Behavioral sensitization to cocaine is not associated with changes in serotonin (5-HT) fiber immunoreactivity in rat forebrain.
We investigated whether cocaine-induced behavioral sensitization is associated with changes in serotonin (5-HT) immunoreactivity. Male Sprague-Dawley rats were injected with either cocaine (15 mg/kg, IP) or saline twice daily for seven days. Their behavior was observed and rated for locomotor activation and stereotypy. One day after the final injection, the brains were processed for 5-HT immunohistochemistry. The intensity of 5-HT immunoreactive staining of 5-HT axons and terminal varicosities was blindly rated in cocaine-sensitized rats and found not to differ from saline-treated rats. The results support the hypothesis that unlike some amphetamine derivatives, repeated cocaine administration which results in behavioral sensitization is not neurotoxic to 5-HT axons and terminals in the forebrain.
Paris
J M
JM
Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston 77550.
Callahan
P M
PM
Lee
J M
JM
Cunningham
K A
KA
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003042:Cocaine / Q000494:pharmacology*; D007150:Immunohistochemistry; D008297:Male; D009412:Nerve Fibers / Q000378:metabolism; D016548:Prosencephalon / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*
D012701:Serotonin; D003042:Cocaine