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Behavioural Neurology
Volume 2018, Article ID 6037015, 10 pages
https://doi.org/10.1155/2018/6037015
Research Article

Gait and Conditioned Fear Impairments in a Mouse Model of Comorbid TBI and PTSD

1VA Portland Health Care System, Portland, OR, USA
2Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
3Portland State University, Portland, OR, USA
4Department of Neurology, Department of Medicine, Division of Pulmonary and Critical Care Medicine, Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA

Correspondence should be addressed to Miranda M. Lim; ude.usho@riml

Received 10 February 2018; Revised 6 July 2018; Accepted 1 August 2018; Published 20 September 2018

Academic Editor: Laura Piccardi

Copyright © 2018 Peyton Teutsch et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Study Objectives. Traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) commonly cooccur. Approaches to research and treatment of these disorders have been segregated, despite overlapping symptomology. We and others have hypothesized that comorbid TBI + PTSD generates worse symptoms than either condition alone. We present a mouse model of comorbid TBI + PTSD to further explore this condition. Methods. A mouse model of TBI + PTSD was generated using the single prolonged stress (SPS) protocol in combination with the controlled cortical impact (CCI) protocol. This resulted in four experimental groups: control, TBI, PTSD, and TBI + PTSD. Behavioral phenotyping included gait analysis, contextual fear conditioning, acoustic startle response, and prepulse inhibition. Results. Mice in the TBI + PTSD group showed a significantly impaired gait compared to their counterparts with TBI alone as well as control mice. Mice in the TBI + PTSD group showed significantly impaired contextual fear recall compared to controls. Prepulse inhibition testing revealed intact acoustic startle and auditory sensory gating. Conclusions. These results indicate that SPS paired with CCI in mice produces unique behavioral impairments in gait and fear recall that are not present in either condition alone. Further studies are underway to examine additional behavioral, physiological, and pathological phenotypes in this combined model of TBI + PTSD.