It is my pleasure to let you know that Erika Zaid’s PhD dissertation, “To sleep or not to sleep: can mating dasyurids provide insight into the evolution and function of sleep?” was passed with minor amendment. She will have her PhD conferred in December.
Erika moved from Italy to Melbourne in 2016 with one very large bag strewn over her back. From Mediterranean climes, she embarked on her first field season in the cold, wet, and occasionally snowy, Otways on the hunt for mainland dusky and agile antechinus. Over two field seasons and leading a team of volunteers, Erika collected activity data on antechinus housed in large, naturalistic enclosures in the Otways to measure sleep & circadian activity rhythms of males and females. As you know from Pat Woolley’s work, antechinus males enjoy only one breeding season and then die in a specular mass-death. Erika wanted to understand how sleep changed in males in response to their looming demise. Using diverse techniques, from filming and accelerometry to endocrinology, metabolomics and electrophysiology, Erika showed that male, but not female, mainland dusky antechinus reduce sleep by 3-h per night, every night, for 3-weeks. In humans, this level of chronic sleep restriction would impair performance. Erika travelled to The Netherlands to use a novel method measuring blood levels of a metabolite, oxalic acid, that is reduced in sleep deprived rodents and humans. In doing so, she provided hints that wild antechinus might be sleep deprived, too. For her multi-year, multi-method study, Erika was rewarded with a paper in the journal Current Biology (Zaid et al., 2024) that attracted much national (ABC, radio) and international attention (Nature, Science, New York Times and others). Equally as important, prior to this paper, Erika brought antechinus into the lab (at La Trobe) for recordings of brain activity. This was one of the first detailed electrophysiological sleep studies on a marsupial, and truly the first to see how sleep is regulated in any marsupial. In doing so, Erika kept antechinus awake for a few hours during the day, and found they have increased sleep intensity when allowed to sleep freely, not unlike your own response after one-too-many episodes on Netflix. A surprising thing arose, unlike other mammals who have few sleep bouts packaged in tens of minutes, or hours, of continuous sleep, antechinus package their sleep much as birds do: hundreds of short sleep bouts, each tens of seconds long. This is a level of sleep fragmentation hitherto unknown for a mammal. Here, Erika was again rewarded with a paper in our top, aptly-named journal, Sleep (Zaid et al., 2022). Erika is pursuing two more papers, one on circadian activity rhythms in fat-tailed dunnarts and another on how lunar phase influences activity in antechinus, which will add to her growing arsenal of original papers. For all her successes, please join me in Congratulating Doctor Erika Zaid!
Sleep Ecophysiology Group 