has subject area Adrenal Glands Amines - Catecholamines Animals Behavior - Motor Activity Biogenic Monoamines - Catecholamines Brain Gene Expression Regulation Genes, fos Lymphatic System - Spleen Male Musculoskeletal Physiological Phenomena - Motor Activity Rats Rats, Sprague-Dawley Stress, Physiological Sympathetic Nervous System Tissues - Spleen