Disruption of vertebrate monosynaptic habituation by ethyl alcohol

The effects of ethyl alcohol on neuronal plasticity were examined using a model systems preparation of monosynaptic habituation: the lateral column to motoneuron pathway of the isolated frog spinal cord. Two fundamental effects of alcohol on this system were demonstrated. First, alcohol always depressed the ventral root responses to lateral column stimulation when stimulus intensity was held constant across conditions. This was accompanied by an increase in the amount of habituation produced as training progressed. Second, when stimulus intensity was increased in the alcohol condition so that responses were equated with pre-alcohol response amplitudes, the amount of habituation was markedly decreased. Results are discussed both in terms of proposed mechanisms of habituation and of possible pharmacological interactions with this simple example of response plasticity.