Serotonin receptors supports distinct dynamics of foraging behavior through their expression patterns throughout the brain
For example mod-1 supports proper locomotion throughout the entirety of NSM activity during continued serotonin release, whereas ser-4 may only be important during the onset of NSM activity.
mod-1 is a 5HT gated chloride channel
ser-4 is a G protein coupled receptor
Both are inhibitory
By swapping sites of expression of the receptors in mutant animals (expressing mod-1 under the ser-4 promotor and vice versa, and no other 5HT receptors), the behaviors remained consistent with the promotor rather than the receptor used.
This supports the conclusion that the downstream neurons activity facilitate the behavioral repertoire of foraging rather than the receptors themselves changing the dynamics of the neurons.