Prior treatment (priming) with caffeine sensitizes D2-dopamine-mediated contralateral rotational behavior in 6-hydroxydopamine-lesioned rats.
OBJECTIVE
In unilaterally dopamine-depleted rats, repeated treatment with dopamine agonists sensitizes contralateral rotational behavior. Since A2a adenosine receptors are co-localized with D2 dopamine receptors in the brain, it was hypothesized that repeated treatment with the adenosine antagonist caffeine could sensitize D2 dopamine-mediated rotational behavior.


METHODS
Rats were unilaterally lesioned with 6-hydroxydopamine (6-OHDA), and pretreated (primed) with 3 injections of caffeine or water. One week later, rats were challenged with the D2 agonist quinpirole (0.25 mg/kg).


RESULTS
6-OHDA rats primed with caffeine (50 mg/kg) displayed contralateral rotational behavior following challenge with quinpirole - an effect not observed with caffeine (10 or 75 mg/kg) or water.


CONCLUSIONS
These results suggest that prior administration of caffeine can sensitize D2 dopamine-mediated rotational behavior in dopamine-depleted rats.
Pollack
Alexia E
AE
Department of Biology, University of Massachusetts-Boston, Boston, MA 02125, USA. alexia.pollack@umb.edu
Dimitrov
Kroum D
KD
Drake
Jonathan D
JD
D058916:Adenosine A1 Receptor Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D058917:Adenosine A2 Receptor Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D002110:Caffeine / Q000008:administration & dosage / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007839:Functional Laterality / Q000187:drug effects; D008297:Male; D008474:Medial Forebrain Bundle / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects*; D016627:Oxidopamine / Q000633:toxicity*; D019257:Quinpirole / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000819:agonists / Q000378:metabolism*; D013563:Sympathectomy, Chemical; D013565:Sympatholytics / Q000633:toxicity*; D013997:Time Factors
D058916:Adenosine A1 Receptor Antagonists; D058917:Adenosine A2 Receptor Antagonists; D000697:Central Nervous System Stimulants; D018491:Dopamine Agonists; D017448:Receptors, Dopamine D2; D013565:Sympatholytics; D019257:Quinpirole; D002110:Caffeine; D016627:Oxidopamine