Traumatic brain injury (TBI) is an important cause of disability in humans.
Neuroactive steroids, such as
progesterone and
dehydroepiandrosterone (
DHEA), are neuroprotective in TBI models. However in order to design potential neuroprotective strategies based on
neuroactive steroids it is important to determine whether its brain levels are altered by TBI. In this study we have used a weight-drop model of TBI in young adult female mice to determine the levels of
neuroactive steroids in the brain and plasma at 24h, 72 h and 2 weeks after injury. We have also analyzed whether the levels of
neuroactive steroids after TBI correlated with the neurological score of the animals. TBI caused neurological deficit detectable at 24 and 72 h, which recovered by 2 weeks after injury. Brain levels of
progesterone, tetrahydroprogesterone (THP), isopregnanolone and 17β-estradiol were decreased 24h, 72 h and 2 weeks after TBI.
DHEA and brain
testosterone levels presented a transient decrease at 24h after lesion. Brain levels of
progesterone and
DHEA showed a positive correlation with neurological recovery. Plasma analyses showed that
progesterone was decreased 72 h after lesion but, in contrast with brain
progesterone, its levels did not correlate with neurological deficit. These findings indicate that TBI alters the levels of
neuroactive steroids in the brain with independence of its plasma levels and suggest that the pharmacological increase in the brain of the levels of
progesterone and
DHEA may result in the improvement of neurological recovery after TBI.