TY - JOUR
T1 - Responses to brief perturbations of stance
T2 - EMG, midline cortical, and subcortical changes
AU - Govender, Sendhil
AU - Hochstrasser, Daniel
AU - Todd, Neil P.M.
AU - Keller, Peter E.
AU - Colebatch, James G.
PY - 2024/9
Y1 - 2024/9
N2 - We studied simultaneous EMG and midline EEG responses, including over the cerebellum, in 10 standing subjects (35 ± 15 yr; 5 females, 5 males). Recordings were made following repeated taps to the sternum, stimuli known to evoke short-latency EMG responses in leg muscles, consistent with postural reflexes. EEG power had relatively more high-frequency components (>30 Hz) when recorded from electrodes over the cerebellum (Iz and SIz) compared with other midline electrodes. We confirmed a previous report using a similar stimulus that evoked short-latency potentials over the cerebellum. We showed clear midlineevoked EEG potentials occurring at short latency over the cerebellum (P23, N31, N42, and P54) and frontally (N28 and N57) before the previously described perturbation-evoked potential (P1/N1/P2). The P23 response correlated with the subsequent EMG response in the tibialis anterior muscles (r = 0.72, P = 0.018), confirming and extending previous observations. We did not find a correlation with the N1 amplitude. We conclude that early activity occurs from electrodes over the inion in response to a brief tap to the sternum. This is likely to represent cerebellar activity and it appears to modulate short-latency postural EMG responses.
AB - We studied simultaneous EMG and midline EEG responses, including over the cerebellum, in 10 standing subjects (35 ± 15 yr; 5 females, 5 males). Recordings were made following repeated taps to the sternum, stimuli known to evoke short-latency EMG responses in leg muscles, consistent with postural reflexes. EEG power had relatively more high-frequency components (>30 Hz) when recorded from electrodes over the cerebellum (Iz and SIz) compared with other midline electrodes. We confirmed a previous report using a similar stimulus that evoked short-latency potentials over the cerebellum. We showed clear midlineevoked EEG potentials occurring at short latency over the cerebellum (P23, N31, N42, and P54) and frontally (N28 and N57) before the previously described perturbation-evoked potential (P1/N1/P2). The P23 response correlated with the subsequent EMG response in the tibialis anterior muscles (r = 0.72, P = 0.018), confirming and extending previous observations. We did not find a correlation with the N1 amplitude. We conclude that early activity occurs from electrodes over the inion in response to a brief tap to the sternum. This is likely to represent cerebellar activity and it appears to modulate short-latency postural EMG responses.
KW - cerebellum
KW - evoked response
KW - perturbation
KW - postural reflexes
KW - posture
UR - http://www.scopus.com/inward/record.url?scp=85204511591&partnerID=8YFLogxK
U2 - 10.1152/jn.00252.2024
DO - 10.1152/jn.00252.2024
M3 - Journal article
C2 - 39140589
AN - SCOPUS:85204511591
SN - 0022-3077
VL - 132
SP - 1014
EP - 1024
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
IS - 3
ER -