An Electronic Circuit Design of the Reciprocal Inhibition Neural Network Generating Walk Patterns

A central pattern generator (CPG) is a half-center rhythm generator, which is constructed from neural networks of the spinal cord. The remarkable CPGʼs phenomena, observed in the experiments on the fictive locomotor activity of decerebrate cats, are that the rhythmic activity that re-emerges following a spontaneous omission of activity (deletion) is often not phase shifted. Rybak et al. (2006) propose a neural network model composed of multiple Hodgkin-Huxley type equations replicating such physiological phenomena. Maeda (2008) proposed a hardware design of the Rybakʼs mathematical model, using the SPICE simulation. Main purpose of this study is to reproduce dynamics of both the CPG and motoneuron networks using electronic circuits. As a result, the hardware CPG-motoneuron complex network showed the same response phenomena to the perturbation, which causes the deletion, as the mathematical model. Furthermore, the phase shift, observed after the perturbation to the rhythm generator of CPG, was nearly constant against increasing the amplitude of perturbation. The phase advanced about 0.2 seconds on average.