Biology - Lydia Leon
The profound psychological effects of lysergic acid diethylamide, or LSD, have fascinated individuals from Huxley to Hendrix. LSD began life in the lab in the late 1930s, with its psychoactive properties only discovered in 1943. It was initially considered a potential treatment for alcohol addiction and depression but its recreational use in the 1960s – when it became the signature drug of psychedelia – led to restrictions. It remains illegal across most of the world.
In April, a team led by the outspoken former government drugs adviser Professor David Nutt published a paper
in the journal PNAS, looking at the neurobiological impact of LSD – one of the first scientific studies of its impact on humans in half a century. The study followed 20 healthy volunteers with previous experience of drug use. The participants were given either LSD or a placebo in two separate sessions. Their brain activity was observed in neuroimaging tests and questionnaires on their “altered states of consciousness” were completed.
Compared to the placebo, LSD appeared to increase connectivity between bits of the brain that are not normally connected. In particular, communication between the visual cortex and other parts of the brain was increased – perhaps underlying the characteristic complex visual hallucinations associated with LSD. There was a relationship between participants reporting a loss of their sense of self, or “ego dissolution”, during an LSD trip and reduction in connectivity between a particular set of neuronal networks. This could offer an opportunity for future research into the treatment of disorders characterised by the loss of a sense of self, such as schizophrenia.
The publication comes at a fascinating time for research into the use of normally illicit drugs for therapeutics, as well as wider legal and political debates about recreational drug use. Novel studies such as this one from Nutt’s lab open up largely unexplored avenues for research. This offers not just potential therapeutic benefit but a greater understanding of the functional and structural underpinning of human consciousness.
Lydia Leon is a PhD student at University College London
Physics - Ceri Brenner
I carry a 500-gigabyte hard drive in my handbag. It’s no bigger or heavier than a smartphone and I can plug it straight into my laptop, enabling me to work with large data sets (and – ahem – watch HD movies) wherever I need to. Seven
years ago, I was lugging around a one-kilogram beast with the same storage size that needed its own power supply and sounded like it was taking off every time I switched it on. Back in 1956, IBM revealed a five-megabyte hard drive –
to put this in perspective, that’s roughly the size of a single song file – that was the size of two fridges.
Miniaturisation of data storage is big business. We want our devices to do more, to save more, to work faster. Yet we also want them to be smaller and lighter. The physics behind designing the smallest storage of conventional computing data lies in the need for that device to contain lots of mini magnets, each of which can store a binary digit, or a “bit”, of information. Memory is stored by locking the mini magnets in either “north” or “south” pole magnetisation, which is then read by a device as the binary digits “0” or “1”. Groups of eight magnets store a code, known as a byte, that tells the computer what to do. For example, the byte for letter A is 01000001. So, the smaller the magnets, the smaller the hard drive.
Work recently published in the journal Science has shown that a single atom can be forced to act as a magnet, making it the smallest memory holder possible. Keeping something as small as an atom magnetised for a length of time is where the challenge comes in, as the storage capability disappears as soon as the magnet does. However, this team has demonstrated that when holmium atoms (nope, I hadn’t heard of that element, either) are layered on to ultra-thin films of magnesium oxide that have been grown on a surface of silver, the atom magnets are stable – albeit at a not entirely practical cryogenic temperature of -233C.
Atomic hard drives appear to be a long way off from the commercial market but I look forward to one day seeing a pocket-sized version of my hard drive.
Ceri Brenner is a physicist who works for the Science and Technology Facilities Council
Chemistry - Mark Lorch
Superfoods are all the rage. The claim is that consuming plenty of this new food group – touted by nutritionists as dense in minerals and vitamins – will ward off disease, helping you to lead a longer, healthier life. Yet just how much benefit you get from eating a punnet of blueberries and kilos of kale is debatable.
Most of these superfoods won’t do you any harm. However, there is one superfood you might want to be careful about. Spirulina is a blue-green algae that is dried and sold in pill and powder form as a dietary supplement. It is particularly rich in protein, iron and other vitamins.
All living things build proteins from amino acids. And those proteins control all the chemistry within our cells. When we eat proteins, we digest them into their constituent amino acids and then reassemble them into the proteins we need. But spirulina sometimes makes an amino acid that our body doesn’t use. Our cellular machinery doesn’t notice and incorporates it into our proteins. It’s a bit like a mechanic installing a part from a Ford into a Volkswagen: unlikely to do any good.
In this case, the amino acid is something called β-N-methylamino-l-alanine (BMAA). A paper published earlier this year in Proceedings of the Royal Society has shown that when it gets incorporated into proteins, it can cause Alzheimer’s-like diseases.
So, does your spirulina supplement actually contain BMAA? That is a tricky question, as BMAA is extremely difficult to identify. Another recent paper has come up with a new method for checking for BMAA. Published in the Journal of AOAC International late last year, researchers analysed 39 samples of spirulina bought in Canadian health food shops. Fourteen contained detectable amounts of BMAA. The levels were low and may not be in toxic concentrations but BMAA bio-accumulates (meaning it will slowly build up within the organism eating it). So I’d be inclined to lay off this particular green power supplement until health food retailers start using the Canadian team’s test to check if their products are BMAA-free.
Mark Lorch lectures in chemistry at Hull University
