Nonsaturation of AMPA and NMDA receptors at hippocampal synapses

AUTOR(ES)

McAllister, A. Kimberley

FONTE

The National Academy of Sciences

RESUMO

An important issue in synaptic physiology is the extent to which postsynaptic receptors are saturated by the neurotransmitter released from a single synaptic vesicle. Although the bulk of evidence supports receptor saturation, recent studies have started to reveal that α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and N-methyl-d-aspartate (NMDA) receptors may not be saturated by a single vesicle of glutamate. Here, we address this question through a study of putative single synapses, made by hippocampal neurons in culture, that are identified by FM1–43 staining. An analysis of the sources of variability in the amplitudes of miniature excitatory postsynaptic currents at single synapses reveals that this variability must arise presynaptically, from variations in the quantity of agonist released. Thus, glutamate receptors at hippocampal synapses are not generally saturated by quantal release.

Documentos Relacionados

• The high variance of AMPA receptor- and NMDA receptor-mediated responses at single hippocampal synapses: Evidence for multiquantal release
• Presynaptic kainate receptors at hippocampal mossy fiber synapses
• Direct imaging of lateral movements of AMPA receptors inside synapses
• Activity differentially regulates the surface expression of synaptic AMPA and NMDA glutamate receptors
• A biophysical model of bidirectional synaptic plasticity: Dependence on AMPA and NMDA receptors