title: Building a 5-HT3A Receptor Expression Map in the Mouse Brain.
abstract: Of the many serotonin receptors, the type 3 receptors (5-HT3R) are the only ionotropic ones, playing a key role in fast synaptic transmission and cognitive and emotional brain function through controlled neuronal excitation. To better understand the various functions of 5-HT3Rs, it is very important to know their expression pattern in the central nervous system (CNS). To date, many distributional studies have shown localized 5-HT3R expression in the brain and spinal cord. However, an accurate pattern of 5-HT3R expression in the CNS remains to be elucidated. To investigate the distribution of 5-HT3R in the mouse brain in detail, we performed immunofluorescent staining using 5-HT3AR-GFP transgenic mice. We found strong 5-HT3AR expression in the olfactory bulb, cerebral cortex, hippocampus, and amygdala; and partial expression in the pons, medulla, and spinal cord. Meanwhile, the thalamus, hypothalamus, and midbrain exhibited a few 5-HT3AR-expressing cells, and no expression was detected in the cerebellum. Further, double-immunostaining using neural markers confirmed that 5-HT3AR is expressed in GABAergic interneurons containing somatostatin or calretinin. In the present study, we built a 5-HT3AR expression map in the mouse brain. Our findings make significant contributions in elucidating the novel functions of 5-HT3R in the CNS.
authors.affiliation: Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Koyama
authors.affiliation: Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kondo
authors.affiliation: Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Shimada
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D059330:GABAergic Neurons / Q000378:metabolism; D007395:Interneurons / Q000378:metabolism; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D044406:Receptors, Serotonin, 5-HT3 / Q000235:genetics* / Q000378:metabolism*; D009435:Synaptic Transmission; D014018:Tissue Distribution
chemical_list: C511230:Htr3a protein, mouse; D044406:Receptors, Serotonin, 5-HT3