Bapta-AM Has No Significant Effects On Synaptic Plasticity At The Crayfish Lateral Extensor Neuromuscular Junction

Abstract

Short-term synaptic plasticity (more specifically, facilitation and depression) has been linked to long-term plasticity, which is involved in memory formation. Facilitation and depression are opposing aspects of plasticity that work dynamically through calcium-mediated mechanisms. We tested the effects of reduced intracellular calcium levels on synaptic plasticity using paired-pulse stimulation ofcrayfish lateral extensor muscles and the fast calcium chelator BAPTAAM (bis-(aminophenoxy)ethane-tetraacetic acid, membrane permeant acetomethoxy ester form). While we expected facilitation, we observed only depression in each of our treatments. The control of DMSO (dimethyl sulfoxide) in saline had significantly greater EJP amplitudes than either the saline control or the BAPTA-AM treatment, which had similar EJP amplitudes. We found that BAPTA had no significant effects on synaptic plasticity at either 25 or 35 msec time delay between paired-pulse intervals, though our control treatments of either saline or DMSO in saline were significantly different for each experiment. Our results did not support or refute previous studies on the role of calcium in synaptic plasticity.