NGF and atrial fibrillation: NGF is known to be a major contributor of sensory axonal sprouting, neural survival, regulation of nociceptive sensory neurons, inflammatory hyperalgesia, and neuropathic pain.29, 30, 39 To determine the expression of NGF with grade of degeneration in human AF cells, we performed immunohistochemistry on AF tissue and we assessed the NGF content by Western blotting on extracted NGF from AF tissue.