Captain Ahab was right about Moby Dick: Humpback whales have “human” brain cells

Humpback whales have a type of neuron cell—spindle neurons—that is the same as one found in humans, according to Patrick R. Hof and Estel Van der Gucht of the Department of Neuroscience at Mount Sinai School of Medicine in New York. In an article in The Anatomical Record, the official journal of the American Association of Anatomists, “The Structure of the Cerebral Cortex of the Humpback Whale, Megaptera novaeangliae (Cetacea, Mysticeti, Balaenopteridae),” Hof and Van Der Gucht compared the brain of an adult humpback whale to that of a fin whale (another type of baleen whale, like the humpack) and also to that of a number of toothed whales (including three bottlenose dolphins, a sperm whale, and a killer whale). Today’s Science Daily notes that:

They found that the humpback cerebral cortex, the part of the brain where thought processes take place, was similar in complexity to smaller sized cetaceans such as dolphins. The large area of cortex found in these mammals is thought to be related to acoustic capabilities and the current study shows that it is organized into a system of core and belt regions. However, substantial variability was found between the cell structure of the cortex in humpbacks compared to toothed whales. The authors suggest that these differences may indicate differences in brain function and behavior in aquatic species that are not yet understood.

Spindle neurons first appeared in hominids about 15 million years ago and in cetaceans about 30 millions years ago.

One feature that stood out in the humpback whale brain was the modular organization of certain cells into “islands” in the cerebral cortex that is also seen in the fin whale and other types of mammals. The authors speculate that this structural feature may have evolved in order to promote fast and efficient communication between neurons. The other notable feature was the presence of spindle cells in the humpback cortex in areas comparable to hominids and in other areas of the whale brain as well. Although the function of spindle neurons is not well understood, they are thought to be involved in cognitive processes and are affected by Alzheimer’s disease and other debilitating brain disorders such as autism and schizophrenia. Spindle neurons were also found in the same location in toothed whales with the largest brains, which suggests that they may be related to brain size. [my emphasis]

The authors note that humpback whales (and also sperm whales and killer whales) “exhibit complex social patterns that included intricate communication skills, coalition-formation, cooperation, cultural transmission and tool usage”; they suggest that these may be related to the “histologic complexity” of the organization of the cetaceans’ brains, as is the case for human brains.

If I may reference a work of fiction—Herman Melville’s novel Moby Dick—perhaps Captain Ahab was not crazy after all in thinking the great white whale a force, an opponent, to be pursued.

“The Structure of the Cerebral Cortex of the Humpback Whale, Megaptera novaeangliae (Cetacea, Mysticeti, Balaenopteridae) was published online on November 27th in The Anatomical Record.