Cell-type specific calcium responses in acute rat hippocampal slices.
The identification of glial cells and neurons in brain slices is often difficult or uncertain. We have previously found that cultured rat cerebellar astrocytes and presumed astrocytes in acute brain slices, but not neurons, respond with cytosolic Ca(2+) transients following Ca(2+) influx in low external K+ concentrations (<1 mM; Cell Calcium 28 (2000) 247). We have now studied the possibility whether this Ca(2+) response can be employed to identify astrocytes during calcium imaging experiments. The Ca(2+) responses to low and high (50 mM) K+ were investigated in cells in culture and in hippocampal slices. In the stratum radiatum of hippocampal slices, S-100B-positive cells, presumed to be astrocytes, preferentially accumulated Fluo-4, while pyramidal neurons, identified by neuron-specific enolase, showed much lower Fluo-4 fluorescence, fixed with ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDAC). 81% of the cells with prominent Fluo-4 fluorescence showed responses to low K+, and 86% of these cells were S-100B-positive. Our results suggest that the responsiveness to low K+ can help to identify astrocytes in acute brain slices.
Dallwig
Roger
R
Abteilung für Allgemeine Zoologie, FB Biologie, Universität Kaiserslautern, Postfach 3049, D-67653 Kaiserslautern, Germany.
Deitmer
Joachim W
JW
D000814:Aniline Compounds; D000818:Animals; D000906:Antibodies; D001253:Astrocytes / Q000737:chemistry / Q000166:cytology / Q000502:physiology*; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D005456:Fluorescent Dyes; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis / Q000276:immunology; D006624:Hippocampus / Q000166:cytology*; D018613:Microscopy, Confocal; D009414:Nerve Growth Factors; D009924:Organ Culture Techniques; D011188:Potassium / Q000494:pharmacology; D017966:Pyramidal Cells / Q000737:chemistry / Q000166:cytology / Q000502:physiology*; D051381:Rats; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000032:analysis / Q000276:immunology; D016707:Tissue Fixation; D014966:Xanthenes
D000814:Aniline Compounds; D000906:Antibodies; C409648:Fluo 4; D005456:Fluorescent Dyes; D005904:Glial Fibrillary Acidic Protein; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D014966:Xanthenes; D011188:Potassium; D002118:Calcium