|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Journal of Experimental Biology, Vol 204, Issue 1 127-138, Copyright © 2001 by Company of Biologists
JOURNAL ARTICLES |
PJ Simmons
Department of Neuroscience, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, UK. p.j.simmons@ncl.ac.uk
Variability in postsynaptic potential (PSP) amplitude due to intrinsic noise limits the reliability of communication between neurons. I measured PSP variability at synapses between a forewing stretch receptor and wing depressor motor neurons in locusts, a pathway that is important in the control of flying. The intrinsic noise in the stretch receptor output synapse was measured by subtracting the background noise, originating in other synaptic pathways onto the motor neuron, from the variability in the amplitudes of PSPs evoked by the stretch receptor. Intrinsic synaptic noise caused successive PSPs to vary by 4-10 % in basalar and subalar flight motor neurons. Recordings from pairs of these wing depressor motor neurons showed that the amount of transmitter released varied independently between different output sites from the stretch receptor. Histograms of excitatory postsynaptic potential amplitude were normal distributions that lacked separate peaks. I estimate that quantal amplitude is significantly less than 0.1 mV and that several hundred quanta are released for each presynaptic spike. This accords well with a previous estimate of the number of discrete anatomical synapses and would facilitate modulation of output from the stretch receptor.
This article has been cited by other articles:
![]() |
P. J. Simmons and R. de Ruyter van Steveninck Reliability of Signal Transfer at a Tonically Transmitting, Graded Potential Synapse of the Locust Ocellar Pathway J. Neurosci., August 17, 2005; 25(33): 7529 - 7537. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. J. Hoover, A. L. Weaver, P. I. Harness, and S. L. Hooper Combinatorial and Cross-Fiber Averaging Transform Muscle Electrical Responses with a Large Stochastic Component into Deterministic Contractions J. Neurosci., March 1, 2002; 22(5): 1895 - 1904. [Abstract] [Full Text] [PDF] |
||||