Connecting a Connectome to Behavior: An Ensemble of Neuroanatomical Models of C. elegans Klinotaxis
Figure 7
Dynamics of the neck motor neurons.
Input-output diagrams for the left (A) and right (B) pair of dorsal and ventral motor neurons. Gray trace, steady-state input-output (SSIO) curve when the head sweep oscillation is absent. Red trace, instantaneous input-output relation when the head sweep oscillation is present. Arrows show the effects of output of the indicated chemosensory neuron on motor neuron input. Shaded areas show the range of oscillation. For each of the SSIO curves, there are dorsal and ventral motor neurons moving out of phase over the red trajectory due to the out of phase input from the oscillatory component. When the dorsal motor neuron is at point a in the curve, the ventral motor neuron is at point d, and vice versa. When the dorsal motor neuron is at point b in the curve, the ventral motor neuron is at point c, and vice versa. For the dorsal/ventral SMBL pair (A), an increase/decrease in chemical concentration would decrease/increase the output of the neuron in d, but not of the neuron in a; decreasing/increasing the difference between the two left neck motor neurons. For the dorsal/ventral SMBR pair (B), a and d represent the opposite regions: a neuron at a is more sensitive to changes in input than the other neuron at d; but the result is the same: an increase/decrease in chemical concentration decreases/increases the difference between the two neck right motor neurons. To different degrees, the same is the case for other points along the curve.