Finally a meeting with usable WiFi access! This is going to be a very fast-paced meeting with 10h days packed with 12min talks of unpublished data, each followed by 10-15min of discussion.

This first day started with Alex Gomez‐Martin talking about odor-driven behaviors in Drosophila larvae. These larvae have a comparatively (e.g., compared to the adult) simple brain and a very straightforward organization of the odor-processing pathways. Alex uses a very neat video-based system autmatically scoring the behavior of larvae with targeted genetic manipulations of the olfactory system.

Next up was André Fiala. André uses laser pulses to activate or inhibit neural activity in adult flies. He told us what happens when he activates the dopaminergic system, which is thought to mediate aversive stimuli in insects: if flies can control this activation by rotating a small styrofoam ball, they rotate it in the direction which switches their dopaminergic system off. Thus, it seems that flies experience activity in their dopaminergic system as generally aversive. The next step is to subdivide this dopaminergic circuit to find out which specific neurons are the ones mediating the aversive effect.

The third speaker was Andreas Thum talking again about larvae and olfaction, but this time olfactory conditioning. He focused on octopamine, for which there is some evidence from several insects that it is involved in appettitive learning. The nice thing about the octopaminergic system in the larva is that most of the 40 known neurons can be individually identified. He mention an interesting detail, namely that they didn't find any tyraminergic cell bodies (tyramine is the precursor of octopamine) in the brain of the animals, only in the thoracic ganglion (but there were tyraminergic arborizations in the brain). Towards the end, Andreas showed that they have identified unpaired neurons in the suboesaphageal ganglion very similar to the famous vumMX1 neuron in honey bees. The last thing he told us was that ablating octopaminergic neurons only in the brain of the animals (by using tsh-GAL80 to block GAL4 in the thoracic ganglion) did not lead to the well-known locomotion phenotype and also left appetitive learning intact.

Next up was Bettina Schnell talking about vision in Drosophila, specifically, horizontal motion detection. Bettina records from identified neurons in the optic lobes of the flies, using the patch-clamp technique, while presenting visual stimuli. The neurons mediating horizontal motion detection are called HS neurons. Bettina characterized the anatomy and physiology of these neurons and showed us that their dendritic trees show a large degree of overlap, as do their receptive fields. Interestingly, these neurons are also dye-coupled to each other ispsilaterally and contralaterally. Indeed, they even are coupled to descending neurons.

Yoshinori Aso was the last speaker of this first session and talked about aversive olfacory conditioning in adult fruit flies. This work is all focused on the so-called mushroom-bodies (MBs), a prominent neuropil in the fly central brain. He told us that dopaminergic neurons innervating the mushroom-bodies, the MB-M3 neurons, are necessary for olfactory aversive learning. Activity in MB-M3 or in another such cluster, the MB-MP1 neurons during odor presentation is sufficient for forming an aversive odor memory. Thus, multiple types of dopaminergic neurons seem to mediate the aversive US in this type of learning. However, not all dopaminergic neurons mediate the US.

This concluded the fist session. I won't be able to live-blog the second session, as I will be presenting in this session and will need my computer for the presentation.