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My lab:
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Just over a year ago, Bruno van Swinderen and I published a paper in the Journal of Neuroscience (local copy) where we described numerous behavioral and electrophysiological defects in a fly mutant called radish. Many of these defects had to do with how the animals processed and responded to stimuli. These defects could be interpreted as a combination of a deficit in attention-like processes and a rather well-defined, oscillatory hyperactivity. Curiously, many of these defects could be successfully treated with Methyphenidate, the active ingredient in Ritalin which is the drug used to treat patients with, you guessed it, ADHD.

What has not been tested for treatment with Ritalin, was the behavioral hyperactivity, an oscillation in the yaw torque behavior of the flies at around 2 Hz. Bruno was able to treat the 2 Hz hyperactivity in the 'brain waves' of the flies, but I needed to get a permission to buy Ritalin first, which I got almost a year later. Now we've treated both the wild type control strain 'Canton S' and the radish mutant flies with Ritalin as they were flying in the Drosophila flight simulator, controlling their flight direction with respect to four identical, vertical stripes. There were two major differences between the experiments I did back then and the experiments now: first, the genetic background was changed from Bruno's Canton S to the Canton S from the lab of Thomas Préat. Second, the patterns in the experiments differed, as the published experiments were carried out with two pairs of t-shaped patterns, to upright and two inverted T's. Now, the patterns were four identical, vertical stripes. In spite of these differences, we found essentially the same peak in the power spectrum of the yaw torque behavior (blue line):



We also found some other peaks, some also in the wildtype control (black line), but by and large, we were able to reproduce the result. Phew.

The most interesting aspect of this work is that the Ritalin treatment almost reduces this big peak to control levels. Not quite, but almost. We interpret that as Ritalin bringing the radish mutant flies closer to the 'normal' wild type flies. In fact, Ritalin even treated the flight defect - radish flies are reluctant to fly in my setup. There are other interesting aspects such as the strong reduction in power at the low frequency end of the spectrum even in wild type flies, but this discussion, together with a more thorough behavioral analysis of the data must be saved for a later time.

For now, I just wanted to share these results with everybody, as they were a big missing piece in our previous publication and if anybody wonders about the outcome of these experiments, I can now point them to this remarkable new platform for sharing figures and data: FigShare, which is where I posted not only the figure, but also the raw data which were used to generate the figure. This allows me to share the results even before they are published in a peer-reviewed journal. Maybe someone has a great idea on what else to do with these results, or has some clever way of further analyzing the data, then they can download the data and try around for themselves. We plan to study, in addition to further behavioral tests, the gene expression differences in essentially these four groups of flies, in a tissue-specific manner. These proteomics experiments will be done in collaboration with Daniela Dieterich in Magdeburg. We will use our behavioral tests as a read-out for the effectiveness of the Ritalin treatment and try to correlate gene-expression with the behavioral effects.

Maybe you also want to try FigShare to keep everyone posted as to what exciting discoveries your are making right now? It is very easy and not a lot of work at all. In fact, this blog post took me longer to write than to post the figure and the data.
Posted on Wednesday 30 March 2011 - 18:17:34 comment: 0
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