title: Immunocytochemical localization of cannabinoid CB1 receptor and fatty acid amide hydrolase in rat retina.
abstract: Cannabinoids have major effects on central nervous system function. Recent studies indicate that cannabinoid effects on the visual system have a retinal component. Immunocytochemical methods were used to localize cannabinoid CB1 receptor immunoreactivity (CB1R-IR) and an endocannabinoid (anandamide and 2-arachidonylglycerol) degradative enzyme, fatty acid amide hydrolase (FAAH)-IR, in the rat retina. Double labeling with neuron-specific markers permitted identification of cells that were labeled with CB1R-IR and FAAH-IR. CB1R-IR was observed in all cells that were protein kinase C-immunoreactive (rod bipolar cells and a subtype of GABA-amacrine cell) as well as horizontal cells (identified by calbindin-IR). There was also punctate CB1R-IR in the distal one-third of the inner plexiform layer (IPL) that could not be assigned to a cell type. FAAH-IR was most prominent in large ganglion cells, whose dendrites projected to a narrow band in the proximal IPL. Weaker FAAH-IR was observed in the soma of horizontal cells (identified by calbindin-IR); the soma of large, but not small, dopamine amacrine cells (identified by tyrosine hydroxylase-IR); and dendrites of orthotopic- and displaced-starburst amacrine cells (identified by choline acetyltransferase-IR) but in less than 50% of the starburst amacrine cell somata. The extensive distribution of CB1R-IR on horizontal cells and rod bipolar cells indicates a role of endocannabinoids in scotopic vision, whereas the more widespread distribution of FAAH-IR indicates a complex control of endocannabinoid release and degradation in the retina.
authors.affiliation: Department of Neurobiology, University at Stony Brook, Stony Brook, New York 11794-5230, USA. yazulla@life.bio.sunysb.edu
authors.forename: S
authors.initials: S
authors.lastname: Yazulla
authors.forename: K M
authors.initials: KM
authors.lastname: Studholme
authors.forename: H H
authors.initials: HH
authors.lastname: McIntosh
authors.forename: D G
authors.initials: DG
authors.lastname: Deutsch
mesh_terms: D000581:Amidohydrolases / Q000032:analysis*; D000818:Animals; D015415:Biomarkers; D063385:Cannabinoid Receptor Modulators; D002186:Cannabinoids / Q000493:pharmacokinetics; D007150:Immunohistochemistry; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D011493:Protein Kinase C / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug / Q000032:analysis*; D012160:Retina / Q000166:cytology / Q000378:metabolism*; D017948:Retinal Rod Photoreceptor Cells / Q000166:cytology / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000032:analysis; D000099252:Fatty Acid Amide Hydrolases
chemical_list: D000581:Amidohydrolases; D015415:Biomarkers; D063385:Cannabinoid Receptor Modulators; D002186:Cannabinoids; D011493:Protein Kinase C; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug; D005680:gamma-Aminobutyric Acid; D000099252:Fatty Acid Amide Hydrolases