title: 5-HT2A receptors are differentially expressed in bullfrog and rat retinas: a comparative study.
abstract: Expression of 5-hydroxytryptamine (5-HT) 2A receptor (5-HT2A) was studied in bullfrog and rat retinas by immunocytochemistry. In the bullfrog retina, 5-HT2A-immunoreactivity was observed in both the outer and inner plexiform layers (OPL and IPL). Double labeling experiments further showed that 5-HT2A was expressed in Müller cells stained by GFAP. Labeling for 5-HT2A was strong in the somata and endfeet and relatively weak in the major processes and fine branchets of Müller cells. In contrast, 5-HT2A immunoreactivity was hardly detected in the rat retina, and no rat Müller cells were labeled. Furthermore, immunocytochemical assay demonstrated that labeling for 5-HT was present in amacrine cells and displaced amacrine cells in the inner retina of bullfrog, but not in the rat retina. These results suggest that 5-HT may modulate retinal information processing via activating 5-HT2A expressed in neuronal and glial elements in bullfrog, but that such modulation is unlikely to occur in rat.
authors.affiliation: Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, 138 Yixueyuan Road, Shanghai 200032, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Han
authors.forename: Yong-Mei
authors.initials: YM
authors.lastname: Zhong
authors.forename: Xiong-Li
authors.initials: XL
authors.lastname: Yang
mesh_terms: D000818:Animals; D007150:Immunohistochemistry; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D011892:Rana catesbeiana; D051381:Rats; D044402:Receptor, Serotonin, 5-HT2A / Q000378:metabolism*; D012160:Retina / Q000166:cytology* / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism
chemical_list: D044402:Receptor, Serotonin, 5-HT2A; D012701:Serotonin