Spinle neurons, also called von Economo neurons (VENs), are a specific class of neurons that participate in signal transmission in the nervous system, and are characterized by a large spindle-shaped soma, gradually tapering into a single apical dendrite (axon) in one direction, with only a single dendrite facing opposite. Whereas other types of neurons tend to have many dendrites, the polar shaped morphology of spindle neurons is unique, having only been found in two very restricted regions in the brains of hominids - the family of species comprising humans and great apes. A recent study, however, has found spindle cells in the brains of the humpback whales, fin whales, killer whales and sperm whales. The name von Economo neuron comes from their discoverer, Constantin von Economo (1876-1931).