Study provides insight into how humans and other vertebrates generate sounds

Cornell researchers have identified regions of a fish brain that reveal the basic circuitry for how humans and other vertebrates generate sound used for social communication.

In a study of midshipman fish, published online today (June 14) in Nature Communications, the researchers identified two distinct groups of neurons that independently control the duration and the frequency of sounds used for calling.

While human speech and bird songs are far more complex than the grunts and hoots produced by some fish, the study provides a very basic wiring diagram of how the brain allows vertebrates to vocalize.

"If you can understand the simplest system, it provides a road map for understanding the fundamental working units in the central nervous system for how you build a vocal system," said Andrew Bass, Cornell professor of neurobiology and behavior and senior author of the paper.

In a 2008 Science paper, Bass and colleagues identified this same region of the brain in larval midshipman fish, showing how it is present in the brains of other animals, including primates. This suggests that the vocal networks in all vertebrates evolved from an ancestrally shared brain area that originated in fishes.

"Studies like these allow us to trace the evolutionary history of the brain," Bass said. "All animals, including humans, share many brain circuits for complex behaviors, including the use of sounds for social communication."