Justin C. Crowley
The neuron is the fundamental processing unit of the brain. Neuronal function is dependent on its synaptic connections with other cells - its inputs and outputs. The population of cells that synapse onto a neuron's dendrites dictate the information available to the neuron, while a neuron's axonal processes are responsible for distributing information to the rest of the brain. The assembly of synaptic connections between neurons is the generation of the biological circuitry that can function as part of the brain's neural systems. Thus the forces that govern the growth and structure of dendrites and axons dictate the way that the brain is able to process information, eventually leading to perception, thought and behavior.
My research focuses on the formation of circuitry in the visual system, specifically the development of neural processing modules in primary visual cortex. The circuitry of primary visual cortex organizes the visual scene encoded by the retinae into "maps" of features: a map of visual space, a map of ocular dominance (eye-specific information), a map of the orientations (angles) of lines, as well as others. The goal of my work is to understand how these circuits are formed and how they process information about the visual scene. The patterning forces underlying the formation of these circuits have been hypothesized to be patterns of gene expression or patterns of neural activity or a combination of these influences. Currently, the roles of these patterning forces and their interaction are a subject of debate within the neurobiology community.
My research employs a combination of physiological and anatomical techniques. Multi-photon imaging enables the examination of the structure and function of living neurons in real time as they develop and change. Optical imaging of intrinsic signal allows the detection of activity patterns of large groups of neurons. Electrical recording of the activity of single neurons enables the high fidelity examination of single processing units. The combination of these approaches facilitates the study of the dynamic interplay between structure and function in the developing brain.