Final answer:
Serotonin and adenosine are neurotransmitters that have been shown to increase REM sleep and overall sleep time. Melatonin production, influenced by serotonin, is crucial for sleep regulation. The REM rebound phenomenon further illustrates the role of neurotransmitters in sleep homeostasis.
Step-by-step explanation:
The question asks which neurotransmitter has been shown to increase REM sleep and increase total sleep time. Serotonin, a monoamine neurotransmitter, plays a key role in both sleep regulation and the production of melatonin, which is involved in the sleep-wake cycle. Melatonin production in the pineal gland, which is signaled by serotonin, affects the sleep-wake cycle and can influence REM sleep and overall sleep duration.
Also, adenosine, a neurotransmitter that builds up in the brain over the course of the day, promotes sleepiness and an increase in sleep duration. As an antagonist, caffeine inhibits adenosine receptors, thus decreasing sleepiness. The treatments for narcolepsy using psychomotor stimulant drugs, which promote wakefulness, highlight that sleep architecture is influenced by neural activity. While traditional stimulants may not directly impact the neurotransmitter systems that are implicated in REM sleep, understanding the mechanisms of actions and the balance of inhibitory and excitatory receptor activity is crucial for treating sleep disorders.
If someone experiences REM sleep deprivation and is later allowed to sleep without disturbances, they will exhibit 'REM rebound', spending more time in REM sleep. This compensatory increase in REM sleep provides evidence for the homeostatic regulation of this sleep stage and the role that neurotransmitters play in maintaining the balance within our sleep cycles.