Time course of neuroinflammation in rats after induction of traumatic brain injury by controlled cortical impact

Traumatic brain injury (TBI) is considered as one of the most common neurologic disorders after stroke and Alzheimer's disease. Understanding the pathogenesis of TBI helps to discover new treatment strategies. Neuroinflammation is the main feature of TBI. We aimed to measure expression level of tumor necrosis factor-α (TNF-α), one of the main factor of neuroinflammation, in the rat brain at different times after induction of TBI.

TBI was exerted to adult male rats under anesthesia by controlled cortical compact (CCI) model. Trauma was exerted to parieto-occipital cortex by 4.5 m/s speed. TBI was confirmed by staining the injured area. TNF-α level was measured in the injured brain region semiquantitatively by western blot technique at 0, 3h. 6h, 24h, and 5 days after TBI.

TBI induced an injury with 2mm depth in the parieto-occipital cortex.  Compared to control and sham-operated rats, TNF-α level significantly increased in the injured brain area 3h and 6h after TBI (p < 0.01).

TNF-α level increases considerably in rat brain during the first hours after TBI in CCI model. This data is useful in designing the pharmacologic or non-pharmacologic protocols for preventing TBI-induced neuroinflammation.