Calligraphed "Spiral Ganglion Neurons" evoke the sea-shell like cochlear spiral below the artist's rendition of a Type II spiral ganglion neuron contacting outer hair cells. Neuron drawing modified from an HRP-filled and traced Type II spiral ganglion neuron (Berglund and Ryugo 1987). Artwork by calligrapher Barbara Glowatzki, developed for a description of Type II spiral ganglion neuron synaptic inputs and excitability (Weisz, Glowatzki and Fuchs 2009). The afferent innervation of the cochlea consists of two types of neurons, Type I and Type II spiral ganglion neurons. Type I neurons comprise 95% of the afferent neuron population, and project to single inner hair cells (IHC) in the organ of Corti. Acoustic information of sound timing, intensity and frequency is encoded by Type I neurons. Type II neurons comprise the remaining 5% of the spiral ganglion neuron population. They project past IHCs to contact several outer hair cells (OHC). The morphology of Type II spiral ganglion neurons has been well described, but a paucity of recordings has precluded any analysis of their function. Indeed, it was previously unknown whether the neurons received functional synaptic inputs or were capable of firing action potentials. The present work demonstrates the first use of a novel technique in which recordings are performed from the neuronal dendrites of Type II neurons near synaptic inputs from OHCs. These are the first recordings to reveal functional excitatory synaptic inputs from OHCs, the ability of the neurons to fire repetitive action potentials, and a striking excitation by exogenous ATP. While the function of the Type II neurons remains speculative, the present results suggest that the neurons may be excited by a large stimulus that activates multiple pre-synaptic OHCs or perhaps induces cellular damage leading to ATP release from ruptured cells. The development of this technique will allowed continued investigation into the function of Type II spiral ganglion neurons.   Weisz, C., Glowatzki, E. & Fuchs, P. The postsynaptic function of type II cochlear afferents. Nature 461, 1126-9 (2009).