Ethanol increases resting potential magnitude and increases EJP amplitude in the presence of serotonin

Abstract

Serotonin has been shown to modulate synapses, and ethanol has been shown to increase serotonin levels in the synaptic cleft. In this experiment, the contribution of ethanol to resting membrane potential (RMP) and excitatory junction potentials (EJP) in crayfish neuromuscular junctions was explored by manipulating the concentrations of serotonin and ethanol in the extracellular fluid and comparing these RMP and EJP values. Results showed that ethanol polarized RMP, an unforeseen effect, and increased EJP amplitude, supporting the hypothesis that ethanol acts to increase serotonin concentration in the synapse, in a concentration dependent manner.