Tethering of the spinal cord in mouse fetuses and neonates with spina bifida

Object. Tethering of the spinal cord is a well-known complication in humans with spina bifida aperta or occulta. Its pathogenesis consists of a pathological fixation of the spinal cord resulting in traction on the neural tissue which, in turn, leads to ischemia and progressive neurological deterioration. Although well established in humans, this phenomenon has not been described in animal models of spina bifida. Methods. A fetal mouse model with naturally occurring, genetically determined spina bifida was produced by generating double mutants between the curly tail and loop-tail mutant strains. Microdissection, labeling with 1,1′-dioctadecyl-3,3,3,′,3′-tetramethylindocarbocyanine perchlorate, immunohistochemistry for neurofilaments, H & E staining of histological sections, and whole-mount skeletal preparations were performed and comparisons made among mutant and normal fetuses. Normal fetuses exhibited the onset of progressive physiological ascent of the spinal cord from embryonic Day 15.5. Spinal cord as...