Modafinil restores memory performance and neural activity impaired by sleep deprivation in mice.

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 electroencephalography recording. Memory performance was evaluated using spontaneous alternation in a T-maze, whereas the neural activity level was estimated by the quantification of the c-Fos protein in various cerebral zones. This study allowed altogether: First, to evidence that a diurnal 10-h sleep deprivation period induced an impairment of spatial working memory. Second, to observe a decrease in c-Fos expression after sleep deprivation followed by a behavioural test, as compared to non-sleep-deprived mice. This impairment in neural activity was evidenced in areas involved in wake-sleep cycle regulation (anterior hypothalamus and supraoptic nucleus), but also in memory (frontal cortex and hippocampus) and emotions (amygdala). Finally, to demonstrate that modafinil 64 mg/kg is able to restore on the one hand memory performance after a 10-h sleep deprivation period, and on the other hand, the neural activity level in the very same brain areas where it was previously impaired by sleep deprivation and cognitive task

Effects of mti-2

Overexpressed in transgenic plants, protease inhibitors showed insecticidal effects against several insect taxa. We transformed potato internodes with the mustard trypsin inhibitor mti-2 gene. Among the 35 independent transgenic potato lines obtained via Agrobacterium tumefasciens transformation, four (DM6, DM7, DM11, and DM19) were selected for their high level of MTI-2 (at least to 30% of trypsin activity inhibition). Feeding assays were carried out to evaluate their effects on the green-peach aphid, Myzus persicae (Sternorrhyncha: Aphididae). Prereproductive period, nymphal mortality, adult fecundity, and doubling time of M. persicae populations were monitored on nontransformed potato plants (NT) and the four selected DM lines. Compared to NT plants, DM19 did not induce any effect on M. persicae. In contrast, DM7 and DM11 increased nymphal survival by approximately 20%. DM6 and DM11 lines slightly enhanced M. persicae daily fecundity and intrinsic rate of natural increase, leading to a reduction of the doubling time of the populations by 1 day. DM6 did not impact nymphal mortality, whereas with the DM11 almost all the nymphs survived. Potato plants transformed with the mti-2 gene variably affected the life history of M. persicae but did not show any insecticidal effect on the aphid

Clinique et biologie de la fatigue liée à l'entraînement

Jouanin Jean-Claude. Clinique et biologie de la fatigue liée à l'entraînement. In: Les Cahiers de l'INSEP, n°14-15, 1996. La récupération en sport : approches des techniques et des moyens. pp. 115-117

Les différents aspects de la récupération à l'École interarmées des sports (EIS)

Jouanin Jean-Claude. Les différents aspects de la récupération à l'École interarmées des sports (EIS). In: Les Cahiers de l'INSEP, n°27, 2000. Sport de haut niveau et récupération. pp. 127-140

Etude descriptive d'une course d'alpinisme (conséquences sur le système nerveux autonome)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocPARIS-Bib. Serv.Santé Armées (751055204) / SudocSudocFranceF

Intérêt de la variabilité de la fréquence cardiaque de repos dans le dépistage de la fatigue et du surentraînement lors du suivi médical d'athlètes de haut niveau

LYON1-BU Santé (693882101) / SudocSudocFranceF

The vastus lateralis neuromuscular activity during all-out cycling exercise

International audienceObjective: The objective of this work was to study modifications in motor control through surface electromyographic (sEMG) activity during a very short all-out cycling exercise. Methods: Twelve male cyclists (age 23 ± 4 years) participated in this study. After a warm-up period, each subject performed three allout cycling exercises of 6 s separated by 2 min of complete rest. This protocol was repeated three times with a minimum of 2 days between each session. The braking torque imposed on cycling motion was 19 N m. The sEMG of the vastus lateralis was recorded during the first seven contractions of the sprint. Time-frequency analysis of sEMG was performed using continuous wavelet transform. The mean power frequency (MPF, qualitative modifications in the recruitment of motor units) and signal energy (a quantitative indicator of modifications in the motor units recruitment) were computed for the frequency range 10-500 Hz. Results: sEMG energy increased (P 6 0.05) between contraction number 1 and 2, decreased (P 6 0.05) between contraction number 2 and 3 then stabilized between contraction number 3 and 7 during the all-out test. MPF increased (P 6 0.05) during the all-out test. This increase was more marked during the first two contractions. Conclusions: The decrease in energy and the increase in the sEMG MPF suggest a large spatial recruitment of motor units (MUs) at the beginning of the sprint followed by a preferential recruitment of faster MUs at the end of the sprint, respectively