Key insights Master Class 2 – A course on sleep research in animal models: experimental design, methodology, sleep scoring and data analysis
1) The 24h environment: Non-invasive home cage activity monitoring to study circadian rhythms and sleep
Associate Professor Stuart Peirson
Professor Pierson had a walk-through into the complexity and perks of studying circadian rhythms in mice – knowing how different they are from humans and especially how we still perform and keep the animals under very artificial conditions.
Pierson highlighted the available COMPASS behavioural phenotyping of sleep – methodology developed by his team, which presents an affordable methodology to study sleep and circadian rhythm through motion sensors, a non-invasive means of studying behavior, real-time analysis, and longitudinal studies (over weeks or months).
Dr. Charlotte Boccara
ERC awardee with the project SleepCog, trying to understand and characterize sleep through development, focusing on studying pup’s sleep. The liter and the moms need to be constantly handled, the pups are head-mounted and there are engineers on the team that were able to make small electrodes and “hats” that would fit such small animals. She also highlighted that there’s no standardized rodent sleep criteria, which makes researchers rely on manual scoring. They have a work progress in the lab, with algorithms to identify sleep in pups.
3) Evaluating sleep in rodents: manual versus automated scoring methods
Dr. Abdelrahman Rayan
Inspiring talk on how conventional sleep classification has existed for decades, with the gold standard being an EMG-like signal and an accelerometer. The next step would be to move to automatic sleep scoring, with recent first authors publications (Rayan et al 2022, Rayan et al 2023), also featured in our SSF.
He provided plenty of tips on how to better select for different brain areas, the depth, electrode placement, and to aim for more than one area, as an improvement from studies from the 90’s. He also provided his GitHub link, where all the relevant scripts/ codes can be downloaded and used: https://github.com/AbdelRayan/Master_Class_Sleep_Scoring_2024
4) Neuropixels and fiber-photometry in waking and sleeping mice
Dr. Julia Harris
Comprehensive talk on the step-by-step path on how to perform a neuropixel or fiber-photometry experiment in waking or sleeping mice, so far only head-fixed, but with great potential to be freely moving in a near future. How to select a mouse strain, with markers to go for, GCaMP (sensitivity x temporal resolution), which fibers, the importance of positive controls, how to perform the surgeries, data processing, and the importance of starting an experiment in the correct phase of the circadian rhythm so that the animals are least affected by the handling.
The 27th congress of the ESRS, Sleep Europe 2024, will be held in Seville, Spain, 24-27 September. Its continued success over the years can be attributed to the invaluable contributions of volunteers at all stages of the congress planning and execution process.
