A fact little known to the public, but known to biologists for over a century, is that fish are quite talkative. They click and grunt, hoot and hum, about the same sorts of things that birds and mammals talk about. Which, of course, are mainly sex and violence, or as biologists call them: courtship and territoriality.

Midshipman fish, which got their name from the rows of fluorescent photophores on their underside resembling the rows of buttons on the uniforms of midshipman in the British navy, are among the most vocal of fish. These fish hide under rocks in the intertidal zone along the west coast of the United States and Canada, and court and mate at night. Visual cues are of little use in such conditions, so these fish are entirely dependent on vocal communication to find mates and fight off rivals. Males establish nest sites under rocks, sit at the entrance, and hum for up to hours at a time to attract a female (see movie clip). Males also use other call types, including grunts and growls, to warn off competing males who get to close to their territory. Females are attracted to the humming of the male, and enter the nest to spawn.

As a neurobiologist, my interest lies in how the brain controls these elaborate behaviors. Over the past few decades, neurobiologists around the world have characterized in great detail how the electrical activity of circuits of neurons control, or pattern, a variety of relatively simple motor behaviors, including locomotion in fish and mammals, arm reaching in monkeys, and the coordinated movements of gut muscles in crustaceans (!). More complex “suites” of behavior, including courtship, territorial aggression, and vocalization are only now beginning to be unraveled in terms of their underlying neural mechanisms.

I have chosen to examine these questions in midshipman fish because, while the behaviors themselves are essentially the same as in so-called “higher” vertebrates, they are simpler in these fish, and hopefully therefore more easily dissected. The specific neural circuits involved in vocalization in these fish seem to be remarkably similar, in both structure and function, to vocal circuits in birds and mammals. Thus, the results we obtain about how neural circuits pattern and modulate vocalization in midshipman fish, will likely have significant bearing on how vocal circuits operate in other species, including humans.

Some specific projects on which I, and students in my lab, are working, include:

     - The role of the periaqueductal gray, a midbrain structure      involved in vocal production across vertebrates, in vocal patterning.

     - The neurophysiological mechanisms by which the neuropeptide arginine-vasotocin modulates vocal behavior.

     - Does dopamine, another common neuromodulator, shape vocal and social behaviors in midshipman fish?

Birds, which of course are well-known songsters, vocalize about much the same things as fish. Songbirds, however, have the added behavioral wrinkle that they learn their songs, doing so by listening to, and memorizing, the songs of their fathers. Later, as they begin to sing themselves, they gradually match their own song to this memorized model. This process of song learning is hypothesized to involve a series of changes to the neural circuit involved in song production, likely including changes in the anatomical connectivity and electrical properties of individual nerve cells within these vocal circuits.  The neural mechanisms of song learning have emerged recently as an important model system for understanding more generally the mechanisms of sensorimotor learning.  My PhD research sought to characterize some of the specific types of neural plasticity involved in song learning.  While I am currently not actively pursuing this research, it remains an area of keen interest, and I am potentially open to future projects studying neural mechanisms of song learning.