Bernd Grünewald had the thankless task of being th first to present on the Sunday monring. He talked about channel physiology in the olfactory learning pathway of the honeybe. Bernd performs classical, pharmacology-based channel electrophysiology in primary cell culture but complements this technique with pharmacological manipulations of intact animals and then testing them for learning performance. Using these techniques, Bernd presented a cellular working model for learning in the mushroom-body Kenyon cells at the end of his talk.
The second speaker Alexander Kapustjansky talked about in vivo imaging of cAMP levels in Drosophila. He is still in a fairly early stage of his project and started out by telling us that he uses a fluorophor with which he can see the effect dopamine application (bath applied to the brain) on cAMP levels in the mushroom-bodies and that odor application does not show an effect on cAMP levels.
Lasse Bräcker talked about context-specific modification of CO2 avoidance. Flies normally avoid CO2, but if the experimenter changes the context of CO2 perception (e.g., by adding attractive odors), this avoidance can be modulated. He then went on to tell us about a GAL4 screen for defects in CO2 avoidance. They found a decrease in CO2 avoidance if a subset of projection neurons is silenced and when dopaminergic/serotonergic neurons are silenced.
The final speaker of this penultimate session was Paul Szyska. His project is related to the one Dana presented yesterday and looks at trace conditioning in honeybees. Honeybees can solve a trace conditioning task with an ISI of 1-6 seconds, even when tested 24h after training. However, the honeybees do not show any evidence of timing their conditioned response to the arrival of the US as signalled by the CS. The last point he made was that the bees only encode the initial phase of the CS presentation and that inserting a second odor in the gap between CS and US does not disrupt learning.