Project protocol - Contents
- Workflow and sampling
- Equipment and supplies
- Reagents and solutions
- Procedure: Fear conditioning, contextual fear, and cued fear
- Definitions and calculations
Day Procedure performed Equipment *Data collected 1 Fear conditioning, training fear conditioning chamber thigmotaxis, velocity, immobility, activity burst 2 Contextual fear test fear conditioning chamber thigmotaxis, velocity, immobility 3 Cued fear test activity monitoring system thigmotaxis, velocity, immobility
* Additional data available in HMDPpheno4_suppdata.xlxs
- Modified Gemini Avoidance System (San Diego Instruments, San Diego CA) [25 cm x 20 cm conditioning chamber with grid floors and white plexiglass]
- Activity monitoring chamber [50 cm x 25 cm]
- Video camera mounted above each test chamber
- EthnoVision Pro tracking system and software (Noldus Information Technology)
Mice were allowed 14 days to become accustomed to the housing facility. On each test day, mice were placed in a holding room for a 30-min acclimation period prior to testing where auditory background white noise (80 dB) was delivered through overhead speakers. [Mice tested between 1000h and 1600h.]
Mice are exposed to a fear conditioning protocol followed by two independent memory tests: contextual and cued fear. Behavior is recorded digitally from a camera mounted above each test chamber then digitized at 15 frames/s. Eighty-two unique endpoints are quantified automatically with software (for more details about this procedure, equipment, and data analysis see Park et al., 2011 and Gale et al., 2009). See HMDPpheno4_suppdata.xlxs for all endpoint data.
- On day 1, mice are placed in the fear conditioning chamber; following a 3-min exploration period, mice receive 3 tone-shock pairings, where auditory conditional stimuli (CS) = 2000 Hz, 15 s, 80 dB with co-termination of a footshock unconditional stimulus (US) = 0.75 mA, 1 s; pairings are delivered with an inter-trial interval of 1 min; mice are removed from test chamber 2 min following final US.
- On day 2, contextual fear is assessed in the same fear conditioning chamber as day 1; neither CS nor US are presented during the 8-min test.
- On day 3, cued fear is assessed following a contextual shift (mice placed in a novel activity chamber); following a 3-min exploration period, mice receive a series of ten CS presentations (1 min inter-trial intervals); US are not presented; mice are removed from the chamber 1 min following the final CS (no US presented during this test).
- Conditional stimulus (CS): tone (2000 Hz, 15 s, 80 dB)
- Unconditional stimulus (US): footshock (0.75 mA, 1s)
- thigmotaxis (wall preference)
- *path shape (meander)
* Available in Supplementary data file only HMDPpheno4_suppdata.xlxs