The role of drebrin in dendritic spines.
Dendritic spines form typical excitatory synapses in the brain and their shapes vary depending on synaptic inputs. It has been suggested that the morphological changes of dendritic spines play an important role in synaptic plasticity. Dendritic spines contain a high concentration of actin, which has a central role in supporting cell motility, and polymerization of actin filaments (F-actin) is most likely involved in spine shape changes. Drebrin is an actin-binding protein that forms stable F-actin and is highly accumulated within dendritic spines. Drebrin has two isoforms, embryonic-type drebrin E and adult-type drebrin A, that change during development from E to A. Inhibition of drebrin A expression results in a delay of synapse formation and inhibition of postsynaptic protein accumulation, suggesting that drebrin A has an important role in spine maturation. In mature synapses, glutamate stimulation induces rapid spine-head enlargement during long-term potentiation (LTP) formation. LTP stimulation induces Ca2+entry through N-methyl-d-aspartate (NMDA) receptors, which causes drebrin exodus from dendritic spines. Once drebrin exits from dendritic spine heads, the dynamic actin pool increases in spine heads to facilitate F-actin polymerization. To maintain enlarged spine heads, drebrin-decorated F-actin is thought to reform within the spine heads. Thus, drebrin plays a pivotal role in spine plasticity through regulation of F-actin.
Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan.
Noriko
N
Koganezawa
Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan.
Kenji
K
Hanamura
Division of Pharmacology, National Institute of Health Sciences, Tokyo 158-8501, Japan.
Yuko
Y
Sekino
Department of Neurobiology and Behavior, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan. Electronic address: tshirao@gunma-u.ac.jp.
Tomoaki
T
Shirao
D000818:Animals; D003712:Dendrites / Q000378:metabolism*; D049229:Dendritic Spines / Q000378:metabolism*; D006801:Humans; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*
D009479:Neuropeptides; C053386:drebrins
Cytoskeleton; Dynamic actin filament; Plasticity; Stable actin filament