Publication
Title
Increased hippocampal noradrenaline is a biomarker for efficacy of vagus nerve stimulation in a limbic seizure model
Author
Abstract
Vagus nerve stimulation (VNS) is an effective adjunctive treatment for medically refractory epilepsy. In this study, we measured VNS-induced changes in hippocampal neurotransmitter levels and determined their potential involvement in the anticonvulsive action of VNS, to elucidate the mechanism of action responsible for the seizure suppressing effect of VNS in an animal model for limbic seizures. We used in vivo intracerebral microdialysis to measure VNS-induced changes in hippocampal extracellular concentrations of noradrenaline, dopamine, serotonin and GABA in freely moving, male Wistar rats. During the same experiment, the effect of VNS on pilocarpine-induced limbic seizures was assessed using video-EEG monitoring. The involvement of VNS-induced increases in hippocampal noradrenaline in the mechanims of action of VNS was evaluated by blocking hippocampal α2-receptors. VNS produced a significant increase in hippocampal noradrenaline concentration (69 ± 16% above baseline levels). VNS also increased the latency between pilocarpine infusion and the onset of epileptiform discharges, and reduced the duration and severity of pilocarpine-induced limbic seizures. A strong positive correlation was found between the noradrenergic and anticonvulsive effects of VNS. Blockade of hippocampal α2-receptors reversed the seizure-suppressing effect of VNS. VNS induces increases in extracellular hippocampal noradrenaline, which are at least partly responsible for its seizure-suppressing effect in a model for limbic seizures, and constitute a potential biomarker for the efficacy of VNS in temporal lobe epilepsy.
Language
English
Source (journal)
Journal of neurochemistry. - Oxford
Publication
Oxford : 2011
ISSN
0022-3042
Volume/pages
117:3(2011), p. 461-469
ISI
000289464500010
Full text (Publisher's DOI)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
External links
Web of Science
Record
Identification
Creation 16.11.2011
Last edited 24.07.2017