The authors of "Central Nervous System Effects of Caffeine and Adenosine on Fatigue," are J. Mark Davis, Zuowei Zhao, Howard S. Stock, Kristen A. Mehl, James Buggy, and Gregory A. Hand, all from the Schools of Public Health and Medicine, University of South Carolina, Columbia, SC. Their findings appear in the February 2003 edition of the American Journal of Physiology Regulatory, Integrative and Comparative Physiology. The journal is one of 14 peer-reviewed publications produced monthly by the American Physiological Society (APS).
Male Wistar rats, five weeks old and weighing 200-250 grams, were used in this study, and randomly assigned to intracerebroventricular or intraperitoneal injection groups. Rats were given two weeks of treadmill acclimation of running for 15 minutes a day. The treadmill speed was slowly increased from eight meters a minute, 7.5 percent grade at the beginning, progressing to 20 meters a minute at the end of the acclimation period. Gentle hand prodding and mild electric shock were combined to encourage the animals to run throughout the study.
After the first two weeks of acclimation, rats assigned to the intracerebroventricular group were anesthetized with pentobarbital sodium, and tubes were implanted bilaterally into the lateral ventricles. After seven days of recovery from surgery, the rats were again acclimated to treadmill running for another one to two weeks, until they were able to run easily for at least 15 minutes per day for 5 consecutive days at a speed of 20 meters a minute at a 7.5 percent grade. Animals that were unable to run at that pace were excluded.