%0 Journal Article
%T Glial activation in white matter following ischemia in the neonatal P7 rat brain
%A Val¨¦rie Biran
%A Luc-Marie Joly
%A Anne H¨¦ron
%A Agn¨¨s Vernet
%A C¨¦line V¨¦ga
%A Jean Mariani
%A Sylvain Renolleau
%A Christiane Charriaut-Marlangue
%J Quantitative Biology
%D 2006
%I arXiv
%X This study examines cell death and proliferation in the white matter after neonatal stroke. In post-natal day 7 injured rat, there was a marked reduction in myelin basic protein (MBP) immunostaining mainly corresponding to numerous pyknotic immature oligodendrocytes and TUNEL-positive astrocytes in the ipsilateral external capsule. In contrast, a substantial restoration of MBP, as indicated by the MBP ratio of left-toright, occurred in the cingulum at 48 (1.27 +- 0.12) and 72 (1.30 +- 0.18, p<0.05) hours of recovery as compared to age-matched controls (1.03 +- 0.14). Ki-67 immunostaining revealed a first peak of newly-generated cells in the dorsolateral hippocampal subventricular zone and cingulum at 72 hours after reperfusion. Double immunofluorescence revealed that most of the Ki-67-positive cells were astrocytes at 48 hours and NG2 pre-oligodendrocytes at 72 hours of recovery. Microglia infiltration occurs over several days in the cingulum and a huge quantity of macrophages reached the subcortical white matter where they engulfed immature oligodendrocytes. The overall results suggest that the persistent activation of microglia involves a chronic component of immunoinflammation, which overwhelms repair processes and contributes to cystic growth in the developing brain.
%U http://arxiv.org/abs/q-bio/0601011v1