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Society for Neuroscience

November 13, 2005 This article courtesy of Nature News.

Jim Giles reports back from the annual brain science jamboree, from 12-16 November in Washington DC.

Day 3: Space anxieties

Does this line of reasoning seem plausible?

Rats exposed to cosmic rays are more reluctant to enter open areas, such as parts of a maze without shelter. This implies that they're more anxious, just like their older counterparts. If astronauts ever go on trip to other planets, they will be exposed to cosmic rays. So NASA should be careful, as the astronauts could act old and anxious too.

This seemed like a logical step too far to me, so I put my scepticism to the researchers from University of Maryland, Baltimore County on whose poster these results appeared. It turns out not to be so unreasonable.

The work is the latest in a line of studies in which rats have been exposed to simulated cosmic rays from a particle accelerator at Brookhaven National Laboratory. The fact that these studies managed to justify the $10,000 an hour that it costs to run the accelerator indicates just how badly NASA wants them done.

In each study the rats have been given behavioural tasks designed assess things like their desire for novelty. And in each case the cosmic rays have caused younger rats to perform more like older animals. In the maze study, old rats tend to be anxious and therefore wary of entering exposed areas. The rays seem to turn wild young rats into stay-at-home oldies.

And it's not such a cosmic leap to suggest that the same thing could happen in humans. Analysis of the rats' brains shows that the rays damage dopamine-producing neurons and limit the generation of new cells in the hippocampus, both of which are known to occur during human ageing.

NASA can't shield astronauts entirely from the rays, since that would make spacecraft too heavy. So the agency is asking the UMBC researchers to investigate which foods can help fend off the harmful effects. So far, it looks like a diet of strawberries and blueberries is the best way to get healthy astronauts to Mars.

Day 2: Model of mind - in a rat?

Lots of excitement this morning around a set of posters on a rat model of autism. It sounds like an odd idea: how can a disease related to subtle concepts like theory of mind be modeled in a rodent?

The answer is through valproic acid, an ingredient in anticonvulsant drugs. It's one of the few environmental triggers thought to induce autism. Like another known trigger - thalidomide - we know this because pregnant women given the drug are more likely to have children who go on to develop autism. But whereas thalidomide has no effect in rats, valproic acid produces a range of symptoms seen in autism, such as repetitive behaviour and an unwillingness to interact socially.

It's early days yet, but the studies of rats given valproic acid attracted a load of interest this morning. Henry Markram, who leads a group at the Mind Brain Institute in Lausanne that is working with the model, say his work has already identified one feature overlooked in human autism research. Once his rats have learnt to fear something -- perhaps an electric shock that follows a tone -- they find it hard to forget the link, even when the shock is no longer associated with the tone. Markram points out that people with autism also find it very hard to unlearn links between disturbing events. Autism researchers are not focusing on this behaviour, says Markram, but he thinks his model suggest they should be.

Day 2: Rejected by Science

This afternoon I wandered down to a session on how to get published in Science. As I mentioned yesterday, this went head-to-head with an equivalent session run by Nature and I wanted, out of curiosity and a healthy dose of journal rivalry, to see which would attract the most researchers.

I checked numbers first at Nature - around 170 people - and strolled down the corridor to Science. They had the edge, I thought, since they were serving post-session drinks. I had just started my head count when up strolled a rather formidable looking lady with a Science badge on.

Her: You're from the competition. I think you should leave. Me: Erm...really? Her: Yes. It's not fair that a Nature editor attends this talk. Me: But I'm not an editor, I'm a journalist. Her: A journalist? So you want to get published in Science? Me: Erm... no...actually I'm just curious. Her: Well I think you should leave.

And so I did, but not before completing my head count: 60 attendees.

Day 1: Popularity contest

A kind of strange popularity contest takes place during the vast conferences like this. The football-pitch sized poster hall is packed, but not everyone is getting the same attention. It's a bit like a singles night. The researchers with the beautiful science are surrounded by crowds of admirers, while colleagues showcasing more mundane conclusions look lonely and a little forlorn.

Paul Young is one of the popular ones. He's got a neat method that allows researchers to visualise brain cells and turn genes on and off in those cells at the same time. The scene around him reminds me of travelling to work on the London underground: scientists are crowding in on his poster like a bunch of harried commuters trying to force their way onto a train. At the neighbouring poster stands a slightly awkward-looking researcher, ignored by the crowd next door.

A similar sort of competition will be taking place tomorrow, as Nature and Science go head-to-head with sessions on how to get published, both happening at the same time in adjoining rooms. Only Science ran a session like this last year, and it was packed. I'll let you know who attracts the most admirers this year.

Day 1: Not so ecstatic

I've often thought that ecstasy users are taking part in a scary long-term experiment. Neuroscientists are only just beginning to work out what the drug does to their heads. Meanwhile, clubbers the world over are popping pills and altering their brain chemistry with gusto.

Ecstasy users might feel differently if they strolled around this conference. We already know that the drug damages receptors for serotonin, a brain chemical that neurons use to exchange signals. Several posters and talks here reveal other disturbing findings. Take the study by Michael Bankson of Boston University. He looked at how ecstasy affects the blood-brain barrier, a layer of cells that can stop harmful substances entering our brains. Bankson found that ecstasy increased permeability of the barrier by 50%.

This isn't as terrifying as it might sound; other things, including stress, can also alter the barrier's permeability. But it is, as Bankson says, yet another example of damage that ecstasy does. No one knows for sure what all this adds up to in term of users' mental and physical health, but we'll find soon enough, since the ecstasy use has probably been widespread for long enough for its effects to start showing up in epidemiological studies.

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