Abstract
Extracellular free calcium ([Ca2+]0) and neuronal activity were measured with double-barreled Ca2+-selective/reference microelectrodes in the CA1 field of rat hippocampal slices during stimulation of Schaffer collaterals and during iontophoretic application of the excitatory amino acid aspartate (Asp). Baseline [Ca2+]0 was 1.5 mM. Repetitive stimulation and aspartate application caused decreases in [Ca2+]0 (ΔCa), which were largest in the pyramidal cell layer. During iontophoretic application of GABA, aspartate often failed to induce significant alterations in [Ca2+]0. Mg2+ (9 mM) and Ni2+ (3 mM) when added to the perfusion medium reduced aspartate-dependent ΔCa by 15 and 70% respectively. In tetrodotoxin (10-6 M) containing Ringer the aspartate-induced ΔCa were about 10% smaller. These findings suggest that the decreases in [Ca2+]0 are mainly due to a postsynaptic Ca2+ entry through selective Ca2+ conductances.
Original language | English |
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Pages (from-to) | 272-277 |
Number of pages | 6 |
Journal | Brain Research |
Volume | 238 |
Issue number | 1 |
DOIs | |
Publication status | Published - Apr 22 1982 |
Keywords
- aspartate
- extracellular free calcium
- hippocampal slice
- rat
ASJC Scopus subject areas
- Developmental Biology
- Molecular Biology
- Clinical Neurology
- Neuroscience(all)