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Microglia activity and inflammation

Une publication d'Agnès Nadjar du laboratoire NutriNeuro

Le 29 août 2013

Early morphofunctional plasticity of microglia in response to acute lipopolysaccharide.
Madore C, Joffre C, Delpech JC, De Smedt-Peyrusse V, Aubert A, Coste L, Layé S*, Nadjar A*, Brain Behavior and Immunity, 2013.
Laboratoire NutriNeuro, INRA UMR1286 - Université de Bordeaux

Un commentaire sur ce papier par 
Agnès Nadjar
In this work, we decipher the consequences of a peripheral inflammation on the resident brain immune cells, so called microglia activity within the CNS. Since 2005, it is known that in the healthy brain, microglia are extremely dynamic, perpetually changing their morphology by extending and retracting highly motile processes on a time scale of minutes (Davalos et al., 2005; Nimmerjahn et al., 2005). 

Pict: Morphological plasticity of microglia is altered 2 hours after LPS injection. Maximum-intensity projections of microglial cells over the time course of a time-lapse recording. In this example, stacks of images were taken every 50 seconds. The red dotted line highlights an extending process while white dotted lines highlight retracting processes. (Extracted from Madore et al., 2013). The microscopy was done in the Bordeaux Imaging Center of the University of Bordeaux Segalen. 

This unexpected finding led to a series of discoveries suggesting potential roles of microglia
in postnatal development, adult neuronal plasticity, and circuit function. However, it was unknown whether a peripheral inflammation changes microglia plasticity and dynamic in the adult brain. Using two-photon microscopy on mice expressing GFP specifically in microglia, we have been able to show for the first time, in vivo, that in response to a peripheral immune challenge, microglial cells change their motility profile, reducing the velocity of processes movements. This response was as early as two hours post-immune activation. 

This morphological plasticity was associated to the release of pro-inflammatory cytokines within the brain together with a significant infiltration of macrophages within the CNS. Macrophages infiltration represents a new route of neuroimmune communication that could lead to changes in the activity of resident immune cells. 

The changes in microglia activity could be involved in the synaptic modifications observed in inflammatory conditions (Yirmiya et Goshen., 2011) and be involved in inflammation-induced emotional behavior alteration (Dinel et al., 2011).

Agnès Nadjar (agnes.nadjar @
Dernière mise à jour le 10.01.2014

1er auteur

Charlotte Madore
Ph.D. student
UMR1286 INRA/Bordeaux2
Research team:
Psychoneuroimmunology and nutrition: experimental and clinical approaches (Sophie Layé)