Christophe Piérard

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Modafinil is a wakeness-promoting drug, which is effective in the treatment of narcolepsy; its effects on learning processes are however little studied. Thus, the present study was aimed at determining the effects of an acute modafinil injection on a serial reversal discrimination task performed in a T-maze in mice. Independent groups of mice varying by the(More)
This study investigated the effects of pretest injection of modafinil on delayed spontaneous alternation rates (SA) used to evaluate working memory in C57 Bl/6 mice. In a first experiment, systemic modafinil at 64 mg/kg, but not at 8 mg/kg or 32 mg/kg doses produced a significant increase of alternation scores (intertrial interval (ITI) 60s) when compared(More)
The aim of this study was to investigate if enhanced peripheral ammonia production during exhaustive exercise increases ammonia detoxication in brain mediated by glutamine synthesis, and subsequently influences glutamate and gamma-aminobutyric acid (GABA) levels. This neurotransmitter production is related to the metabolism of glutamine. A group of rats was(More)
We investigated the long-term (up to 90 days) consequences of soman intoxication in mice on weight, motor performances (grip strength, rotarod) and mnemonic cognitive processes (T-maze, Morris water maze test). First, a relative weight loss of 20%, measured 3 days after intoxication, was evidenced as a threshold beyond which neuropathological damage was(More)
Some long work or shift work schedules necessitate an elevated and prolonged level of vigilance and performance but often result in sleep deprivation (SD), fatigue and sleepiness, which may impair efficiency. This study investigated the effects of a slow-release caffeine [(SRC) at the daily dose of 600 mg] on vigilance and cognitive performance during a 64(More)
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(More)
The present study was aimed at simultaneously determining on the same subject, the effects of stress on retrieval of flexible (contextual or temporal) or stable (spatial) information. Three behavioral paradigms carried out in a four-hole board were designed as follows: (1) Simple Discrimination (SD), in which mice learned a single discrimination; (2)(More)
The original aims of our study have been to investigate in sleep-deprived mice, the effects of modafinil administration on spatial working memory, in parallel with the evaluation of neural activity level, as compared to non-sleep-deprived animals. For this purpose, an original sleep deprivation apparatus was developed and validated with continuous(More)
The effects of modafinil, a vigilance-enhancing drug, on brain metabolism were investigated directly in situ by the 2D COSY 1H-NMR spectroscopy in anesthetized rats. Modafinil (600 mg/kg, i.p.) induced significant increases in both aspartate (72% +/- 15%) and glutamate-glutamine pool (28% +/- 8%) simultaneously with increases in inositol (51% +/- 19%) and(More)
We measured the effects of slow-release caffeine (SRC) and melatonin (Mlt) on sleep and daytime sleepiness after a seven-time zone eastbound flight. In a double-blind, randomized, placebo-controlled study, each of three groups of nine subjects was given either 300 mg SRC on recovery day 1 (D1) to D5 (0800) or 5 mg Mlt on preflight D-1 (1700), flight day D0(More)