Acupuncture Points and Their Relationship with Multireceptive Fields of Neurons

This review article presents a comprehensive analysis of the neurological basis of acupuncture points, exploring their relationship with the receptive fields of multireceptive neurons. The Mexican authors propose that the efficacy of acupuncture can be explained through the concept of neural receptive fields, offering a bridge between traditional Chinese theory and modern neuroscience.

The central concept of the work is that receptive fields are areas of the skin through which a sensory neuron can be activated by specific stimuli. The authors demonstrate that the majority of acupuncture points are located near or over peripheral nerve trunks, blood vessels, and nerve endings, suggesting that the meridians correspond to relevant deep peripheral nerve trajectories.

The methodology consists of a narrative review that analyzes experimental evidence from studies in humans and animals, integrating knowledge from neurophysiology, anatomy, and traditional Chinese medicine. The authors examine how acupuncture stimulation activates multiple central neural pathways, from dorsal root ganglia to supraspinal structures such as the thalamus and cerebral cortex.

An important finding is the concept of 'acupoint sensitization,' in which points become more sensitive when internal organs are in pathological condition. Experimental studies have demonstrated that visceral inflammation results in the expansion of the receptive fields of spinal neurons, explaining why certain points become more responsive during illness. For example, in patients with peptic ulcer, sensitive points along the stomach meridian become more pronounced.

Multireceptive neurons, which receive both somatic and visceral information, are identified as key targets of acupuncture stimulation. This convergence of inputs explains how cutaneous stimulation can influence internal organs through viscerosomatic reflexes. Electrophysiology shows that the activity of these neurons can be modulated by acupuncture stimulation, resulting in therapeutic effects.

The work also addresses the concept of 'dynamic states of acupoints,' suggesting that the size and function of the points are not static but vary according to the individual's physiological state. This neural plasticity explains why the exact location of points may vary between individuals and clinical conditions, challenging the notion of fixed points in traditional medicine.

The clinical implications are significant, as the receptive field model can explain both the specific and nonspecific effects of acupuncture. Stimulation of non-acupoint areas may activate sensitized receptive fields, producing therapeutic effects comparable to traditional acupuncture, especially in patients with central sensitization.

The authors propose that the optimal efficacy of acupuncture depends on the efficiency and specificity of the stimulation site and on the activation of particular pathways in the central nervous system. Precise identification of points becomes challenging because the receptive fields may be enlarged or modified by changes in the individual's physiological conditions.

This work represents an important advance in the scientific understanding of acupuncture, providing a robust neurophysiological framework that can guide future research and optimize clinical protocols. The integration between traditional knowledge and modern neuroscience offers promising perspectives for the development of more effective and personalized treatments.