has characteristic innervates cochlear outer hair cell spiral ganglion neuron type 2 spiral ganglion neuron Outer hair cells form reciprocal synapses onto type 2 spiral ganglion cells, suggesting that the type 2 cells have both afferent and efferent roles. type II spiral ganglion cell A spiral ganglion neuron that innervates outer hair cells. Type 1 spiral ganglion neurons are unmyelinated and unipolar. unipolar neuron morphology neuron projection bundle