In the same capsaicin-induced migraine model in adult guinea pigs, VPA suppressed the elevated c-Fos expression in the trigeminal nucleus caudalis (TNC) (Cutrer et al., 1995a) in a manner mediated via GABAA, but not GABAB, receptors (Cutrer and Moskowitz, 1996). The gene discussed is FOS; the disease is migraine disorder.