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Autonomic responses to blast overpressure can be elicited by exclusively exposing the ear in rats.

ABSTRACT: Blast overpressure has become an increasing cause of brain injuries in both military and civilian populations. Though blast's direct effects on the cochlea and vestibular organs are active areas of study, little attention has been given to the ear's contribution to the overall spectrum of blast injury. Acute autonomic responses to blast exposure, including bradycardia and hypotension, can cause hypoxia and contribute to blast-induced neurotrauma. Existing literature suggests that these autonomic responses are elicited through blast impacting the thorax and lungs. We hypothesize that the unprotected ear also provides a vulnerable locus for blast to cause autonomic responses. We designed a blast generator that delivers controlled overpressure waves into the ear canal without impacting surrounding tissues in order to study the ear's specific contribution to blast injury. Anesthetized adult rats' left ears were exposed to a single blast wave ranging from 0 to 110 PSI (0-758?kPa). Blast exposed rats exhibited decreased heart rates and blood pressures with increased blast intensity, similar to results gathered using shock tubes and whole-body exposure in the literature. While rats exposed to blasts below 50 PSI (345?kPa) exhibited increased respiratory rate with increased blast intensity, some rats exposed to blasts higher than 50 PSI (345?kPa) stopped breathing immediately and ultimately died. These autonomic responses were significantly reduced in vagally denervated rats, again similar to whole-body exposure literature. These results support the hypothesis that the unprotected ear contributes to the autonomic responses to blast.

SUBMITTER: Sandlin DS

PROVIDER: S-EPMC6291641 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

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Autonomic responses to blast overpressure can be elicited by exclusively exposing the ear in rats.

Sandlin David S DS Yu Yue Y Huang Jun J Zhang Chunming C Arteaga Alberto A AA Lippincott John K JK Peeden Erin O H EOH Guyton Ryan R RR Chen Lan L Beneke Laura L S LLS Allison Jerome C JC Zhu Hong H Zhou Wu W

Journal of otology 20180309 2

Blast overpressure has become an increasing cause of brain injuries in both military and civilian populations. Though blast's direct effects on the cochlea and vestibular organs are active areas of study, little attention has been given to the ear's contribution to the overall spectrum of blast injury. Acute autonomic responses to blast exposure, including bradycardia and hypotension, can cause hypoxia and contribute to blast-induced neurotrauma. Existing literature suggests that these autonomic ...[more]

PMID: 30559764

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Dataset Information

Autonomic responses to blast overpressure can be elicited by exclusively exposing the ear in rats.

Publications

Autonomic responses to blast overpressure can be elicited by exclusively exposing the ear in rats.

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