An in vitro "scratch-wound" model was
used to evoke and investigate
some astroglial responses to mechanical injury. The changes in the
morphology,
locomotion, and proliferation of injured astrocytes were analysed under
culture
conditions devoid of blood-derived cells responsible for activating the
inflammatory cascade. The rate of proliferation was determined by
immunocytochemical detection of BrdU-incorporating cells located next
to or far
from the wound. The motility of individual cells and the
mass-advancement of
cell-assemblies were monitored by computer controlled video-microscopy
both in
injured monolayers and in preparations of single cells or aggregates of
astrocytes. The large sets of digitalized data allowed a reliable
statistical
evaluation of changes in cell positions providing a quantitative
approach for
studies on dynamics of cell locomotion. The results indicated that
cultivated
astrocytes respond to injury (1) with enhanced nestin immunoreactivity
at the
expanding processes, (2) with increased mitotic activity exceeding the
rate
caused by the liberation from contact inhibition, but (3) without
specific,
injury-induced activation of cell locomotion. Some advantages and
drawbacks of
"scratch-wound" models of astrocytic responses to mechanical injury
are presented and discussed. Copyright 2000 Wiley-Liss, Inc.
Published in
J Neurosci Res 2000 Aug 15;61(4):421-9
Supplemental movies
Rat embrionic type-I astroglia culture:
10 Mbyte mpeg stream.
Objective: 20X (Field of view: 210um X 160um).
Duration of recording: 3 days.
Number of frames: 937 (5 min/frame).
Note the cessation of locomotory activity at confluence.
Migration from aggregates:
9 Mbyte mpeg stream.
Objective: 10X (Field of view: 420um X 320um).
Duration of recording: 3 days.
Number of frames: 824 (5 min/frame).
Note the rather coordinated motion of the cells despite the high local
cell density.
Cell invasion after mechanical injury of the monolayer: 8 Mbyte mpeg stream.
Objective: 10X (Field of view: 420um X 320um).
Duration of recording: 2 days.
Number of frames: 560 (5 min/frame).
Note the similar behavior to that seen for the expanding aggregates.
The bright localised "flashes" are cell divisions.
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