Cerebral Barrier Breakdowns Following High Velocity Impacts and Rotational Acceleration: Neuropathological and Behavioral Assessment
Abstract
Rotational acceleration and high velocity impacts are the predominant causes of traumatic brain injury (TBI). In this project, the effects of shock wave exposure and mechanical impact-rotational acceleration were investigated in male and female mice using two pre-clinical TBI models. In the first study, functional outcomes, neuronal activation, and blood-brain barrier (BBB) permeability were evaluated in mice after ventral exposure to primary (shock wave) and tertiary (impact/acceleration) effects in an Advanced Blast Simulator. Behavioral testing indicated no differences on anxiety- or depressive-like tests after blast TBI, but mice demonstrated greater activity levels on the elevated zero maze test, where female mice travelled the farthest. On the tail suspension test, injured mice displayed reduced immobility compared to uninjured mice; possibly an indication of an agitated behavior state in this task. There were sex differences in c-Fos expression in the paraventricular thalamic nucleus and greater c-Fos activation in the amygdala of female mice that may correlate with reported hyperactivity in females post-injury. Four hours after shock wave exposure, BBB permeability was evident on the superficial brain parenchyma of injured animals, but not sham mice. This study demonstrated behavioral and neuronal activation correlates in female rodents after blast injury, which could be relevant to post-traumatic stress disorder in women. TBI research has primarily focused on effects related to the brain, but reports of traumatic meningeal enhancement in TBI patients may have clinical significance. The second study focused on the consequences of impact-rotational acceleration on the meninges and visual system after one or four injuries produced by the Closed-Head Impact Model of Engineered Rotational Acceleration (CHIMERA) device. In male mice, meningeal dynamic contrast enhancement was elevated soon after single or repetitive impacts.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 14, 2022
- Accession Number
- AD1186297
Entities
People
- Eileen Mcnamara
Organizations
- Uniformed Services University of the Health Sciences