Email: brian.chen [at] mcgill.ca (brian.chen @ mcgill.ca)
Tel.: 514-934-1934 ext. 42379
Assistant Professor | Neurology & Neurosurgery, Medicine (Dept. & Faculty)
Researcher | Research Institute of the McGill University Health Centre
Now recruiting post-docs and students.
How to build a brain
My research focuses on the cellular and molecular mechanisms of how neural circuits wire up with precision. One of the central puzzles in neuroscience is how a neuron chooses the correct synaptic contacts during development when faced with tens of thousands of potential targets. To uncover the different molecules and strategies neurons use to self-assemble into a neural circuit, my lab combines high-resolution imaging techniques with advanced molecular genetics in different model systems to look inside living animals while their neurons form synapses. My research uses invertebrate organisms to identify underlying genetic mechanisms of neural wiring, and vertebrates to investigate the common molecular rules that may be used to wire up the human brain.
One molecule that may be involved in this wiring decision process is Down Syndrome Cell Adhesion Molecule (Dscam). Dscam is a surface receptor in the immunoglobulin superfamily that has been shown to have conserved functions in neural circuit formation across invertebrates to mammals. These functions include axon guidance, dendritic branching, and synaptic targeting (reviewed in Schmucker and Chen, 2009). The human DSCAM gene is located on chromosome 21 in the Down Syndrome Critical Region and has been implicated in several aspects of Down Syndrome phenotypes. Thus far there is little direct evidence that DSCAM is involved in the abnormal neural development in Down Syndrome individuals.
My lab currently investigates 4 main questions:
1) What is the role of the alternatively-spliced isoform diversity of Drosophila Dscam in mediating synaptic targeting and neuronal branch extension?
2) What is the role of the vertebrate DSCAM genes on the in vivo dynamics of axonal and dendritic branches and dendritic spines, and the contributions of DSCAM to Down syndrome mental retardation?
3) What other molecules are involved in synaptic partnering decisions in Drosophila, and what similar functions do they perform in vertebrates?
4) Can molecules involved in synaptic targeting instruct axonal re-growth or synaptogenesis after brain and spinal cord injury?
This research will provide insight into how the brain’s wiring diagram is encoded in the genome, and how this program can go awry in mental disorders and mental retardation. These insights will be invaluable in uncovering fundamental causes of mis-wiring during abnormal brain development and for treatments in re-wiring neurons after injury.
For more details see the Chen Lab Website.