Multiple spatiotemporal modes of actin reorganization by NMDA receptors and voltage-gated Ca2+ channels.
Cytoskeleton is believed to contribute to activity-dependent processes underlying neuronal plasticity, such as regulations of cellular morphology and localization of signaling proteins. However, how neuronal activity controls actin cytoskeleton remains obscure. Taking advantage of confocal imaging of enhanced GFP-actin in the primary culture of hippocampal neurons, we show that synaptic activity induces multiple types of actin reorganization, both at the spines and at the somatic periphery. Activation of N-methyl-d-aspartate receptors, accompanied with a local rise in [Ca(2+)]i, was sufficient to trigger a slow and sustained recruitment of actin into dendritic spines. In contrast, opening of voltage-gated Ca(2+) channels rapidly and reversibly enhanced cortical actin at the somatic periphery but not in the spines, in keeping with a high transient rise in somatic [Ca(2+)]i. These data suggest that spatiotemporal dynamics of [Ca(2+)]i, triggered by activation of N-methyl-d-aspartate receptors and voltage-gated Ca(2+) channels, provides the molecular basis for activity-dependent actin remodeling.
Furuyashiki
Tomoyuki
T
Department of Pharmacology, Kyoto University Faculty of Medicine, Japan Science and Technology Corporation, Sakyo-ku, Kyoto 606-8315, Japan.
Arakawa
Yoshiki
Y
Takemoto-Kimura
Sayaka
S
Bito
Haruhiko
H
Narumiya
Shuh
S
D000199:Actins / Q000235:genetics / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D002478:Cells, Cultured; D003712:Dendrites / Q000378:metabolism* / Q000502:physiology; D049452:Green Fluorescent Proteins; D006624:Hippocampus / Q000166:cytology; D015640:Ion Channel Gating; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013347:Subcellular Fractions; D009435:Synaptic Transmission
D000199:Actins; D015220:Calcium Channels; D008164:Luminescent Proteins; D016194:Receptors, N-Methyl-D-Aspartate; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins