Correlation between mEPSC Amplitude and Rise Time upon the Blockade of AMPA Receptor Desensitization at Hippocampal Synapses.
- Author:
Su Hyun JUNG
1
;
Sukwoo CHOI
Author Information
1. Department of Neuroscience, Ewha Institute of Neuroscience (EIN), School of Medicine, Ewha Womans University, Seoul, Korea. sukwoo@mm. ewha.ac.kr
- Publication Type:Original Article
- Keywords:
Fusion pore;
Neurotransmitter release;
Postfusional control;
mEPSC
- MeSH:
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid*;
Excitatory Postsynaptic Potentials;
Neurotransmitter Agents;
Receptors, AMPA*;
Receptors, Glutamate;
Receptors, Neurotransmitter;
Synapses*;
Synaptic Transmission
- From:The Korean Journal of Physiology and Pharmacology
2002;6(2):81-86
- CountryRepublic of Korea
- Language:English
-
Abstract:
Conventional views of synaptic transmission generally overlook the possibility of "postfusional- control" the regulation of the speed or completeness of transmitter release upon vesicular fusion. However, such regulation often occurs in non-neuronal cells where the dynamics of fusion-pore opening is critical for the speed of transmitter release. In case of synapses, the slower the transmitter release, the smaller the size and rate-of-rise of postsynaptic responses would be expected if postsynaptic neurotransmitter receptors were not saturated. This prediction was tested at hippocampal synapses where postsynaptic AMPA-type glutamate receptors (AMPAR) were not generally saturated. Here, we found that the small miniature excitatory postsynaptic currents (mEPSCs) showed significantly slower rise times than the large mEPSCs when the sucrose-induced mEPSCs recorded in cyclothiazide (CTZ), a blocker for AMPAR desensitization, were sorted by size. The slow rise time of the small mEPSCs might result from slow release through a non-expanding fusion pore, consistent with postfusional control of neurotransmitter release at central synapses.
