The Dynamic Active Neural Cycle (DANC): Sleep/rest-gated peripheral nerve mechanical cycle and its failure in fibromyalgia

The Dynamic Active Neural Cycle (DANC) is a proposed, as yet unrecognised physiology of the peripheral nervous system: a sleep/rest-gated cycle of compression and expansion in the peripheral nerves, orchestrated by the CNS. Its expansion is driven by muscles working against the skeleton, while its compression is generated within the nerve itself. It holds that this cycle emerged during vertebrate evolution in response to a continuous pressure for a mechanism that could provide the biological infrastructure for higher rate of fire and more accurate firing. This version adds one new subsection to the framework's speculative Section 5, on the rate of evolutionary change. Section 5 is now divided in two: 5.1 keeps the argument across lineages, and the new 5.2 asks whether the same holds within a single body. It takes the Asian sheephead wrasse (kobudai) as a fish in mid-transition. The cycle runs through the whole animal, but its gain in firing rate and accuracy has reached only the front half, which has diverged from its relatives while the rear has not. On this account, its front vertebrae interlock more stiffly, with a stronger skull–spine joint and a deeper arch; its column has not yet been examined for these features. The subsection states its limits and a falsifier: if the front half proves no more innervated than the rear, and fires no faster or more accurately, the reading is wrong. Two references are added; apart from the author's location, the rest of the paper is unchanged.