Regeneration of a lesioned CNS axon of a mature neuron, determined to be subject to regeneration inhibition by Smad23 signaling, is promoted by contacting the neuron with an inhibitor of Smad23 signaling sufficient to promote regeneration of the axon. The receiving system includes a signal receiving unit, an equalizer, a turbo decoder, a demultiplexer, first and second error correctors, and a block interleaver. The conduit 60 also has at least one side wall surrounding an ion transfer channel 115.