title: Microtubule-associated protein 2-positive cells derived from microglia possess properties of functional neurons.
abstract: Microglia are believed to play an important role in the regulation of phagocytosis, neuronal survival, neuronal cell death, and inflammation. Recent studies have demonstrated that microglia are multipotential stem cells that give rise to neurons, astrocytes, and oligodendrocytes. However, the functional properties of neurons derived from microglia are poorly understood. In this study, we investigated the possibility that microglia differentiate into functional neurons. Immunocytochemical study demonstrated that microtubule-associated protein 2 (MAP2)-positive cells were derived from microglia under differentiation conditions. Intracellular Ca(2+) imaging study demonstrated that KCl caused no significant changes in [Ca(2+)](i) in microglia, whereas it caused a remarkable increase in [Ca(2+)](i) in microglia-derived cells. Furthermore, electrophysiological study demonstrated that the spike waveform, firing rate, and tetrodotoxin sensitivity of extracellular action potentials evoked by 4-aminopyridine from microglia-derived MAP2-positive cells were nearly identical to those from cultured cortical neurons. These results suggest that microglia-derived MAP2-positive cells possess properties of functional neurons.
authors.affiliation: Department of Neuroscience for Drug Discovery, Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Matsuda
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Niidome
authors.forename: Hideki
authors.initials: H
authors.lastname: Nonaka
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Goto
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Fujimura
authors.forename: Masaru
authors.initials: M
authors.lastname: Kato
authors.forename: Masaya
authors.initials: M
authors.lastname: Nakanishi
authors.forename: Akinori
authors.initials: A
authors.lastname: Akaike
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kihara
authors.forename: Hachiro
authors.initials: H
authors.lastname: Sugimoto
mesh_terms: D000200:Action Potentials; D000818:Animals; D015220:Calcium Channels / Q000502:physiology; D002454:Cell Differentiation; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry; D017628:Microglia / Q000166:cytology*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009474:Neurons / Q000502:physiology*; D051381:Rats
chemical_list: D015220:Calcium Channels; D005904:Glial Fibrillary Acidic Protein; D008869:Microtubule-Associated Proteins