Premium
C‐fos and egr‐1 Immediate‐early Gene Induction by Cocaine and Cocaethylene in Rat Brain: A Comparative Study
Author(s) -
THIRIET NATHALIE,
AUNIS DOMINIQUE,
ZWILLER JEAN
Publication year - 2000
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2000.tb05182.x
Subject(s) - nucleus accumbens , dopamine , dopamine transporter , immediate early gene , serotonergic , caudate nucleus , serotonin transporter , pharmacology , chemistry , gene expression , serotonin , biology , endocrinology , dopaminergic , gene , biochemistry , receptor
The induction of immediate‐early genes can now be considered as a tool to study neuronal activation in different brain structures. These genes, which are rapidly and transiently induced in response to diverse extracellular stimulation, coordinate alterations in gene expression underlying neuronal plasticity. Using in situ hybridization, we found that acute i.p. cocaine (20 mg/kg) injection produced a strong expression of egr‐1 and c‐fos genes in the nucleus accumbens, caudate‐putamen, and frontal cortex in the rat. Cocaethylene is an active metabolite of cocaine that is formed when cocaine is consumed together with ethyl alcohol. Injection of cocaethylene at a dose equivalent to cocaine induced the expression of the two immediate‐early genes in the same brain structures, but to a lesser extent. A high dose of ethanol increased egr‐1 and c‐fos expression in the frontal cortex and in the lateral part of the caudateputamen. Since cocaine is known to potently inhibit both dopamine and serotonin transporters, whereas cocaethylene only inhibits the dopamine transporter, our results strongly suggest that the serotonergic system participates in the mode of action of cocaine in its ability to trigger immediate‐early gene transcription.