Red: theory; black, fact
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| Solanum dulcamara, a plant with anticholinesterase activity. |
“Life is difficulty.” -The Buddha Gautama
My PhD thesis was about a neuromodulator (acetylcholine) acting on mammalian brain. It was tough to decapitate so many rats; I never got used to it.
The basic theory
I conjecture that the primordial function of any type of transmitter substance acting on the g-protein-coupled cell-surface receptors or nuclear receptors of neurons was to coordinate the whole-organism response to some class of perils.
Table 1.
| Peril | Substance | Failure mode |
| Extremes of heat and cold | glutamate and GABA | ? |
| Predator | serotonin | depression |
| Parasite | histamine | phobia |
| Rival conspecific | noradrenaline | paranoia |
Social isolation |
