Resultados de investigación

Exercise has been demonstrated to have a positive impact on psychological well-being and mental health, including improvements in motivational symptoms such as fatigue and anergia.  Nucleus Accumbens (Nacb) dopamine (DA) has been implicated in regulating the energizing component of motivated behavior, including effort-related decision making. In the present study, we evaluated the relationship between individual differences in endurance on a voluntary running wheel (RW), and differences in neurotrophic and DA-related parameters in Nacb of adult male CD1 mice. Performance was evaluated in 2-hour sessions for 4 weeks. High and low running groups (HR and LR) were determined using the two extreme quartiles. Additionally, after these 4 weeks, training stopped and animals were assessed in a T-maze-RW task in which they freely interacted with 3 reinforcers: a RW, sweet pellets, or a floral odor, and also in a T- maze-barrier task, in which the high density of reinforcement is obtained by climbing a vertical barrier. HR animals spent significantly more time in the RW, and less time in contact with the more sedentary reinforcer (odor) compared to LR mice. There were no differences between HR and LR groups in the T-maze-barrier task. Phosphorylation of pDARPP32-Thr34 and Thr75 did not show differences between groups. However, cerebral DA neurotrophic factor (CDNF) immunoreactivity in the Nacb core was higher in HR mice. These results suggest that differences in basal levels of voluntary exercise increase predisposition to choose physically demanding reinforcers that require high levels of activation, and CDNF expression is related to those differences.

The study compares single-trial multilevel analysis and averaged-trial repeated measures anova methods for analyzing event-related potentials by means of simulation procedures. Sample size, number of stimulus repetitions, effect size, and presence or absence of random slopes were systematically manipulated. Five thousand iterations were used in each simulation condition. The first and second files contain code for obtaining comparative Power and Type I error rates, as well as other indicators of comparative inferencial evidence like coverage and bias for experimental effects. The third and fourth files contain results for the individual runs in the multilevel and repeated measures anova simulations. The last file contains summary results.