PiN Faculty Member - Matthew Pecot, PhD

Matthew Pecot, PhD

Assistant Professor of Neurobiology

Harvard Medical School
Department of Neurobiology
Goldenson 420, 220 Longwood Avenue
Boston, MA 02115

Our nervous systems comprise vast numbers of different neuronal cell types, yet in order for us to detect, interpret, and respond to changes in our environment, neurons must be organized into highly precise synaptic networks. How do neurons navigate cellular complexity and synapse with the right partners amidst so many inappropriate ones? To address this question we study neural circuit assembly in the Drosophila visual system. Our goal is to understand how intercellular communication regulates synaptic specificity.
The fly visual system is similar to the mammalian retina in structure and cellular complexity, yet contains genetic tools that provide exquisite control of specific cell-types, allowing gene function to be studied in a cell autonomous manner. In flies, visual information is captured by photoreceptors in the retina and processed in the brain by large ensembles of neurons. Anatomically, these neurons are organized in a modular fashion into columns and layers. Columns process information regarding discrete points in visual space and different visual features (e.g. motion and color) are computed within specific layers. Within each column, information is relayed to three pathways; two motion sensitive pathways and a color pathway. Each pathway comprises a discrete set of neuronal cell types with characteristic morphologies and layer specificities that are connected through synapses in a stereotyped manner.

Work in the laboratory is focused on understanding how intercellular interactions coordinate assembly of these columnar circuits. We use cell-type-specific RNA sequencing, molecular genetics, in vivo protein localization and synaptic tagging studies to address the following questions:

How do neurons achieve their characteristic morphologies and layer specificities? Our work suggests that layers are established in a stepwise manner through intercellular interactions that regulate the shape and position of neuronal processes during development. Currently we are working towards understanding the sequence of interactions that regulates the morphology and layer-position of neurons within the color pathway.

How do synapses between specific neurons develop and what are the molecular mechanisms that control cellular specificity? Through synaptic tagging methods we can visualize synapse formation during development in vivo in specific cell types and with single cell resolution through light microscopy. Genes important for this process can then be identified in microscopy-based genetic screens.

What is the developmental logic that underlies circuit formation in the visual system? Ultimately, we hope our findings lead to the discovery of general molecular and developmental strategies that underlie circuit formation. Thus far, our work indicates that circuits arise sequentially, through choreographed interactions between specific cell types within the same motion/color pathway.

Last Update: 7/1/2014


For a complete listing of publications click here.



© 2015 by the President and Fellows of Harvard College