Chronic Histological Outcomes of Indirect Traumatic Optic NEU-Ropathy in Adolescent Mice: Persistent Degeneration and Tem-Porally Regulated Glial Responses

Hetzer, Shelby M.; Shalosky, Emily M.; Torrens, Jordyn N.; Evanson, Nathan K.

doi:10.20944/preprints202111.0097.v1

Cited by 4 publications

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

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

Hetzer,

O’Connell,

Lallo

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

Over 3 million people in the United States live with long-term disability as a result 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. Blast, repeat blast, and blunt injury 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 right optic chiasm and tract whereas bilateral injury follows a single blunt injury. 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 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 suggest 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.

show abstract

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

Hetzer,

O’Connell,

Lallo

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

An Update to Biomechanical and Biochemical Principles of Retinal Injury in Child Abuse

Shahraki,

Suh

2024

Children

View full text Add to dashboard Cite

Abusive head trauma (AHT) is an extreme form of physical child abuse, a subset of which is shaken baby syndrome (SBS). While traumatic injury in children is most readily observed as marks of contusion on the body, AHT/SBS may result in internal injuries that can put the life of the child in danger. One pivotal sign associated with AHT/SBS that cannot be spotted with the naked eye is retinal injury (RI), an early sign of which is retinal hemorrhage (RH) in cases with rupture of the retinal vasculature. If not addressed, RI can lead to irreversible outcomes, such as visual loss. It is widely assumed that the major cause of RI is acceleration–deceleration forces that are repeatedly imposed on the patient during abusive shaking. Still, due to the controversial nature of this type of injury, few investigations have ever sought to delve into its biomechanical and/or biochemical features using realistic models. As such, our knowledge regarding AHT-/SBS-induced RI is significantly lacking. In this mini-review, we aim to provide an up-to-date account of the traumatology of AHT-/SBS-induced RI, as well as its biomechanical and biochemical features, while focusing on some of the experimental models that have been developed in recent years for studying retinal hemorrhage in the context of AHT/SBS.

show abstract

Brief Oxygen Exposure after Traumatic Brain Injury Hastens Recovery and Promotes Adaptive Chronic Endoplasmic Reticulum Stress Responses

Torrens

Hetzer

Evanson

2023

IJMS

Self Cite

View full text Add to dashboard Cite

Traumatic brain injury (TBI) is a major public health concern, particularly in adolescents who have a higher mortality and incidence of visual pathway injury compared to adult patients. Likewise, we have found disparities between adult and adolescent TBI outcomes in rodents. Most interestingly, adolescents suffer a prolonged apneic period immediately post-injury, leading to higher mortality; therefore, we implemented a brief oxygen exposure paradigm to circumvent this increased mortality. Adolescent male mice experienced a closed-head weight-drop TBI and were then exposed to 100% O2 until normal breathing returned or recovered in room air. We followed mice for 7 and 30 days and assessed their optokinetic response; retinal ganglion cell loss; axonal degeneration; glial reactivity; and retinal ER stress protein levels. O2 reduced adolescent mortality by 40%, improved post-injury visual acuity, and reduced axonal degeneration and gliosis in optical projection regions. ER stress protein expression was altered in injured mice, and mice given O2 utilized different ER stress pathways in a time-dependent manner. Finally, O2 exposure may be mediating these ER stress responses through regulation of the redox-sensitive ER folding protein ERO1α, which has been linked to a reduction in the toxic effects of free radicals in other animal models of ER stress.

show abstract

Chronic Histological Outcomes of Indirect Traumatic Optic NEU-Ropathy in Adolescent Mice: Persistent Degeneration and Tem-Porally Regulated Glial Responses

Cited by 4 publications

References 50 publications

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

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

An Update to Biomechanical and Biochemical Principles of Retinal Injury in Child Abuse

Brief Oxygen Exposure after Traumatic Brain Injury Hastens Recovery and Promotes Adaptive Chronic Endoplasmic Reticulum Stress Responses

Contact Info

Product

Resources

About