Fatigue‐induced increase in intracortical communication between mid/anterior insular and motor cortex during cycling exercise

Abstract

In the present study, intracortical communication between mid/anterior insular and motor cortex was investigated during a fatiguing cycling exercise. From 16 healthy male subjects performing a constant-load test at 60% peak oxygen consumption (VO(2peak)) until volitional exhaustion, electroencephalography data were analysed during repetitive, artefact-free periods of 1-min duration. To quantify fatigue-induced intracortical communication, mean intra-hemispheric lagged phase synchronization between mid/anterior insular and motor cortex was calculated: (i) at the beginning of cycling; (ii) at the end of cycling; and (iii) during recovery cycling. Results revealed significantly increased lagged phase synchronization at the end of cycling, which returned to baseline during recovery cycling after subjects' cessation of exercise. Following previous imaging studies reporting the mid/anterior insular cortex as an essential instance processing a variety of sensory stimuli and signalling forthcoming physiological threat, our results provide further evidence that during a fatiguing exercise this structure might not only integrate and evaluate sensory information from the periphery, but also act in communication with the motor cortex. To the best of our knowledge, this is the first study to empirically demonstrate that muscle fatigue leads to changes in interaction between structures of a brain's neural network.

Effect of a Reduced-CHO Diet on the Rate of Perceived Exertion Curve During an Incremental Test

“…It has been suggested that lactate may act as a signal to the CNS and influence the RPE response to exercise (Hampson et al, 2001). In this model, lactate and other peripheral signals would be perceived by group III and IV muscle afferents, stimulating sensorial areas in the brain (e.g., mid/anterior insular), which in turn could increase RPE and influence the motor cortex (Hilty et al, 2011). However, fatigue does not appear to be associated with lactate accumulation, but rather with changes in pH (Gladden, 2004).…”

Fatigue and Exhaustion in Hypoxia: The Role of Cerebral Oxygenation

“…Quantifying these cortical activity changes during hypoxic exercise would help us identify the specific regions of interest, perhaps even help locate an ''origin'' of central fatigue in the brain. Some early promising work by Hilty et al (2011aHilty et al ( , 2011bHilty et al ( , 2011c indicates that muscle fatigue leads to changes in interaction between mid/ anterior insular, thalamus, and the motor cortex.…”

Psilocybin-induced spiritual experiences and insightfulness are associated with synchronization of neuronal oscillations

“…Thus, it removes the instantaneous component, which is driven by non-physiological effects and intrinsic physical artifacts that occur due to volume conduction and low spatial resolution (Nolte et al 2004;Stam et al 2007;Schoffelen and Gross 2009;Pascual-Marqui et al 2011). Accordingly, lagged phase synchronization has been increasingly used in recent studies (Canuet et al 2011;Hilty et al 2011;Canuet et al 2012;Guggisberg et al 2014;Kühnis et al 2014;Olbrich et al 2014;Ramyead et al 2014;Steinmann et al 2014;Elmer et al 2015;Vecchio et al, 2015) and has received cross-modal validation by studies combining EEG-based lagged phase synchronization measurements with MRI-based diffusion tensor imaging (Vecchio et al 2015).…”