Figure 5.

Neuronal correlates of spontaneous motor pattern switching. (A) Extracellular recordings of radula motor patterns (top three traces) and intracellular recordings of the essential B64 neuron and the optional B51 cell of the retractor generator. Switching between ingestion and egestion motor patterns during tonic (2 Hz) stimulation of n.2,3 (Stim. n.2,3) was associated with the spontaneous, all-or-none activation or absence (*) of bursting in B51. (B) Endogenous plateau property of B51 revealed by brief intracellular current injections in the absence of n.2,3 stimulation. Note that a burst-generating plateau in B51 also elicited closure motor activity that normally occurs during the retraction phase of ingestion patterns [see (A)].