Ursula I. Tuor1, 2, Melissa Morgunov1, Manasi Sule1, Min Qiao1, Tadeusz Foniok2, Adam Kirton3
1Physiology and Pharmacology and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada; 2Experimental Imaging Centre, University of Calgary, Calgary, Alberta, Canada; 3Pediatrics and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
Cerebral hypoxia-ischemia (HI) in neonates causes perinatal brain damage and subsequent injury in descending tracts (e.g. cerebral peduncle). Diffusion tensor imaging (DTI) and histological changes were investigated at 2h,1d,2d and 7d post-HI in neonatal rats. In cerebral peduncle: ADC and eigenvalues were reduced acutely normalizing/increasing by 7d; FA ratios, fiber tracts and neurofilament staining were reduced ipsilaterally at all times; staining for myelin, microglia/macrophages or reactive astrocytes was unchanged acutely. Axonal changes in cerebral peduncle are detected within hours following hypoxia+unilateral ischemia using standard imaging and DTI. FA detects well axonal degenerative changes at acute and subacute time points.