Elevated dopamine D2High receptors in alpha-1b-adrenoceptor knockout supersensitive mice.
Synapse
; 61(7): 569-72, 2007 Jul.
Article
in En
| MEDLINE
| ID: mdl-17447259
ABSTRACT
Although amphetamine induces hyperactivity by releasing dopamine (DA), mice that lack alpha1b-adrenoceptors do not release DA in response to amphetamine and do not, therefore, exhibit locomotor supersensitivity to amphetamine. However, such mice reveal hyperlocomotion to p-chloroamphetamine (PCA). Because these alpha1b-adrenoceptor knockout mice have no alterations in the striatal densities of DA D1 or D2 receptors, the basis for any possible dopaminergic contribution to the PCA-induced hyperlocomotion to PCA is unclear. Therefore, because supersensitive animals are generally known to have a higher proportion of DA D2 receptors in the high-affinity state for DA D2(High), we investigated whether there was any change in the alpha1b-adrenoceptor knockout striata in the proportion of DA D2(High) receptors to determine whether there could be a DA-based contribution to the PCA-induced hyperlocomotion. We found that the proportion of D2(High) in the wild type striata was 23 +/- 3.3%, whereas that in the alpha1b-adrenoceptor knockout striata was 52 +/- 2.9%, an increase of 2.3-fold. This elevation agrees with other types of DA-supersensitive animal striata and could assist in eliciting a supersensitive response in these alpha1b-adrenoceptor knockout mice.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Gene Expression Regulation
/
Receptors, Dopamine D2
/
Receptors, Adrenergic, alpha-1
Limits:
Animals
Language:
En
Journal:
Synapse
Journal subject:
NEUROLOGIA
Year:
2007
Document type:
Article
Affiliation country:
France