Neuro- and molecular genetic analysis of complex behavior patterns in Drosophila
Project management at the University of Würzburg:
A new apparatus for odor learning was developed which allows us to do 4 experiments at a time. This version has new, robust shock vials which have the copper wires embedded in the wall of the tube (instead of the rolled-up electric grids). Learning values (performance indices, PIs) are at 0.6 (rather instead of 0.9 of the old apparatus).
We have reinvestigated context generalization and asked whether after a context change that suppresses retrieval of the memory contents, the latter can be retrieved in the old context. It turns out that even in the old context the memory trace gets lost after exposure to the new context. The loss is not immediate. The memory trace is still sigificant at 15 s but not any more at 30 s.
We have received and tested UAS-GAL4 effector constructs for genetic intervention in the mushroom bodies. One, from U. Heberlein (San Francisco), is a newly generated tetanus toxin light chain (TNT) insert which has minimal leakiness and does no obvious harm at its insertion site. This construct is fully viable and has no deleterious effects on olfactory learning by itself. Several mushroom body (MB) GAL4 lines that did not grow with the old constructs do so now with the new one. The other effector gene construct has been provided by T. Kitamoto (Duarte, California) and is a temperature sensitive, dominant negative mutant form of dynamin (shibiri-ts1). Growing GAL4-MB247/UAS- shibiri-ts1 flies at 24°C, testing them, shifting them to 32°C and testing them again, we could show that intervention in the MBs blocks olfactory memory within less than 15 min.
Furthermore we have started to quantify the expression patterns of 40 MB GAL4 lines. This comprises counting the number of Kenyon cells, localizing the clusters of Kenyon cell bodies and measuring the level and distribution of label in the peduncle and lobes. This work will provide a solid base for attributing the various MB dependent behavioral defects to MB substructures.
Projekt period: from 04.2000 to 03.2003
Sonstige öffentliche Mittel ( HFSP ) ,Granting date: 28.03.2000