Carboxy PTIO decreases the amplitude of EPSP generated in the crayfish tail extensor muscle despite changes in temperature

Abstract

Our objective was to investigate the effect that a NO scavenger, Carboxy PTIO, has on the EPSP (excitatory postsynaptic membrane potential) of the crayfish tail extensor muscle, with changing temperature. We measured the membrane potential of the extensor muscle fibres from a dissected crayfish tail in the absence and presence of NO at specific temperatures ranging from 17 C to 0C using intra-cellular recording. Our hypotheses, that EPSP amplitude increases with a decrease in temperature, and decreases in the absence of NO, were supported by our experimental findings. We observed that EPSP amplitude increased as we decreased the temperature and this increase was reduced after saturating the crayfish saline with Carboxy PTIO, demonstrating the effects of simultaneously altering temperature and NO (present vs. absent).