Ratlarda optik kiazmaya uygulanan deneysel bası sonrası optik sinirin demiyelinizasyon ve remiyelinizasyon süreçlerinin araştırılması

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Thesis Type: Expertise In Medicine

Institution Of The Thesis: Kocaeli University, Tıp Fakültesi, Cerrahi Tıp Bilimleri, Turkey

Approval Date: 2020

Thesis Language: Turkish

Student: ATAKAN EMENGEN

Supervisor: İhsan Anık

Open Archive Collection: AVESIS Open Access Collection

Abstract:

INTRODUCTİON: The limited regeneration ability of the nervous system has been the subject of many experimental and clinical studies. In the central nervous system; The optic nerve is frequently used in degeneration models because regenerated axon and glial tissue can be easily examined. The aim of this study is; to demonstrate demyelination secondary to mass compression by presenting a new optic nerve degeneration model and to direct clinical studies that will accelerate optic nerve regeneration especially after excision of sellar lesions. MATERIALS AND METHODS: This study was carried out with forty Wistar albino rats by forming four experimental and one control group. The control group was decapitated and removed by dissecting the optic nerves. The animals in the other group were fixed using the stereotaxy device under general anesthesia and a balloon catheter was placed under the optic chiasm by opening a burrhole 6,2 mm in front of the bragma according to the cranial atlas coordinates. The demyelination group was decapitated on the 10th day. In the remyelination groups, the catheter was removed on the 10th day and the animals were decapitated 10 days after this procedure. Optic nerve samples taken from the groups were placed in gluceraldehyde solution and examined under electron microscope. RESULTS: Demyelination, degeneration and loss of myelin, myelin lamina disintegration, and vacuolization of axons and glia were observed in all demyelination and remyelination groups after low and high compression, except the control group. While moderate degeneration was observed in Groups 2 and 4 evaluated after low compression, severe degeneration showing Wallerian degeneration damage accompanied by dark axon damage was observed in Groups 3 and 5. While oligodendrocytes were observed in the environment except for Group 5, oligodendrocytes were not observed in Group 5, but the majority of erythrocytes and lymphocytes were observed. CONCLUSION: Our study aimed at a new model that shows degeneration that develops after tumoral compression on the optic nerve, examined under electron microscope and demonstrated demyelination in all groups except the control group. This new model, which demonstrates degeneration without the use of a toxic and chemical agent, will guide future research for remyelination processes that are still elusive today.