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Supported by the generosity of the Killam Trusts, The Neuro's Killam Seminar Series invites outstanding guest speakers whose research is of interest to the scientific community at The Neuro and 海角社区.

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Franck Polleux

Professor of Neuroscience, Columbia University

Host:听eric.shoubridge [at] mcgill.ca (Eric Shoubridge )

Abstract:听Two of the most striking distinguishing features of human cortical pyramidal neurons (CPNs) are: (1) human CPNs receive significantly more excitatory and inhibitory synapses than any other mammalian species including non-human primates and (2) synaptic development is strikingly neotenic in humans, taking years to reach maturation compared to weeks or months in other mammalian species. Our lab identified two human-specific gene duplications called SRGAP2B/C which, by inhibiting all known functions of the post-synaptic ancestral protein SRGAP2A, leads to slower (neotenic) rates of excitatory (E) and inhibitory (I) synaptic maturation and increased E and I synapse number. We also demonstrated that this increased density of E synapses in layer 2/3 cortical pyramidal neurons (CPNs) originates from increased cortico-cortical connections, leading to changes in the coding properties of these neurons in vivo and improved behavioral performance in a sensory discrimination task in mice humanized for SRGAP2C expression. I will summarize recent results demonstrating (1) the function of human-specific genes SRGAP2B/C as critical modifiers of synaptic development in human neurons using xenotransplantation and (2) that SRGAP2B/C also act as human-specific disease modifiers in the context of neurodevelopmental disorders.