Cytoplasmic Ca2+ Changes in Reference to Long-Term Potentiation in the Hippocampal Slice

Microfluorometry of the guinea-pig hippocampal slice loaded with Ca2+-indicator was carried out in parallel with extracellular population spike recording. Increase of the fluorescence, most probably representing elevation of Ca2+ level in postsynaptic cytoplasm of CA1 pyramidal cells, occurred upon establishment of LTP. However, exposure to high K medium or NMDA which did not lead to LTP also evoked comparable fluorescence increase.