The effects of expoure of rats to ethanol fedding ( at concentrations 4 % , 8 T , and 16 % ) for 1 and 2 weeks on the response of rat phrenic - nerve diaphragm perpartion to repeated stimulation by supramaximal shocks were investigated .Two rates of stimulation were used , namely ; I and 5 / second . with a rate of stimulation I / second the results showed that 4 To ethanol feeding for one week was without effect . Increasing the time of 4 % ethanol feeding to 2 weeks resulted in a significant decrease in the height of the indirect response , both at the beginning and end of the experiment . The decrease in the indirect response was potentiated by increasing the concentration of ethanol and the time of exposure to alcohol feeding . with the rate of stimulation 5 / second , complete neuromuscular block occurred readily in the preparations taken from rats fed 8 % ethanol for 2 weeks and 16 % ethanol for one and two weeks .