Mild Experimental Brain Injury in the Rat Induces Cognitive Deficits Associated with Regional Neuronal Loss in the Hippocampus

Publisher Website
Google Scholar
Abstract
Memory dysfunction following mild human traumatic brain injury (TBI) is a common clinical observation, but the pathologic substrate underlying this loss of function has not been well-characterized. In the present study, we examined the effects of a mild lateral fluid percussion (FP) brain injury on memory dysfunction, neuronal cell loss in specific regions of the hippocampus, and breakdown of the blood–brain barrier (BBB). A Morris Water Maze (MWM) memory paradigm was used to assess memory retention in rats 42 h after lateral FP brain injury (n = 11) or sham injury (n = 10). At the completion of cognitive testing, animals were sacrificed and neuronal cell loss in the hippocampi was examined with Nissl staining. Immunoreactivity to anti-rat IgG was used to evaluate the extent of BBB disruption. A significant correlation was observed between posttraumatic memory scores and neuronal loss in the hilus of the dentate gyrus (p < 0.005). To our knowledge, these observations are the first to suggest an association between cognitive deficits following a mild experimental brain injury and neuropathological changes in the hippocampus.