||Is a hindbrain interneuron. Giant reticulospinal neurons possessing thick crossed axons and positioned dorsally in the hindbrain tegmentum at the level of entrance of the eighth cranial nerve. The Mauthner neuron is paired. The M-cell has two large invariant dendrites: The lateral dendrite terminates in the sensory neuropil of the acoustico-lateral area, and the ventral dendrite terminates in the neuropil of the motor tegmentum. Fine dendrites are present, and mostly arise from three regions; from the terminus of each major dendrite and from the ventral surface of the perikaryon.