The end of 2022 is nigh – an appropriate time to reflect upon the successes achieved and a glimpse of more to come in 2023.
Firstly, Mr Robin Johnsson became Dr Robin Johnsson after the sterling review of his dissertation entitled, “Cognition and sleep in Australian magpies”. Soon afterwards, Robin relocated to the USA to work with A/Prof Tim Roth on cognition in painted turtles and chickadees. And Mr Adrian Russo became Dr Adrian Russo after the rapid review of his dissertation, “The role of serotonin synthesis in a mouse model of social behaviour, anxiety and sleep”. He has now landed his dream job as a psychologist. Shauni Omond has been hired as a Sleep Scientist at Eastern Health in Box Hill where she will get hands-on experience in human sleep recording, scoring, and disorders. Well done, All!
Secondly, we had a slew of output from everyone; and so, in alphabetical order…
Connelly F, et al. 2022. Urban noise does not affect cognitive performance in wild Australian magpies. Anim Behav 188, 35-44. *While urban noise disrupts sleep in magpies (Connelly et al. 2020), it doesn’t influence subsequent waking cognition (Connelly et al. 2022).
Johnsson RD, et al. 2022a. Homeostatic regulation of NREM sleep, but not REM sleep, in Australian magpies. Sleep 45, zsab218. *Several studies now indicate that REM sleep does not appear to be regulated in Australian magpies (Aulsebrook et al. 2020; Connelly et al. 2020; Johnsson et al. 2022a). This study was also the first to demonstrate that daytime naps reduce nighttime SWA in birds.
Johnsson RD, et al. 2022b. Sleep loss impairs cognitive performance and alters song output in Australian magpies. Sci Rep 12, 6645. *Sleep loss via gentle handling for 12-h impairs cognitive performance in magpies (Johnsson et al. 2022b), unlike that following more modest sleep loss experienced from 6-h sleep loss (Johnsson et al. 2022b) and urban noise (Connell et al. 2022).
Johnsson RD, et al. 2022c. Preliminary evidence of tool use in an Australian magpie? Behaviour 159, 1483-1497. *At least one Australian magpie can use a stick to obtain a food reward. Whether this behaviour is repeatable and commonly-used by wild birds is unclear.
Kelly ML, et al. 2022. Energy conservation characterizes sleep in sharks. Biol Lett 18, 20210259. *Oxygen consumption in sleeping sharks is lower than in sharks sitting quietly awake, providing evidence for an energetic benefit to sleep.
Lesku JA and Schmidt MH. 2022. Energetic costs and benefits of sleep. Curr Biol 32, R656-R661. *Indeed, other animals show energetic benefits (and costs) to sleeping, which suggest a sleep function that relates to energy conservation (or perhaps energy reallocation).
Lesku JA and Rattenborg NC. 2022. The missing cost of ecological sleep loss. Sleep Adv 3, zpac036. *But some animals forgo sleep seemingly without any cost. Here, several recent studies are reviewed with a call for urgent research into animals that tolerate (or endure, or thrive) little sleep.
Omond SET, et al. 2022. Neurotransmitters of sleep and wakefulness in flatworms. Sleep 45, zsac053. *A very comprehensive study into the biochemical regulation of sleep and wake in flatworms. While flatworms sleep (Omond et al. 2017), simple animals have a simplified complements of neurotransmitters that regulate these states; only GABA has a conserved sleep-promoting role across all species studied (Omond et al. 2022).
Rattenborg NC, et al. 2022. Sleep in nonmammalian vertebrates. In: Kryger M, et al. (eds.), Principles and Practice of Sleep Medicine, 7th edition. Philadelphia: Elsevier, 106-120. *Finally! The return of the avian sleep chapter to P&PSM after a 28-year hiatus.
Russo AM, et al. 2022. Acute treatment with 5-hydroxytryptophan increases social approach behaviour but does not activate serotonergic neurons in the dorsal raphe nucleus in juvenile male BALB/c mice: a model of human disorders with deficits of sociability. J Psychopharmacol 36, 806-818. *A serotonin-precursor makes mice more friendly, but the mechanisms involved are unclear.
Zaid E, et al. 2022. Sleep architecture and regulation of male dusky antechinus, an Australian marsupial. Sleep 45, zsac114. *Antechinus are marsupials, yet sleep like birds – falling asleep within seconds after they stop moving and sleeping with hundreds of episodes per 24-h day. Similar to other mammals (and birds), antechinus increase SWA following extended wakefulness – the first demonstration of sleep homeostasis in a marsupial.
Phew! What a slew! And more to come in 2023 with the ‘already-submitted’: Connelly F, et al.; Johnsson RD, et al.; Omond SET and Lesku JA (x2); Tan H, et al.
Lastly, what else to expect in 2023? My crystal ball tells me: *We will be joined by Sophia Lee (USA) in six short weeks who will start her Honours (and hopefully a MSc) looking at sleep in fiddler rays; *Hannah Elmes will publish her first paper on sunning white-capped noddys; *Vincent Knowles will submit his MSc thesis and publish his very cool data on (de)synchronization of activity patterns in paired black swans; *Shauni Omond will submit her fourth paper of her dissertation and submit that dissertation itself for review. Perhaps as early as January!; *Erika Zaid will submit her third manuscript – No spoilers here though. Once accepted, this will be followed by the submission of her dissertation.
Well done, everyone, on what has been a very productive year for each of you. Happy & Safe Holidays!
Sleep Ecophysiology Group 