Effects of Blast-induced Neurotrauma on Pressurized Rodent Middle Cerebral Arteries

Uylissa A. Rodriguez, Yaping Zeng, Margaret A. Parsley, Bridget Hawkins, Donald Prough, Douglas Dewitt

Research output: Contribution to journalArticle

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Abstract

Though there have been studies on the histopathological and behavioral effects of blast exposure, fewer have been dedicated to blast's cerebral vascular effects. Impact (i.e., non-blast) traumatic brain injury (TBI) is known to decrease pressure autoregulation in the cerebral vasculature in both humans and experimental animals. The hypothesis that blast-induced traumatic brain injury (bTBI), like impact TBI, results in impaired cerebral vascular reactivity was tested by measuring myogenic dilatory responses to reduced intravascular pressure in rodent middle cerebral arterial (MCA) segments from rats subjected to mild bTBI using an Advanced Blast Simulator (ABS) shock tube. Adult, male Sprague-Dawley rats were anesthetized, intubated, ventilated and prepared for Sham bTBI (identical manipulation and anesthesia except for blast injury) or mild bTBI. Rats were randomly assigned to receive Sham bTBI or mild bTBI followed by sacrifice 30 or 60 min post-injury. Immediately after bTBI, righting reflex (RR) suppression times were assessed, euthanasia at the time points post-injury was completed, the brain was harvested and the individual MCA segments were collected, mounted and pressurized. As the intraluminal pressure perfused through the arterial segments was reduced in 20 mmHg increments from 100 to 20 mmHg, MCA diameters were measured and recorded. With decreasing intraluminal pressure, MCA diameters steadily increased significantly above baseline in the Sham bTBI groups while MCA dilator responses were significantly reduced (p < 0.05) in both bTBI groups as evidenced by the impaired, smaller MCA diameters recorded for the bTBI groups. In addition, RR suppression in the bTBI groups was significantly (p < 0.05) higher than in the Sham bTBI groups. MCA's collected from the Sham bTBI groups exhibited typical vasodilatory properties to decreases in intraluminal pressure while MCA's collected following bTBI exhibited significantly impaired myogenic vasodilatory responses to reduced pressure that persisted for at least 60 min after bTBI.

Original languageEnglish (US)
JournalJournal of visualized experiments : JoVE
Issue number146
DOIs
StatePublished - Apr 1 2019

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Middle Cerebral Artery
Rodentia
Brain
Pressure
Righting Reflex
Traumatic Brain Injury
Rats
Blood Vessels
Brain Concussion
Blast Injuries
Euthanasia
Wounds and Injuries
Shock tubes
Sprague Dawley Rats

ASJC Scopus subject areas

  • Neuroscience(all)
  • Chemical Engineering(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)

Cite this

Effects of Blast-induced Neurotrauma on Pressurized Rodent Middle Cerebral Arteries. / Rodriguez, Uylissa A.; Zeng, Yaping; Parsley, Margaret A.; Hawkins, Bridget; Prough, Donald; Dewitt, Douglas.

In: Journal of visualized experiments : JoVE, No. 146, 01.04.2019.

Research output: Contribution to journalArticle

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