The occurrence of read-through transcripts from exon 1a through the constant region of TRIP8b was verified through RT-PCR (data not shown). Lentivirus was stereotactically injected into the dorsal hippocampi of 5-week-old mice. Transverse hippocampal slices (400 μm) were prepared two http://www.selleckchem.com/products/Bortezomib.html weeks after viral injection. Animals were sacrificed in accordance to institutional IACUC standards. For solution composition and detailed methods see Supplemental Experimental Procedures. Virally infected neurons

were identified by EGFP fluorescence. Following recordings of infected neurons, slices were fixed for 30 min in PFA and imaged to ensure that all dye-filled cells were also EGFP+ and that the dendritic structure of infected cells was normal. Series resistance was less than 15 MΩ; capacitance and series resistance were monitored and compensated throughout

the experiments. Recordings were performed at 32°C. All data was aquired with Pclamp software (Molecular Devices) and analyzed with IGORPro Selleckchem SCH727965 (wavemetrics). This work was supported by grants NS36658 and MH80745 from NIH, by fellowships from NIH F32NS064732 (R.P.), the Italian Academy for Advanced Studies in America (B.S.) and a Research Grant from the Epilepsy Foundation (B.S.). We gratefully acknowledge Terunaga Nakagawa and Morgan Sheng for providing the pLLhS and Pavel Osten for providing the pFCK(0.4)GW lentiviral vectors, and Frank Müller for generously providing the rat 7C3 monoclonal HCN1 antibody. We thank Ming-Kuei Jang and Thomas Yocum for preliminary experiments, Haiying Liu for technical assistance and Vivien Chevaleyre for experimental advice. “
“The majority of synaptic inputs onto neurons in the neocortex originate from nearby neurons within the same cortical area, producing local microcircuits that are ubiquitous in neocortex (Braitenberg and Schüz, 1998, Douglas and Martin, 2004 and White, 2007). Local excitatory

connections provide the major excitatory input to neocortical principal neurons, are highly recurrent, and are critically important for information processing, particularly in sensory neocortex (Douglas et al., 1995, Buonomano and Maass, 2009 and Rigas and Castro-Alamancos, 2009). Despite the ubiquitous PDK4 nature of local excitatory circuits, very little is known about their organization and almost nothing known about development at the level of connections between individual neurons, thus leading to a poor understanding of mature network architecture. Layer 4 of the rodent barrel cortex is the primary input layer for ascending sensory information arriving via thalamocortical fibers (Petersen, 2003). Layer 4 contains clusters of neurons, named barrels, each of which receives topographically mapped input from a corresponding whisker; this provides an anatomical correlate for whisker receptive fields.