To establish the electric controlled cortical impact (eCCI)-induced traumatic brain injury (TBI) model in rats with different severity in degree, which may serve as a suitable platform to provide experimental evidence for the pathophysiological following TBI.

A total of 40 male Wistar rats were randomly divided into 3 experimental groups and sham group. TBI rats (n=10/group) were positioned beneath the controlled cortical impactor device (eCCI) and subjected to impact injury at 2 mm depth of penetration, for a sustained depression of 200 ms, at 4 m/s, 5 m/s, 6 m/s velocity for mild, moderate, and severe TBI, respectively. Sham-operated rats (n=10) underwent identical surgical procedures, including craniotomy, without receiving the cortical impact. Neurological function and regional cerebral flow (24 h after CCI), contusion volume, histopathological, and ultrastructural changes (48 h after CCI) were measured, respectively.

The severity of the pathological changes in rats was increased as the injury aggravated. The eCCI device impacted the brain at 4 m/s, 5 m/s, 6 m/s velocity for mild, moderate, and severe TBI, respectively. TBI groups showed impaired neurological function, and decreased rCBF lower than that of sham-operated group (all P<0.01). Furthermore, neuronal pathological abnormalities in TBI groups, including neuron shrinking, perineuronal vacuole, and structural abnormalities of mitochondria. Increased severity of injury was apparent following the increased level of the impacted velocity, and significant differences were observed between TBI groups (P<0.05).

The TBI animal model with mild, moderate, and severe brain injury can be established successfully by 4 m/s, 5 m/s, and 6 m/s of impact velocity respectively with the eCCI-6.3 device. The novel eCCI-induced TBI model in rats possibly serves as a novel useful approach in the development of TBI models.

Traumatic brain injury (TBI); Controlled cortical impact(CCI); Animal model; Rats