Clearance of glutamate inside the synapse and beyond.
The heated debate over the level of postsynaptic receptor occupancy by transmitter has not been extinguished - indeed, new evidence is fanning the flames. Recent experiments using two-photon microscopy suggest that the concentration of glutamate in the synaptic cleft does not attain levels previously suggested. In contrast, recordings from glial cells and studies of extrasynaptic receptor activation indicate that significant quantities of glutamate escape from the cleft following exocytosis. Determining the amount of glutamate efflux from the synaptic cleft and the distance it diffuses is critical to issues of synaptic specificity and the induction of synaptic plasticity.
Bergles
D E
DE
Vollum Institute, L474 Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97201, USA.
Diamond
J S
JS
Jahr
C E
CE
D000818:Animals; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*
D018698:Glutamic Acid