The recently discovered profound differential sensitivity of cerebellar Purkinje (P) cells in long-sleep (LS) versus short-sleep (SS) mice to the depressant effects of locally applied ethanol was extended in this study. First, the sensitivity of Purkinje neurons from HS mice (an outbred stock of mice from which the LS and SS lines were derived), was found to be almost exactly intermediate between the values for the long-sleep and short-sleep animals. Second, no differential sensitivity in long-sleep versus short-sleep hippocampal pyramidal neurons was observed. This was true using both spontaneous and evoked activity. Third, no differential sensitivity of P cells was seen in long- versus short-sleep mice with local application of halothane. Taken together with previous reports, these data strongly suggest that whatever genetically determined central nervous alterations result in the differential soporific effects of ethanol in the two (LS and SS) mouse lines, such alterations are brain region- and depressant drug-specific rather than generalized.