Björn Brembs

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Coded the regression analysis

on Thursday, September 7th, 2023 2:16

I now switched the sign of the Optomotor Asymmetry Index in flies that were punished on producing right-turning torque, such that weaker punished torque shows up as a positive index. After that was done, I plotted the correlation between the optomotor index and the preference index:

I had to get rid of eight flies where the optomotor response was already asymmetric before the training started, so now I only have 33 flies. But with these flies, there is no correlation before training and a very significant correlation after training.

Any suggestions about appearance of the graphs?

Would it be useful to plot optomotor and performance indices as raincloudplots next to the regressions?

This would be the complete figure:

Optomotor project nearing completion

on Monday, September 4th, 2023 1:59

The results of comparing optomotor responses after self-learning remain solid. There still is a small asymmetry between the left/right groups, but nothing dramatic:

Little by little

on Monday, July 24th, 2023 1:59

Despite very warm weather, some flies did fly, even though the learning performance of the control flies was really poor. At least for now, it looks like all stocks are learning and that rut and rsh flies learn at least equally well as the Berlin flies. I’ve also managed to fix the positive preference problem:

Kicked out Canton S

on Thursday, June 29th, 2023 5:25

Since the Canton S strain I used wasn’t a perfect genetic background strain anyway and didn’t fly properly, I kicked it out and replaced it with the wild type Berlin data I had collected just prior to the rut and rsh mutants. Now I can collect data for two projects in one go: I check the rut/rsh learning mutants if they still behave the way they should and with the wtb control strain and continue collecting data to evaluate their optomotor responses after training. So now the learning scores for the three strains look like this:

It still doesn’t look like rut is better than wtb, so I’m still skeptical that the strain is really what it should be. The rsh data also don’t look very promising, but I still need to get more flies with a negative preference before the training.

Suspicion and progress!

on Monday, June 26th, 2023 2:03

Suspicion: rut may not be rut

Carsten Duch is identifying the muscles involved in operant self-learning:

It’s a start

on Friday, June 16th, 2023 4:42

The first few rutabaga and radish mutants have been measured and so far it looks good: standard duration yaw torque learning – the situation all three groups should learn.

Optomotor asymmetry after torque learning

on Tuesday, June 6th, 2023 3:31

Only a few more flies compared to the first week, but the difference between optomotor responses after punishing left or right torque, respectively, is starting to show:

These data suggest I should fill the groups up to a sample size beyond 20 if I want to use these data somewhere…

Optomotor effects after torque learning?

on Friday, May 26th, 2023 5:04

After training 14 flies it looks as if the new setup is working as it should:

Looking at the optomotor traces more closely now that (a) we know that motor neurons are the only site of plasticity and (b) we routinely record optomotor behavior after training, something very interesting appeared when comparing flies that have been trained on one turning direction with flies trained on the other side:

Flies trained to avoid right turning show reduced optomotor response to the right and vice versa! The weaker effect for ‘left’ may be due to the weaker learning in this group?

Anyway, I have never seen this and find it quite exciting!

Machine works, flies are not learning

on Monday, May 22nd, 2023 11:48

The old software is installed with the new hardware and I’ll be testing the new software in parallel to experiments with the old software. Technically, everything seems to be working now, but the first six flies I tested did not show learning after training:

However, avoidance looks fairly ok, only the last training period gives away that something still isn’t quite the way it should be:

So I’ll go ahead and train a new batch of flies this week. I’ll focus on training/avoidance and make sure it is perfect, before I shorten the training.

NWG Poster on MBON-02 regulating habit formation

on Thursday, March 23rd, 2023 12:18

If you missed it at the Göttingen NWG meeting, you can download our poster from here: