LTP in the rat basal amygdala induced by perirhinal cortex stimulation in vivo

The present study examined the effects of ventral perirhinal cortex (vPRC) stimulation on evoked field potentials (EPs) in the basal amygdala (BN), us ing extracellular recording techniques. Single pulse stimulation of the VPR C reliably evoked a negative field potential in the BN that was missing in the lateral nucleus. Paired-pulses delivered to the VPRC induced a short-la sting facilitation at intervals between 15 and 120 ms. Application of brief theta burst stimulation to the vPRC produced an enduring long-term potenti ation (LTP) that reached 150% of control values. The induction of LTP was n or accompanied by a decrease in paired-pulse facilitation. These results su ggest that emotional learning involving complex stimulus representations ma y be mediated by cortico-amygdalar projections amenable to LTP. NeuroReport 11:525-530 (C) 2000 Lippincott Williams & Wilkins.