December 14, 2010 14:00 - 16:00
Proximal-to-distal sequencing of limb segments is characteristic of a number of motor behaviors including throwing, hitting, jumping, and perhaps even reach-to-grasp. Moreover, shoulder- and elbow-related neurons in primary motor cortex (MI) have been shown to activate earlier than wrist- and finger-related neurons in monkeys performing a button-press task (Murphy et al, 1985, J. Neurophys., 53, 435-445). We recently discovered that beta frequency oscillations in the local field potential (LFP) spontaneously propagate as travelling waves across the surface of the motor cortex along a rostral-to-caudal axis while monkeys perform a variety of visuo-motor tasks. Moreover, movement-initiating, visual stimuli can generate evoked waves that propagate from the rostral to caudal parts of the motor cortex. We hypothesize that these evoked propagating LFP waves may promote proximal-to-distal recruitment of motor cortical neurons. This is consistent with a number of intracortical microstimulation experiments in MI demonstrating a topographic gradient such that proximal movements of the shoulder and elbow are evoked more rostrally on the precentral gyrus while wrist and finger movements are elicited more caudally including within the bank of the central sulcus. We have begun to test this hypothesis by correlating the propagating waves in motor cortex with the sequential recruitment of shoulder, elbow, and wrist movements and muscles of monkeys performing a variety of tasks.
- BSI Private Event
RIKEN people can also attend this event.
- Gruen Lab/Diesmann Lab