The Mechanics of Dreaming
As dreams weave their intricate stories, the body doesn't merely remain a passive spectator. In tandem with the mind's escapades, there's a discernible surge in our physiological metrics. Adrenaline courses more rapidly, the heartbeat accelerates, and blood pressure mounts. Given this heightened state, it brings into perspective the tragic instances where individuals with vulnerable hearts succumb during slumber. The heart, already delicately poised, might find it challenging to navigate these intense and fluctuating demands, leading to unfortunate consequences.
When you're deep in a dream, your eyes take center stage, fluttering quickly beneath your closed lids – a phenomenon aptly termed as Rapid Eye Movement or REM. Found within the fourth stage of our sleep cycle, REM accounts for a significant 15-20% of our nightly rest. While the journey to this dream realm begins 30 to 90 minutes after sleep onset, the trek is undertaken multiple times, with 4 to 7 excursions in a single night.
Even though the heart races and blood pressure seesaws during REM, the body adopts a paradoxically serene stance. Muscles are bathed in relaxation, rendering you immobile. Yes, while you might toss and turn occasionally during the night, REM ensures a state of profound stillness – a phenomenon referred to as "REM Paralysis".
During REM sleep, the mental theater comes alive, mirroring the liveliness experienced during wakefulness. Yet, the chemical cast backstage paints a different picture. The performance of REM is directed by the cholinergic neurons' excitability levels. Notably absent from this act are two stars: noradrenaline and serotonin. These crucial brain chemicals play leading roles in tasks, problem-solving, and memory. Their absence during REM provides insight into the elusive nature of dreams, explaining why the morning often greets us with mere fragments of the vivid tales spun in the night.