The effects of age and genotype upon the jaw-jerk reflex in inbred mice

The threshold of the jaw-jerk reflex to electrical stimulation of the hard palate was measured in a cross-sectional design using C57BL/6J and DBA/2J mice at 2, 8, 20, 25, and 30 mo of age, in order to assess CNS sensitivity as a function of increasing age. The thresholds of DBA/2J mice were higher than those of C57BL/6J mice at all ages tested. No age-related changes in threshold were observed in mice of either strain.