Neuron
Volume 29, Issue 2, February 2001, Pages 469-484
Journal home page for Neuron

A Developmental Switch in Neurotransmitter Flux Enhances Synaptic Efficacy by Affecting AMPA Receptor Activation

https://doi.org/10.1016/S0896-6273(01)00219-7Get rights and content
Under an Elsevier user license
open archive

Abstract

Formation of glutamatergic synapses entails development of “silent” immature contacts into mature functional synapses. To determine how this transformation occurs, we investigated the development of neurotransmission at single synapses in vitro. Maturation of presynaptic function, assayed with endocytotic markers, followed accumulation of synapsin I. During this period, synaptic transmission was primarily mediated by activation of NMDA receptors, suggesting that most synapses were functionally silent. However, local glutamate application to silent synapses indicated that these synapses contained functional AMPA receptors, suggesting a possible presynaptic locus for silent transmission. Interference with presynaptic vesicle fusion by exposure to tetanus toxin reverted functional to silent transmission, implicating SNARE-mediated fusion as a determinant of the ratio of NMDA:AMPA receptor activation. This work reveals that functional maturation of synaptic transmission involves transformation of presynaptic silent secretion into mature synaptic transmitter release.

Cited by (0)