<prompt> Which of the following is observed during sleep induction?Norepinephrine and serotoninAcetyl CholineHistamineGABA  <response>: The cholinergic neurons in pontine reticular formation on stimulation, induce sleep. When the activity of norepinephrine and serotonin containing neurons locus coeruleus and raphe nuclei is dominant, there is a reduced level of activity in acetylcholine-containing neurons in the pontine reticular formation leading to wakefulness. The reverse of this pattern leads to REM sleep. A more even balance in the activity of these groups of neurons is associated with NREM sleep. Ref: Ganongs Review of Medical Physiology 25th edition Pgno: 279 