Electrophysiological Characterization of AMPA and NMDA Receptors in Rat Dorsal Striatum.
10.4196/kjpp.2009.13.3.209
- Author:
Seung Hyun JEUN
1
;
Hyeong Seok CHO
;
Ki Jung KIM
;
Qing Zhong LI
;
Ki Wug SUNG
Author Information
1. Department of Pharmacology, Medical Research Center for Cell Death Disease Research Center, The Catholic University of Korea, Seoul 137-701, Korea. sungkw@catholic.ac.kr
- Publication Type:Original Article
- Keywords:
Striatum;
AMPA;
Glutamate receptor;
NMDA;
Patch clamp
- MeSH:
6-Cyano-7-nitroquinoxaline-2,3-dione;
Adamantane;
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid;
Animals;
Excitatory Postsynaptic Potentials;
N-Methylaspartate;
Piperidines;
Plastics;
Rats;
Receptors, AMPA;
Receptors, Glutamate;
Receptors, N-Methyl-D-Aspartate;
Synaptic Transmission;
Thalamus
- From:The Korean Journal of Physiology and Pharmacology
2009;13(3):209-214
- CountryRepublic of Korea
- Language:English
-
Abstract:
The striatum receives glutamatergic afferents from the cortex and thalamus, and these synaptic transmissions are mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and N-methyl-D-aspartate (NMDA) receptors. The purpose of this study was to characterize glutamate receptors by analyzing NMDA/AMPA ratio and rectification of AMPA and NMDA excitatory postsynaptic currents (EPSCs) using a whole-cell voltage-clamp method in the dorsal striatum. Receptor antagonists were used to isolate receptor or subunit specific EPSC, such as (DL)-2-amino-5-phosphonovaleric acid (APV), an NMDA receptor antagonist, ifenprodil, an NR2B antagonist, CNQX, an AMPA receptor antagonist and IEM-1460, a GluR2-lacking AMPA receptor blocker. AMPA and NMDA EPSCs were recorded at -70 and +40 mV, respectively. Rectification index was calculated by current ratio of EPSCs between +50 and -50 mV. NMDA/AMPA ratio was 0.20+/-0.05, AMPA receptor ratio of GluR2-lacking/GluR2-containing subunit was 0.26+/-0.05 and NMDA receptor ratio of NR2B/NR2A subunit was 0.32+/-0.03. The rectification index (control 2.39+/-0.27) was decreased in the presence of both APV and combination of APV and IEM-1460 (1.02+/-0.11 and 0.93+/-0.09, respectively). These results suggest that the major components of the striatal glutamate receptors are GluR2-containing AMPA receptors and NR2A-containing NMDA receptors. Our results may provide useful information for corticostriatal synaptic transmission and plasticity studies.
