Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 7-Day Trial for You or Your Team.

Learn More →

Tonic transmitter release in a graded potential synapse

Tonic transmitter release in a graded potential synapse Abstract 1. We studied graded synaptic transmission in the fly photoreceptor-interneuron synapse by using intracellular in situ recordings from pre- and postsynaptic cells. 2. A large presynaptic hyperpolarization after light adaptation, caused by the activation of the electrogenic Na+/K+ pump, drastically reduced the conspicuous postsynaptic dark noise. At the same time, the postsynaptic neurons depolarized, with an increase of input resistance of 5-10 M omega. 3. The spectral characteristics of the postsynaptic membrane noise in dark and during noise reduction, together with the other results, suggested that the transmitter release decreased dramatically approximately 12 mV below the resting potential of the presynaptic photoreceptors. 4. During the postsynaptic noise reduction, the saturated and subsaturated first-order visual interneuron responses were increased up to 9 mV with a time constant of recovery of approximately 10 s. This increase was shown to be caused by the negative shift of the reversal potential of the transmitter-gated (mainly Cl-) conductance, caused apparently by the reduced transmitter input. 5. The results strongly suggest that the photoreceptor transmitter release in fly is tonic, even in dark, and further support the modulation of the synaptic voltage transfer by postsynaptic Cl- extrusion. Copyright © 1995 the American Physiological Society http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Neurophysiology The American Physiological Society

Tonic transmitter release in a graded potential synapse

Download PDF
4 pages

Loading next page...
 
/lp/the-american-physiological-society/tonic-transmitter-release-in-a-graded-potential-synapse-DANA4V562A

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
The American Physiological Society
Copyright
Copyright © 1995 the American Physiological Society
ISSN
0022-3077
eISSN
1522-1598
Publisher site
See Article on Publisher Site

Abstract

Abstract 1. We studied graded synaptic transmission in the fly photoreceptor-interneuron synapse by using intracellular in situ recordings from pre- and postsynaptic cells. 2. A large presynaptic hyperpolarization after light adaptation, caused by the activation of the electrogenic Na+/K+ pump, drastically reduced the conspicuous postsynaptic dark noise. At the same time, the postsynaptic neurons depolarized, with an increase of input resistance of 5-10 M omega. 3. The spectral characteristics of the postsynaptic membrane noise in dark and during noise reduction, together with the other results, suggested that the transmitter release decreased dramatically approximately 12 mV below the resting potential of the presynaptic photoreceptors. 4. During the postsynaptic noise reduction, the saturated and subsaturated first-order visual interneuron responses were increased up to 9 mV with a time constant of recovery of approximately 10 s. This increase was shown to be caused by the negative shift of the reversal potential of the transmitter-gated (mainly Cl-) conductance, caused apparently by the reduced transmitter input. 5. The results strongly suggest that the photoreceptor transmitter release in fly is tonic, even in dark, and further support the modulation of the synaptic voltage transfer by postsynaptic Cl- extrusion. Copyright © 1995 the American Physiological Society

Journal

Journal of Neurophysiology – The American Physiological Society

Published: Jul 1, 1995

There are no references for this article.