Neural circuits for touch-induced locomotion in Caenorhabditis elegans

In this paper, We demonstrate biomimetic neural circuits (CMOS circuits) responsible for touch induced-locomotion in the nematode Caenorhabditis elegans (C. elegans). Our circuits model the neural network responsible for touch-induced locomotion of C. elegans worm (Chalfie and Sulston, 1985 [1]). Most animals use action potentials (spikes) for information transfer across neurons. Our initial touch-sensitive neural circuit presented here uses spiking neurons from the BioRC library. However, C. elegans neurons communicate with each other through graded potentials instead of action potentials, requiring redesign of the BioRC neuromorphic circuits to mimic a non-spiking neural network representing motion in C. elegans. Each neuron designed uses basic circuits like spike-responsive or graded-potential excitatory or inhibitory synapses, a voltage adder (dendritic computations) and an axon hillock (for spiking motor neurons). A neuromorphic neural network was constructed in CMOS using our neural circuits to implement touch-induced locomotion. We simulated spiking and non-spiking neural networks to demonstrate how signals propagate from sensory neurons to motor neurons when either posterior or anterior gentle touch is applied to the worm. We have demonstrated similarity between simulation results and biological measurements.