the science of sleep

Why do we have to sleep? Well, ok, for humans it is easy to come up with a whole range of reasons why we need a certain budget of sleep - our lives are tiring, our complex brains need rebooting once a day, and sleep does all sorts of good things for us.

However, as research keeps discovering sleep behaviour in more and more primitive animals, including invertebrates that don't even have a brain, the phenomenon is getting harder to explain. If they want a bit of a rest at night, that could be easily regulated in a circadian cycle which most multicellular organisms have anyway. But why did our common animal ancestors, more than half a billion years ago, go to the trouble of evolving a budgeting mechanism of the kind that troubles us when we missed out on sleep and have to catch up?

The short answer is, we don't really know - but the quest to understand this does yield some very interesting insights into the hidden lives of all sorts of animals. My feature on this issue is out now:


The reasons of sleep

Current Biology Volume 29, issue 15, pages R775-R777, August 19, 2019


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Oh, and if I got my maths right, this is the 200th feature in this series - since I took on the challenge to write a feature for every issue, back in February 2011. Since the first one, there have only been three or four issues without one, for one reason or another.



Most mammals are very much like humans in their sleep behaviour. Attempts to explain the evolution of sleep with the mental benefits it has for humans and other mammals are undermined, however, by the findings that some of its features are shared across the animal kingdom. (Photo: RoyBuri/Pixabay.)

memories are made of what exactly?

Today's issue of Current Biology is a special issue on memory, with lots of great articles on various aspects of memory. Oh, and there's also a feature from me, on sharp-wave ripples and whether or not they're important for memory.

Are memories just ripples in time?

Current Biology, Volume 23, Issue 17, R734-R736, 9 September 2013

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All the themed content in this issue will remain on free access for a month after publication date, apparently.

By coincidence, there is also a new book out about one of the most extensively studied patients with memory loss, H.M. While this isn't directly linked to ripples, the cause of his memory loss was removal of his hippocampi, and they are also the source of ripples, so that was a good enough excuse for me to mention his case.

drugs prohibition kills

I wrote a feature about psychoactive drugs a few weeks ago, mainly inspired by the recent paper from David Nutt and colleagues who argued that the blanket ban of psychoactive drugs harms progress in neuroscience (apart from ruining the lives of millions of people with the unwinnable "war on drugs").

Since then, tragic events, including the death of a teenage girl here in Oxford, have highlighted the issue. There is a properly dangerous drug making the rounds in the UK right now, PMA (paramethoxyamphetamine) (probably called Dr Death for a reason), but as drugs are banned regardless of their harm, it's hard to know what is and what isn't dangerous. Plus, there is no quality control, and if kids buy an illegal pill, it could contain anything. In the Netherlands, by contrast, there are labs checking up on what is being traded, and they haven't had problems with PMA yet.

Essentially, my bottom line is, people always have used mind-altering drugs and always will do, and if there wasn't this blanket prohibition banning harmless and dangerous things alike, it would be much safer for them to do so. Hardline prohibitionists are just creating most of the problems they are pretending to solve.

Oh well. Don't get me started on this, it drives me up the wall in no time. Just read my feature:

Drugs prohibition is criminals’ gain, neuroscience’s loss

Current Biology, Volume 23, Issue 14, R585-R588, 22 July 2013 doi:10.1016/j.cub.2013.07.012

which is freely accessible (and legal, still!) as

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Cannabis sativa - picture credit: GW pharmaceuticals.

PS: couple of further links re. the recent deaths linked to PMA:

• Ian Birrell in The Guardian
• Excellent piece from Archie Bland in the Independent
• Martha Fernback post-mortem inconclusive (BBC news)

PPS only after publishing this blog entry I became aware of the organisation Transform Drug Policy Reform, which has published detailed suggestions for a drugs regulation based on actual scientific evidence and on policies that are feasible (borrowing bits and pieces from established frameworks such as the handling of prescription drugs). "After the War on Drugs: Blueprint for Regulation" is freely available as a PDF download, but if you would like to support the organisation, you can also order it as a book from them. You can also download the executive summary only, which is also available in several other languages including Spanish, Russian, and Italian.

hearts and minds

My latest feature in Current Biology juxtaposes a highly acclaimed project to simulate the function of the heart and a somewhat controversial, but well-funded one to do the same for the brain.

Simulating hearts and minds

Current Biology, Volume 23, Issue 5, R177-R180, 4 March 2013

doi:10.1016/j.cub.2013.02.032

Free access to the full text in HTML and in PDF format.

