Demonstration of glutamate-positive axon terminals forming asymmetric synapses in cat neocortex.
Electron microscopic examination of sections immunocytochemically processed with an anti-glutamate serum reveals that many asymmetric synapses in the cat neocortex contain elevated levels of immunodetectable glutamate. These labelled axon terminals are likely to use glutamate as neurotransmitter. Axon terminals forming symmetric contacts were never labelled. Since glutamate is known to exert potent excitatory effects on neocortical neurons, the present finding gives immunocytochemical evidence that asymmetric synapses are excitatory.
Institute of Human Physiology, University of Ancona, Italy.
J
J
DeFelipe
F
F
Conti
S L
SL
Van Eyck
T
T
Manzoni
D000818:Animals; D001369:Axons / Q000502:physiology* / Q000648:ultrastructure; D002415:Cats; D005971:Glutamates / Q000502:physiology*; D008854:Microscopy, Electron; D013003:Somatosensory Cortex / Q000502:physiology* / Q000648:ultrastructure; D013569:Synapses / Q000502:physiology* / Q000648:ultrastructure; D014793:Visual Cortex / Q000502:physiology* / Q000648:ultrastructure
D005971:Glutamates