Zn2+ modulates the responses of rat dorsal horn neuron to C-fiber stimulation and excitatory amino acids.
- Author:
Chang Hoon AHN
1
;
Hong Kee SHIN
;
Jin Hyuk KIM
Author Information
1. Department of Physiology, College of Medicine, Hanyang University, 17 Haengdang-Dong, Sungdong-Gu, Seoul, South Korea. shinhg@email.hanyang.ac.kr
- Publication Type:Original Article
- Keywords:
Dorsal horn neuron;
C-fiber stimulation;
NMDA;
Kainate;
Zinc;
Ca2 -EDTA
- MeSH:
Animals;
Central Nervous System;
Electric Stimulation;
Excitatory Amino Acids*;
Hyperalgesia;
Kainic Acid;
N-Methylaspartate;
Neurons;
Posterior Horn Cells*;
Rats*;
Spinal Cord;
Zinc
- From:The Korean Journal of Physiology and Pharmacology
2000;4(6):455-461
- CountryRepublic of Korea
- Language:English
-
Abstract:
Zinc contained in the neurons of central nervous system is activity-dependently released and then attenuates NMDA (N-methyl-D-aspartate)-induced neurotoxicity while augmenting non-NMDA-induced neurodegeneration. Zinc also has been reported to produce antinociceptive action on the inflammation- and nerve injury-induced hyperalgesia in the behavioral test. In this study, we investigated the effects of zinc on the responses of dorsal horn cells to NMDA, kainate and graded electrical stimulation of C-fibers. In the majority of WDR cells (70.6%), zinc current-dependently inhibited WDR cell responses to NMDA and in the remaining cells, produced biphasic responses; excitation followed by inhibition. Zinc augmented the responses of WDR cells to iontophoretical application of kainate. The dominant effect of Zn2+ on the responses of WDR cells to C-fiber stimulation was excitatory, but inhibition, excitation-inhibition and no change of the responses to C-fiber stimulation were induced. Ca2+-EDTA antagonized the excitatory or inhibitory effects of Zn2+ on the WDR cell responses. These experimental findings suggest that Zn2+ modulates the transmission of sensory information in the rat spinal cord.
