Heterogeneity among astroglial cells with respect to 5HT-evoked cytosolic Ca2+ responses. A microspectrofluorimetric study on single cells in primary culture.
The effect of 5-hydroxytryptamine (5HT) on cytoplasmic Ca2+ concentration was examined at the single cell level in astroglial enriched primary cultures from newborn rat cerebral cortex. Type 1 astroglial cells were identified and the Ca2+ indicator dye fura 2/AM was used in a microspectrofluorimetric system. Pharmacological studies indicated that the Ca2+ responses were mediated by 5HT2 receptors. Four different patterns of 5HT evoked cytosolic Ca2+ responses were identified including two different types of spike patterns and two types of Ca2+ oscillations (low amplitude and base-line spiking behaviour). In addition, cells with spontaneous Ca2+ oscillations were of two types, those responding to 5HT and those not responding to 5HT. The different responses were identified already on day 7 in culture and were followed up to day 21 with a concomitant increase in the number of responding cells, although the response patterns did not differ during culture. The triggering 5HT concentration was 1 microM. The results suggest that subpopulations of astrocytes exist with respect to 5HT2-evoked cytosolic Ca2+ mobilization.
Institute of Neurobiology, University of Göteborg, Sweden.
M
M
Nilsson
E
E
Hansson
L
L
Rönnbäck
D000818:Animals; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D003600:Cytosol / Q000378:metabolism; D016257:Fura-2 / Q000378:metabolism; D007650:Ketanserin / Q000494:pharmacology; D051381:Rats; D011985:Receptors, Serotonin / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence
D011985:Receptors, Serotonin; D012701:Serotonin; D007650:Ketanserin; D002118:Calcium; D016257:Fura-2