N-Acetylaspartylglutamate and Glutamate Carboxypetidase II are Present at the Crayfish Neuromuscular Junction

Abstract

N-acetylaspartylglutamate (NAAG) is the most abundant neuropeptide in the mammalian central nervous system and has been shown to be involved in axon-glia communication in crayfish. Studies have established that NAAG is hydrolyzed by glutamate carboxypetidase II (GCP II), resulting in the breakdown of NAAG into NAA and glutamate. Additionally, NAAG is an agonist of the metabotropic glutamate receptor, type 3 (mGluR3). In our study, we explored the existence of GCP II at the crayfish neuromuscular junction by inhibiting GCP II and mGluR3. We measured excitatory post synaptic potentials (EPSPs) in control settings, in the presence of GCP II inhibitors and in the presence of mGluR3 antagonists with GCP II inhibitors to determine if GCP II affected the strength of the potentials generated at the neuromuscular junction. Reductions in EPSPs in experimental groups compared to the control suggest that GCP II plays a role at the crayfish neuromuscular junction.