Na+ signals at central synapses.
A basic characteristic of animal cells is the maintenance of a steep inwardly directed electrochemical gradient for sodium ions. In vertebrate neurons, this Na+ gradient energizes intracellular ion regulation and enables influx of Na+ during action potentials and excitatory postsynaptic currents. Several studies suggested that Na+ ions could also play a role in activity-dependent synaptic plasticity. This review focuses on recent studies that demonstrated the presence of substantial intracellular Na+ transients during action potential firing or excitatory synaptic transmission in postsynaptic dendrites and dendritic spines. The large amplitudes of these activity-induced Na+ transients suggest that this signal will significantly alter electrical and biochemical properties of spines and dendrites and might influence the properties of synaptic transmission.
Rose
C R
CR
Physiological Institute, University of Munich, Germany. rose@lrz.uni-muenchen.de
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002490:Central Nervous System / Q000378:metabolism*; D009473:Neuronal Plasticity; D009474:Neurons / Q000502:physiology; D012964:Sodium / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology
D012964:Sodium