Reduced spontaneous activity in the dorsal cochlear nucleus of Scn8a mutant mice

Spontaneous activity was recorded in the dorsal cochlear nucleus of brain s lices from mice homozygous for the med-J and jolting mutations in the neuro nal sodium channel alpha-subunit Scn8a. Densities of spontaneously active n eurons in slices from both mutants were significantly lower than in control slices. Spontaneous firing patterns with bursts of action potentials were recorded from approximately 50% of the neurons in control slices, but the t ypical bursting patterns were not observed in neurons of med-J and jolting mouse slices. The results suggest that this voltage-gated sodium channel is essential for the spontaneous bursting firing of cochlear nucleus cartwhee l neurons. This mutant animal model may be useful for the study of the func tional roles of cochlear nucleus neurons. (C) 1999 Elsevier Science B.V. Al l rights reserved.