Citation

Washington PM, Forcelli PA, Wilkins T, Zapple D, Parsadanian M, Burns MP. J. Neurotrauma 2012; 29(13): 2283-2296.

Affiliation

Georgetown University, Department of Neuroscience, Washington, District of Columbia, United States; pmw37@georgetown.edu.

Copyright

(Copyright © 2012, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2012.2456

PMID

22642287

Abstract

Traumatic brain injury (TBI) can cause a broad array of behavioral problems including cognitive and emotional deficits. Human studies comparing neurobehavioral outcome after TBI suggest that cognitive impairments increase with injury severity, but emotional problems such as anxiety and depression do not. To determine whether cognitive and emotional impairments increase as a function of injury severity we exposed mice to sham, mild, moderate or severe controlled cortical impact (CCI) and evaluated performance in a variety of neurobehavioral tests in the same animals before assessing lesion volume as a histological measure of injury severity. Increasing cortical impact depth successfully produced lesions of increasing severity in our model. We found that cognitive impairments in the Morris water maze increased with injury severity, as did the degree of contralateral torso flexion, a measure of unilateral striatal damage. TBI also caused deficits in emotional behavior as quantified in the forced swim test, elevated plus maze and prepulse inhibition of acoustic startle - but these deficits were not dependent on injury severity. Stepwise regression analyses revealed that Morris water maze performance and torso flexion predicted the majority of the variability in lesion volume. In summary, we find that cognitive deficits increase in relation to injury severity, but emotional deficits do not. Our data suggest the threshold for emotional changes after experimental TBI is low, with no variation in behavioral deficits between mild and severe brain injury.

Language: en