The Dependence of Optimal Post-Tetanic Potentiation in Crayfish Muscle Cells on Nitric Oxide Concentration

Abstract

We conducted this research to determine how synaptic activity, namely post-tetanic potentiation (PTP) amplitude and duration, in crayfish muscle cells is affected by differing levels of nitric oxide (NO). We hypothesized that, relative to control conditions, medium (100 μm sodium nitroprusside) levels of NO would have no effect on PTP, high (200 μm sodium nitroprusside) and low (50 μm sodium nitroprusside) levels of NO would negatively impact PTP, and an absence of NO would result in a lack of PTP. Through the use of two drugs, L-NAME and sodium nitroprusside, we exposed a dissected crayfish to various levels of NO before using intracellular recording to measure PTP several times for each NO concentration. Compared to control levels, we found that all NO concentrations below or equal to that provided by 100 μm nitroprusside resulted in a decrease of PTP while high NO levels resulted in an increase in PTP thus disproving our hypothesis.