Comparison of sensitization elicited by amphetamine and pertussis toxin: characterization of locomotor behavior and limbic dopamine release.
1. Male, Sprague-Dawley rats were pretreated with one of several regimens of repeated, intermittent amphetamine or with a single-dose of intra-VTA pertussis toxin (PTX). 2. An amphetamine challenge dose (0.5 mg/kg, i.p.) produced increased locomotor activity in both amphetamine and pertussis toxin-pretreated rats. 3. The magnitude of activity in PTX pretreated rats exceeded 5-fold that of the amphetamine-pretreated rats. 4. There were no significant differences in the levels of sensitized behavior elicited by 4 distinct amphetamine pretreatment protocols. 5. Neither of the drug pretreatments caused significant changes in the ability of 10 microM amphetamine to promote dopamine efflux from nucleus accumbens or striatal tissue in vitro. 6. The sensitized behaviour cannot be explained by in vitro alterations in pre-synaptic dopamine release, which may suggest an up-regulation of post-synaptic activity.
Weinstein
D M
DM
Ohio State University College of Pharmacy, Columbus, USA.
Narayanan
S
S
Byrnes
J J
JJ
Uretsky
N J
NJ
Wallace
L J
LJ
D000661:Amphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D066298:In Vitro Techniques; D008032:Limbic System / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D037342:Pertussis Toxin; D051381:Rats; D017207:Rats, Sprague-Dawley; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism; D017557:Ventral Tegmental Area; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D018765:Dopamine Uptake Inhibitors; D010566:Virulence Factors, Bordetella; D000661:Amphetamine; D037342:Pertussis Toxin; D004298:Dopamine