Astrocytic gap junctions remain open during ischemic conditions.
Gap junctions are highly conductive channels that allow the direct transfer of intracellular messengers such as Ca2+ and inositol triphosphate (IP3) between interconnected cells. In brain, astrocytes are coupled extensively by gap junctions. We found here that gap junctions among astrocytes in acutely prepared brain slices as well as in culture remained open during ischemic conditions. Uncoupling first occurred after the terminal loss of plasma membrane integrity. Gap junctions therefore may link ischemic astrocytes in an evolving infarct with the surroundings. The free exchange of intracellular messengers between dying and potentially viable astrocytes might contribute to secondary expansion of ischemic lesions.
Cotrina
M L
ML
Department of Cell Biology, New York Medical College, Valhalla, New York 10595, USA.
Kang
J
J
Lin
J H
JH
Bueno
E
E
Hansen
T W
TW
He
L
L
Liu
Y
Y
Nedergaard
M
M
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001253:Astrocytes / Q000166:cytology / Q000502:physiology*; D002545:Brain Ischemia / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000098:blood supply / Q000166:cytology; D002544:Cerebral Infarction / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005456:Fluorescent Dyes / Q000493:pharmacokinetics; D017629:Gap Junctions / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D006624:Hippocampus / Q000098:blood supply / Q000166:cytology; D006863:Hydrogen-Ion Concentration; D007476:Ionophores / Q000494:pharmacology; D007546:Isoquinolines / Q000493:pharmacokinetics; D008297:Male; D009924:Organ Culture Techniques; D010766:Phosphorylation; D011522:Protons; D051381:Rats; D017207:Rats, Sprague-Dawley; D015290:Second Messenger Systems / Q000502:physiology; D019284:Thapsigargin / Q000494:pharmacology
D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D007476:Ionophores; D007546:Isoquinolines; D011522:Protons; D019284:Thapsigargin; C017475:lucifer yellow; D002118:Calcium