Parasympathetic denervation of rat pial vessels does not increase infarction vol-ume following middle cerebral artery occlusion

To clarify whether the postganglionic parasympathetic nerves innervating the vascular bed of the cerebral hemispheres play a protective role in cerebral ischemia,we transected the nerves of one side near ethmoidal foramen in rat.later occluded the middle cerebral artery of the same side and then checked if the volume of cerebral infarction increased.The volume was measured 24 h after the occlusion by adding the le-sions of 6 coronal slides.In 3 of the 4 groups,i.e. group A（nerve transection with middle cerebral artery occlusion, group B nerves exposed but not transected and middle cerebral artery occluded）and group C（middle carebral artery occluded only）,infaction volumes （mean+SD）were 153±42 mm3, 147±42 mm3 and 148±45mm3 respectively.The difference were not statistically significant （P＞0.05） and the location of in-farction had no difference. In group D（sham-operated）,infarction was not detected the protective role of the nerves in the pathophy-siologic process of cerebral ischemia has not been proved in this study.