RT Journal Article
SR Electronic
T1 Regulation of Motor Representation by Phase–Amplitude Coupling in the Sensorimotor Cortex
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 15467
OP 15475
DO 10.1523/JNEUROSCI.2929-12.2012
VO 32
IS 44
A1 Takufumi Yanagisawa
A1 Okito Yamashita
A1 Masayuki Hirata
A1 Haruhiko Kishima
A1 Youichi Saitoh
A1 Tetsu Goto
A1 Toshiki Yoshimine
A1 Yukiyasu Kamitani
YR 2012
UL http://www.jneurosci.org/content/32/44/15467.abstract
AB High-γ amplitude (80–150 Hz) represents motor information, such as movement types, on the sensorimotor cortex. In several cortical areas, high-γ amplitudes are coupled with low-frequency phases, e.g., α and θ (phase–amplitude coupling, PAC). However, such coupling has not been studied in the sensorimotor cortex; thus, its potential functional role has yet to be explored. We investigated PAC of high-γ amplitude in the sensorimotor cortex during waiting for and the execution of movements using electrocorticographic (ECoG) recordings in humans. ECoG signals were recorded from the sensorimotor cortices of 4 epilepsy patients while they performed three different hand movements. A subset of electrodes showed high-γ activity selective to movement type around the timing of motor execution, while the same electrodes showed nonselective high-γ activity during the waiting period (>2 s before execution). Cross frequency coupling analysis revealed that the high-γ amplitude during waiting was strongly coupled with the α phase (10–14 Hz) at the electrodes with movement-selective high-γ amplitudes during execution. This coupling constituted the high-γ amplitude peaking around the trough of the α oscillation, and its strength and phase were not predictive of movement type. As the coupling attenuated toward the timing of motor execution, the high-γ amplitude appeared to be released from the α phase to build a motor representation with phase-independent activity. Our results suggest that PAC modulates motor representation in the sensorimotor cortex by holding and releasing high-γ activity in movement-selective cortical regions.