The original aims of our study were to investigate the dose-effect relationship of modafinil administration on working memory performance, in parallel with the measurement of plasma corticosterone in chronically-stressed mice, as compared to control mice. Memory performance was evaluated by spontaneous alternation in a T-maze. Vehicle or modafinil (8, 16 or 32 mg/kg) were administered after or without chronic stress (immobilization and exposure to light) for 15 min/day over a period of consecutive 14 days. Immediately after behavioral testing, blood was sampled to measure plasma corticosterone levels. Under non-stress conditions, corticosterone significantly increased with 16 and 32 mg/kg modafinil administration. Interestingly, optimal working memory performance was revealed at the 16 mg/kg dose. Moreover, no correlation was evidenced between working memory performance and plasma corticosterone level in modafinil-treated animals. Under stress conditions, corticosterone level was lowered at 8 mg/kg and remained unchanged at 16 and 32 mg/kg modafinil. An optimal working memory performance was evidenced at 8 mg/kg, which indicated a decrease in the efficiency threshold of modafinil under stress. Furthermore, an inverse correlation emerged between working memory performance and corticosterone level. Our study evidenced for the first time the interaction between stress and memory, in the emotional modulation of working memory performance, as a function of the administered dose of modafinil.

383 --Mothers of offspring Balb/c mice were stimulated after birth by two substances, a bacterial lysate (LAB) and a chemical, diethyldithiocarbamate (DETC). Anti-sheep red blood cell (SRBC) antibodies were studied after immunization of stimulated mothers or offspring. An increase of anti-SRBC was observed in LAB-stimulated mothers, but these antibodies were decreased in their offspring before weaning. Sometimes, these antibodies were increased in LABstimulated newborn mice. DETC stimulation of mothers induced an elevation of antibody response in mothers and newborns. The same results were obtained in previous investigations where the pregnant mother was stimulated with the same agents.immunomodulation ; pregnant mice ; offspring miceIn a recent study we demonstrated that the antibody response of newborn mice could be modulated by non-specific immunomodulation of the mother during gestation ; we observed an inhibition of the anti-sheep red blood cells by a bacterial lysate (LAB) and potentiation of this response if diethyldithiocarbamate sodium (DETC) was used. Recent investigations have demonstrated the immunomodulatory properties of hormones (Deschaux et al. 1980), or of other factors which appear during gestation (Koutab et al. 1976;Noonan et al. 1979). In the same way, a significant immunosuppressor activity in the splenic cells of newborn mice was observed. (Argyris 1978(Argyris , 1979(Argyris , 1982.In this investigation we intended to examine whether the mother's immunomodulatory factors, responsible for variations in the antibody response observed in our own prior investigation, could be transferred to the offspring