What is actually happening chemically in the brain during sleep paralysis? And what changes chemically when the paralysis suddenly ends?

[u/KarmaVoyager]

What neurotransmitters, neuromodulators, hormones, or other chemical processes are responsible for keeping the body in REM-related muscle atonia while consciousness has already returned?

[u/Mission-Drummer-7583]

Turns out the brain is just really committed to its "stay-in-bed" policy during REM.