Age-related changes of cortical excitability and connectivity in healthy humans: non-invasive evaluation of sensorimotor network by means of TMS-EEG. (15th August 2017)

• Record Type: Journal Article
• Authors: Ferreri, Florinda; Guerra, Andrea; Vollero, Luca; Ponzo, David; Maatta, Sara; Mervaala, Esa; Iannello, Giulio; Di Lazzaro, Vincenzo
• Is Part Of: Neuroscience. Volume 357(2017)
• Page Start: 255
• Page End: 263
• Publication Date: 2017-08-15
• Subjects: EEG electroencephalography -- GMFP global-mean field power -- MEPs motor-evoked potentials -- rMT resting motor threshold -- TEPs TMS-evoked EEG potentials -- TMS transcranial magnetic stimulation; navigated transcranial magnetic stimulation -- TMS-EEG co-registration -- motor cortex excitability -- motor cortex connectivity -- aging; Neurochemistry -- Periodicals; Neurophysiology -- Periodicals; Neurology -- Periodicals; Neurochimie -- Périodiques; Neurophysiologie -- Périodiques; Neurochemistry; Neurophysiology; Electronic journals; Periodicals; Electronic journals; 612.8
• DOI: 10.1016/j.neuroscience.2017.06.014
• Languages: English
• ISSNs: 0306-4522

Abstract

Highlights: We used TMS-EEG to study the effects of physiological aging on sensorimotor system. We demonstrated that some TEPs of the left M1 are selectively modulated by aging. Some sensorimotor system alterations might reflect secondary consequences of aging. Some other alterations might be compensatory mechanisms to such changes. Abstract: The sensorimotor cortical system undergoes structural and functional changes across its lifespan. Some of these changes are physiological and parallel the normal aging process, while others might represent pathophysiological mechanisms underlying neurodegenerative disorders. In the last years, the study of possible age-related modifications in brain sensorimotor functional characteristics has been the focus of several research projects. Here we have used the transcranial magnetic stimulation (TMS)-electroencephalography (EEG) navigated co-registration to investigate the influence of physiological aging on the excitability and connectivity of the human sensorimotor cortical system. To this end, we compared the TMS-evoked EEG potentials (TEPs) collected after stimulating the dominant primary motor cortex (M1) in healthy young subjects (mean age 24.5 years) with those collected in healthy older adults (mean age 67.6 years). We have shown that, after stimulation of the left motor cortex, TEPs are significantly affected by physiological aging. This phenomenon has a clear spatio-temporal specificity and we speculate that normal aging per se leads to some changes in the excitability of specific cortical neural assemblies whereas other alterations could reflect compensatory mechanisms to such changes.