THE ANTINARCOLEPTIC DRUG MODAFINIL INCREASES GLUTAMATE RELEASE IN THALAMIC AREAS AND HIPPOCAMPUS

THE antinarcoleptic drug modafinil [(diphenyl-methyl)sulfinyl-2-acetam ide; Modiodal] dose-dependently inhibits the activity of GABA neurons in the cerebral cortex and in the nucleus accumbens, as well as in sle ep-related brain areas such as the medial preoptic area and the poster ior hypothalamus. This study examined the effects of modafinil (30-300 mg/kg, i.p.) on dialysate glutamate and GABA levels in the ventromedi al (VMT) and ventrolateral (VLT) thalamus and hippocampal formation (H ip) of the awake rat. The results show a maximal increase in glutamate release in these brain regions at the 100 mg/kg dose, associated with a lack of effect on GABA release. Thus modafinil may increase excitat ory glutamatergic transmission in these regions, altering the balance between glutamate and GABA transmission.