title: Colocalization of dopamine receptor subtypes with dopamine and cAMP-regulated phosphoprotein (DARPP-32) in rat brain.
abstract: In the present study using indirect immunofluorescence immunohistochemistry, co-immunoprecipitation and western blot analysis we determined the colocalization of dopamine receptors 1-5 and dopamine and cAMP-regulated phosphoprotein (DARPP-32) in rat brain cortex and striatum. All five DR subtypes and DARPP-32 were expressed in rat brain cortex and striatum. DARPP-32 positive neurons displayed comparative colocalization with DR1-5. In cingulate cortex, the colocalization of DR subtypes was greatly different from frontal or temporal cortex. D1R is one of the most predominant subtypes which colocalized with DARPP-32 in cortex as well as striatum and followed by D2R, D3R, D4R and D5R. Amongst all DR subtypes D5R was coexpressed the least with DARPP-32 positive neurons. Consistent with immunohistochemical data, western blot analysis also reveals comparable distribution of DR subtypes and DARPP-32 in cortex and striatum. Colocalization studies were also supported by using co-immunoprecipitate assay displaying DARPP-32 expression in DR immunoprecipitate from tissue lysate prepared from cortex and striatum. Taken together our data support receptor specific association of DARPP-32 with DR subtypes that might shed new information in drugs of abuse and pathophysiology of neurodegenerative diseases as well as neuropsychiatric disorders such as schizophrenia.
authors.affiliation: Faculty of Pharmaceutical Sciences, Division of Pharmacology and Toxicology, The University of British Columbia, Vancouver, BC, Canada.
authors.forename: Padmesh S
authors.initials: PS
authors.lastname: Rajput
authors.forename: Geetanjali
authors.initials: G
authors.lastname: Kharmate
authors.forename: Rishi K
authors.initials: RK
authors.lastname: Somvanshi
authors.forename: Ujendra
authors.initials: U
authors.lastname: Kumar
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002540:Cerebral Cortex / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32 / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006179:Gyrus Cinguli / Q000378:metabolism; D008297:Male; D018613:Microscopy, Confocal; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000378:metabolism*
chemical_list: D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; C497930:Ppp1r1b protein, rat; D011954:Receptors, Dopamine