Carbon Monoxide Modulation of Nitric Oxide Induced Retrograde Signaling in Crayfish Neuromuscular Junction

Abstract

We tested the effects of nitric oxide (NO), and nitric oxide with carbon monoxide (CO) on retrograde signaling in crayfish extensor muscle cells. Nitric oxide is known to increase retrograde signaling, and therefore increase the amplitude of excitatory post-synaptic potentials (EPSPs). We predicted that EPSPs would increase in amplitude when exposed to NO, and when NO was paired with CO we predicted that the EPSPs would further increase. We tested this hypothesis through intracellular recording of excitatory postsynaptic potentials (EPSPs). We found that in comparison to baseline measurements (without NO and NO+CO), the experimental groups did show significant increases in the amplitudes of the measured EPSPs. Furthermore, the NO+CO experimental group had the greatest average increase in EPSP amplitude, and therefore the greatest increase in retrograde signaling.