Behavior of subicular RS cells during spontaneous subicular SPW activity.

<p>(A) Neuronal discharge pattern and microphotograph of an RS cell. RS cells do not fire bursts and show little or no sag potential. They respond to a depolarizing current injection with a train of single APs. RS cells show a typical pyramidal cell morphology. (A, right) The accommodation behavior (n = 19 IB cells; n = 16 RS cells) reveals a significant difference between subicular IB and RS cells (level of significance indicated by the asterisks, <i>p</i> < 0.0001). (B) Example of a RS cell at RMP (top left) and under the condition of depolarizing current injection (bottom left) during spontaneous SPW is given with the same type of illustration as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0123636#pone.0123636.g003" target="_blank">Fig 3</a>. Intracellular example recording of a silent RS cell at RMP (top left) depicting a SPW associated postsynaptic depolarization without AP generation. The population data (n = 7, right next) do not contain any APs, but aggregate a phase-locked mixed postsynaptic current (PSP) instead. When depolarized by current injection previously silent RS cells display a tonic AP firing mode (bottom left). In stark contrast to the IB cells, data of spontaneous active and depolarized RS cells reveal a prominent SPW peak correlated pause of AP generation (n = 11, bottom, middle left). EPSPs and IPSPs examples are displayed in correlation to the LFP (middle right). The EPSPs and IPSPs were recorded at −80 mV and at 0 mV, respectively. (right) Accumulated mean EPSP/IPSP with respect to the maximum SPW peak deflection. (C) EPSP (left) and IPSP (right) amplitudes for both cell classes. IB cells receive significantly higher synaptic excitation than RS neurons (indicated by the asterisk, <i>p</i> = 0.033; IB: n = 12; RS: n = 13), while there was no significant difference in IPSP (<i>p</i> = 0.52; IB: n = 3; RS: n = 4).