Figure 6.

A schematic illustrating the shift in network activation between escape and swimming in socially dominant and subordinate animals. In dominant animals, a low level or absence of inhibition from inhibitory interneurons with the continuous excitatory input from swim CPG potentiates swimming activity. However, in subordinate animals, an increase in excitability of the inhibitory neurons suppresses the slow MNs and swimming behavior. Simultaneously, an increase in Mauthner sensitivity promotes the excitation of the escape circuit and inhibition of the swim circuit. In the illustrated example, stimulation of the left M-cell activates the right fast MN and bilateral suppression of the slow MNs. Suppressed pathways are dimmed, while strengthened synaptic pathways are emphasized in black (for details, see Materials and Methods and Results).