For long time microglia have been considered quiescent cells, activated only in cases of infections or threats to the brain homeostasis. However, the literature over the past decades has literally revolutionized this view, introducing a new definition, ‘surveying microglia’ as opposed to ‘resting’, to pinpoint constantly active cells, continuously monitoring the brain parenchyma and the synaptic function. In particular, during early brain development, several studies have revealed a critical role for microglia as shapers of neural circuits, by providing trophic factors, and by remodeling and pruning synapses.
Schematic representation of the possible mechanisms mediating synapse loss by microglia. From Rajendran and Paolicelli, Journal of Neurosci 2018.
Interestingly, synapse loss is the major correlate of cognitive impairment in many neurodegenerative diseases. Recent literature suggests that microglia, which mediate synaptic pruning during brain development, can be responsible for synapse loss in neurodegeneration. Although the underlying mechanisms are poorly understood, growing evidence indicates that dysfunctional microglia affect synapses number and function in pathology. Genome-wide association studies reveal that the majority of risk genes associated with neurodegenerative disorders are highly expressed in microglia. However, while such studies clearly implicate these cells in the pathogenesis of the disease, little is still known about the causal mechanisms that link microglial risk variants to loss of synapses.
Background from left to right: Elsa Hoti, Kyllian Ginggen, Anne-Claire Compagnion, Alessandro Matera, Anastasija Milentijevic, Nathalie Stefanoni
Foreground from left to right: Fanny Martineau, Evangelina Christoforidi, Rosa Chiara Paolicelli, An Buckinx, Katia Monsorno
Rosa Chiara Paolicelli, Assistant Professor
|
|
Rosa C. Paolicelli earned her bachelor of Medical Biotechnology at the University of Bologna, Italy, in 2006, and her MSc in Molecular Neuroscience at the University of Bristol, UK, in 2007. She graduated in 2011 with a PhD in Cellular and Molecular Biology, from the European Molecular Biology Laboratory (EMBL), where she investigated the role of microglia in refining neural circuits during development. After completing her PhD, Dr. Paolicelli worked as postdoc at the University of Zurich, Switzerland, in the Department of Systems and Cell Biology of Neurodegeneration (2012-2018). During this time, she studied the cellular and molecular mechanisms underlying microglia-mediated synapse loss in neurodegenerative diseases, by using a combination of in vitro and in vivo approaches. In 2018 Dr. Paolicelli got a position as Assistant Professor at the Department of Physiology, University of Lausanne, where she established her lab on microglia biology, focusing on the molecular mechanisms regulating microglia-synapse interaction in physiological and pathological contexts. She recently obtained an ERC starting grant to investigate the role of microglia in neurodegeneration. |
Gloria Colombo, Postdoc
 |
Gloria Colombo obtained a BSc in molecular biotechnology and a MSc in neurobiology at the University of Pavia, in Italy. In 2016, she joined the graduate school program at the institute of Science and Technology Austria (ISTA) and affiliated to Prof Siegert’s group. Her PhD project aimed at developing a new algorithm to analyze the impact of region and sex on microglial morphology in health and disease and to map microglial morphology from regions of interest. After obtaining her PhD, she started her postdoc in the Paolicelli’s group, where she works to dissect the contribution of microglial lactate metabolism in ischemic stroke. |
Anne-Claire Compagnion, Postdoc
 |
Anne-Claire followed her studies at Sorbonne University in Paris, France, where she obtained her bachelor in Life Sciences and her master degree in Neurosciences. In 2015, she joined the group of Dr.Tronche in the Institut de Biologie Paris-Seine, Sorbonne University where she started her PhD under the supervision of Dr. Vyas. For four years, she studied the differential impact of alpha-synuclein assemblies on microglial reactivity. She obtained her PhD in 2019, and stayed to study the involvement of transcription factors in social and addictive behavior. Since March 2021, she is a post-doctoral researcher in the Paolicelli’s group focusing her work on the molecular and cellular mechanisms of microglia-mediated synapse loss in neurodegeneration. |
Kyllian Ginggen, PhD student
 |
Kyllian obtained his bachelor’s degree in biology and his master’s degree in medical biology at the University of Lausanne. During his master’s degree, he decided to focus on neuroscience, especially on glial cells. For his master thesis, he aimed to disrupt basolateral amygdala astrocytes activity by using chemogenetics to prevent the association of cocaine hedonic behavior to its environmental associated cue. In May 2019, he started a Ph.D. in the team of professor Paolicelli, focusing on the function of microglia in synapse plasticity, both in physiological and pathological contexts
|
Fanny Martineau, Postdoc
 |
Fanny studied at Aix-Marseille University in France where she earned her bachelor in Biology and her master degree in Developmental Biology, Immunology and Neurobiology. In 2013, she joined Dr. A. Represa’s group at the Mediterranean Institute for Neurobiology (Marseille, France) to start her PhD in Neurosciences under the joint supervision of Dr. JB. Manent and F. Watrin. For four years, she investigated how laminar misplacement resulting from neuronal migration failure in the cortex influences neuronal maturation and overall rat behavior. She graduated in November 2017 and temporarily joined Dr. V. Crépel’s lab to work on pathological kainate synapses in the context of temporal lobe epilepsy. Fanny moved to Dr. R. C. Paolicelli’s lab in July 2019 to investigate the molecular mechanisms underlying microglia-mediated synapse loss in pathology. |
Alessandro Matera, PhD student
 |
Alessandro obtained the Bachelor degree in Biological Sciences at “La Sapienza”, University of Rome. He continued his studies earning the Master degree in Neurobiology. He worked on physiological and developmental processes of Schwann cells involved in the axonal regeneration. Now, he is a PhD in Prof. Paolicelli’s laboratory, working on microglia biology, focusing on microglia-synapse interaction. |
Katia Monsorno, PhD student
 |
Katia obtained her Bachelor and Master degrees in Molecular Biology from the University of Trento (Italy), where she specialized in Neurobiology. She is particularly interested in investigating glial cells physiology, aiming to understand how their alterations could lead to the onset of neuropathology. During her Master thesis, she addressed the modulation exerted by several inflammatory factors on astrocytes metabolism, as well as the roles played by microglia in establishing this regulation. In January 2019 she joined Rosa Chiara Paolicelli’s group as a PhD student, focusing on the metabolic control of microglia. |
