To test if diazepam may alter also photopreference in the T-maze, I first tried to replicate a previous experiment published recently in “Ancient Anxiety Pathways Influence Drosophila Defense Behaviors“, to ensure the method of delivering diazepam to the flies was effective.

The published methodology was only slightly modified. I used a round glas petri dish (diameter 100 mm, height 15 mm) above a luminous plate instead of a square plastic chamber (10 x 10 x 1.6 mm) which was lit from the sides. Also, the flies fed on filter paper soaked with a 5mM diazepam solution (in 10% ethanol, 5% sucrose, 5% yeast and food dye), instead on the CAFE capillaries. After starvation over night and 6h diazepam treatment, WTB flies were tested at 25°C.

(D = Diazepam; nD = no Diazepam)

In the paper, it was shown that the speed of flies which got the diazepam treatment gradually decreases. In this data here there can also be seen that the median speed is slightly lower than in the control group, suggesting that the treatment seems to be working.

The following heatmaps also show a tendency that diazepam treated flies may be spending more time in the center of the dish than the control flies.

However, these effects are not nearly of the size as those in the published paper, so I’ll have to try and play around some more with the size of the container to see if this is the reason why my effects are so tiny.