Differential firing patterns of the peptide-containing cholinergic motor neurons B15 and B16 during feeding behavior in Aplysia.

During egestive responses neuron B16 fires at 20 Hz, while neuron B15 is not active. During ingestive responses B16 fires for 0.5-1.0 s at 15-20 Hz, then B15 and B16 fire together, with B15 firing at 7.5-12 Hz. The duration of activity during ingestive responses depends on consumption of food: when food is not consumed, bursts are shorter (e.g. 2 vs 4 s). This study establishes a basis for investigating the role of peripheral neuromodulation under physiologically relevant conditions.