Ever wondered the reason why people sleep through anything? Few people sleep through the explosion while few wake through the gentle quiet breeze. Here is the answer to it.
People who sleep through anything show more frequent bursts of sleep spindles. Individuals known as "Super Slumberers," who experience exceptionally high-quality sleep, produce an increased number of sleep spindles—brain wave bursts that indicate heightened activity in the thalamus.
What are Sleep Spindles?
Sleep spindles, high-frequency brain waves generated by the thalamus and cortex. These sleep spindles are likely to represent the strength and flexibility of the thalamus, which is the key to promoting memory, learning, and sound sleep. They help in maintaining sleep by blocking the sensory inputs it might be as sound or, touch from disturbing the night's sleep. They predominated during stage 2 (N2) of the non-REM sleep.
How the Thalamus Works During Sleep
Thalamus as relay station: The thalamus plays a multifactorial role and indeed relay hub, connecting subcortical areas to the cerebral cortex, and transmitting sensory signals.
Thalamus in the sensory system: It is responsible for processing sensory information from various systems (sight, touch, hearing, etc.) and routing it to the relevant cortical regions.
Thalamus and sleep spindles: During sleep, especially non-REM stages, the thalamus interacts with the cortex, producing rhythmic electrical activity known as sleep spindles. These spindles help modulate sensory input by temporarily blocking, essentially shielding the brain from external stimuli, effectively suppressing sensory perception, such as touch and sound.
Deeper sleep and spindle activity: Increased spindle activity is linked to reduced perception of external stimuli, which contributes to deeper and more restful sleep.
Here Dr. Sermed Mezher, a Locum General Practitioner explains in gist the reason behind the individual's sleep through anything and sleep stability, and gives insights on the future interest of the scientist in drugs that increase the thalamic activity and help all people enter the super-slumber state.
Busier the Brains, Deeper the Sleep
Dr. Jeffrey M. Ellenbogen, Neurologist, Harvard Medical School
According to the study conducted by Dr. Jeffrey M. Ellenbogen and his colleagues, 12 healthy volunteers spent three consecutive nights in a sleep laboratory. On the first night, the environment was quiet, while the second and third nights introduced common sounds such as traffic sounds, phone rings, and mechanical disturbances. EEG (electroencephalogram) was used to track the sleep spindles at night. During quiet nights, individuals exhibited higher sleep spindles and enjoyed more stable sleep compared to noisy nights.
The results suggest that individuals with a greater number of sleep spindles can maintain better sleep despite external disruptions. However, the study noted that spindle rates and the ability to tolerate noise tend to diminish with age, which affects the quality of sleep.
Reference:
1. Dang-Vu TT, McKinney SM, Buxton OM, Solet JM, Ellenbogen JM. Spontaneous brain rhythms predict sleep stability in the face of noise. Current biology. 2010 Aug 10;20(15):R626-7.
2. Deshong, A. (2024, February 1). Sleep spindles. Sleep Doctor. https://sleepdoctor.com/how-sleep-works/sleep-spindles/
3. Busy Brains Make for Deeper Sleep. (2021). Science.org. [online] doi:https://doi.org/10.1126/article.30054.
By Josna Lewis
MSM
