Distinct physiologic properties of microglia and blood-borne cells in rat brain slices after permanent middle cerebral artery occlusion

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Item Type:	Article
Title:	Distinct physiologic properties of microglia and blood-borne cells in rat brain slices after permanent middle cerebral artery occlusion
Creators Name:	Lyons, S.A., Pastor, A., Ohlemeyer, C., Kann, O., Wiegand, F., Prass, K., Knapp, F., Kettenmann, H. and Dirnagl, U.
Abstract:	The authors investigated the time course of leukocyte infiltration compared with microglial activation in adult rat brain slices after permanent middle cerebral artery occlusion (MCAO). To distinguish peripheral leukocytes from microglia, the blood cells were prelabeled in vivo with Rhodamine 6G (Rhod6G) IV before induction of ischemia. At specific times after infarct, invading leukocytes, microglia, and endothelial cells were labeled in situ with isolectin (IL)B4-FITC (ILB4). Six hours after MCAO only a few of the ILB4+ cells were colabeled by Rhod6G. These cells expressed the voltage-gated inwardly and outwardly rectifying K+ currents characteristic of macrophages. The majority of the ILB4+ cells were Rhod6G− and expressed a lack of voltage-gated channels, recently described for ramified microglial cells in brain slices, or exhibited only an inward rectifier current, a unique marker for cultured (but unstimulated) microglia. Forty-eight hours after MCAO, all blood-borne and the majority of Rhod6G− cells expressed outward and inward currents indicating that the intrinsic microglial population exhibited physiologic features of stimulated, cultured microglia. The ILB4+/Rhod6G− intrinsic microglial population was more abundant in the border zone of the infarct and their morphology changed from radial to ameboid. Within this zone, the authors observed rapidly migrating cells and recorded this movement by time-lapse microscopy. The current findings indicate that microglial cells acquire physiologic features of leukocytes at a later time point after MCAO.
Keywords:	Focal Cerebral Ischemia, K+ Current, Leukocytes, Patch-Clamp, Time-Lapse Video Microscopy, Animals, Rats
Source:	Journal of Cerebral Blood Flow and Metabolism
ISSN:	0271-678X
Publisher:	Nature Publishing Group
Volume:	20
Number:	11
Page Range:	1537-1549
Date:	November 2000
Official Publication:	https://doi.org/10.1097/00004647-200011000-00003
PubMed:	View item in PubMed

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