Haloperidol increases proenkephalin mRNA levels in the caudate-putamen of the rat: a quantitative study at the cellular level using in situ hybridization.
Brain Res
; 388(1): 33-41, 1987 Apr.
Article
em En
| MEDLINE
| ID: mdl-3580841
ABSTRACT
Previous immunocytochemical studies have shown that the opioid peptides, Met-enkephalin and Leu-enkephalin, are present in medium-sized, spiny projection neurons of the caudate-putamen. It has also been demonstrated that chronic treatment of rats with the dopamine receptor blocker, haloperidol, results in an increase in the levels of enkephalin peptides and proenkephalin mRNA in this brain region. To determine whether this increase in proenkephalin mRNA content is exhibited by all enkephalinergic neurons of the caudate-putamen or by only a subpopulation, we have used in situ nucleic acid hybridization to examine the haloperidol-induced increase in proenkephalin mRNA levels at the cellular level. Results of in situ hybridization suggest that all enkephalinergic neurons in the caudate-putamen can respond to haloperidol treatment with an increase in steady state levels of proenkephalin mRNA, and that the mean induction is an approximate 3-fold increase in the message levels. This suggests that dopamine exerts a tonic inhibitory effect on the expression of the proenkephalin gene in all of the enkephalinergic neurons of the caudate-putamen. Dot blot analysis indicated a 2.4-fold increase in the tissue levels of this mRNA. The agreement between the in situ hybridization results and dot blot analysis supports in situ hybridization as a reliable method for quantitative studies of alterations in neuropeptide precursor mRNAs in the brain.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Precursores de Proteínas
/
Putamen
/
RNA Mensageiro
/
Encefalinas
/
Dopamina
/
Núcleo Caudado
/
Haloperidol
Limite:
Animals
Idioma:
En
Revista:
Brain Res
Ano de publicação:
1987
Tipo de documento:
Article