Roles of serotonin 5-HT3 receptor in the formation of dendrites and axons in the rat cerebral cortex: an in vitro study.
The serotonin type 3 (5-HT(3)) receptor is an only ligand-gated ion channel among 14 serotonin receptors. Here, we examined the roles of the 5-HT(3) receptor in the formation of dendrites and axons, using a dissociation culture of embryonic rat cerebral cortex. Cortical neurons at embryonic day 16 were cultured for 4 days in the presence of a selective 5-HT(3) receptor agonist with or without an antagonist. Neurons were then immunostained by antibodies against microtubule-associated protein 2 (MAP2) and glutamic acid decarboxylase (GAD) 65. All cells expressed MAP2, whereas only limited number of cells expressed GAD65. From the immunoreactivity and the cell shape, we tentatively divided neurons into 3 types; GAD-positive multipolar, GAD-positive bipolar/tripolar and GAD-negative neurons. The total length of axons and dendrites, the number of primary dendrites and the dendritic branching of GAD-negative neurons were decreased by the agonist (10 or 100nM), most of which were reversed by the concomitant treatment of the antagonist. In contrast, no or little effect was observed on the formation of dendrites and axons of GAD-positive multipolar neurons, and the neurite formation of GAD-positive bipolar/tripolar neurons. The present study revealed differential roles of the 5-HT(3) receptor in the formation of dendrites and axons of subtypes of cortical neurons.
Hayashi
Takahiro
T
University of Tsukuba, Graduate School of Comprehensive Human Sciences, Doctoral Program in Kansei, Behavioral and Brain Sciences, 1-1-1 Tennodai, Tsukuba 305-8577, Japan.
Ohtani
Akiko
A
Onuki
Fumiaki
F
Natsume
Masaki
M
Li
Fei
F
Satou
Tomomi
T
Yoshikawa
Masaaki
M
Senzaki
Kouji
K
Shiga
Takashi
T
D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology*; D003712:Dendrites / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian; D005968:Glutamate Decarboxylase / Q000378:metabolism; D066298:In Vitro Techniques; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D044406:Receptors, Serotonin, 5-HT3 / Q000378:metabolism*; D058827:Serotonin 5-HT3 Receptor Agonists; D058831:Serotonin 5-HT3 Receptor Antagonists; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
C489787:MAP2 protein, rat; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D010880:Piperidines; D044406:Receptors, Serotonin, 5-HT3; D058827:Serotonin 5-HT3 Receptor Agonists; D058831:Serotonin 5-HT3 Receptor Antagonists; D017366:Serotonin Receptor Agonists; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2; C083009:4-amino-1-(6-chloro-2-pyridyl)piperidine hydrochloride