Febrile convulsions affect ultrasonic vocalizations in the rat pup.

Febrile convulsions are common among preschool children and are studied experimentally with hyperthermia in rat pups. Although heat-induced convulsions (HC+) can affect behaviors in adulthood, to date no one has examined the effects on behavior in the neonatal period. We examined the effects of HC+ on ultrasonic vocalizations (USVs) and mother-pup interactions in P10- and P12-aged rat pups. On P7, 34 pups were subjected to HC+ (32 controls, HC-) and behaviors were observed on P10 and P12. For mother-pup interactions, a trend for a sex x treatment interaction was found, with HC- females and HC+ males interacting more often with their dam. Further, HC+ pups vocalized more than controls (HC-) and male pups vocalized more than females. Interestingly, females and HC+ pups displayed less efficient USVs. However, mother-pup interactions did not significantly differ between HC+ and HC- pups, despite greater vocalization. Thus, dams differentiate among their pups, perhaps through USVs.