title: Blast overpressure induces shear-related injuries in the brain of rats exposed to a mild traumatic brain injury.
abstract: BACKGROUND
  Blast-related traumatic brain injury (TBI) has been a significant cause of injury in the military operations of Iraq and Afghanistan, affecting as many as 10-20% of returning veterans. However, how blast waves affect the brain is poorly understood. To understand their effects, we analyzed the brains of rats exposed to single or multiple (three) 74.5 kPa blast exposures, conditions that mimic a mild TBI.
  
  
  RESULTS
  Rats were sacrificed 24 hours or between 4 and 10 months after exposure. Intraventricular hemorrhages were commonly observed after 24 hrs. A screen for neuropathology did not reveal any generalized histopathology. However, focal lesions resembling rips or tears in the tissue were found in many brains. These lesions disrupted cortical organization resulting in some cases in unusual tissue realignments. The lesions frequently appeared to follow the lines of penetrating cortical vessels and microhemorrhages were found within some but not most acute lesions.
  
  
  CONCLUSIONS
  These lesions likely represent a type of shear injury that is unique to blast trauma. The observation that lesions often appeared to follow penetrating cortical vessels suggests a vascular mechanism of injury and that blood vessels may represent the fault lines along which the most damaging effect of the blast pressure is transmitted.
authors.affiliation: Department of Veterans Affairs Medical Center, General Medical Research Service, Bronx, New York, USA. miguel.gama-sosa@mssm.edu.
authors.forename: Miguel A Gama
authors.initials: MA
authors.lastname: Sosa
authors.forename: Rita
authors.initials: R
authors.lastname: De Gasperi
authors.forename: Alejandro J
authors.initials: AJ
authors.lastname: Paulino
authors.forename: Paul E
authors.initials: PE
authors.lastname: Pricop
authors.forename: Michael C
authors.initials: MC
authors.lastname: Shaughness
authors.forename: Eric
authors.initials: E
authors.lastname: Maudlin-Jeronimo
authors.forename: Aaron A
authors.initials: AA
authors.lastname: Hall
authors.forename: William G M
authors.initials: WG
authors.lastname: Janssen
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Yuk
authors.forename: Nathan P
authors.initials: NP
authors.lastname: Dorr
authors.forename: Dara L
authors.initials: DL
authors.lastname: Dickstein
authors.forename: Richard M
authors.initials: RM
authors.lastname: McCarron
authors.forename: Mikulas
authors.initials: M
authors.lastname: Chavko
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Hof
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Ahlers
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Elder
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001753:Blast Injuries / Q000150:complications / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D020201:Brain Hemorrhage, Traumatic / Q000209:etiology / Q000473:pathology / Q000503:physiopathology / Q000523:psychology; D001930:Brain Injuries / Q000209:etiology / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology; D003712:Dendrites / Q000473:pathology / Q000502:physiology; D004195:Disease Models, Animal; D005106:Exploratory Behavior / Q000502:physiology; D005911:Gliosis / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D008297:Male; D017628:Microglia / Q000473:pathology / Q000502:physiology; D009474:Neurons / Q000473:pathology / Q000502:physiology; D011312:Pressure; D011897:Random Allocation; D051381:Rats; D020318:Rats, Long-Evans; D065853:Spatial Learning / Q000502:physiology; D013997:Time Factors