Intra-amygdala spermidine administration improves inhibitory avoidance performance in rats

In the present study, we investigated the effect of immediate post-training bilateral infusion of spermidine, a polyamine agonist, into the amygdala o n inhibitory avoidance learning of rats. Bilateral microinjection of spermi dine (0.02-20 nmol) caused an increase in test step-down latencies at high concentrations. Administration of arcaine (0.002-0.2 nmol), an antagonist o f the NMDA receptor polyamine binding site, decreased test step-down latenc ies. On the other hand, co-administration of arcaine and spermidine complet ely reversed the spermidine-induced increase of test step-down latencies. T hese results provide evidence that polyamines may be involved in learning a nd memory modulation in the amygdala. (C) 2001 Elsevier Science B.V. All ri ghts reserved.