Turkish Neurosurgery 2023 , Vol 33 , Num 5
Investigation of Demyelination and Remyelination Processes of the Compressed Optic Chiasm: An Experimental Model
1Kocaeli State Hospital, Department of Neurosurgery, Kocaeli, Turkey
2Kocaeli University, Department of Neurosurgery, Pituitary Research Center, Kocaeli, Turkey
3Istanbul University, Faculty of Medicine, Department of Histology and Embryology, Istanbul, Turkey
4Kocaeli University, Faculty of Medicine, Department of Physiology, Kocaeli, Turkey
5Kocaeli University, Medical Faculty, Department of Ophthalmology, Izmit, Kocaeli, Turkey
6Taksim Education and Research Hospital, Department of Neurosurgery, Istanbul, Turkey
7Kocaeli University, Faculty of Medicine, Department of Radiology, Kocaeli, Turkey
8Kocaeli University, Faculty of Medicine, Department of Histology and Embryology, Kocaeli, Turkey
DOI : 10.5137/1019-5149.JTN.41743-22.2 AIM: To demonstrated demyelination and remyelination of the optic nerve histologically by electron microscopy in an experimental model similar to the compression of pituitary adenomas on the optic chiasm.

MATERIAL and METHODS: The rats were fixed to a stereotaxic device under deep anesthesia, and a balloon catheter was placed under the optic chiasm through a burr hole which was in front of the bregma in accordance with the brain atlas of rats. The animals were divided into five groups (n=8): control, mild compression demyelination, severe compression demyelination, mild compression remyelination, severe compression remyelination. The fine structures of the tissues obtained were evaluated using electron microscopy.

RESULTS: We found a significant difference in the severity of degeneration when comparing group 1 with group 5 (p<0.001); there was no degeneration in group 1 rats and severe degeneration in all of the group 5 rats. Oligodendrocytes were found in all rats in group 1 and none of the rats in no group 2. The nuclei were preserved in the group 1 rats but damaged in all of the group 5 rats. There were no lymphocytes or erythrocytes in group 1 and all positives in group 5.

CONCLUSION: This technique, which induced degeneration without causing damage to the optic nerve with toxic or chemical agents, revealed Wallerian degeneration similar to tumoral compression. After compression relief, the optic nerve remyelination process can be better understood, particularly for sellar lesions. In our opinion, this model may guide future experiments to identify protocols to induce and accelerate remyelination. Keywords : Degeneration, Optic chiasm, Optic nerve, Pituitary tumors, Remyelination, Rats

Corresponding author : Atakan EMENGEN, dratakanemengen@gmail.com