Exposure to a Predator Scent Induces Chronic Behavioral Changes in Rats Previously Exposed to Low-level Blast: Implications for the Relationship of Blast-Related TBI to PTSD.
Blast-related mild traumatic brain injury (mTBI) has been unfortunately common in veterans who served in the recent conflicts in Iraq and Afghanistan. The postconcussion syndrome associated with these mTBIs has frequently appeared in combination with post-traumatic stress disorder (PTSD). The presence of PTSD has complicated diagnosis, since clinically, PTSD and the postconcussion syndrome of mTBI have many overlapping symptoms. In particular, establishing how much of the symptom complex can be attributed to the psychological trauma associated with PTSD in contrast to the physical injury of traumatic brain injury has proven difficult. Indeed, some have suggested that much of what is now being called blast-related postconcussion syndrome is better explained by PTSD. The relationship between the postconcussion syndrome of mTBI and PTSD is complex. Association of the two disorders might be viewed as additive effects of independent psychological and physical traumas suffered in a war zone. However, we previously found that rats exposed to repetitive low-level blast exposure in the absence of a psychological stressor developed a variety of anxiety and PTSD-related behavioral traits that were present months following the last blast exposure. Here, we show that a single predator scent challenge delivered 8 months after the last blast exposure induces chronic anxiety related changes in blast-exposed rats that are still present 45 days later. These observations suggest that in addition to independently inducing PTSD-related traits, blast exposure sensitizes the brain to react abnormally to a subsequent psychological stressor. These studies have implications for conceptualizing the relationship between blast-related mTBI and PTSD and suggest that blast-related mTBI in humans may predispose to the later development of PTSD in reaction to subsequent psychological stressors.
Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Georgina
G
Perez-Garcia
Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Miguel A
MA
Gama Sosa
Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Rita
R
De Gasperi
Department of Neurotrauma, Operational and Undersea Medicine, Naval Medical Research Center , Silver Spring, MD , USA.
Margaret
M
Lashof-Sullivan
Department of Neurotrauma, Operational and Undersea Medicine, Naval Medical Research Center , Silver Spring, MD , USA.
Eric
E
Maudlin-Jeronimo
Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA; Department of Neurosurgery, University of Virginia, Charlottesville, VA, USA.
James R
JR
Stone
Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Fatemeh
F
Haghighi
Department of Neurotrauma, Operational and Undersea Medicine, Naval Medical Research Center , Silver Spring, MD , USA.
Stephen T
ST
Ahlers
Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Neurology Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY, USA.
Gregory A
GA
Elder
animal models; blast; post-traumatic stress disorder; postconcussion syndrome; rat; traumatic brain injury