An integrated circuit (IC) chip (100) expanded to nerve fiber (602) growth in the third dimension by through-silicon via-holes (TSV) (131), with an electrically conductive inner sidewall (303) having a roughness (303a) suitable for supporting the growing fiber and conductive connections (210) to the circuitry (101). The TSVs are fabricated parallel to each other and may be arrayed in regular patterns. The chip, provided with a pad (230) for contacting a nerve end and attaching a neuron, acts as a permanent protective sheath for the parallel growing fibers. Nerve fiber growth is stimulated by combining in the chip electrical and magnetic pulses and neurotrophic factors (603); continuous communication with external monitors is provided. The IC provides each TSV with a signal generator, electric and magnetic field generator, power source, potential sensor, and transceiver. The electronic signals may initiate a predetermined action potential in the adjacent nerve fiber end and a sensor is configured for sensing the action potential in the nerve fiber end.