EN
Hippocampal formation (HPC) theta rhythm is approximately sinusoidal, most prominent and well-documented EEG pattern recorded from the mammalian brain. Following the discovery of cholinergically induced theta rhythm recorded in slice preparations of HPC, central mechanisms underlying theta generation have been successfully studied in the in vitro conditions. In our previous work we have attempted to record an EEG activity of three types of transected hippocampal slices (CA1 trans-slice, CA3c trans-slice, and DG trans-slice) examining activity of separated intrahippocampal theta generators. Data obtained in those studies revealed that dentate gyrus isolated from generators located in CA1 and CA3c fi elds respectively, is not able to generate theta rhythm in the in vitro conditions. The purpose of the present study was to extend our previous in vitro studies concerning the activity patterns of theta related cells. This time theta cells were recorded in transacted hippocampal slices i.e. CA1 trans-slice, CA3c trans-slice, and DG trans-slice. Sixty cells were isolated and recorded from transected slices, including thirty cells from CA3c (20 theta-on cells, 6 theta-off cells, and 4 gating cells), and thirty cells from CA1 (15 theta-on cells, 13 thetaoff cells, and 2 gating cells). None of DG transected slices tested generated any synchronous fi eld potentials and accompanying cell activity. Supported by MNiSW grant No. N N 303 091 834.