During rem sleep, specific brainstem neurons show reduced activity. what types of neurotransmitters are released by these neurons?

Serotonin and norepinephrine are the types of neurotransmitters that are released.

REM sleep is the rapid eye movement sleep and mostly it occurs after 90 minutes when you sleep and at that time specific brainstem neurons have their activity reduced and you can also have intense dreams in that time period. There are also stages during rapid eye movement sleep.