The surgical approach for complete corpus callosotomy in mice

Corpus callosum is a major bundle of white mater fibers that connects both hemispheres by forming important interhemispheric commissures of brain. Complete callosotomy is interhemispheric commissures dissecting surgery. In clinical practice complete or partial callosotomy is performed to reduce frequency of generalized seizures of patients with pharmacologically untreatable epilepsy. In preclinical studies, animal corpus callosotomy is a long-term research topic with few numbers of studies. Furthermore, the most of studies lack the precise description of surgical technique and present some disadvantages. In this study, we describe a new approach for corpus callosotomy procedure by using electrocautery in mice. For this study, we used C57BL/6 8-12-week-old male mice (20-24g) that underwent corpus callosotomy surgery. Anesthetized mouse was placed in stereotaxic frame and rostral-caudal skin incision was made along midline, to expose the skull. Cranial window was performed by drilling circular section of the skull. Dura mater and superior sinus was carefully pulled aside to reveal corpus callosum. Corpus callosum dissection was made by electrocautery and cranial window was closed by circular skull bone flap. Skin incision was stitched. Two weeks after surgery, animals were sacrificed and corpus callosum integrity was examined by Nissl staining. Two weeks of post-surgical observation did not showed any pathological behavioral changes, like locomotor and eating habits in mice. The obtained sections of callostomized mice brain revealed absence of corpus callosum integrity in midline, along all corpus callosum length. Electrocautery can be used as additional tool for corpus callosotomy in mice. Therefore, further preclinical research is needed.Acknowledgements ERA-NET project No. ES RTD/2018/29 “Multi-scale investigation of synaptic dysfunction after stroke (MISST)” and the UL Research Grant “Research of biomarkers and natural substances for acute and chronic diseases' diagnostics and personalized treatment”.