Presynaptic calcium transients evoked by paired-pulse stimulation in the hippocampal slice

摘要: The fluorescent dye Calcium Green and optical recording techniques were used to record intracellular Ca2+ transients resulting from paired-pulse stimulation in stratum moleculare of area CA1 guinea-pig hippocampal slices. Presumed presynaptic calcium recorded while glutamatergic synaptic transmission was blocked by kynurenic acid. Peak responses paired-pulses (10-160 ms interval) higher than single pulses same strength (42-23% increase). isolated response the second pulse, however, smaller magnitude comparison first one; difference depended on interstimulus interval. Thus, residual free concentration may be responsible for facilitation hippocampus. At time, a use-dependent inactivation channels occur.