Here is a video about the Alya Red project featured in my article:

Alya Red: A Computational heart

This video recently won Science magazine's prize for science communication.

amyloid and Alzheimer's disease

Back in the late 90s, I was working with some model peptides which I had designed for use in studies of nascent protein folding, but they kept aggregating. Chris Dobson suggested to check whether the aggregates had the hallmark featres of amyloid, and indeed they had, so I slipped into the study of amyloid, which is the kind of tangled protein aggregate one finds in Alzheimer's disease, BSE, and Parkinson's. Quite a few others did at the time, as many proteins and peptides had the ability to form these structures, even if their native states had no disease association whatsoever.

I haven't done much about amyloid since publishing my last research papers, but recently spotted a few papers that looked promising both for the understanding of amyloid formation and for the treatment of Alzheimer's disease, so I wrote a feature about these things, which is out in Current Biology today.

Understanding amyloid and Alzheimer's disease

Current Biology, Volume 22, Issue 10, R381-R384, 22 May 2012

doi:10.1016/j.cub.2012.05.006

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(NB: my features remain on free access only until the next issue appears, i.e. normally 2 weeks, sometimes 3, and they return to free access a year after publication)

Alois Alzheimer (1864-1915)

(Wikipedia)

illuminating brain function

As I have followed the story of bacteriorhodopsin - the biological computer that never happened - for many years now, I was very pleased to learn that somebody found something very clever to do with this and similar microbial opsins. Specifically, the recently developed methodology of "optogenetics" involves expressing microbial light-responsive ion channels or pumps in neurons, meaning that one can activate or inactivate these neurons by shining light of a certain wavelength onto them.

Stanford researcher and practicing psychiatrist Karl Deisseroth, who invented the method and pioneered its use, is keen to apply it directly to psychiatric questions. Others think a few fundamental things need to be sorted out first. Read more about all this in my feature, which is out in today's issue of Current Biology:

Shining new light on the brain
Current Biology, Volume 21, Issue 20, R831-R833, 25 October 2011
doi:10.1016/j.cub.2011.10.007
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sesame street on the brain

Rule no. one of science: if you give boring names to the things that you discover, nobody will pay any attention. So researchers studying the development of the brain have named two key proteins ERNI and BERT (obviously, as Sesame Street was also supposed to serve the development of the brain, and as these proteins tend to fight each other), and bingo, they got my attention. I have to say in my defence, though, that it was a very slow news week for science last week, so there wasn't much else really.

Anyhow, here's their story:

BERT and ERNI proteins control brain development

Scientists at University College London have discovered how two proteins ¬called BERT and ERNI interact in embryos to control when different organ systems in the body start to form, deepening our understanding of the development of the brain and nervous system and expanding our knowledge of stem cell behavior.
The new research published this week in the open-access journal PLoS Biology solves the puzzle of how vertebrates prioritize the order in which they begin to develop different sets of structures. During development, only a few signals instruct cells to form thousands of cell types, so the timing of how cells interpret these signals is critical. An international research team led by Professor Claudio Stern of the UCL Department of Anatomy & Developmental Biology has shown that the first stage of development of the brain and nervous system is, paradoxically, a block on its progression.
The scientists describe a sequence of reactions that take place when vertebrate embryos are only a few hours old that together act as a timing mechanism, temporarily preventing the development of neural cells (cells that go on to form the brain and nervous system). This gives a head start to other cells in the embryo that will go on to create the body’s internal organs and skin, and prevents the nervous system from developing prematurely.
Dr. Costis Papanayotou of the Stern laboratory discovered a new protein, BERT, which then binds with the protein ERNI (also discovered by Professor Stern’s team) and other proteins to unblock a gene called Sox2, which gives the green light to cells to start forming the brain and nervous system.
Professor Stern said, “Scientists have been looking for a long time for the switches that determine when cells in the embryo take on specific roles. Our work shows that the proteins BERT and ERNI have an antagonistic relationship: BERT is stronger and overrides ERNI’s suppression of the Sox2 gene, which has a crucial function in setting up the nervous system. As the Sox2 gene is also needed for stem cells to retain their ability to take on a variety of roles in the body and to renew themselves, this research also advances our knowledge of stem cell behavior in adults, which could have implications for this growing area of medical research.”


Citation: Papanayotou C, Mey A, Birot AM, Saka Y, Boast S, et al. (2008) A mechanism regulating the onset of Sox2 expression in the embryonic neural plate. PLoS Biol 6(1): e2.doi:10.1371/journal.pbio.0060002