NTRK1 and osteoporosis: Consequently, the progressive activation of NMDA receptors, the activation of microglia, the overexpression of ASIC3 and TRPV1 ion channels on nociceptive sensory neurons and the increase in TrkA+ nerve fibres are the consequence of this third NC injury phase in osteoporosis, leading to changes in spinal cord dorsal horn circuits, as is explained in the narrative review of Mattia et al. [1].