you can try to glue it to the bottom of your preparation by wound-glue.

Another posibility is to use a mesh or an insect pin (just lid down) to hold the brain mechanically fixed, although both may interfiere the image.

Thank you for your advices. Did you actually try by yourself.

In my hands, a pin was not the ideal technique...

Gluing works well for late embryonic fillet preparation. just a suggestion for adult CNS, could work for you. The glue can be applied via glass capillary connected to the silicone tube controlled by mouth.

Ok, I'll try... thank you again.

Hi Martine, use a petri dish with sylgard and pin both optic lobes carefully in the sylgard. I have done this and it takes quite some practice plus not every brain works super well. Alternatively if you want to try some recordings in the living fly there is also some pretty good technique: Article Calcium Imaging of Odor-evoked Responses in the Drosophila A...

Alternatively, you can use Microfluidics systems to immobilize the whole larva for CNS imaging, while the larva is fully intact.