SUMMARY
Neuromodulators promote adaptive behaviors in response to either environmental or internal physiological changes. These responses are often complex and may involve concerted activity changes across circuits that are not physically connected. It is not well understood how neuromodulatory systems act across circuits to elicit complex behavioral responses. Here we show that the C. elegans NLP-12 neuropeptide system shapes responses to food availability by selectively modulating the activity of head and body wall motor neurons. NLP-12 modulation of the head and body wall motor circuits is generated through conditional involvement of alternate GPCR targets. The CKR-1 GPCR is highly expressed in the head motor circuit, and functions to enhance head bending and increase trajectory reorientations during local food searching, primarily through stimulatory actions on SMD head motor neurons. In contrast, NLP-12 activation of CKR-1 and CKR-2 GPCRs regulates body bending under basal conditions, primarily through actions on body wall motor neurons. Thus, locomotor responses to changing environmental conditions emerge from conditional NLP-12 stimulation of head or body wall motor neuron targets.
Competing Interest Statement
The authors have declared no competing interest.