Welcome to the Banerjee Lab at CSHL

​The amazing diversity of animal behaviors all around us prompts an important but often understudied question: How do complex behaviors evolve? In mammals, the cerebral cortex is posited to play a critical role in facilitating complex behavioral innovations. However, the computations, algorithms, and mechanistic basis for such behavioral evolution remains elusive. 

 

Vocal innovations, such as birdsong or human speech, represent particularly striking examples of how neural circuits can evolve to generate novel behaviors while maintaining ancestral functions. Of particular interest to us is the Costa Rican singing mouse (Scotinomys teguina), which has evolved a dramatic behavioral innovation absent even in recently-diverged rodents. They stand on their hind-legs, raise their heads in an operatic posture and produce human-audible, rhythmic songs that are used for long-distance vocal interactions, while retaining the ancestral ultrasonic vocalizations for short-range interactions. This dual communication system in the singing mouse provides a unique opportunity to understand how neural circuit modifications can generate novel behavioral (vocal) capacities. 

 

Our research so far reveals both conservation and innovation in the underlying neural machinery. Surprisingly, vocal repertoire expansion occurred by co-opting a conserved brainstem production machinery, suggesting that the basic vocal production mechanism remained largely unchanged. However, we found evidence for expanded cortical control underlying this vocal innovation, with the orofacial motor cortex playing a crucial role in controlling the novel song mode.

 

By integrating systems neuroscience, ecology, development, and evolutionary biology, we are identifying principles of how cellular and circuit-level changes in neural circuits can generate novel behaviors while preserving essential ancestral functions. Such design principles of neural circuit evolution offers broader insights into how cognitive capacities may emerge in any intelligent system—natural or artificial. ​​​