After 7 attempts to figure out the treatment with the dopamine-synthesis inhibitor 3IY we finally managed to get it right.

Trial 6 was a minor set back since I used the same method that had worked before but prepared 8 mL instead of 2 mL. 3IY is not really soluble so I thought that the first “fraction” of the solution might not contain enough of the inhibitor to sufficiently deplete dopamine. I tested WTB flies with the first fraction of the 8 mL preparation.

I did not observe differences between groups. N(3IY)= 14; N(SUC) = 12

Since I cannot prepare the 3IY for each vial I am going to use (~ 8 per testing day) separately and put them on the vortex for 30 minutes each I tried if shortly vortexing and stirring afterwards would enough. Additionally, I tried tissue and filter paper again since the previous tissue paper trial might have had the same problem that 3IY was not present in high enough amounts in the first fraction.

N= 14 for each group; FP = fitler paper; TP = tissure paper

Since this method seems to work, I can now prepare enough vials at the same time and start with the actual experiments. I only need to figure out how to apply the ATR….

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C= Experiment Group

N=20

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C= Experiment Group

N=20

N(WTB_3IY) = 10; N(WTB_SUC) = 6

N= 16

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N=16

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We were having some issues with our Negative Control for the JoyStick. Without ATR the flies should not avoid optogenetic activation since the channel should not be functional, yet still they did. We lowered the light intensity from 800 Lux to 650 to see whether the light was to strong and would activate the Chrimson channel, even without ATR.

Alisa’s experiments

Alisa+Daniel experiments

I confirmed the action of the dopamine synthesis inhibitor 3-Iodo-L-tyrosine (3IY) in a previous trial, where treated flies showed decreased walking speed and distance when tested in an open field. In this trial I tested the flies “fresh out of the tube” so that they were able to feed on 3IY right to the point where they were tested. For the main experiment however, flies will be transferred from the food 2-5 hours before the experiment. To confirm, that the effect of 3IY treatment will persist also after this time span I moved flies from 3IY supplemented vials to fresh, empty vials at least 4 hours before measuring walking behavior in the open field. The results confirm, that the effect of 3IY is still present after this time.

N=12

N=8

For this trial I prepared 2mL of 3IY (10mg/ml in 5% Sucrose) 30 minutes before applying it to 8 pieces of filter paper stacked in the glass vial. I pipetted the whole volume of 2mL into the vial and discarded the excess liquid.