  We develop a biophysically realistic model of the nematode C. elegans that
includes: (i) its muscle structure and activation, (ii) key connectomic
activation circuitry, and (iii) a weighted and time-dynamic proprioception. In
combination, we show that these model components can reproduce the complex
waveforms exhibited in C. elegans locomotive behaviors, chiefly omega turns.
This is achieved via weighted, time-dependent suppression of the proprioceptive
signal. Though speculative, such dynamics are biologically plausible due to the
presence of neuromodulators which have recently been experimentally implicated
in the escape response, which includes an omega turn. This is the first
integrated neuromechanical model to reveal a mechanism capable of generating
the complex waveforms observed in the behavior of C. elegans, thus contributing
to a mathematical framework for understanding how control decisions can be
executed at the connectome level in order to produce the full repertoire of
observed behaviors.
