Relation of Behavioral Asymmetry to the Functions of Hypothalamus-Pituitary-Adrenal and Reproductive Systems in Vertebrates
It is well known that the cerebral hemispheres are involved in the regulation of motor systems and modulation of perceptual cues coming from the contralateral side of the body, and unilateral motor and sensory activity can feedback to brain asymmetry. Recent data also suggest that the right and left cerebral hemispheres differ in their ability to regulate auto nomic processes, and direct unilateral stimulation of the brain provokes side-dependent endo crine, immune and other visceral reactions. An important theoretical and practical question of whether or not autonomic processes can be asymmetrically regulated via the activation of the lateral behavioral reactions remains unexplored. In this study, we report that the chronic pre sentation of an important stimulus-food-from the left side, improves reproductive perfor mance in both cows having normal and poor feed. The unilateral presentation of food can also influence lactation, but in this case the side-dependent effects are different under varying feed ing conditions. In the laboratory experiments on rats asymmetrical feeding provoked side de pendent changes in dynamic of corticosteroids and gastric ulcer development. Given the un derlying mechanisms are similar in all vertebrates including man, these results suggest a simple practical approach of influencing basic somatic functions and have broad applications in agri culture, medicine, ergonomics, and other fields of human activity.