I’m in the +1 portion of my 4+1 program. We’re researching how attention and sensory input changes time perception, which includes our participant sitting in room doing nothing for an hour as a baseline, so we get more downtime than we’d like sometimes lmao.

That’s a hard question because of the interconnected-ness and complexity of the systems but I’ll give it a shot.

Neurotransmitters: ~30 Neuromodulators: ~10-20 (some transmitters also act as modulators) Hormones: 10 Growth Factors: ~5 Endocannabinoids: 2 Gaseous Neurotransmitters: 2 Peptides: ~30 Ion concentrations: ~5

So all that together I want to say there’s about 100 or so distinct “analog” signaling systems, but a lot of these molecules can function in multiple capacities, like neurotransmitters can act as neuromodulators and etc.