抄録
The medial prefrontal cortex (mPFC) receives monosynaptic ascending projections from both the hippocampus (HP) and the amygdala (AM, mainly the posterior basolateral nucleus) in rats. We have observed that HP- and AM-PFC pathways express long-term potentiation and depression (LTP and LTD), and that the HP-PFC consists of two kinds of electrophysiological properties in posterior dorsal and ventral CA1s (i.e., pdCA1- and vCA1-PFC pathways) in urethane-anesthetized rats. We examined here the synaptic interaction between the pdCA1 (or vCA1)- and the AM-PFC in an evoked potential level, and the effect of tetanization of AM on synaptic plasticity of the HP-PFC. Under conditions where both the pdCA1 and the AM evoked mPFC field potential at one recording site, semi-LTP of pdCA1-PFC increased as a result of in-phase high-frequency burst tetanization of AM-PFC but decreased when it was out-of-phase. We also observed the in- and out-of-phase effects of high or low frequent burst tetanization of AM on the semi-LTP of vCA1-PFC or the semi-LTD of pdCA1-PFC, respectively. Our results suggest that the synaptic interaction between HP- and AM-PFC pathways is controlled in both timing-dependent and -independent manners. [Jpn J Physiol 54 Suppl:S190 (2004)]
