Influence of Experimental Skull Defects on Brain

This study was aimed to observe the effects of skull defects on the brain in rats and further to investigate its underlying pathophysiological. Three different sizes of skull were removed in rats to produce models of skull defect, and then the behavioral changes were detected using a grip strength meter and neurobehavioral severity scale scores. The authors further examined the levels of cell apoptosis and autophagy, the cerebral blood flow with immunoblotting, and immunofluorescence micro-ultrasound system, respectively. The authors found that the sensory function but not the grip was impaired on the 6th day after a 5 × 10 mm defect while the motor function was on the 2nd day. In addition, the authors found an increment in B-cell lymphoma-2/BCL2-Associated X (Bcl2/Bax) and LC3 II/I expression, a maker of apoptosis and autophagy, respectively, in the defective hemisphere especially at the edge of the defective area. Importantly, the blood flow of internal carotid artery began to decline at 2 hours, and reached minimum on the 4th day, but began to recover on the 6th day in the hemi-defect group. In conclusion, a larger skull defect could impair the cognitive function but not the motor function and its underlying pathophysiology were mainly related to a decrease in cerebral flow.