine which cell type(s) displayed dendritic changes after repeated cocaine treatment. We found that cocaine-induced changes in dendritic parameters occurred in MSNs of both the direct (D1-expressing) and indirect (D2-expressing) pathways.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Receptors, Dopamine D2
/
Cocaine
/
Dopamine Uptake Inhibitors
/
Dendrites
/
Receptors, Dopamine D3
/
Dopaminergic Neurons
/
Nucleus Accumbens
Limits:
Animals
Language:
En
Journal:
Neurosci Lett
Year:
2012
Document type:
Article