title: Age-Related Reduced Somatosensory Gating Is Associated with Altered Alpha Frequency Desynchronization.
abstract: Sensory gating (SG), referring to an attenuated neural response to the second identical stimulus, is considered as preattentive processing in the central nervous system to filter redundant sensory inputs. Insufficient somatosensory SG has been found in the aged adults, particularly in the secondary somatosensory cortex (SII). However, it remains unclear which variables leading to the age-related somatosensory SG decline. There has been evidence showing a relationship between brain oscillations and cortical evoked excitability. Thus, this study used whole-head magnetoencephalography to record responses to paired-pulse electrical stimulation to the left median nerve in healthy young and elderly participants to test whether insufficient stimulus 1- (S1-) induced event-related desynchronization (ERD) contributes to a less-suppressed stimulus 2- (S2-) evoked response. Our analysis revealed that the minimum norm estimates showed age-related reduction of SG in the bilateral SII regions. Spectral power analysis showed that the elderly demonstrated significantly reduced alpha ERD in the contralateral SII (SIIc). Moreover, it was striking to note that lower S1-induced alpha ERD was associated with higher S2-evoked amplitudes in the SIIc among the aged adults. Conclusively, our findings suggest that age-related decline of somatosensory SG is partially attributed to the altered S1-induced oscillatory activity.
authors.affiliation: Department of Occupational Therapy and Graduate Institute of Behavioral Sciences, Chang Gung University, Taoyuan, Taiwan ; Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chia-Hsiung
authors.initials: CH
authors.lastname: Cheng
authors.affiliation: Department of Occupational Therapy and Graduate Institute of Behavioral Sciences, Chang Gung University, Taoyuan, Taiwan ; Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Pei-Ying S
authors.initials: PY
authors.lastname: Chan
authors.affiliation: McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, No. 3801, University Street, Montreal, QC, Canada H3A 2B4.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Baillet
authors.affiliation: Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan ; Department of Neurology, National Yang-Ming University, Taipei, Taiwan ; Institute of Physiology, National Yang-Ming University, Taipei, Taiwan ; Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan ; Laboratory of Neurophysiology, Taipei Veterans General Hospital, Taipei, Taiwan ; Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Yung-Yang
authors.initials: YY
authors.lastname: Lin
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D000513:Alpha Rhythm / Q000502:physiology*; D003344:Cortical Synchronization / Q000502:physiology*; D004558:Electric Stimulation; D005071:Evoked Potentials; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D055139:Sensory Gating / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology; D055815:Young Adult