<abstract xmlns="http://www.w3.org/1999/xhtml">
<p>Squirrels are diurnal rodents with high visual acuity including unique properties well-suited for their natural environment. This study was conducted to explore some ocular microscopic features of tree-harbouring squirrels in the University of Ibadan, Ibadan, Nigeria. Two male squirrels were cage-trapped within the University premises. Light microscopic analysis was carried on paraffin-embedded eye samples harvested from the animals. The densely compacted stromal fibres, 351 ± 52.5 µm thick, formed the thickest part of the cornea, and the basement membrane of the corneal epithelium, 63.8 ± 13.0 µm thick, was notably positive with Periodic Acid Schiff (PAS) stain. Strong pigmentation was present at the choroid as well as the iridal and ciliary epithelia. The multiple layering of the retinal structure exhibited densely packed ganglion cells at the ganglion cell layer which together with the nerve fibre layer was observed to be thinnest at the more peripheral portion but becomes thicker towards the optic disc. Strongly positive glia fibrillary acidic protein (GFAP+) cells with their abundant fibrous processes were demonstrated immunohistochemically at the retinal nerve fibre layer and the optic nerve. Histological features of the retinal cellular components of the tree squirrels investigated has thus highlighted the structural adaptation of these animal species to their environmental arboreal habitat and diurnal lifestyle. Findings from this study, while further noted to be similar to that in human, showed that African tree squirrels represent promising rodent model for human retinal/ocular research.</p>
</abstract>

Squirrels are diurnal rodents with high visual acuity including unique properties well-suited for their natural environment. This study was conducted to explore some ocular microscopic features of tree-harbouring squirrels in the University of Ibadan, Ibadan, Nigeria. Two male squirrels were cage-trapped within the University premises. Light microscopic analysis was carried on paraffin-embedded eye samples harvested from the animals. The densely compacted stromal fibres, 351 ± 52.5 µm thick, formed the thickest part of the cornea, and the basement membrane of the corneal epithelium, 63.8 ± 13.0 µm thick, was notably positive with Periodic Acid Schiff (PAS) stain. Strong pigmentation was present at the choroid as well as the iridal and ciliary epithelia. The multiple layering of the retinal structure exhibited densely packed ganglion cells at the ganglion cell layer which together with the nerve fibre layer was observed to be thinnest at the more peripheral portion but becomes thicker towards the optic disc. Strongly positive glia fibrillary acidic protein (GFAP+) cells with their abundant fibrous processes were demonstrated immunohistochemically at the retinal nerve fibre layer and the optic nerve. Histological features of the retinal cellular components of the tree squirrels investigated has thus highlighted the structural adaptation of these animal species to their environmental arboreal habitat and diurnal lifestyle. Findings from this study, while further noted to be similar to that in human, showed that African tree squirrels represent promising rodent model for human retinal/ocular research.

Histomorphological Investigation of the Eye of the Tree Squirrel: A Preliminary Study

Neuroscience Unit,  Department of Veterinary Anatomy, Faculty of Veterinary Medicine

Folia Veterinaria

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Squirrels are diurnal rodents with high visual acuity including unique properties well-suited for their natural environment. This study was conducted to...

Histomorphological Investigation of the Eye of the Tree Squirrel: A Preliminary Study

Publié en ligne: 22 mars 2024

Pages: 1 - 14

Reçu: 06 oct. 2023

Accepté: 31 janv. 2024

DOI: https://doi.org/10.2478/fv-2024-0001

Mots clés
diurnal lifestyle, histology, ocular structures, retinal ganglion cells, tree squirrel

© 2024 James O. Olopade et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Histomorphological Investigation of the Eye of the Tree Squirrel: A Preliminary Study

Publié en ligne: 22 mars 2024

Pages: 1 - 14

Reçu: 06 oct. 2023

Accepté: 31 janv. 2024

DOI: https://doi.org/10.2478/fv-2024-0001

Mots clésdiurnal lifestyle, histology, ocular structures, retinal ganglion cells, tree squirrel

© 2024 James O. Olopade et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Mots clés
diurnal lifestyle, histology, ocular structures, retinal ganglion cells, tree squirrel