Phosphorylation of extracellular-regulating kinase in NMDA receptor antagonist-induced newly generated neurons in the adult rat dentate gyrus.
Neurogenesis in the adult brain is promoted by various stimulations. NMDA receptor blockade enhances neurogenesis in the hippocampal dentate gyrus. There is no agreed conclusion, however, as to whether newly generated neurons after NMDA receptor blockade obtain functional properties. We investigated the functional maturation of newly generated neurons after NMDA receptor blockade. In the dentate gyrus, 80% of newly generated cells differentiated into the phenotype of mature neurons at 29 days after the single intraperitoneal injection of an NMDA receptor antagonist MK-801. The number of newly generated neurons after MK-801 treatment was significantly greater than that in the saline-treated group. The neurogenic basic helix-loop-helix transcription factor NeuroD protein in the dentate gyrus after MK-801 treatment was expressed transiently in proliferative cells, but not in mature neurons. To determine functional properties of newly generated neurons, we administered NMDA to the lateral ventricle. As an in vivo response, we assessed extracellular-regulating kinase (ERK) phosphorylation. The newly generated neurons showed ERK phosphorylation by NMDA administration as seen in surrounding mature neurons. The number of newly generated neurons, which responded to NMDA receptor stimulation, increased with time after MK-801 treatment. The present study provides evidence that newly generated neurons in the adult hippocampus after NMDA receptor blockade acquire biochemical function in vivo.
Okuyama
Noriko
N
Faculty of Pharmaceutical Sciences, Department of Pharmacology, Tokyo University of Pharmacy & Life Science, Tokyo, Japan.
Takagi
Norio
N
Kawai
Takayuki
T
Miyake-Takagi
Keiko
K
Takeo
Satoshi
S
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002455:Cell Division; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D018891:Dentate Gyrus / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018257:Helix-Loop-Helix Motifs; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors* / Q000378:metabolism
D051792:Basic Helix-Loop-Helix Proteins; D016291:Dizocilpine Maleate; D020928:Mitogen-Activated Protein Kinases; D009419:Nerve Tissue Proteins; D016194:Receptors, N-Methyl-D-Aspartate; C093564:Neurogenic differentiation factor 1