How are neurons organized into functional circuits?
I n the developing nervous system, billions of neurons form intricate networks that detect, transmit and process different types of information, such as vision, movement, and memory. Remarkably, though each neural network ultimately acquires the specific properties appropriate for its distinct function, they are all built from the same basic cellular and molecular building blocks through shared developmental events, from cell differentiation to synapse formation. In contrast to the molecular basis of discrete cellular events, little is known about how generic events are coordinated within a single neuron.
To learn how different types of neural networks acquire their unique properties, we use mouse genetics, live imaging, sequencing, and behavior to study circuit assembly in two model systems: spiral ganglion neurons of the inner ear and retinal amacrine cells. Most of our work is focused on the inner ear, where we can easily link changes in the organization of auditory circuits to the animal's ability to perceive sound and motion. Additional insights into how different kinds of networks acquire their unique features come from studies of retinal circuits, which exhibit a striking laminated pattern.