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Purpose: To investigate the effects of bilateral dorsolateral prefrontal cortex high-definition transcranial direct-current stimulation (HD-tDCS) on physiological and performance responses during exercise at the upper limit of the severe-intensity exercise domain in elite-level road cyclists. Methods: Eleven elite-level road cyclists (VO2peak: 71.8 [3.1] mL·kg−1·min−1) underwent the HD-tDCS or SHAM condition in a double-blind, counterbalanced, and randomized order. After 20 minutes of receiving either HD-tDCS on dorsolateral prefrontal cortex (F3 and F4) or SHAM stimulation, participants completed a 10-minute constant-load trial (CLT1) at 90% of the first ventilatory threshold and a 2-minute CLT (CLT2) at peak power output. Thereafter, they performed a simulated 2-km time trial (TT). Maximal oxygen uptake, respiratory exchange ratio, heart rate, and rating of perceived exertion were recorded during CLT1 and CLT2, whereas performance parameters were recorded during the TT. Results: In 6 out of 11 cyclists, the total time to complete the TT was 3.0% faster in HD-tDCS compared to SHAM. Physiological and perceptual variables measured during CLT1 and CLT2 did not change between HD‐tDCS and SHAM. Conclusions: HD-tDCS over the dorsolateral prefrontal cortex seemed to improve cycling TT performance within the upper limit of the severe-intensity exercise domain, suggesting that an upregulation of the prefrontal cortex could be critical even in this exercise intensity domain. However, the limited dimension and the high interindividual variability require further studies to test these putative ergogenic effects. [ABSTRACT FROM AUTHOR]

Background: The effects of anodal transcranial direct-current stimulation (tDCS) on endurance exercise performance are not yet fully understood. Different stimulated areas and low focality of classical tDCS technique may have led to discordant results. Purpose: This study investigated the effect of a bilateral anodal high-definition tDCS (HD-tDCS) of the dorsolateral prefrontal cortex on the cycling time-trial (TT) performance and physiological and perceptual response at moderate intensity in elite cyclists. Methods: A total of 8 elite cyclists (maximal oxygen consumption: 72.2 [4.3] mL·min−1·kg−1) underwent in a double-blind, counterbalanced, and randomized order the experimental treatment (HD-tDCS) or control treatment (SHAM). After 20 minutes of receiving either HD-tDCS on the dorsolateral prefrontal cortex (F3 and F4) or SHAM stimulation, the participants completed a constant-load trial (CLT) at 75% of the second ventilatory threshold. Thereafter, they performed a simulated 15-km TT. The ratings of perceived exertion, heart rate, cadence, oxygen consumption, and respiratory exchange ratio were recorded during the CLT; the ratings of perceived exertion and heart rate were recorded during the TT. Results: The total time to complete the TT was 1.3% faster (HD-tDCS: 1212 [52] s vs SHAM: 1228 [56] s; P =.04) and associated with a higher heart rate (P <.001) and a tendency toward higher mean power output (P =.05). None of the physiological and perceptual variables measured during the CLT highlighted differences between the HD-tDCS and SHAM condition. Conclusions: The findings suggest that bilateral HD-tDCS on the dorsolateral prefrontal cortex improves cycling TT performance without altering the physiological and perceptual response at moderate intensity, indicating that an upregulation of the prefrontal cortex could enhance endurance exercise performance. [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxias type 2 (SCA2) is a rare genetic disorder characterised by the degeneration of the Cerebellum, its connections and many Brainstem areas. A voxel-based morphometry (VBM) analysis was performed on 12 genetically determined SCA2 patients and 31 controls, normalising the brains with two different atlases: one was created in-house with DARTEL (a diffeomorphic registration method) and the other was SUIT (an exclusive Cerebellum atlas). We administered two versions of a popular executive/planning functions test: the Tower of London, in the traditional and in a computerised version that does not require the use of hands, to correlate the regional atrophy with the tests' performances and to discover the different associations of Cerebellum's areas to cognitive dysfunctions. SCA2 showed a diffuse infratentorial atrophy with the whole Cerebellum and Brainstem affected, the overall patterns were highly overlapping between atlases with some minor differences. The DARTEL VBM also allowed detecting two sovratentorial clusters of atrophy, one in the left Inferior Parietal Lobule and the other in the Corticospinal Tracts. Additional analyses revealed a partial involvement of many White Matter tracts and of the Thalamus in the pathology. The classical Tower of London version correlated maximally with the right Lobule IV-V, when the computerised version correlated with the right Crus 1. The correlations of different versions of the test suggested a dissociation between the dysfunctions in SCA2: the Posterior Cerebellum was linked to the executive dysfunction while the Anterior Cerebellum was linked to the coordinative dysfunction. [ABSTRACT FROM AUTHOR]