Sleeping our cares away
Associate Professor Laura Jacobson is the Florey’s Head of Sleep and Cognition laboratory. She spends her days considering the impact of sleep architecture; and its links to learning and memory.
We spend a third of our lives asleep,” Laura says. “It’s not wasted time, it’s critically important.” Indeed, while we sleep our brain is busy testing connections, replaying key moments and, reconfiguring itself.
While the vast majority of international sleep research focuses on activating GABAA receptors to turn off neurons in the brain to promote sleep, Laura is involved in a different line of research which concentrates on the orexin system, neurons that control our awake-sleep activity. The dual orexin receptor antagonists (better known as DORAs) are drugs such as Suvorexant and Belsomra that target the receptors that are activated by orexin when we’re awake.
Her work is particularly interested in how sleep and dreaming act as mechanisms that allow our brains to dump information.
“My opinion is that dreaming is in part a re-run of aspects of the day’s memory and it’s testing out the wiring.”
A/Prof Laura Jacobson’s research is helping us understand the way we process emotional memories and may even help us diagnose Alzheimer’s disease. Estimations of what type of neural patterns are associated with that. For example, there has been some research done on ‘place cells’ – when an animal runs in a maze, they make a mental map of the maze and as they go through it, with different cells in the brain’s memory region firing depending on where they are in the maze. We can actually see that process re-running in their brain during sleep.”
Dementia scientists have shown that clumps of a protein in the brain known as tau indicate that someone is developing Alzheimer’s, as well as frontotemporal dementia. Tau build-up appears to run alongside elevated levels of orexin in the fluid surrounding the brain. Broken or reduced sleep and increased time awake is often a symptom of Alzheimer’s, well before any memory issues become apparent, so Laura is exploring whether manipulating sleep using DORAs to block orexin activity, might help slow Alzheimer’s progression.
“In our work with animal models of Alzheimer’s disease, we are testing whether reducing time awake and increasing Rapid Eye Movement sleep can help to improve memory and slow the development of Alzheimer’s. Achieving this would be a very welcome development for individuals affected by this devastating disorder.”