Acute toluene exposure decreases extracellular γ-aminobutyric acid in the globus pallidus but not in striatum: a microdialysis study in awake, freely moving rats

Abstract

Intracerebral brain microdialysis was performed in awake, freely moving rats to study the effect of acute inhalation exposure of toluene (2000 ppm, 2 h) on extracellular levels of γ-aminobutyric acid (GABA) within the globus pallidus and the striatum. GABA within the globus pallidus decreased (20%) during and after (26%) exposure to toluene, while no reduction was seen in the striatal GABA level during exposure. After the exposure there was a tendency towards an increase (maximally 37%) in striatal GABA. 2 h of perfusion with tetrodotoxin (10⁻⁶ M) decreased (32%) the extracellular GABA levels within the globus pallidus. The results suggest that the effect of acute toluene exposure varies with brain region and that the GABA output from the striatum to globus pallidus is more affected by the exposure than the GABA release within the striatum.