Steroid profiling in brain and plasma of adult zebra finches following traumatic brain injury

Traumatic brain injury (TBI) is a serious health concern and a leading cause of death. Emerging evidence strongly suggests that steroid hormones (estrogens, androgens, and progesterone) modulate TBI outcomes by regulating inflammation, oxidative stress, free radical production, and extracellular calcium levels. Despite this growing body of evidence on steroid-mediated neuroprotection, very little is known about the local synthesis of these steroids following injury. Here, we examine the effect of TBI on local neurosteroid levels around the site of injury and in plasma in adult male and female zebra finches. Using ultrasensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS), we examined estrogens, androgens, and progesterone in the entopallium and plasma of injured and uninjured animals. Three days after injury, elevated levels of 17 beta-estradiol (E-2), estrone (E-1), and testosterone (T) were detected near injured brain tissue with a corresponding increase in E-2 also detected in plasma. Taken together, these results provide further evidence that TBI alters neurosteroid levels and are consistent with studies showing that neurosteroids provide neuroprotection following injury.

Automated summary

Traumatic brain injury (TBI) is a serious health concern that can lead to death. This study investigates the effect of TBI on local neurosteroid levels near the injury site and in plasma. The results show that TBI alters the levels of estrogen, androgen, and progesterone, which may contribute to neuroprotection.