Changes in reindeer sleep regulation across the year: a central role for rumination? In this episode, I am joined by Melanie Furrer, who recently presented her study on sleep in reindeer.
Most non-hibernating animals maintain daily “circadian ”rhythms of sleep across the year, as well as “homeostatic” sleep-wake patterns in which increasing time awake is followed by increased sleep amount or intensity. Strikingly, ruminant reindeer in the Arctic show 24-h rhythmicity at the equinoxes but none at either solstice; summertime activity greatly exceeds wintertime activity. So far, nothing is known about their sleep or how it might be seasonally modulated.
Methods: We simultaneously recorded non-invasive electroencephalography EEG in four adult female reindeer for four days at The Arctic University of Norway in Tromsø, Norway in July, September, and December. Rapid eye movement, REM sleep, non-REM NREM sleep, and rumination were visually identified from the EEG, and slow-wave activity SWA, EEG power 1–18 4.5 Hz during NREM sleep, the classic marker for homeostatic changes in sleep pressure, was calculated.
Results: Although sleep in reindeer generally resembled that of other mammals, key novel adaptations were observed in July/September: n=4, December: n=3. Like most species, sleep-wake distribution paralleled daily activity during seasonally changing light-dark conditions and SWA during NREM sleep increased after prolonged wake periods.
Surprisingly, total sleep duration was roughly equal across seasons, and prolonged waking produced a lower SWA response in summer than in winter. As reported for some domestic ruminants, EEG during rumination showed typical characteristics of NREM sleep. Furthermore, rumination appeared to substitute for sleep under all observed conditions. Accordingly, SWA decreased across rumination, and total rumination and NREM sleep durations were negatively correlated. Homeostatic modelling of SWA further suggested that rumination was equivalent to sleep. Conclusions: We suggest that less pronounced SWA increases across waking in summer might indicate higher baseline sleep pressure during this season, possibly resulting from increased activity, food intake and light exposure. Within this context, rumination might partially substitute conventional sleep, permitting near-constant feeding in the arctic summer while compensating for increased sleep pressure.
Contact or follow Melanie https://www.kispi.uzh.ch/forschungszentrum/person/furrer-melanie.
https://www.researchgate.net/profile/Melanie-Furrer-2
Contact me at iandunican@sleep4performance.com.au or www.sleep4performance.com.au and check out the YouTube channel.
Check out our sponsor LMNT. Click on the link to order and get a free LMNT Sample Pack when you order through the custom link below. Key details: • The LMNT Sample Pack includes 1 packet of every flavour.
This is the perfect offer for anyone interested in trying all of our flavours or who wants to introduce a friend to LMNT. • This offer is exclusively available through VIP LMNT Partners – you won’t find this offer publicly available. • This offer is available for new and returning customers • They offer refunds on all orders with no questions – you don’t even have to send it back! DrinkLMNT.com/sleep4performance
S4P Radio, Season 4 Episode 3: Sleep and Performance in Basketball with Jordan Fox
S4P Radio, Season 4, Episode 2: Open Water Swimming with Bec Johnson and Paul Blackbeard
S4P Radio, Sleep Science Audio Abstract 13: A Critical Review of Consumer Wearables
S4P Radio, Season 4, Episode 1: Circadian Rhythm and Light Therapy with Dr Myriam Juda
S4P Radio, Special Episode - Fitness and Health with Jason Donaldson
S4P Radio, Season 3, Episode 12: Sleep and Mental Health with Dr. Michael Grandner
S4P Radio, Season 3, Episode 11: Dr David Cunnington, Sleep Physician
S4P Radio, Sleep Science Audio Abstract 12: Sleep and Weight Cutting in Combat Sports Athletes
S4P Radio, Season 3, Episode 10: Nutrition and Shiftwork with Charlotte Gupta
S4P Radio, Season 3, Episode 9: Athletes and Sleep with Dr. Meeta Singh
S4P Radio, Season 3, Episode 8: Sleep and Fatigue Offshore with Vanessa Riethmeister
S4P Radio, Special Episode, Cyrus Milne - Swimming the English Channel
S4P Radio, Season 3, Episode 7: Circadian Rhythms with Professor Sean Cain
S4P Radio, Season 3, Episode 6: Sleep and Fatigue Research with Dr. Raymond Matthews
S4P Radio, Sleep Science Audio Abstract 11: Sleep practices implemented by team sport coaches and sport science support staff
S4P Radio, Special Episode, Dr. Marc Bubbs - Peak: The New Science of Performance that is Revolutionizing Sports
S4P Radio, Season 3, Episode 5: Fighting, Sleeping and Philosophy with Ciaran O'Regan
S4P Radio, Season 3, Episode 4: Exercise and its effects on sleep and mental illness with Oscar Lederman
S4P Radio, Sleep Science Audio Abstract 10: Weekend ‘catch-up sleep’ is a lie.
S4P Radio, Season 3, Episode 3: Achieving Balance. Business, Study & Martial Arts with Lachlan Giles
Join Podbean Ads Marketplace and connect with engaged listeners.
Advertise Today
Create your
podcast in
minutes
It is Free
DNA Today: A Genetics Podcast
Museum of the Missing
Strange by Nature Podcast
Sasquatch Chronicles
Hidden Brain