title: Electrophysiological mapping of rat sensorimotor lumbosacral spinal networks after complete paralysis.
abstract: Stimulation of the spinal cord has been shown to have great potential for improving function after motor deficits caused by injury or pathological conditions. Using a wide range of animal models, many studies have shown that stimulation applied to the neural networks intrinsic to the spinal cord can result in a dramatic improvement of motor ability, even allowing an animal to step and stand after a complete spinal cord transection. Clinical use of this technology, however, has been slow to develop due to the invasive nature of the implantation procedures and the difficulty of ascertaining specific sites of stimulation that would provide optimal amelioration of the motor deficits. Moreover, the development of tools available to control precise stimulation chronically via biocompatible electrodes has been limited. In this chapter, we outline the use of a multisite electrode array in the spinal rat model to identify and stimulate specific sites of the spinal cord to produce discrete motor behaviors in spinal rats. The results demonstrate that spinal rats can stand and step when the spinal cord is stimulated tonically via electrodes located at specific sites on the spinal cord. The quality of stepping and standing was dependent on the location of the electrodes on the spinal cord, the specific stimulation parameters, and the orientation of the cathode and anode. The spinal motor evoked potentials in selected muscles during standing and stepping are shown to be critical tools to study selective activation of interneuronal circuits via responses of varying latencies. The present results provide further evidence that the assessment of functional networks in the background of behaviorally relevant functional states is likely to be a physiological tool of considerable importance in developing strategies to facilitate recovery of motor function after a number of neuromotor disorders.
authors.affiliation: Departments of Integrative Biology and Physiology, University of California, Los Angeles, CA, USA.
authors.forename: Parag
authors.initials: P
authors.lastname: Gad
authors.affiliation: Departments of Integrative Biology and Physiology, University of California, Los Angeles, CA, USA; Brain Research Institute, University of California, Los Angeles, CA, USA.
authors.forename: Roland R
authors.initials: RR
authors.lastname: Roy
authors.affiliation: Departments of Integrative Biology and Physiology, University of California, Los Angeles, CA, USA; Department of Neuroscience, University of California, Los Angeles, CA, USA.
authors.forename: Jaehoon
authors.initials: J
authors.lastname: Choe
authors.affiliation: Departments of Integrative Biology and Physiology, University of California, Los Angeles, CA, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhong
authors.affiliation: Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, USA.
authors.forename: Mandheeraj Singh
authors.initials: MS
authors.lastname: Nandra
authors.affiliation: Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, USA.
authors.forename: Yu-Chong
authors.initials: YC
authors.lastname: Tai
authors.affiliation: Departments of Integrative Biology and Physiology, University of California, Los Angeles, CA, USA; Pavlov Institute of Physiology, St. Petersburg, Russia; Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia.
authors.forename: Yury
authors.initials: Y
authors.lastname: Gerasimenko
authors.affiliation: Departments of Integrative Biology and Physiology, University of California, Los Angeles, CA, USA; Department of Neurobiology, University of California, Los Angeles, CA, USA; Department of Neurosurgery, University of California, Los Angeles, CA, USA; Brain Research Institute, University of California, Los Angeles, CA, USA. Electronic address: vre@ucla.edu.
authors.forename: V Reggie
authors.initials: VR
authors.lastname: Edgerton
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004599:Electric Stimulation Therapy; D004567:Electrodes, Implanted; D004576:Electromyography; D005080:Exercise Test; D005260:Female; D008161:Lumbosacral Region / Q000473:pathology*; D018482:Muscle, Skeletal / Q000503:physiopathology; D010243:Paralysis / Q000209:etiology / Q000473:pathology* / Q000628:therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000473:pathology / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000150:complications
keywords: electric enabling motor control; electrode array; locomotion; neurorehabilitation; spinal cord epidural stimulation; spinal motor evoked potentials