Members & Research

We are interested in understanding how complex motor sequences are learned and generated by the nervous system. What is the identity of the neural circuits involved in motor learning and how do their respective functions change as the animal learns to execute a stereotyped motor sequence? By studying these questions in two different model systems - songbird and mouse we hope to identify general principles of how neural circuits underlie the learning and execution of complex motor acts.

Songbirds
Our main focus is to understand the neural circuit mechanisms underlying vocal learning in songbirds. The zebra finch, our species of choice, learns its song in a manner that is similar to how we learn many of our motor > skills by imitating a tutor. It first listens and memorizes the tutor song, then proceeds with trial-and-error vocal experimentation, producing highly variable song. By continuously evaluating its own performance relative to the memorized song template, the songbird slowly converges on a copy of the tutor song. The ultimate goal of our research is to arrive at a mechanistic description of how this learning algorithm is implemented by neurons and their connections. This involves identifying the neural circuits involved and understanding their function. To this end we manipulate, measure from, and model the neural circuits involved in song learning and song production.

Rodents
To explore how motor sequences are learned and executed by neural circuits in mammals we use the mouse, a genetic model system that offers us tremendous power to manipulate and measure from the circuits involved in motor learning. Our approach is to teach rodents motor sequences using operant conditioning paradigms. We are currently characterizing the capacity for motor sequence learning in mice and rats. Initial experiments have been encouraging, showing that mice can indeed learn precisely timed motor sequences. By recording neural activity during behavior, using optical imaging techniques such as voltage sensitive dye imaging and calcium imaging, we will explore how and where information about movement sequences is encoded in the mouse motor cortex. This combined with electrophysiology and targeted manipulations of the circuit will allow us to describe how motor sequence learning is implemented by neural circuits in the mammalian brain.