Rabbit experimental sensory ataxic neuropathy: anti-GD1b antibody-mediated trkC downregulation of dorsal root ganglia neurons.

We previously reported experimental sensory neuropathy in rabbit induced by the immunization of ganglioside GD1b. The major pathological change in diseased rabbits was degeneration of primary sensory neurons with central axons extending to the dorsal column of the spinal cord. The loss of primary sensory neurons that mediate proprioceptive sensation prompted us to investigate the expression of trkC in dorsal root ganglia (DRG) because this type of neuron is thought depend mainly on neurotrophin-3-mediated trkC signaling. Northern blotting analysis revealed markedly reduced expression of trkC in DRG of diseased rabbits in acute phase. This result together with the absence of lymphocytic infiltration in DRG of diseased rabbits at any stage suggests the anti-GD1b antibody-mediated downregulation of trkC expression could be one of the pathogenesis of this experimental sensory ataxic neuropathy.