Nonlinear Frequency-Domain Analysis of the Transformation of Cortical Inputs by a Motoneuron Pool-Muscle Complex

Author(s)

Watanabe, Renato Naville ^{[1, 2]} ; Kohn, Andre Fabio ^[1]

Affiliation

^[1] Univ Sao Paulo, Biomed Engn Lab, Escola Politecn, BR-05508010 Sao Paulo - Brazil

^[2] Fed Univ ABC, Biomed Engn Program, BR-09606045 Sao Bernardo Do Campo, SP - Brazil

• Document type: Journal article
• Source: IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING; v. 25, n. 11, p. 1930-1939, NOV 2017.
• Web of Science Citations: 1

Abstract

Corticomotor coherence in the beta and/or gamma bands has been described in different motor tasks, but the role of descendingbrain oscillationson force control has been elusive. Large-scale computational models of a motoneuron pool and the muscle it innervates have been used as tools to advance the knowledge of how neural elements may influence force control. Here, we present a frequency domain analysis of a NARX model fitted to a large-scale neuromuscular model by the means of generalized frequency response functions (GFRF). The results of such procedures indicated that the computational neuromuscular-model was capable of transforming an oscillatory synaptic input (e.g., at 20 Hz) into a constant mean muscle force output. The nonlinearity uncovered by the GFRFs of the NARX model was responsible for the demodulation of an oscillatory input (e.g., a beta band oscillation coming from the brain and forming the input to the motoneuron pool). This suggests a manner by which brain rhythms descending as command signals to the spinal cord and acting on a motoneuron pool can regulate a maintained muscle force. In addition to the scientific aspects of these results, they provide new interpretations that may further neural engineering applications associated with quantitative neurological diagnoses and robotic systems for artificial limbs. (AU)

• FAPESP's process: 15/21819-3 - The use of a biologically realistic computational model of the neuromuscular system to the study of neurodegenerative diseases
• Grantee: Renato Naville Watanabe
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 11/17193-0 - Behavioral, brain and reflex responses to mechanical and electrical stimuli to study proprioception and the spinal cord in humans
• Grantee: André Fábio Kohn
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/21103-7 - Model identification for a human postural control study
• Grantee: Renato Naville Watanabe
• Support Opportunities: Scholarships in Brazil - Doctorate