Laetitia Weinhard, PhD

Human Frontier Science Program Postdoctoral Fellow

PhD, EMBL Rome, 2016

MS, Paris Descartes University, 2011

Efficient learning is critical for mammals to constantly adapt to their environment. Learning and memory formation are generally acknowledged to rely on synaptic plasticity: the capacity of synaptic circuits to gain or lose strength and to eventually rewire via the formation of new synaptic connections and the elimination of pre-existing ones.

During my PhD in the lab of Cornelius Gross, I focused on the role of microglia in eliminating synapses. Contrary to previous assumptions, I observed that microglia do not eliminate postsynaptic spines, but indiscriminately nibble on presynaptic axons with no preference for the synaptic compartment. Additionally, I observed that microglia associate with the formation of postsynaptic spine precursors, suggesting that microglia may promote synapse formation rather than elimination.

My postdoctoral research aims to better understand the mechanisms underlying microglia synaptogenic function. In the Littman lab, I will explore how immune responses in the periphery modulate microglia-mediated synaptic plasticity in the brain.

 

Publications:

  1. Basilico, B., Pagani, F., Grimaldi, A., Cortese, B., Di Angelantonio, S., Weinhard, L., Gross, C.T., Limatola, C., Maggi, L., Ragozzino, D. (2019) Microglia shape presynaptic properties at developing glutamatergic synapses. Glia, 67(1):53– 67.

  2. Weinhard, L., Bartolomei, G., Bolasco, G., Machado, P., Schieber, N. L., Neniskyte, U., Exiga, M., Vadisiute, A., Raggioli, A., Schertel, A., Schwab, Y., Gross, C. T. (2018). Microglia remodel synapses by presynaptic trogocytosis and spine head filopodia induction. Nature Communications, 9(1):1228.

  3. Weinhard, L., d’Errico, P., Leng Tay, T. (2018). Headmasters: Microglial regulation of learning and memory in health and disease. AIMS Molecular Science, 5(1), 63–89.

  4. Bolasco, G., Weinhard, L., Boissonnet, T., Neujahr, N., Gross, C.T. (2018). Three-dimensional nanostructure of an intact microglia cell. Frontiers in neuroanatomy, 12, 105.

  5. Weinhard, L., Neniskyte, U., Vadisiute, A., di Bartolomei, G., Aygün, N., Riviere, L., Zonfrillo, F., Dymecki, S., Gross, C. T. (2017). Sexual dimorphism of microglia and synapses during mouse postnatal development. Developmental Neurobiology, 78(6):618-626.

  6. Zhan, Y., Paolicelli, R. C., Sforazzini, F., Weinhard, L., Bolasco, G., Pagani, F., Vyssotski, A., Bifone, A., Gozzi, A., Ragozzino, D., Gross, C. T. (2014). Deficient neuron-microglia signaling results in impaired functional brain connectivity and social behavior. Nature Neuroscience, 17(3):400–406.