Sickness behaviors following medial frontal cortical contusions in male rats

Behaviors associated with sickness (food consumption, weight maintenance, exploratory activity and grooming frequency) were examined on post-surgical days 1, 3, 5, 7 and 9 in male rats treated with progesterone (4 mg/kg) and/or vehicle. Rats with medial frontal cortex contusions showed reduced food consumption on days 1 and 3 (p < 0.01), reduced weight maintenance on days 1, 3, 5, 7 and 9 (p < 0.01), reduced grooming frequency on day 1 (p < .01), and reduced exploratory activity on day 1 (p < 0.01), after injury compared to sham rats. Contusion induced behaviors were not attenuated with 5 days of progesterone treatment (p > 0.05). Progesterone did reduce lesion size at 9 days after injury (p < 0.05). Our results suggest sickness behaviors occur after traumatic brain injury and that they might not respond to some neurosteroidal agents.