CATECHOL O-METHYLTRANSFERASE INHIBITOR TOLCAPONE HAS MINOR INFLUENCE ON PERFORMANCE IN EXPERIMENTAL MEMORY MODELS IN RATS

Two catechol O-methyltransferase inhibitors, peripherally acting entac apone and also centrally acting tolcapone, were tested regarding their capacity to influence learning and memory in adult intact rats. Tolca pone was also studied in rats treated with scopolamine, in adult rats lesioned in the nuclei basalis magnocellularis, and in aged rats. Spat ial working memory performance (radial-arm maze) of intact rats was fa cilitated following pretraining i.p. administration of tolcapone (10 m g/kg). Entacapone was ineffective at doses of 10 and 30 mg/kg. Senesce nt poor performers improved their accomplishment in the spatial memory task (linear-arm maze) under the influence of tolcapone. Scopolamine (1 mg/kg) impaired working memory performance. Bilateral lesions in th e nucleus basalis magnocellularis reduced choline acetyltransferase ac tivity in the frontal cortex by 26% and retarded the learning rate of spatial place task. Tolcapone was not able to counteract the performan ce deficits in these models. It is concluded that tolcapone can either slightly improve or impair the memory functions depending on task spe cific elements and performance factors.