CALP2 Calcium/Calmodulin Agonist does not affect End-Plate Potential Amplitudes at the Crayfish Neuromuscular Junction

Abstract

Ca²⁺/calmodulin (CaM) is a protein that can bind to and activate a variety of target proteins within the pre- and postsynaptic cells of the neuromuscular junction (NMJ). An important presynaptic CaM target is CaM-kinase II (CaMKII). Upon activation, CaMKII has been shown to increase neurotransmitter release from the vertebrate presynaptic terminal. This study addressed the effects of CALP2, a CaM agonist, at the crayfish NMJ. No previous research has studied the effect of CaM agonists on end-plate potential (EPP) amplitudes at the crayfish NMJ, hence the novelty and importance of our experiments. Using single and paired-pulse stimulation of the motor nerve, we measured EPPs in the absence and presence of CALP2. Our results indicate that the application of CALP2 had no significant effect on EPPs. However, this preliminary research highlights the need for a more in-depth investigation to circumvent concerns of small sample sizes and possible CALP2 degradation.