Topic Overview:

The corticospinal tract is an important target for motor recovery after spinal cord injury (SCI). Voluntary motor output depends on the performance of synapses between corticospinal axons and spinal motoneurons, which can be modulated by the precise timing of neuronal spikes. Using noninvasive techniques, Perez developed tailored protocols for precise timing of the arrival of descending and peripheral volleys at corticospinal-motoneuronal synapses of an intrinsic finger muscle in humans with chronic incomplete SCI. Perez’s team found that arrival of presynaptic volleys prior to motoneuron discharge enhanced corticospinal transmission and hand voluntary motor output. The reverse order of volley arrival and sham stimulation decreased or did not affect voluntary motor output and electrophysiological outcomes. Modulation of residual corticospinal-motoneuronal synapses may present a novel therapeutic target for enhancing voluntary motor output in SCI and other disorders of the corticospinal tract.

The focus of Perez's research is on understanding how the brain and spinal cord control voluntary movements in healthy people and in individuals with spinal cord injury. Current research projects address interhemispheric interactions between primary motor cortices during hand movements, and intermanual transfer of motor learning in healthy people and in individuals with spinal cord injury.