[The influence of hippocampal field CA1 on the theta activity during rat orienting behavior]

The influence of CA1 hippocampal field on theta-activity production depending on the efficiency of CA1 synaptic inputs was studied in freely moving rats during their orienting behaviour. The long-term potentiation of Shaffer collaterals resulted in an increase in regularity of the theta activity due to a decrease in its amplitude-frequency modulation and variability of the waveform from cycle to cycle. Additionally, an increase in amplitude and decrease in frequency were observed. The results reveal the influence of CA1 field on the work of the septal theta activity oscillator.