The neuroregulatory principle of acupuncture in treating insomnia is mainly based on its regulatory effect on the central nervous system and the autonomic nervous system. By stimulating specific acupoints, it regulates the secretion of neurotransmitters, neural electrical activity and neuroendocrine function, thereby improving sleep quality. The following analysis is conducted from three aspects: neurotransmitter regulation, neural electrical activity regulation, and neuroendocrine regulation:

First, neurotransmitter regulation

Increase inhibitory neurotransmitters: Acupuncture can stimulate acupoints and promote the release of inhibitory neurotransmitters such as gamma-aminobutyric acid (GABA). GABA can inhibit the excessive excitement of the central nervous system, reduce the excitability of the cerebral cortex, and make the body more likely to enter a relaxed state, thereby improving insomnia symptoms such as difficulty falling asleep, frequent dreams and easy awakening.

Regulating monoamine neurotransmitters: Acupuncture can regulate the levels of monoamine neurotransmitters such as serotonin (5-HT) and dopamine (DA). 5-HT is closely related to mood regulation and the sleep-wake cycle. An imbalance in its level may lead to insomnia. Acupuncture can increase the synthesis and release of 5-HT, raise its concentration in the synaptic cleft, and help stabilize emotions and promote sleep. At the same time, the regulation of dopamine can also improve sleep structure and enhance sleep quality.

Second, regulation of neural electrical activity

Regulating brainwave activity: Through acupuncture stimulation, the electrical activity pattern of the brain can be changed. For instance, increase the activity of alpha waves and theta waves, and reduce the activity of beta waves. Alpha waves usually occur in a relaxed state, theta waves are associated with the light sleep stage, and beta waves are related to wakefulness and tension. Acupuncture regulates brainwave activity, which helps the brain smoothly transition from an awakened state to a sleeping state and maintain a good sleep rhythm.

Regulating autonomic nerve electrical activity: Patients with insomnia often have autonomic nerve dysfunction, manifested as increased excitability of the sympathetic nerve and decreased excitability of the parasympathetic nerve. Acupuncture can regulate the electrical activity of the autonomic nerve, reduce the excitability of the sympathetic nerve, enhance the activity of the parasympathetic nerve, keep the body in a relaxed state, and be conducive to the occurrence and maintenance of sleep.

Third, neuroendocrine regulation

Regulating the hypothalamic-pituitary-adrenal axis (HPA axis) : Excessive activation of the HPA axis is closely related to insomnia. Acupuncture can reduce the secretion of stress hormones such as cortisol by regulating the function of the HPA axis. Excessive cortisol levels can cause the body to be in a state of stress and affect sleep. Acupuncture regulates the HPA axis, normalizes cortisol secretion, reduces the body’s stress response, and thereby improves sleep.

Regulating melatonin secretion: Melatonin is an important hormone that regulates sleep, and its secretion has a distinct circadian rhythm. Acupuncture can stimulate the pineal gland, promote the synthesis and secretion of melatonin, adjust the sleep-wake cycle, and restore the sleep rhythm of patients with insomnia to normal.