…This release of inflammatory mediators stimulates the peripheral nervous system response through the afferent nerve fibers. Their stimulation results in a segmental analgesic response that activates descending anti-nociceptive signals via the dorsal horn of the spinal cord. I should note that there are various techniques used to achieve stimulation—manual vs. Estim etc…
The stimulation of these fibers triggers the release of endogenous opioids and neurotransmitters including, serotonin, norepinephrine, GABA, glycine and dopamine. This results in the patient feeling a calm sense of euphoria that is often reported by patients after an Acupuncture treatment. The release of neurotransmitters will also affect the brain with greater impacts that will ripple throughout the body.
Another thing Acupuncture has been demonstrated to do is lower heart rate. It also has been demonstrated to modulate the Autonomic Nervous System by lowering the sympathetic tone and increasing the parasympathetic tone. The resulting implications help with treating chronic pain and other conditions where chronic stress plays a significant role such as gastric motility, cardiovascular issues, metabolism and hormone regulation by way of the endocrine system.
Brain imaging studies have demonstrated acupuncture stimulation of the hypothalamus with implications for regulation of the hypothalamus with implications for regulation of the hypothalamus-pituitary-adrenal axis and restoration of homeostasis. In conjunction, there is a downregulation of limbic structures and modulation of the prefrontal cortex. This has an affect for reducing hypervigilance, hyperarousal, and emotional liability.
Functional MRI and PET imaging studies have also shown acupuncture-induced activation of the somatosensory and motor cortices corresponding with Acupuncture point location, with implications for treating chronic pain, neuropathic pain and conditions affecting mobility. This includes post-stroke sequelae and palsies.
As I said at the beginning of this discussion, I will not water down this discussion. I f you find this discussion too technical, I ask you to atleast appreciate that Acupuncture and its mechanism are being discussed fully in Western scientific terms.