Functional clustering of dendritic activity during decision-making.

Key resources table

Reagent type (species) or resource Designation Source or reference Identifiers Additional information Genetic reagent ( M. musculus ) Syt17 NO14 (Mouse) GENSAT MMRRC Cat# 034355-UCD, RRID: MMRRC_034355-UCD Genetic reagent ( M. musculus ) CamK2a-tTA JAX IMSR Cat# JAX:007004, RRID: IMSR_JAX:007004 Genetic reagent ( M. musculus ) Ai93 JAX IMSR Cat# JAX:024103, RRID: IMSR_JAX:024103 Genetic reagent ( M. musculus ) Chrna2 OE25 GENSAT MMRRC Cat# 036502-UCD, RRID: MMRRC_036502-UCD Genetic reagent ( M. musculus ) ZtTA JAX IMSR Cat# JAX: 012266, RRID: IMSR_JAX:012266 Software and Algorithms Matlab Mathworks RRID: SCR_001622 Software and Algorithms ScanImage Vidrio RRID: SCR_014307 Software and Algorithms Neuromantic University of Reading RRID: SCR_013597 Software and Algorithms Thunder Janelia RRID: SCR_016556 Software and Algorithms Spark Apache RRID: SCR_016557 Other MIMMS microscope 1.0 (2016) Janelia RRID: SCR_016511 Other Tip-Tilt-Z Sample Positioner Janelia RRID: SCR_016528 Animals All procedures were in accordance with protocols approved by the Janelia Institutional Animal Care and Use Committee. Triple transgenic mice (both male and female) sparsely expressing GCaMP6f in a subset of layer 2/3 (Syt17 NO14 x CamK2a-tTA x Ai93; MGI:4940641 x JAX:007004 x JAX:024103) and layer 5 (Chrna2 OE25 x ZtTA x Ai93; MGI:5311721 x JAX:012266 x JAX:024103), were housed in a 12 hr:12 hr reverse light:dark cycle. We never observed seizures in these mice, as has been reported for Emx1-Cre x Camk2a-tTa x Ai93 crosses ( Steinmetz et al., 2017 ). Surgical procedures were performed under isoflurane anesthesia (3% for induction, 1–1.5% during surgery). A circular (∼2.5 mm diameter) craniotomy was made above left ALM (centered at 2.5 mm anterior and 1.5 mm lateral to bregma). A window (triple #1 coverglass 2.5/2.5/3.5 mm diameter; Potomac Photonics, Baltimore, MD) was fixed to the skull using dental adhesive (C and B Metabond; Parkell, Edgewood, NY). A metal bar for head fixation was implanted posterior to the window with a metal loop surrounding the window using dental acrylic. After the surgery, mice recovered for 3–7 days with free access to water. Then, mice were water restricted to 1 mL daily. Training started 3–5 days after the start of water restriction. On days of behavioral training, mice were tested in experimental sessions lasting 1 to 2 hr where they received all their water. Unless otherwise noted in the figure legend, N = 14 neurons, seven mice for figure panels regarding layer 2/3 neurons and N = 5 neurons, four mice for figure panels regarding layer five neurons. Tactile decision task Mice solved an object localization task with their whiskers (modified from Guo et al., 2014a ; Guo et al., 2014b ). The stimulus was a metal pin (0.9 mm in diameter) mounted on a galvo motor to reduce vibrations. The pole swung into one of two possible positions ( Figure 2A ). The posterior pole position was approximately 5 mm from the center of the whisker pad. The anterior pole position was 4 mm anterior to the posterior position. A two-spout lickport (4.5 mm between spouts) delivered water reward and recorded the timing of licks. The sample epoch is defined as the time between the pole movement onset to pole retraction onset (sample epoch, 1.2 s total). The delay epoch lasted for another 2 s after the beginning of pole retraction (delay epoch, 2 s total). An auditory ‘response’ cue indicated the end of the delay epoch (pure tone, 3.4 kHz, 0.1 s duration). Licking early during the delay period resets the delay-period timer (2 s). Licking the correct lickport after the auditory ‘response’ cue led to a small drop of water reward. Licking the incorrect lickport was not rewarded nor punished. Trials in which mice did not lick after the ‘response’ cue were rare and typically occurred only at the end of a session. Animals were trained daily until they reached ∼70% correct. Thereafter behavior was combined with imaging (typically 20–40 days after surgery).

Microscope design

Ultrafast pulses (