Decoding hindlimb movement for a brain machine interface after a complete spinal transection.

Author: Anitha Manohar; Robert D Flint; Eric Knudsen; Karen A Moxon
Language: English
Published: 2012
Source: Directory of Open Access Journals: DOAJ Articles
Online Access: http://europepmc.org/articles/PMC3531410?pdf=render
https://doaj.org/toc/1932-6203
1932-6203
doi:10.1371/journal.pone.0052173
https://doaj.org/article/9f9d2ed1dde740a8a72433614e550b8d
https://doi.org/10.1371/journal.pone.0052173
https://doaj.org/article/9f9d2ed1dde740a8a72433614e550b8d
Identification number: ftdoajarticles:oai:doaj.org/article:9f9d2ed1dde740a8a72433614e550b8d

Summary

Stereotypical locomotor movements can be made without input from the brain after a complete spinal transection. However, the restoration of functional gait requires descending modulation of spinal circuits to independently control the movement of each limb. To evaluate whether a brain-machine interface (BMI) could be used to regain conscious control over the hindlimb, rats were trained to press a pedal and the encoding of hindlimb movement was assessed using a BMI paradigm. Off-line, information encoded by neurons in the hindlimb sensorimotor cortex was assessed. Next neural population functions, or weighted representations of the neuronal activity, were used to replace the hindlimb movement as a trigger for reward in real-time (on-line decoding) in three conditions: while the animal could still press the pedal, after the pedal was removed and after a complete spinal transection. A novel representation of the motor program was learned when the animals used neural control to achieve water reward (e.g. more information was conveyed faster). After complete spinal transection, the ability of these neurons to convey information was reduced by more than 40%. However, this BMI representation was relearned over time despite a persistent reduction in the neuronal firing rate during the task. Therefore, neural control is a general feature of the motor cortex, not restricted to forelimb movements, and can be regained after spinal injury.