Presynaptic alpha-7 nicotinic acetylcholine receptors modulate excitatory synaptic transmission in hippocampal neurons.
- Author:
Zhen-Wei LIU
1
;
Sheng YANG
;
Yong-Xiang ZHANG
;
Chuan-Hui LIU
Author Information
1. Beijing Institute of Pharmacology and Toxicology, Beijing 100850. zhenwei_Liu@yahoo.com
- Publication Type:Journal Article
- MeSH:
Animals;
Bungarotoxins;
physiology;
Dimethylphenylpiperazinium Iodide;
pharmacology;
Glutamic Acid;
pharmacology;
Hippocampus;
physiology;
Male;
Neurons;
physiology;
Nicotinic Agonists;
pharmacology;
Pacemaker, Artificial;
Patch-Clamp Techniques;
Rats;
Rats, Wistar;
Receptors, Nicotinic;
physiology;
Receptors, Presynaptic;
physiology;
Synapses;
physiology;
Synaptic Transmission;
alpha7 Nicotinic Acetylcholine Receptor
- From:
Acta Physiologica Sinica
2003;55(6):731-735
- CountryChina
- Language:English
-
Abstract:
The effects of presynaptic nicotinic acetylcholine receptors (nAChRs) on excitatory synaptic transmission in CA1 pyramidal neurons of the rat hippocampus were examined by blind whole-cell patch clamp recording from hippocampal slice preparations. Local application of the nAChRs agonist dimethylphenyl-piperazinium iodide (DMPP) did not induce a postsynaptic current response in CA1 pyramidal cells. However, DMPP enhanced the frequency and amplitude of spontaneous excitatory postsynaptic current (sEPSC) in these cells in a dose-dependent manner. This enhancement was blocked by the selective nicotinic alpha-7 receptor antagonist alpha-bungarotoxin, but not by the antagonist mecamylamine, hexamethonium or dihydro-beta-erythroidine. The frequency of miniature excitatory postsynaptic current (mEPSC) in CA1 pyramidal neurons was also increased by application of DMPP, indicating a presynaptic site of action of the agonist. Taken together, these results suggest that activation of presynaptic nAChRs in CA1 pyramidal neurons, which contain alpha-7 subunits, potentiates presynaptic glutamate release and consequently modulate excitatory synaptic transmission in the hippocampus.
