JN AJP: Endocrinology and Metabolism
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Neurophysiol 74: 470-473, 1995;
0022-3077/95 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Uusitalo, R. O.
Right arrow Articles by Weckstrom, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Uusitalo, R. O.
Right arrow Articles by Weckstrom, M.

Journal of Neurophysiology, Vol 74, Issue 1 470-473, Copyright © 1995 by APS

ARTICLES

Tonic transmitter release in a graded potential synapse

R. O. Uusitalo, M. Juusola, E. Kouvalainen and M. Weckstrom
Department of Physiology, University of Oulu, Finland.

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.


This article has been cited by other articles:


Home page
 J. Gen. Physiol.Home page
L. Zheng, G. G. de Polavieja, V. Wolfram, M. H. Asyali, R. C. Hardie, and M. Juusola
Feedback Network Controls Photoreceptor Output at the Layer of First Visual Synapses in Drosophila
J. Gen. Physiol., April 24, 2006; 127(5): 495 - 510.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
J. Borycz, J. A. Borycz, M. Loubani, and I. A. Meinertzhagen
tan and ebony Genes Regulate a Novel Pathway for Transmitter Metabolism at Fly Photoreceptor Terminals
J. Neurosci., December 15, 2002; 22(24): 10549 - 10557.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
R. O. Uusitalo and M. Weckstrom
Potentiation in the First Visual Synapse of the Fly Compound Eye
J Neurophysiol, April 1, 2000; 83(4): 2103 - 2112.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
O Schmachtenberg and G Bicker
Nitric oxide and cyclic GMP modulate photoreceptor cell responses in the visual system of the locust
J. Exp. Biol., January 1, 1999; 202(1): 13 - 20.
[Abstract] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online