Fumitremorgin A (FTA) is the most potent mycotoxin among fumitremorgins, a series of tremorgenic toxins isolated from Aspergillus fumigatus by Yamazaki et al. in 1971. When injected intravenously in experimental animals, FTA causes tremor and generalized tonic-clonic convulsion. Both dopaminergic and gamma-aminobutyric acid (GABA)-ergic systems are involved in FTA-induced abnormal behaviors. On the other hand insignificant participation of serotonergic mechanism in modulation of those behavioral states elicited by FTA is conclusively suggested.