Cocaine-induced dendritic spine formation in D1 and D2 dopamine receptor-containing medium spiny neurons in nucleus accumbens.
Psychostimulant-induced alteration of dendritic spines on dopaminoceptive neurons in nucleus accumbens (NAcc) has been hypothesized as an adaptive neuronal response that is linked to long-lasting addictive behaviors. NAcc is largely composed of two distinct subpopulations of medium-sized spiny neurons expressing high levels of either dopamine D1 or D2 receptors. In the present study, we analyzed dendritic spine density after chronic cocaine treatment in distinct D1 or D2 receptor-containing medium-sized spiny neurons in NAcc. These studies made use of transgenic mice that expressed EGFP under the control of either the D1 or D2 receptor promoter (Drd1-EGFP or Drd2-EGFP). After 28 days of cocaine treatment and 2 days of withdrawal, spine density increased in both Drd1-EGFP- and Drd2-EGFP-positive neurons. However, the increase in spine density was maintained only in Drd1-EGFP-positive neurons 30 days after drug withdrawal. Notably, increased DeltaFosB expression also was observed in Drd1-EGFP- and Drd2-EGFP-positive neurons after 2 days of drug withdrawal but only in Drd1-EGFP-positive neurons after 30 days of drug withdrawal. These results suggest that the increased spine density observed after chronic cocaine treatment is stable only in D1-receptor-containing neurons and that DeltaFosB expression is associated with the formation and/or the maintenance of dendritic spines in D1 as well as D2 receptor-containing neurons in NAcc.
Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY 10021, USA.
Ko-Woon
KW
Lee
Yong
Y
Kim
Amie M
AM
Kim
Kathryn
K
Helmin
Angus C
AC
Nairn
Paul
P
Greengard
D000818:Animals; D049109:Cell Proliferation; D003042:Cocaine / Q000494:pharmacology*; D049229:Dendritic Spines / Q000187:drug effects*; D005786:Gene Expression Regulation / Q000187:drug effects; D051379:Mice; D008822:Mice, Transgenic; D009714:Nucleus Accumbens / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D017447:Receptors, Dopamine D1 / Q000235:genetics / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000235:genetics / Q000378:metabolism*
C483819:Fosb protein, mouse; D016760:Proto-Oncogene Proteins c-fos; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D003042:Cocaine