Stress is one of the most critical influences on behavior, performance and disease. Recent findings from our laboratory have shown that stress represents a major modulator of motor function in the intact and damaged brain. The mechanisms by which stress and stress hormones affect motor system function, however, have not yet been determined. The objective of this thesis was to determine the route of action of stress and stress hormones on the motor system in a rat model. The first experiment investigates whether corticosterone is involved in mediating stress-induced motor impairments. The second experiment compares the role of glucocorticoid and mineralocorticoid receptors in regard to modulating the motor response to stress. The third experiment determines the differential effects of stress on motor function in males and females. The final experiment systematically describes changes in neuronal cell signaling that affect normal function of motor areas. The results indicate that disturbance of fine motor control by stress is not associated with stress hormone increases. Furthermore, it is modulated through the glucocorticoid and mineralocorticoid receptors. Stress differentially impairs motor function in males and females. These changes in motor behaviour could possibly be the result of changes in neuronal cell signaling within the motor system. This research provides new insights into physiological influences in motor system function and disorders of the motor system. / ix, 128 leaves : ill. (some col.) ; 29 cm.