Table 1.
Modes of neuromodulation, from local to global.
| type of neuromodulationa | neuropeptideb | featuresc |
|---|---|---|
| executive signalling (local) | TK, sNPF | small neurons (restricted branching) |
| acts in specific circuits | ||
| local neuromodulation (fast) | ||
| can act as co-transmitter | ||
| sensory gain control | ||
| context-specific signalling (intermediate) | LK, AstA | intermediate sized neurons |
| regulates several circuits | ||
| context-specific inputs | ||
| affects behavioural choices | ||
| orchestrating signalling (global) | SIFa, DSK | widely branching neurons |
| global regulation (slow, sustained) | ||
| multiple inputs and targets | ||
| state- and context-dependent | ||
| affects behavioural choices | ||
| orchestrates behaviour | ||
| hormonal orchestrating signalling (global) | DILPs, AKH | IPCs, APCsd |
| acts via circulation (slow, sustained) | ||
| interorgan signalling | ||
| nutrition-dependent | ||
| orchestrates behaviour | ||
| regulates physiology | ||
| DILPs can affect GPCR expressione |
aRefers to the modes of neuromodulation discussed in this review.
bThese are only the neuropeptides discussed in this review, so not comprehensive.
cMain characteristics of signalling. The fast, slow and sustained refers to temporal aspects of modulation/action.
dIPCs, brain insulin-producing cells; APCs, AKH-producing cells in corpora cardiaca.
eDILP signalling regulates expression of sNPF and TK receptors (GPCRs) in the olfactory system and thereby affects executive signalling at the first synapse between olfactory sensory neurons and interneurons (gain control).