Microtubule-associated protein 2-positive cells derived from microglia possess properties of functional neurons.
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.
Matsuda
Satoru
S
Department of Neuroscience for Drug Discovery, Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
Niidome
Tetsuhiro
T
Nonaka
Hideki
H
Goto
Yasuaki
Y
Fujimura
Kazuhiko
K
Kato
Masaru
M
Nakanishi
Masaya
M
Akaike
Akinori
A
Kihara
Takeshi
T
Sugimoto
Hachiro
H
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
D015220:Calcium Channels; D005904:Glial Fibrillary Acidic Protein; D008869:Microtubule-Associated Proteins