**5. Mechanisms of acupuncture effects**

We consider the mechanism of acupuncture's effect on dystonia to be as follows: First, cutaneous stimulation by acupuncture needles becomes a painful stimulus that ascends the lateral spinal thalamic tract, synapses in the thalamus, and projects to the somatosensory cortex as tertiary neurons. The inhibitory effects in the somatosensory and motor cortices then work at the cortical level to inhibit the descending pyramidal tract and α-motor neurons, resulting in relaxation of muscle tone.

The other is that a similar stimulus may have caused inhibition of extrapyramidal impulses at the thalamic and cortical levels, resulting in a reduction in muscle tone due to inhibition of γ-motor neurons.
