Model of small-focal ischemic cerebral infarction as a basis for the development of new methods of stroke therapy

Abstract

Background. Among the existing experimental models of cerebral stroke in large animals, there is no possibility to create a focal brain infarction of limited volume, which would provide an opportunity to evaluate both the endogenous potential of neuroregeneration and to establish the effectiveness of new drugs on postischemic brain remodeling.
 Aim. Development of a method for modeling small-focal ischemic infarction of the cerebral cortex in a mini-pig.
 Material and methods. The study used mature female mini-pigs of the Vietnamese fold-bellied breed. Two-level occlusion of the great vessels was performed by ligation of the right common carotid artery and subsequent cauterization of the distal branches of the middle cerebral artery. In the postoperative period, the survival rate of animals and neurological deficit were assessed. On the 7th day, the animals were taken out of the experiment, the brain was isolated from the cranial box. Macroscopic and microscopic examinations included analysis of the localization and area of cerebral infarction, as well as morphological changes in the infarcted and peri-infarcted areas of the cerebral cortex.
 Results. With a 100% survival rate of experimental animals on the 3rd day after the operation, a neurological examination revealed violations of skin sensitivity and muscle tone in the hind and fore limbs, which partially recovered a week after the onset of ischemic stroke. Macroscopic examination of the brain on the 7th day after the operation visually revealed a small-focal ischemic cerebral infarction in the parietal lobe of the left hemisphere. Histological analysis of the cerebral cortex revealed a wedge-shaped necrotic focus of ischemic injury. In the peri-infarction region of the brain, reactive tissue changes with preserved nerve cells, mostly without visible damage, were found.
 Conclusion. The developed two-level method of stroke modeling in a mini pig induces ischemic cerebral infarction of limited volume in the parietal lobe; non-critical histological changes in the peri-infarct area and a slight neurological deficit suggest the possibility of using this model to develop new methods of stroke therapy.