Descending motor circuitry required for NT-3 mediated locomotor recovery after spinal cord injury in mice
Abstract
Locomotor function, mediated by lumbar neural circuitry, is modulated by descending spinal pathways. Spinal cord injury (SCI) interrupts descending projections and denervates lumbar motor neurons (MNs). We previously reported that retrogradely transported neurotrophin-3 (NT-3) to lumbar MNs attenuated SCI-induced lumbar MN dendritic atrophy and enabled functional recovery after a rostral thoracic contusion. Here we functionally dissected the role of descending neural pathways in response to NT-3-mediated recovery after a T9 contusive SCI in mice. We find that residual projections to lumbar MNs are required to produce leg movements after SCI. Next, we show that the spared descending propriospinal pathway, rather than other pathways (including the corticospinal, rubrospinal, serotonergic, and dopaminergic pathways), accounts for NT-3-enhanced recovery. Lastly, we show that NT-3 induced propriospino-MN circuit reorganization after the T9 contusion via promotion of dendritic regrowth rather than prevention of dendritic atrophy.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 20, 2019
- Source ID
- 10.1038/s41467-019-13854-3
Entities
People
- Christopher B. Shields
- George M. Smith
- Heqiao Dai
- Josue D. Ordaz
- Nai-kui Liu
- Qi Han
- Wei Wu
- Wenrui Qu
- Xiao-Ming Xu
- Yi Ping Zhang
- Ying Wang
- Yongzhi Xia
- Zoe Richardson
Organizations
- Foundation for the National Institutes of Health
- Indiana State Department of Health
- Shriners Hospitals for Children
- United States Department of Defense
- United States Department of Veterans Affairs