DOI: 10.5061/dryad.8cz8w9gxj
title: Single unit electrophysiology of optogenetically identified dopamine neurons in classical conditioning with probabilistic outcome of reward and punishment

description: We collected single-unit data (.mat file) from optogenetically identified
 dopamine neurons in the lateral VTA in mice. These dopamine neurons were
 recorded while animals performed 4 different variation of classical
 conditioning tasks with different ratio of probabilistic outcomes of water
 reward and aversive air puff. In one task, one cue was associated with
 both water and puff in a probabilistic manner.
description: We recorded extracellularly from
 multiple neurons simultaneously using a custom-built
 200-μm-fiberoptic-coupled screw-driven microdrive with six or eight
 implanted tetrodes (four wires wound together). Tetrodes were glued to the
 fiber optic (Thorlabs) with epoxy (Devcon). The ends of the tetrodes were
 350–500 μm from the end of the fiber optic. Neural signals and time stamps
 for behavior were recorded using a DigiLynx recording system (Neuralynx).
 Broadband signals from each wire filtered between 0.1 and 9000 Hz were
 recorded continuously at 32 kHz. To extract the timing of spikes, signals
 were band-pass-filtered between 300 and 6000 Hz. Spikes were sorted
 offline using MClust-3.5 software (David Redish). At the end of each
 session, the fiber and tetrodes were lowered by 20–80 μm to record new
 neurons. Sessions of recordings were continued until the tetrodes reached
 the bottom of the brain where no units were recorded and large
 fluctuations of voltage traces were recorded from tetrodes. After the
 completion of the recording sessions, tetrodes were moved up to the depth
 where units were recorded or the depth where light-identified dopamine
 neurons were recorded to ensure that the following electrolytic lesions
 were in the brain. To
 verify that our recordings targeted dopamine neurons, we used ChR2 to
 observe stimulation-locked spikes (Cohen et al.,
 2012). The optical fiber was coupled with a diode-pumped
 solid-state laser with analogue amplitude modulation (Laserglow
 Technologies). Before and after each behavioral session, we delivered
 trains of 10 light pulses, each 5-ms long, at 1, 2, 5, 10, 20 and 50 Hz at
 473 nm at 5–20 mW mm<sup>−2</sup>. Spike shape was measured
 using a broadband signal (0.1–9000 Hz) sampled at 30 kHz. This ensured
 that particular features of the spike waveform were not missed.
description: # Single unit electrophysiology of optogenetically identified dopamine
 neurons in classical conditioning with probabilistic outcome of reward and
 punishment
 [https://doi.org/10.5061/dryad.8cz8w9gxj](https://doi.org/10.5061/dryad.8cz8w9gxj) These are single-unit data (.mat file) from optogenetically identified dopamine neurons in the lateral VTA. The recording coordinate from each mouse is indicated in a file, 'Coordinate\_Information.mat.'   These dopamine neurons were recorded in four different classical conditioning tasks. A summary of the task conditions is described in Table 1 of the original paper (Matsumoto et al., Elife, 2016). ## Description of the data and file structure Example: The dataset 'hr036\_2014-04-02\_14-17-54\_TT1\_1\_Mixed.mat' contains Ephys data from a single dopamine neuron. This data was obtained using tetrode 1, which was implanted in the mouse ‘hr036’ on April 2, 2014. The label ‘Mixed’ indicates the task name used.   Each neuron’s data contains the following information: **taskname**: describe the task name that was used to record this neuron.   **labels**: you will find information related to 'odor' and 'trial type,' which correspond to the 'odorID' and 'trialType' used in the 'events' data. For example, 'labels.odor' contains a string like '1:water90,' indicating that 'odorID=1' (matching the 'odorID' used in 'events') represents a '90% water CS.' Likewise, 'labels.trialtype' contains a string such as '1:CS\_water\_US\_water,' signifying that 'trialType=1' (matching the 'trialType' used in 'events') represents a 'water CS followed by water US' trial type."   **events**: contains timestamps (ts), odor IDs (odorID), and trial types (trialType). ts (in milliseconds): time stamps for the following events—odorOn, odorOff, rewardOn, airpuffOn, freeRewardOn, freeAirpuffOn, freeLaserOn, and trialStart. odorID & trialType: These fields contain odor ID and trial type information for each behavioral task. Further details about odorID and trialType can be found in the 'labels' section. The total number of trials in a session corresponds to the length of 'event.odorOn.' NaNs in 'event.odorOn,' 'event.odorOff,' and 'event.odorID' indicate free reward or free airpuff trials. NaNs in 'event.rewardOn' indicate no reward deliveries in these trials, and NaNs in 'event.airpuffOn' indicate no airpuffs in these trials. The following event variables ('laserOn,' 'laserOff,' 'firstLick,' 'leverOn' under 'events') are not related to this behavioral task and do not contain any data; they are all NaNs.    **responses**: includes spike and lick timestamps in milliseconds, along with a summary for optogenetic cell identification.   **checkLaser**: **checkLaser**: contains some results of raw and filtered waveforms for spontaneous spikes and light-evoked spikes etc. NaNs indicate that no light-evoked spikes were detected within a specific time window after light stimulations.   **header:** refers to the original source data address. ## Sharing/Access information Links to other publicly accessible locations of the data: * None