, 2012). Our results obtained on the in vivo firing patterns of identified bistratified and O-LM cells, taken together with results on PV+ basket (Lapray et al., 2012 and Varga et al., 2012) and axoaxonic cells (Viney et al., 2013) demonstrate that, on average, during each cycle of the theta oscillations, inhibition is redistributed from the axon initial segment through

Talazoparib supplier the soma to the progressively more distal dendrites of pyramidal cells, thus governing the repeated cycles of mnemonic processing such as memory encoding and retrieval in the hippocampal “chronocircuit” (Cutsuridis and Hasselmo, 2012, Dupret et al., 2013 and Hasselmo et al., 2002). We hypothesize that the effect of these interneurons will be different on repeatedly firing versus silent pyramidal cells. Similarly, during SWRs, inhibition is redistributed by increased GABA release to the soma and CA3-innervated parts of the dendritic tree, while it is withdrawn from the axon initial segment (Viney et al., PF-02341066 research buy 2013) and the entorhinal input zone of the dendrites, as shown here. All procedures on animals were approved by the UK Home Office and by the Animal Care and Use Committees of the University of Oxford and of the Medical University, Vienna. Data reported are from nine male Sprague-Dawley rats (375–565 g; 2.8–5.3 months) recorded between 8 a.m. and 6 p.m. (see Supplemental

Information). Implantations of the head-mounted recording setup, craniotomies, and duratomies were performed using analgesic and antibiotic treatments as reported in Lapray et al. (2012) (see Supplemental Information). Procedures were carried out as reported in Lapray et al. (2012). Rats were anesthetized briefly by isoflurane and connected to the recording setup. One hour after recovery, recordings oxyclozanide commenced using a glass electrode (Figure S1B) filled with neurobiotin (1.5% or 3%, w/v, in 0.5 M NaCl). After recording and juxtacellularly labeling a cell, the rat was deeply anesthetized and perfusion fixed 1–3 hr later (see Supplemental Information). Following the criteria defined

in Lapray et al. (2012) (Figure 4), recording sessions have been segmented according to movement, sleep, and quiet wakefulness. We have detected and analyzed theta oscillatory epochs (5–12 Hz), SWRs (130–230 Hz), and LOSC using Spike2 and MATLAB (Wavelet Toolbox, v7.9-R2009b, MathWorks). For a given cell type, we quantified the mean depth of theta modulation and the preferential mean theta phase of firing (circular mean ± circular SD) from individual cells using circular statistics and compared the preferred theta phase angles of different types of interneurons (see Supplemental Information). We have developed an analysis in order to reveal the variability (e.g., cells being silent on some SWRs but firing with rates above average on others) in firing of single neurons during individual SWRs.