Humpbacks have unusual type of brain cells also found in humans

Humpback whales are unusual among cetaceans for having a type of neural cells in their brains that also are found in humans.

The structure of the neurons, researchers say, promotes the speedy transmission of information and might play a role in supporting the humpback's complex social life and sophisticated ability to communicate.

A study in the current edition of the Anatomical Record reports that the humpback brain contains "islands" of neural cells in the cerebral cortex that are generally not seen in the smaller-toothed whales and dolphins but are found in primates and other large-brained whales.

The function of these "spindle" neurons is not well understood, but they are thought to be involved in processing thoughts and information and are affected by Alzheimer's disease and other debilitating brain disorders.

The study's authors, from the department of neuroscience at Mount Sinai School of Medicine in New York, say that spindle neurons probably first appeared in the common ancestor of humans about 15 million years ago and that they are found in great apes and humans but not in lesser apes and other primates.

In whales and dolphins they evolved earlier, possibly as early as 30 million years ago.

"Humpback whales exhibit complex social patterns that include intricate communication skills, coalition-formation, cooperation, cultural transmission and tool usage," the authors write. "It is thus likely that some of these abilities are related to comparable (tissue) complexity in brain organization in cetaceans and in hominids."