Sleep plays an important role in the endocrine system, which regulates hormones in the bloodstream. While sleeping, the body attempts to repair damage done by stress and prepares us to handle new stresses coming our way. During sleep, levels of the stress hormone cortisol decrease and we secrete more growth hormone (a key tissue-repair substance). Without enough sleep, cortisol can remain elevated, keeping the body in a state of alertness and driving up blood pressure, which increases the risk of heart attack and stroke. Sleep deprivation may also lead to a rewiring of the brain’s emotional circuitry and put us into a state of hyper-arousal.
Researchers from Harvard and Berkeley studied 26 healthy students after either an all-nighter or a full night’s sleep. As the students looked at pictures, researchers did brain scans of the amygdala, a midbrain structure responsible for decoding emotion. The amygdala scans of the sleep-deprived participants showed 60 percent more activity than those of the participants who had slept — and more than five times the number of neurons being fired.
In participants who slept, the amygdala seemed to be talking to the medial prefrontal cortex, an outer layer of the brain that helps mediate experiences and emotions. In the sleep-deprived brains, the amygdala seemed to be rerouted to a brain-stem area called the locus coeruleus, which secretes norepinephrine, a precursor of the hormone adrenaline that triggers fight-or-flight reactions.
Acupuncture has a direct effect in patients who have elevated cortisol levels associated with stress and lack of sleep. It can calm the “wired and tired” symptoms in the body and balance the adrenal glands that are responsible for releasing cortisol in the body. After acupuncture treatments, patients leave the office feeling more grounded and focused, so they are able to concentrate more effectively throughout their day.