Altered morphological dynamics of activated microglia after induction of status epilepticus.
J Neuroinflammation. 2015-11-04; 12(1):
DOI: 10.1186/s12974-015-0421-6
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1. J Neuroinflammation. 2015 Nov 4;12:202. doi: 10.1186/s12974-015-0421-6.
Altered morphological dynamics of activated microglia after induction of status
epilepticus.
Avignone E(1)(2), Lepleux M(3)(4), Angibaud J(3)(4), Nägerl UV(5)(6).
Author information:
(1)Interdisciplinary Institute for Neurosciences, CNRS UMR 5297, 33077, Bordeaux,
France. .
(2)Université de Bordeaux, CNRS UMR 5297, 33077, Bordeaux, France.
.
(3)Interdisciplinary Institute for Neurosciences, CNRS UMR 5297, 33077, Bordeaux,
France.
(4)Université de Bordeaux, CNRS UMR 5297, 33077, Bordeaux, France.
(5)Interdisciplinary Institute for Neurosciences, CNRS UMR 5297, 33077, Bordeaux,
France. .
(6)Université de Bordeaux, CNRS UMR 5297, 33077, Bordeaux, France.
.
BACKGROUND: Microglia cells are the resident macrophages of the central nervous
system and are considered its first line of defense. In the normal brain, their
ramified processes are highly motile, constantly scanning the surrounding brain
tissue and rapidly moving towards sites of acute injury or danger signals. These
microglial dynamics are thought to be critical for brain homeostasis. Under
pathological conditions, microglial cells undergo “activation,” which modifies
many of their molecular and morphological properties. Investigations of the
effects of activation on motility are limited and have given mixed results. In
particular, little is known about how microglial motility is altered in epilepsy,
which is characterized by a strong inflammatory reaction and microglial
activation.
METHODS: We used a mouse model of status epilepticus induced by kainate
injections and time-lapse two-photon microscopy to image GFP-labeled microglia in
acute hippocampal brain slices. We studied how microglial activation affected the
motility of microglial processes, including basal motility, and their responses
to local triggering stimuli.
RESULTS: Our study reveals that microglial motility was largely preserved in
kainate-treated animals, despite clear signs of microglial activation. In
addition, whereas the velocities of microglial processes during basal scanning
and towards a laser lesion were unaltered 48 h after status epilepticus, we
observed an increase in the size of the territory scanned by single microglial
processes during basal motility and an elevated directional velocity towards a
pipette containing a purinergic agonist.
CONCLUSIONS: Microglial activation differentially impacted the dynamic scanning
behavior of microglia in response to specific acute noxious stimuli, which may be
an important feature of the adaptive behavior of microglia during
pathophysiological conditions.
DOI: 10.1186/s12974-015-0421-6
PMCID: PMC4634193
PMID: 26538404 [Indexed for MEDLINE]