Neural Stem Cell Grafts Form Extensive Synaptic Networks that Integrate with Host Circuits after Spinal Cord Injury

Steven Ceto1, Kohei J Sekiguchi2, Yoshio Takashima3, Axel Nimmerjahn2, Mark H Tuszynski4

  1. Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA; Veterans Administration Medical Center, San Diego, La Jolla, CA 92161, USA. Electronic address: steven.ceto@epfl.ch.
  2. Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
  3. Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Veterans Administration Medical Center, San Diego, La Jolla, CA 92161, USA.
  4. Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Veterans Administration Medical Center, San Diego, La Jolla, CA 92161, USA. Electronic address: mtuszynski@health.ucsd.edu.

Abstract

Neural stem/progenitor cell (NSPC) grafts can integrate into sites of spinal cord injury (SCI) and generate neuronal relays across lesions that can provide functional benefit. To determine if and how grafts become synaptically organized and connect with host systems, we performed calcium imaging of NSPC grafts in SCI sites in vivo and in adult spinal cord slices. NSPC grafts organize into localized and spontaneously active synaptic networks. Optogenetic stimulation of host corticospinal tract axons regenerating into grafts elicited distinct and segregated neuronal network responses throughout the graft. Moreover, optogenetic stimulation of graft-derived axons extending from the graft into the denervated spinal cord also triggered local host neuronal network responses. In vivo imaging revealed that behavioral stimulation likewise elicited focal synaptic responses within grafts. Thus neural progenitor grafts can form functional synaptic subnetworks whose activity patterns resemble intact spinal cord.

Presented By Steven Ceto | ORCID iD

NeuroscienceNicholas Liao2020-09 (Sep)