[3H]inositol trisphosphate specific binding in two brain regions of long and short sleep mice

The present investigation determined the binding characteristics of the radiolabeled second messenger, [3H]In(1,4,5)P3, in cerebral cortical and cerebellar membrane fragments from ethanol sensitive (LS) and resistant (SS) mice. The data demonstrated that in the two brain regions examined, LS and SS mouse lines do not differ with regard to their maximal receptor binding capacities or dissociation constants for [3H]In(1,4,5)P3. Moreover, [3H]In(1,4,5)P3 specific binding in cerebellum is inhibited in the presence of ethanol to the same extent in both mouse lines. It is concluded that the differential behavioral and cerebellar sensitivities to ethanol previously observed in these mouse lines do not reflect differences in [3H]In(1,4,5)P3 receptor binding characteristics of the brain regions examined.