Research into the glucocorticoid pharmacology on motor nerve terminals and spinal cord reflex pathways will continue. Our studies have defined for the first time: (a) the striking enhancement of a motor nerve terminal facilitatory function by both single and chronic doses of glucocorticoids; (b) the biphasic actions of the glucocorticoids on motor neurons, wherein a transient suppression of the motor nerve terminal facilitatory function is superceded by the striking enhancement of the facilitatory function; (c) that the perikaryon is not involved in these drug actions; (d) the preservation and enhancement of motor nerve terminal facilitation by glucocorticoids in trophically deprived and chemically injured motor nerves; (e) the description of the molecular requirements for this glucocorticoid enhancement of motor nerve terminal facilitatory function. The research projected for the coming year will define: (a) the sites of action at nerve terminals; (b) the effects of glucocorticoids on transmitter dynamics; (c) the pharmacokinetic parameters of single dose glucocorticoid administration; (d) the relationship between blood levels and neuronal uptake, concentration and distribution. Physiologic and therapeutic significances will be determined by parallel studies in adrenalectomized animals. These projected studies will give further insight into the direct actions of these hormones on the nervous system.