Skip to main content
release_alert
Welcome to the new Scholars 3.0! Read about new features and let us know what you think.
cancel

Independent sources of quantal variability at single glutamatergic synapses.

Publication ,  Journal Article
Franks, KM; Stevens, CF; Sejnowski, TJ
Published in: J Neurosci
April 15, 2003

Variability in the size of single postsynaptic responses is a feature of most central neurons, although the source of this variability is not completely understood. The dominant source of variability could be either intersynaptic or intrasynaptic. To quantitatively examine this question, a biophysically realistic model of an idealized central axospinous synapse was used to assess mechanisms underlying synaptic variability measurements. Three independent sources of variability were considered: stochasticity of postsynaptic receptors ("channel noise"), variations of glutamate concentration in the synaptic cleft (Deltaq), and differences in the potency of vesicles released from different locations on the active zone [release-location dependence (RLD)]. As expected, channel noise was small (8% of the total variance) and Deltaq was the dominant source of variability (58% of total variance). Surprisingly, RLD accounted for a significant amount of variability (36%). Our simulations show that potency of release sites decreased with a length constant of approximately 100 nm, and that receptors were not activated by release events >300 nm away, which is consistent with the observation that single active zones are rarely >300 nm. RLD also predicts that the manner in which receptors are added or removed from synapses can dramatically affect the nature of the synaptic response, with increasing receptor density being more efficient than merely increasing synaptic area. Saturation levels and synaptic geometry were also important in determining the size and shape of the distribution of amplitudes recorded at different synapses.

Duke Scholars

Published In

J Neurosci

DOI

EISSN

1529-2401

Publication Date

April 15, 2003

Volume

23

Issue

8

Start / End Page

3186 / 3195

Location

United States

Related Subject Headings

  • Synaptic Vesicles
  • Synaptic Transmission
  • Synapses
  • Stochastic Processes
  • Reproducibility of Results
  • Receptors, N-Methyl-D-Aspartate
  • Receptors, AMPA
  • Particle Size
  • Neurology & Neurosurgery
  • Monte Carlo Method
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Franks, K. M., Stevens, C. F., & Sejnowski, T. J. (2003). Independent sources of quantal variability at single glutamatergic synapses. J Neurosci, 23(8), 3186–3195. https://doi.org/10.1523/JNEUROSCI.23-08-03186.2003
Franks, Kevin M., Charles F. Stevens, and Terrence J. Sejnowski. “Independent sources of quantal variability at single glutamatergic synapses.J Neurosci 23, no. 8 (April 15, 2003): 3186–95. https://doi.org/10.1523/JNEUROSCI.23-08-03186.2003.
Franks KM, Stevens CF, Sejnowski TJ. Independent sources of quantal variability at single glutamatergic synapses. J Neurosci. 2003 Apr 15;23(8):3186–95.
Franks, Kevin M., et al. “Independent sources of quantal variability at single glutamatergic synapses.J Neurosci, vol. 23, no. 8, Apr. 2003, pp. 3186–95. Pubmed, doi:10.1523/JNEUROSCI.23-08-03186.2003.
Franks KM, Stevens CF, Sejnowski TJ. Independent sources of quantal variability at single glutamatergic synapses. J Neurosci. 2003 Apr 15;23(8):3186–3195.

Published In

J Neurosci

DOI

EISSN

1529-2401

Publication Date

April 15, 2003

Volume

23

Issue

8

Start / End Page

3186 / 3195

Location

United States

Related Subject Headings

  • Synaptic Vesicles
  • Synaptic Transmission
  • Synapses
  • Stochastic Processes
  • Reproducibility of Results
  • Receptors, N-Methyl-D-Aspartate
  • Receptors, AMPA
  • Particle Size
  • Neurology & Neurosurgery
  • Monte Carlo Method