IN-VIVO LONG-TERM POTENTIATION IN THE INSULAR CORTEX - NMDA RECEPTOR DEPENDENCE

It has been demonstrated that the insular cortex (IC) plays an importa nt role in the acquisition and storage of different aversive motivated learning tasks like conditioned taste aversion, spatial maze and inhi bitory avoidance. It is of particular interest to investigate whether activity-dependent modification of synaptic efficacy, a presumptive me chanism for learning and memory, is present in this cortical region. H ere, we address this issue by examining the induction of synaptic plas ticity, long-term potentiation (LTP) in in vivo preparations. The resu lts showed that high frequency stimulation of the basolateral amygdalo id nucleus (Bla) induced LTP in the IC. The LTP induced by tetanus was blocked by application of the N-methyl-D-aspartate (NMDA) receptor an tagonists CPP and MK-801, indicating that NMDA receptors were responsi ble for its induction. These results suggest that in vivo tetanus indu ced LTP of the Bla-IC projection is a possible mechanism for the memor y-related functions performed by the IC. (C) 1998 Elsevier Science B.V .