Effect of complete arrest of cerebral circulation on learning and retention in dogs

Complete arrest of cerebral circulation for 6 or 8 min. was accomplished by occlusion of the aorta, inferior vena cava, and the superior vena cava above the azygos vein in 23 dogs. The effect upon learning, retention, psychomotor performance, and EEG was tested. 6 min. of circulatory arrest had no effect upon either learning, retention, or psychomotor performance; 8 min. of cerebral circulatory occlusion severely impaired learning ability but did not affect retention, as measured by movement discrimination and delayed response tests, or psychomotor performance. Cortical and subcortical EEG recordings showed the reticular systems to be the most refractory to anoxia, although no correlations could be found between the EEG recordings and the behavioral tests. (PsycINFO Database Record (c) 2006 APA, all rights reserved).