Dynamic Reorganization of Motor Networks During Recovery from Partial Spinal Cord Injury in Monkeys

Cereb Cortex. 2019 Jul 5;29(7):3059-3073. doi: 10.1093/cercor/bhy172.

Abstract

After spinal cord injury (SCI), the motor-related cortical areas can be a potential substrate for functional recovery in addition to the spinal cord. However, a dynamic description of how motor cortical circuits reorganize after SCI is lacking. Here, we captured the comprehensive dynamics of motor networks across SCI in a nonhuman primate model. Using electrocorticography over the sensorimotor areas in monkeys, we collected broadband neuronal signals during a reaching-and-grasping task at different stages of recovery of dexterous finger movements after a partial SCI at the cervical levels. We identified two distinct network dynamics: grasping-related intrahemispheric interactions from the contralesional premotor cortex (PM) to the contralesional primary motor cortex (M1) in the high-γ band (>70 Hz), and motor-preparation-related interhemispheric interactions from the contralesional to ipsilesional PM in the α and low-β bands (10-15 Hz). The strengths of these networks correlated to the time course of behavioral recovery. The grasping-related network showed enhanced activation immediately after the injury, but gradually returned to normal while the strength of the motor-preparation-related network gradually increased. Our findings suggest a cortical compensatory mechanism after SCI, where two interdependent motor networks redirect activity from the contralesional hemisphere to the other hemisphere to facilitate functional recovery.

Keywords: cortical reorganization; electrocorticography (ECoG); motor cortex; network connectivity; spinal cord injury (SCI).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Efferent Pathways / physiopathology*
  • Functional Laterality / physiology*
  • Macaca
  • Motor Cortex / physiopathology*
  • Recovery of Function / physiology*
  • Spinal Cord Injuries / physiopathology*