'Priming' enhances the relationship of striatal L-dopa concentration to behavior.
Rats with unilateral 6-hydroxydopamine (6-OHDA) lesions were exposed to L-DOPA treatments, 25 mg kg-1 L-DOPA methyl ester/2 mg kg-1 carbidopa, or to saline. Fourteen days later, both sets of animals were tested with the L-DOPA/carbidopa treatment. The L-DOPA pre-exposed animals exhibited behavioral sensitization as indexed by a higher frequency of contralateral rotations. Although striatal L-DOPA and HVA concentrations were equivalent in the two groups, the L-DOPA treatment induced a 10 fold variation in the range of L-DOPA concentrations in the 6-OHDA striatum in both sets of animals. Importantly, significant correlations between striatal L-DOPA concentration and behavior were obtained only for the L-DOPA pre-exposed animals.
Pinheiro-Carrera
M
M
University of Sao Paulo, Ribeirao Preto SP, Brazil.
Tomaz
C
C
Huston
J P
JP
Dai
H
H
Carey
R J
RJ
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001923:Brain Chemistry / Q000187:drug effects; D004298:Dopamine / Q000378:metabolism; D006719:Homovanillic Acid / Q000378:metabolism; D007980:Levodopa / Q000493:pharmacokinetics / Q000494:pharmacology*; D008297:Male; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D016627:Oxidopamine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013238:Stereotaxic Techniques
D007980:Levodopa; D016627:Oxidopamine; D004298:Dopamine; D006719:Homovanillic Acid