(+)-epi-Clausenamide, but not (−)-epi-clausenamide, showed more potential than (−)-clausenamide on facilitating synaptic transmission in CA1 region of hippocampal synapses

Effect of (+)-epi-clausenamide and (−)-epi-clausenamide on synaptic transmission in CA1 region of hippocampal slice was compared in this study. (+)-epi-Clausenamide showed more potency than (−)-clausenamide on either induction or maintenance of long term potentiation (LTP). Effect of (+)-epi-clausenamide on potentiating basic synaptic transmission was also superior to (−)-clausenamide. However, (−)-epi-clausenamide showed only slight effects on synaptic transmission, suggesting that the effect of (+)-epi-clausenamide and (−)-epi-clausenamide on synaptic transmission depended on their chirality. Calcium influx was not involved in (+)-epi-clausenamide facilitating synaptic transmission in this study. (+)-epi-Clausenamide might promote glutamate release through the activation of Synapsin I(Ser9) to activate the downstream effectors which play a key role in synaptic plasticity. Elucidating the mechanism of each optical isomer of clausenamide by electrophysiological methods provided basis for therapeutic strategies for neurological disorders.

► (+)-epi-clausenamide potentiated synaptic transmission in a dose dependent manner. ► Calcium influx was not involved in (+)-epi-clausenamide facilitating synaptic transmission. ► Excitatory transmitter release might play key roles in the mechanism.