Favorable modulation in neurotransmitters: effects of chronic anterior thalamic nuclei stimulation observed in epileptic monkeys.

Abstract

Anterior thalamic nuclei (ATN) stimulation has been shown to be effective in seizure reduction. Nevertheless, the underlying mechanisms remain unclear. This study investigated the changes in the amino acid levels during chronic, single-sided ATN-stimulation in the hippocampi of rhesus monkeys with mesial temporal lobe epilepsy induced by kainic acid (KA). The concentrations of glutamate, γ-aminobutyric acid, aspartate and taurine in the dialysates from bilateral hippocampi were determined at multiple time points using high-performance liquid chromatography. The results showed that after KA administration, the aspartate, γ-aminobutyric acid and taurine levels increased significantly in the sham-stimulation group, although the γ-aminobutyric acid and taurine levels gradually returned to the basal levels in the chronic stage. The glutamate level showed an initial decrease in the acute stage and a subsequent increase in the chronic stage. Chronic ATN-stimulation reversed the increases in the glutamate and aspartate levels, and maintained the initial increases in the γ-aminobutyric acid and taurine levels till the end of the experiment. These amino acid levels, however, were not affected by either contralateral KA injection or contralateral ATN-stimulation, suggesting that the observed effects of ATN-stimulation are restricted to the ipsilateral hemisphere. Our data suggest that chronic ATN-stimulation may induce favorable modulations in the amino acid levels in the hippocampi of epileptic monkeys, which may be an important mechanism underlying the effects of ATN-stimulation in epilepsy treatment.

• Authors: Lin Shi, An-Chao Yang, Jun-Ju Li, Da-Wei Meng, Bo Jiang, Jian-Guo Zhang
• Journal: Experimental neurology (Exp Neurol) Vol. 265 Pg. 94-101 (Mar 2015) ISSN: 1090-2430 [Electronic] United States
• PMID: 25596526 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier Inc. All rights reserved.

Chemical References

• Neurotransmitter Agents

Topics

• Animals
• Anterior Thalamic Nuclei (chemistry, metabolism)
• Deep Brain Stimulation (methods)
• Epilepsy, Temporal Lobe (metabolism, therapy)
• Macaca mulatta
• Male
• Microdialysis (methods)
• Neurotransmitter Agents (analysis, metabolism)