Now that we’ve finally gotten all the preparatory work out of the way, we got to start our actual experimenting today. The room was filled with teens decapitating fly heads, connecting batteries to vials, and trapping flies in chambers.
Personally, I was testing for fly anxiety with a social space assay and memory with, well, a memory assay. The social space assay went smoothly. I had 16 glass chambers and worked knocking out and transferring flies to these chambers down to a science. In five minute increments, I went down the line and took photos of each chamber, and the assay was done quickly.
Okay, that wasn’t too bad. I was doing pretty well.
But then came the memory assay. Ah, yes, the dreaded, challenging memory assay that only one girl in the history of TRIP conquered without giving up like the rest. I hoped to be like that girl.
The procedures seemed simple. Knock out the starved flies with ice, throw them into the training apparatus, and just move the slider back and forth for 30 seconds per scent. Once they are trained, put them into the testing device and hit record on a camera.
There are two scents in the training apparatus. One smells like pineapples. The other smells like bananas. The one that smells like bananas has a sucrose solution to condition the flies to go to the banana smell. There’s a rest vial in between.
But you see how in the photo, the flies have to travel up into the vials to reach the smell and sucrose? Well, these flies were lazy, and they thought, “Hm, how about we just stay in the bottom vial, so we don’t even get to associate any smell with sucrose?” The flies wouldn’t cooperate.
I thought the memory assay difficulty was exaggerated, but when the flies themselves don’t do what they’re supposed to, it’s kind of hard to actually go through with the experiment.
So I had to improvise, scrap the techniques, and make up my own method separate from anything I had knowledge of existing. I got petri dishes, added the scents to those, and put the flies in the dishes, so they’re actually exposed to what they were supposed to smell.
And it might have worked if I didn’t have a 5% survival rate, meaning I started with 120 flies, and I was down to 7 by the end of the ordeal. Some died from drowning after being left in ice for too long, some got stuck in the sucrose, some inhaled too many fumes, and others spontaneously died for seemingly no reason at all (although they were weak from starvation, so…)
The moral of the story is that the memory assay was quite the adventure, and I felt like I had failed (but hey, that’s when you learn the most). However, I’m planning on trying a glucose assay on Tuesday since it’s not worth risking killing off my actual flies since these were just practice ones. Then Thursday, I might give this another go, now that I know what needs to be improved. Wish me luck.
Author: Sasha Temerte