Excitability of auditory neurons in the dorsal and ventral cochlear nuclei of DBA2 and C57BL6 mice

Extracellular response properties were studied in neurons of the dorsal and ventral divisions of the cochlear nucleus (DCN and VCN, respectively) of $\text{DBA}\text{2}$ (DBA) and $\text{C57BL}\text{6}$ (C57) mice. Mice of the former inbred strain show susceptibility to audiogenic seizures and have severe high frequency hearing loss when young; mice of the latter strain do not. Whereas afterdischarges had been readily observed in the inferior colliculus of DBA mice in a previous study, they were never observed in the cochlear nucleus. The incidence of nonmonotonic intensity functions, the slopes of intensity functions, and the incidence of inhibition in response areas indicated that inhibition was diminished in the DCN of DBA mice. However, in the VCN, these response properties did not differ between the two strains. There appeared to be an “amplification” of excitability (i.e., attenuation of inhibition) from VCN to DCN to inferior colliculus in DBA mice.