STIMULATION OF DORSAL-ROOT GANGLIA AND DEGRADATION OF RABBIT ANNULUS FIBROSUS

The authors sought to determine whether narrowing of the intervertebral neuron foramen, by itself and in association with vibration, would stimulate the mechanosensitive dorsal root ganglia and result in degradation of proteoglycan and collagen of the annulus fibrosus, as proposed in their working model of dorsal root ganglia-neuropeptide-mediated degeneration of the spinal motion segment. Degradation of proteoglycan and collagen of rabbit annulus was observed when there was narrowing of the neural foramen and the degradation process was accelerated by vibration. Vibration alone, in the absence of structural abnormalities of the spinal motion segment, did not induce matrix degradation probably because of a less pronounced stimulation of the dorsal root ganglia. Biological events similar to those postulated here, formented by a combination of structural abnormalities and environmental factors, could be involved in human disc degeneration.