RDX binds to the GABA(A) receptor-convulsant site and blocks GABA(A) receptor-mediated currents in the amygdala: A mechanism for RDX-induced seizures

Williams, LR; Aroniadou-Anderjaska, V; Qashu, F; Finne, H; Pidoplichko, V; Bannon, DI; Braga, MFM

HERO ID

1065723

Reference Type

Journal Article

Year

2011

Language

English

PMID

21362589

HERO ID 1065723
In Press No
Year 2011
Title RDX binds to the GABA(A) receptor-convulsant site and blocks GABA(A) receptor-mediated currents in the amygdala: A mechanism for RDX-induced seizures
Authors Williams, LR; Aroniadou-Anderjaska, V; Qashu, F; Finne, H; Pidoplichko, V; Bannon, DI; Braga, MFM
Journal Environmental Health Perspectives
Volume 119
Issue 3
Page Numbers 357-363
Abstract <strong>BACKGROUND: </strong>Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a high-energy, trinitrated cyclic compound that has been used worldwide since World War II as an explosive in both military and civilian applications. RDX can be released in the environment by way of waste streams generated during the manufacture, use, and disposal of RDX-containing munitions and can leach into groundwater from unexploded munitions found on training ranges. For &gt; 60 years, it has been known that exposure to high doses of RDX causes generalized seizures, but the mechanism has remained unknown.<br /><br /><strong>OBJECTIVE: </strong>We investigated the mechanism by which RDX induces seizures.<br /><br /><strong>METHODS AND RESULTS: </strong>By screening the affinity of RDX for a number of neurotransmitter receptors, we found that RDX binds exclusively to the picrotoxin convulsant site of the γ-aminobutyric acid type A (GABA(A)) ionophore. Whole-cell in vitro recordings in the rat basolateral amygdala (BLA) showed that RDX reduces the frequency and amplitude of spontaneous GABA(A) receptor-mediated inhibitory postsynaptic currents and the amplitude of GABA-evoked postsynaptic currents. In extracellular field recordings from the BLA, RDX induced prolonged, seizure-like neuronal discharges.<br /><br /><strong>CONCLUSIONS: </strong>These results suggest that binding to the GABA(A) receptor convulsant site is the primary mechanism of seizure induction by RDX and that reduction of GABAergic inhibitory transmission in the amygdala is involved in the generation of RDX-induced seizures. Knowledge of the molecular site and the mechanism of RDX action with respect to seizure induction can guide therapeutic strategies, allow more accurate development of safe thresholds for exposures, and help prevent the development of new explosives or other munitions that could pose similar health risks.
Doi 10.1289/ehp.1002588
Pmid 21362589
Wosid WOS:000287926700025
Is Certified Translation No
Dupe Override No
Comments Source: Web of Science WOS:000287926700025
Is Public Yes
Language Text English
Keyword amygdala; GABA(A) currents; GABA(A) receptors; RDX; seizures
Is Qa No
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