Non-invasive brain stimulation (NIBS) methods such as paired associative stimulation (PAS), transcranial direct current stimulation (tDCS), and transcranial alternating current stimulation (tACS) are used to modulate cortical excitability and reduce symptoms in a variety of psychiatric disorders. Recent studies have shown significant inter-individual variability in the physiological response to these techniques when they are applied over the hand representation of primary motor cortex (M1). The goal of the present study was to identify neurophysiological, neuroanatomical, and neurochemical baseline characteristics that may predict response to commonly used NIBS protocols using data from a previously published study (Therrien-Blanchet et al.
View Article and Find Full Text PDFPhysical activity (PA) has been shown to benefit various cognitive functions and promote neuroplasticity. Whereas the effects of PA on brain anatomy and function have been well documented in older individuals, data are scarce in young adults. Whether high levels of cardiorespiratory fitness (CRF) achieved through regular PA are associated with significant structural and functional changes in this age group remains largely unknown.
View Article and Find Full Text PDFThe present study aimed at investigating the long-term stability and test-retest reliability of neuronavigated transcranial magnetic stimulation (nTMS) measures of cortical excitability, inhibition, and facilitation in the primary motor cortex. To fulfill these aims, thirty-one healthy adults underwent four nTMS sessions, over an average one-month period. Stability and test-retest reliability statistics were computed and analyzed to produce smallest real difference statistics, which indicate the absolute variation in a measurement that is likely to be the result of error (randomness).
View Article and Find Full Text PDFThis study aimed at better understanding the neurochemistry underlying transcranial magnetic stimulation (TMS) and magnetic resonance spectroscopy (MRS) measurements as it pertains to GABAergic activity following administration of allosteric GABA receptor agonist lorazepam. Seventeen healthy adults (8 females, 26.0 ± 5.
View Article and Find Full Text PDFThe purpose of the present study was to investigate the long-term stability of water-referenced GABA and Glx neurometabolite concentrations in the sensorimotor cortex using MRS and to assess the long-term stability of GABA- and glutamate-related intracortical excitability using transcranial magnetic stimulation (TMS). Healthy individuals underwent two sessions of MRS and TMS at a 3-month interval. A MEGA-PRESS sequence was used at 3 T to acquire MRS signals in the sensorimotor cortex.
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