EFFECTS OF CHRONIC ETHANOL ON CURRENTS CARRIED THROUGH CALCIUM CHANNELS IN APLYSIA

Voltage clamp techniques were used to monitor the effects of chronic exposure to ethanol (EtOH) on current carried through calcium channels in an identified neuron of cultured abdominal ganglia from Aplysia californica. Exposure to 200 mM EtOH for periods up to 3 weeks did not change the baseline characteristics of current carried through calcium channels, nor did it alter its acute sensitivity to either 100 mM or 300 mM EtOH challenge. The currents that we examined were equivalent when carried by calcium or barium, and EtOH had similar effects on currents carried by these two ions. The population of voltage-dependent calcium channels studied here does not show development of tolerance after chronic exposure to EtOH.