The Role of NAAG as a Possible Postsynaptic Modulator at the Crayfish Neuromuscular Junction

Abstract

We investigated the effects of NAAG and ?-NAAG on synaptic transmission in the crayfish neuromuscular junction (NMJ). Previous research has shown that exogenous NAAG regulates EPSPs in mammals both presynaptically and postsynaptically. To determine whether NAAG modulates synaptic transmission at the crayfish NMJ (and whether the modulation is pre- or postsynaptic), we measured paired-pulse ratios (PPRs) and excitatory post-synaptic potential (EPSP) magnitudes before and after adding NAAG or ?-NAAG. We observed no change in PPR for any experiment, and we found that ?-NAAG had no effect on EPSP magnitude. However in one experiment, we observed a decrease in EPSP magnitude after applying NAAG.