Intracellular θ-rhythm generation in identified hippocampal pyramids

摘要: The hippocampal EEG and the transmembrane potential of CA1-CA3 pyramids were recorded in curarized urethanized rats. Pyramids identified by antidromic driving intracellular staining with Lucifer yellow. During θ-rhythm most showed 10–20 mV sustained depolarization oscillations either consisting 5–10 smooth sine-like waves or slow spikes up to 60 mV. Fast Na+ slow, probably Ca2+-mediated, triggered depolarizing pulses spontaneously. Depolarizations15mV rhythmic at θ-frequency, but if<15 mV, irregular lower rates. With depolarizations <10 no triggered. Sine-like θ-wave amplitudes increased hyper-and decreased pulses, showing behavior EPSPs. Periodic fast spike bursts θ-correlated. Cells θ could fire periodic random, bu always a preferred phase θ-wave. Slow generated above threshold driven Intracellular is reflection EPSPs spikes; oscillatory phenomena are not exclusively generated, as previously hypothesized, network properties which may, however, contribute tuning modulatory elements. determining events θ-generation intrinsic biophysical characteristics pyramidal neuron membrane.