Embryos were then placed back into the abdominal cavity and the abdominal wall was sutured. At postnatal 32 days, mice were perfused with PBS followed by 4% paraformaldehyde in PBS. After Vemurafenib datasheet 2 days of immersion fixation, brains were cryoprotected in 30% sucrose in 0.1 M phosphate buffer and cut in cold PBS at 100 μm in the coronal plane with a vibratome. Brain sections were mounted on a glass slide and coverslipped with Immu-Mount (Thermo Scientific). Protocols were approved by the Animal Care Committee, consistent with Canadian Council on Animal Care and Use guidelines. Whole-cell voltage-clamp recordings were made from cultured hippocampal pyramidal neurons

(DIV12–14) that

had been transfected with sh-con or sh-TrkC#1. The experimenter was blind to the DNA each neuron had received. Cells were patched under visual guidance in extracellular solution containing 140 mM NaCl, 5.4 mM KCl, 10 mM HEPES, 33 mM glucose, 1.3 mM CaCl2, 1.3 mM MgCl2, 0.0005 mM TTX, 0.01 mM bicuculine, and 0.05 mM D-AP5. The intracellular solution contained 130 mM CsMeSO4, 10 mM HEPES, 4 mM Mg.ATP, 0.3 mM Na.GTP, 0.5 mM EGTA, 5 mM QX315.Br, and 8 mM NaCl (pH 7.2, 280 mOsm). Cells were held at −70mV and series resistance was less than 30 MΩ. Currents were recorded with the WinLTP software (Anderson and Collingridge, 2007) and analyzed offline with the Mini Analysis software (Synaptosoft). All image acquisitions, analyses, and quantifications were performed by investigators Small molecule library blind to the experimental condition. For cocultures, fields for imaging were chosen only by the CFP and phase-contrast channels, for the

presence of CFP-positive COS cells in a neurite-rich region. The synapsin or uptaken SynTag channel was thresholded and the total intensity of puncta within all regions positive for both CFP and dephospho-tau but negative for MAP2 was measured. The VGLUT1 or VGAT channel was thresholded and the total intensity of all puncta within CFP-positive regions was measured. For binding of Fc-fusion proteins, measures indicate average intensity of bound Fc MYO10 protein per COS cell area minus off-cell background with intensity normalized by average CFP intensity of COS cells expressing indicated CFP-tagged proteins. For bead experiments, regions for analysis were chosen by the YFP and phase-contrast channels. Beads overlapping neurites positive for dephospho-tau but negative for MAP2 were judged as attached to axons. Beads overlapping MAP2-positive neurites were judged as attached to dendrites. After subtracting off-cell background, the average gray value associated with beads was measured by using a concentric ∼2 μm circle. In the case of aggregated beads, a random two beads among them were measured.