Model matters : Differential outcomes in traumatic optic neuropathy pathophysiology between blunt and blast-wave mediated head injuries

Copyright © 2023 Elsevier Inc. All rights reserved..

Over 3 million people in the United States live with long-term disability because of a traumatic brain injury (TBI). The purpose of this study was to characterize and compare two different animal models of TBI (blunt head trauma and blast TBI) to determine common and divergent characteristics of these models. With recent literature reviews noting the prevalence of visual system injury in animal models of TBI, coupled with clinical estimates of 50-75% of all TBI cases, we decided to assess commonalities, if they existed, through visual system injury. A unilateral (left directed) blast and repeat blast model injury with coup-contra-coup injury patterns were compared to a midline blunt injury. Injuries were induced in adult male mice to observe and quantify visual deficits. Retinal ganglion cell loss and axonal degeneration in the optic tract, superior colliculus, and lateral geniculate nuclei were examined to trace injury outcomes throughout major vision-associated areas. Optokinetic response, immunohistochemistry, and western blots were analyzed. Where a single blunt injury produces significant visual deficits a single blast injury appears to have less severe visual consequences. Visual deficits after repeat blasts are similar to a single blast. Single blast injury induces contralateral damage to the right optic chiasm and tract whereas bilateral injury follows a single blunt TBI. Repeat blast injuries are required to see degeneration patterns in downstream regions similar to the damage seen in a single blunt injury. This finding is further supported by amyloid precursor protein (APP) staining in injured cohorts. Blunt injured groups present with staining 1.2 mm ahead of the optic nerve, indicating axonal breakage closer to the optic chiasm. In blast groups, APP was identifiable in a bilateral pattern only in the geniculate nucleus. Evidence for unilateral neuronal degeneration in brain tissue with bilateral axonal ruptures are pivotal discoveries in this model differentiation. Analysis of the two injury models suggests that there is a significant difference in the histological outcomes dependent on injury type, though visual system injury is likely present in more cases than are currently diagnosed clinically.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:372

Enthalten in:

Experimental neurology - 372(2024) vom: 14. Feb., Seite 114613

Sprache:

Englisch

Beteiligte Personen:

Hetzer, S M [VerfasserIn]
O'Connell, C [VerfasserIn]
Lallo, V [VerfasserIn]
Robson, M [VerfasserIn]
Evanson, N K [VerfasserIn]

Links:

Volltext

Themen:

Amyloid beta-Protein Precursor
Blast injury
Closed-head injury
Journal Article
Neuro ophthalmology
Neurodegeneration
Optic neuropathy
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Traumatic brain injury
Visual neuroscience

Anmerkungen:

Date Completed 03.01.2024

Date Revised 17.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.expneurol.2023.114613

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM36487211X