Generational stress assay
To asses any possible effects of stressful conditions experienced by the parental generation (G0) on generation 1 (G1) flies on day 0 of the assay the air volume for the 60 experimental flies was reduced by ca. 1/7 by positioning the cotton plug ~ 10mm above the food surface. For the 30 flies of the control group the cotton plug was not positioned differently. Crowding took place 48h on 25°C. On day 2 the control flies were transferred into a big vial with fresh yeast. The experimental group was anesthetized with CO2 and separated to the usual number of flies per vial, 20 females and 10 males, and also transferred into a big vial with fresh yeast. After 24h all the flies in the vials were discarded. On day 12 newly hatched G1 flies were collected and incubated for 24h at 25°C before the ATR treatment.
To differentiate the effects on learning behaviour of G1 flies that experienced stress but their parents have not been stressed (group 1), G1 flies whose parents have been stressed and also experienced stress themselves (group 2), G1 flies that have never experienced stress wether their parents nor themselves (group 3) and G1 flies whose parents have been stressed but they haven´t experienced stress (group 4), following steps were taken.
For the ATR treatment, on day 13, four small vials without yeast were prepard with ATR. The collected males from the experimental and the control group, were again separated into 2 different vials each. the 4 different vials represent the following four groups:
Group_1: control group; stressed
Group_2: experimental group; stressed
Group_3: control group; not stressed (Positive control)
Group_4: experimental group; not stressed
After again 48h incubation at 25°C all 4 groups were prepared and tested in the Joystick.
Joystick experiments
The following are the pooled results of seven days of testing over the last two months.
Another sample set of stressor `cold´
20.03.2026:
The first set (19.02.2026):
The two sets pooled:
stressor: cold (18°C; 48h)
control group: Pos_CTRL
experimental group: Gr28bd+TrpA1(cold)
Last stressor for pre-test: sleep deprivation
stressor: Sleep deprivation (24h, room temperature)
POS_CTRL: control group
Gr28bd+TrpA1(sleep): experimental group
First feeding essay and wiggle factor
On the left, there are the results of the experimental group: social isolation, with the usual R Skript. The right side shows the same results but with an adjusted “flat threshold” (for movement) of 0.4 instead of 0.9.
First Feeding essay for experimental group “crowding” and “sleep deprivation”:
stressor: heat
stressor: heat (37°C; 6min)
POS_CTRL: control group
Gr28bd+TrpA1(heat): experimental group
Stressors: cold and crowding
For the stressor ‘cold’ the flies were kept on 18°C for 48h on ATR.
stressor: cold (18°C for 48h)
POS_CTRL: control group
Gr28bd+TrpA1(cold): experimental group
For the stressor ‘crowding’ ca. 60-65 flies were kept in one vial for 48h on ATR.
The effect of crowding was created by the volume of air available to the flies in the vial. This was altered via change in the height of the cotton plug in the vial. The control group had the cotton plug at the usual height of ca. 60mm above the food in the vial and the experimental group only 20mm.
stressor: crowding (maintained in smaller volume for 48h on ATR)
POS_CTRL: control group
Gr28bd+TrpA1(Crow): experimental group
stressor: social isolation
The experimental group was kept in single vials on a ATR+Sucrose mixture for 48h.
stressor: social isolation
Pos_CTRL: control group
Gr28bd+TrpA1(Iso): experimental group
First pilot experiments on different stressors
On Wednesday I tested the “heatshock” group, using light (with the same intensity as the aversive stimulus in the joystick experiment: ~800lux) for 5 minutes before testing, to stress the flies.
Stressor: heat (5min; 7.4V; ~800lux)
Gr28bd+TrpA1(Co): control group
Gr28bd+TrpA1: experimental group
On Friday I tested flies who were maintained in a cold environment (18°C) during the ATR treatment (2 days).
Stressor: cold (18°C; 48h)
Gr28bd+TrpA1(Co): Control group
Gr28bd+TrpA1: Experimental group
First set of joystick experiments
Last week I started to test CsChrimson (NorpA, 20xUAS-Chrimson) flies with the joystick set up, to reproduce Daniels’ data on the positive control and to get used to the experimental set up.
There is a noticeable improvement (from my end) from the first two days of testing to the last two days.
These are the results of the first four days of testing. All in all, the positive control shows good avoidance. Althoug, there is a remarkable change in the error bars starting with the fifth period. Maybe due to exhaustion or any other effect that I don’t know of yet.