D1 priming enhances both D1- and D2-mediated rotational behavior and striatal Fos expression in 6-hydroxydopamine lesioned rats.
Rats with unilateral 6-hydroxydopamine (6-OHDA) lesions exhibit behavioral sensitization upon repeated treatment with dopamine agonists, a phenomenon called 'priming'. We examined the effectiveness of priming with D1 or D2 agonists on rotational behavior and striatal Fos expression following challenge with D1 or D2 agonists. Twenty-one days post-lesion, rats received three priming injections, spaced 3-6days apart, with water, D1 agonist SKF38393 (10mg/kg) or D2 agonist quinpirole (1mg/kg). One week later, 6-OHDA rats were challenged with water, SKF38393 (1 or 10mg/kg) or quinpirole (0.25mg/kg). 6-OHDA rats challenged with SKF38393 (1mg/kg) showed no contralateral rotational behavior, but robust striatal Fos expression in D1-primed animals. Challenge with SKF38393 (10mg/kg) led to pronounced contralateral rotational behavior and striatal Fos expression in all priming groups - with the largest behavioral response in D1- and D2-primed rats. Quinpirole challenge (0.25mg/kg) led to robust contralateral rotational behavior and striatal Fos expression in D1-primed animals, but only mild rotational behavior and baseline levels of striatal Fos expression in D2-primed animals. These data suggest that D1- or D2-priming enhances rotational behavior following challenge with D1 or D2 agonist, but only D1-priming enhances D1- and D2-mediated striatal Fos expression in 6-OHDA rats.
Department of Biology, University of Massachusetts-Boston, 100 Morrissey Blvd., Boston, MA 02125, United States. alexia.pollack@umb.edu
Alexia E
AE
Pollack
Lindsay I
LI
Thomas
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D018491:Dopamine Agonists / Q000494:pharmacology; D008297:Male; D016627:Oxidopamine / Q000494:pharmacology*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D019257:Quinpirole / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000502:physiology*; D017448:Receptors, Dopamine D2 / Q000502:physiology*
D018491:Dopamine Agonists; D016760:Proto-Oncogene Proteins c-fos; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D019257:Quinpirole; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D016627:Oxidopamine