Neural circuits for visual behaviors

A fundamental question in in neuroscience is how sensory information is represented within the brain and transformed into a behavioral response. In order for an animal to respond to a visual stimulus, the pattern of photons falling on the retina must be classified as a particular type of stimulus, and the brain must generate a spatially appropriate behavior, e.g. toward or away from the stimulus.

The goal of my research is to understand how neurons at different levels of the visual system represent the key features of the stimulus, and how this information is read out and transformed into a motor command.

Techniques
We use 2-photon imaging with an electrically tunable lens to record from a large volume of the zebrafish brain while presenting visual stimuli and recording behavior. This allows us to record the activity of individual neurons and analyse the populations of neurons that are activated by particular stimuli or during visual behaviors.

We also use holographic 2-photon optogenetics to selectively manipulate groups of neurons and asses their impact on function and behavior.

Valence encoding and identification of prey and predators by the visual system

How do animals know whether they should hunt, freeze, or escape from a visual object? We take advantage of optical access to the zebrafish brain to record from neurons in all visual areas to determine their roles in identifying stimuli and making the decision to behave.

How do interactions between astrocytes and neurons generate and modulate behavior?

Glia have been increasingly identified as important players in neural circuits, but their full range of functions remains unknown. We are using in vivo calcium imaging and optogenetic manipulation of astrocytes to identify novel roles for these cells in a broad range of behaviors.

How do internal states modulate behavior?

Animals react differently to stimuli depending on internal factors such as fear and hunger, but how these states affect visuomotor circuits remains unclear. We are using our established visual behaviors to study how natural and drug-induced states affect the decision to hunt, freeze or escape.