Neurotransmitter evaluation in the hippocampus of rats after intracerebral injection of TsTX scorpion toxin

Abstract

ABSTRACT:TsTX is an α-type sodium channel toxin that stimulates the discharge of neurotransmitters from neurons. In the present study we investigated which neurotransmitters are released in the hippocampus after TsTX injection and if they are responsible for electrographic or histopathological effects. Microdialysis revealed that the toxin increased glutamate extracellular levels in the hippocampus; however, levels of gamma-aminobutyric acid (GABA), glycine, 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were not significantly altered. Neurodegeneration in pyramidal cells of hippocampus and electroencephalographic alterations caused by the toxin were blocked by pretreatment with riluzole, a glutamate release inhibitor. The present results suggest a specific activity of TsTX in the hippocampus which affects only glutamate release.

Tb1, a Neurotoxin from Tityus bahiensis Scorpion Venom, Induces Epileptic Seizures by Increasing Glutamate Release

“…All of these events are consistent to what has already been described for other scorpion toxins [11,25,51,52], and they are in accordance with the ability of scorpion toxins to act on ion channels, modifying their functioning. Similar convulsive effects are found in clinical cases of severe envenomation worldwide [53][54][55][56][57][58].…”