Dependence of visual and cognitive outcomes on animal holder configuration in a rodent model of blast overpressure exposure

Rachael S Allen; Cara T Motz; Anayesha Singh; Andrew Feola; Lauren Hutson; Amber Douglass; Sriganesh Ramachandra Rao; Lara A Skelton; Lidia Cardelle; Katie L Bales; Kyle Chesler; Kaavya Gudapati; C. Ross Ethier; Matthew M Harper; Steven J Fliesler; Machelle T Pardue

doi:10.1016/j.visres.2021.07.008

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Dependence of visual and cognitive outcomes on animal holder configuration in a rodent model of blast overpressure exposure

Journal article

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Dependence of visual and cognitive outcomes on animal holder configuration in a rodent model of blast overpressure exposure

Rachael S Allen, Cara T Motz, Anayesha Singh, Andrew Feola, Lauren Hutson, Amber Douglass, Sriganesh Ramachandra Rao, Lara A Skelton, Lidia Cardelle, Katie L Bales, …

Vision research (Oxford), Vol.188, pp.162-173

11/2021

DOI: 10.1016/j.visres.2021.07.008

PMCID: PMC8440444

PMID: 34333201

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Abstract

•Type of animal holder used in blast studies affects visual and cognitive outcomes.•Enclosed holders may cause secondary damage to the contralateral eye.•Damage may involve concussive injury or blast wave reflection off the holder wall.•Open holders may damage the brain due to head movement (whiplash).•Effects other than the primary blast wave should be considered post-blast exposure. Blast-induced traumatic brain injury is the signature injury of modern military conflicts. To more fully understand the effects of blast exposure, we placed rats in different holder configurations, exposed them to blast overpressure, and assessed the degree of eye and brain injury. Anesthetized Long-Evans rats received blast exposures directed at the head (63 kPa, 195 dB-SPL) in either an “open holder” (head and neck exposed; n = 7), or an “enclosed holder” (window for blast exposure to eye; n = 15) and were compared to non-blast exposed (control) rats (n = 22). Outcomes included optomotor response (OMR), electroretinography (ERG), and spectral domain optical coherence tomography (SD-OCT) at 2, 4, and 6 months post-blast, and cognitive function (Y-maze) at 3 months. Spatial frequency and contrast sensitivity were reduced in ipsilateral blast-exposed eyes in both holders (p < 0.01), while contralateral eyes showed greater deficits with the enclosed holder (p < 0.05). Thinner retinas (p < 0.001) and reduced ERG a- and b- wave amplitudes (p < 0.05) were observed for both ipsilateral and contralateral eyes with the enclosed, but not the open, holder. Rats in the open holder showed cognitive deficits compared to rats in the enclosed holder (p < 0.05). Overall, the animal holder configuration used in blast exposure studies can significantly affect outcomes. Enclosed holders may cause secondary damage to the contralateral eye by concussive injury or blast wave reflection off the holder wall. Open holders may damage the brain via rapid head movement (contrecoup injury). These results highlight additional factors to be considered when evaluating patients with blast exposure or developing models of blast injury.

Blast

Eye

Retina

TBI

Traumatic brain injury

Details

Title: Subtitle: Dependence of visual and cognitive outcomes on animal holder configuration in a rodent model of blast overpressure exposure
Creators: Rachael S Allen - Emory University
Cara T Motz - Emory University
Anayesha Singh - Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States.
Andrew Feola - Emory University
Lauren Hutson - Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States.
Amber Douglass - Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States.
Sriganesh Ramachandra Rao - Research Service, VA Western NY Healthcare System, Buffalo, NY, United States
Lara A Skelton - University at Buffalo
Lidia Cardelle - Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States.
Katie L Bales - Emory University
Kyle Chesler - Emory University
Kaavya Gudapati - Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States.
C. Ross Ethier - Emory University
Matthew M Harper - University of Iowa
Steven J Fliesler - University at Buffalo
Machelle T Pardue - Emory University
Resource Type: Journal article
Publication Details: Vision research (Oxford), Vol.188, pp.162-173
DOI: 10.1016/j.visres.2021.07.008
PMID: 34333201
PMCID: PMC8440444
NLM abbreviation: Vision Res
ISSN: 0042-6989
eISSN: 1878-5646
Publisher: Elsevier Ltd
Grant note: DOI: 10.13039/100008065, name: Georgia Research Alliance; DOI: 10.13039/100000053, name: National Eye Institute; DOI: 10.13039/100000738, name: Department of Veterans Affairs
Language: English
Date published: 11/2021
Academic Unit: Biology; Ophthalmology and Visual Sciences
Record Identifier: 9984180937902771

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