Maintenance of presynaptic function by AMPA receptor-mediated excitatory postsynaptic activity in adult brain.
Activity-dependent synaptic modification occurs in both developing and mature animals. For reliable information transfer and storage, however, once established, synapses must be maintained stably. We investigated how chronic blockade of neuronal activity or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors affects excitatory climbing fiber (CF) to Purkinje cell (PC) synapses in adult mouse cerebellum. Both treatments caused reduced glutamate concentration transient at the synaptic cleft, decreased frequency of quantal excitatory postsynaptic current, and diminished CF innervation of PC shaft dendrites but no change in CF's release probability. These results indicate that, in the mature cerebellum, AMPA receptor-mediated excitatory postsynaptic activity maintains CF's functional glutamate-release sites and its innervation of PC shaft dendrites.
Kakizawa
Sho
S
Department of Cellular Neurophysiology, Graduate School of Medical Science, Kanazawa University, Kanazawa 920-8640, Japan.
Miyazaki
Taisuke
T
Yanagihara
Dai
D
Iino
Masamitsu
M
Watanabe
Masahiko
M
Kano
Masanobu
M
D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D002531:Cerebellum / Q000187:drug effects / Q000378:metabolism; D003712:Dendrites / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D018698:Glutamic Acid / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008854:Microscopy, Electron; D009043:Motor Activity; D016202:N-Methylaspartate / Q000737:chemistry; D009474:Neurons / Q000378:metabolism; D011145:Polyvinyls / Q000494:pharmacology; D017729:Presynaptic Terminals / Q000378:metabolism*; D011689:Purkinje Cells / Q000166:cytology; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D018091:Receptors, AMPA / Q000737:chemistry / Q000378:metabolism*; D012964:Sodium / Q000737:chemistry; D013569:Synapses / Q000378:metabolism; D013779:Tetrodotoxin / Q000494:pharmacology; D013997:Time Factors; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000378:metabolism
D000779:Anesthetics, Local; D011145:Polyvinyls; D011810:Quinoxalines; D018091:Receptors, AMPA; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; C016438:ethylenevinylacetate copolymer; D018698:Glutamic Acid; D013779:Tetrodotoxin; D016202:N-Methylaspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D012964:Sodium; D002118:Calcium