Long-term potentiation of neuronal excitation in the central nucleus of the rat amygdala revealed by imaging with a voltage-sensitive dye

We examined the propagation pattern of neuronal excitation in slices from the central nucleus of the rat amygdala (CeA) using optical imaging with a voltage-sensitive dye. We analyzed the mechanisms for the long-term potentiation (LTP) of neuronal excitation induced by conditioning stimulation. High-frequency conditioning stimulation induced NMDA receptor-, cAMP-, and PKA-dependent LTP of neuronal excitation in the lateral part of the CeA. The bath application of forskolin also induced LTP that was PKA-dependent. These results suggest that the potentiation of neuronal excitation in the lateral part of the CeA is induced by the activation of intracellular cAMP/PKA signaling, which is triggered by the influx of Ca2+ via NMDA receptors.