Mice were placed on a warm blanket (37°C) and kept anesthetized with 0.5% isoflurane and sedated with chlorprothixene (20-40 μL at 0.33 mg/ml, i.m.)30. Imaging was performed using a custom-built two-photon microscope (designs available at research.janelia.org/Svoboda) equipped with a resonant galvo scanning module (Thorlabs), controlled by ScanImage (scanimage.org)60. The light source was a Mai Tai femtosecond pulsed laser (Spectra-Physics) running at 940 nm. The objective was a 16× water immersion lens (Nikon, 0.8 NA, 3 mm working distance). The power used was 35-50 mW for full field imaging (Fig. 2) and 20-40 mW for higher zoom imaging (Fig. 3-6).
