More brain fun: endocannabinoids, which can send signals between neurons, usually “backwards”, from the postsynaptic cell to the presynaptic cell. They’re hydrophobic, but can pass easily among the membranes of nearby cells, so they’re used for short-distance signaling via diffusion. They have a bunch of roles, including something to do with memory, though the details are still vague.
A general rule of thumb for biological systems is that you can safely bet on them being more complicated than they look at any given moment. Don’t even get me started on how we evolve immunity to new pathogens whenever we come down with a cold (literally evolve—there are somatic DNA changes involved), or the struggle in our genome between parasitic DNA sequences and the systems suppressing them. A modern molecular biology textbook would make H. P. Lovecraft blush.
More brain fun: endocannabinoids, which can send signals between neurons, usually “backwards”, from the postsynaptic cell to the presynaptic cell. They’re hydrophobic, but can pass easily among the membranes of nearby cells, so they’re used for short-distance signaling via diffusion. They have a bunch of roles, including something to do with memory, though the details are still vague.
A general rule of thumb for biological systems is that you can safely bet on them being more complicated than they look at any given moment. Don’t even get me started on how we evolve immunity to new pathogens whenever we come down with a cold (literally evolve—there are somatic DNA changes involved), or the struggle in our genome between parasitic DNA sequences and the systems suppressing them. A modern molecular biology textbook would make H. P. Lovecraft blush.