Neuromodulatory and sensory-motor networks in insects
Active locomotion is a feature of all animals, and to achieve this animals have developed (i) muscles which are innervated by excitatory motor neurones, inhibitory neurones and neuromodulatory neurones, (ii) sensory receptors that monitor the effects of movements, ...
The flight performance of mutant Drosophila that lack octopamine
Recently, in collaboration with Prof. Dr. Carsten Duch (Tempe, Arizona, USA) and PD Dr. Björn Brembs, Berlin, Frauke Christiansen carried out her Diploma thesis on mutant Drosophila that lack the Tyramine-beta-hydroxylase gene, and therefore cannot produce octopamine but ...
Tyramine is a precursor of octopamine and an independent transmitter.
Recently we used antibodies against tyramine and octopamine to label the distribution of the respective neurones in the brain and all segmental ganglia, We found pure tyraminergic neurones predominantly in the brain, and a relative small number in fused segmental ganglia.
Neuromodulatory terminals: their function, morphology and ultrastructure (DFG-project in collaboration with the group of Stephan Sigrist at FU Berlin).
This project tries to reveal the function, morphology and ultrastructure of neuromodulatory terminals on target muscles. In the fruit fly (Drosophila melanogaster) motor terminals or neuromuscular junctions between glutamatergic motor neurones and muscles form type I- terminals and those of tyraminerghic/octopaminergic neuromodulatory neurones form type II-terminals.
Electrical and cellular properties of identified DUM neurons and optophysiological recordings
According to our results octopaminergic DUM/VUM neurones are divided into subpopulations that are specifically recruited (activated or inhibited) during motor behavior, that behave very differently to sensory stimulation and that also exhibit different electrical properties.
Development of sensory hairs and their first order interneuron
We also examine the postembryonic changes of a sensory-motor circuit in locusts which is used for flight steering in the adult animal. Detailed studies are concerned with the organisation of the receptive field of an identified ventral cord interneurone (A4I1), and how hormones and ...
Last but not least, we are interested in the behavioural function of identified circuits which may change during development of hemi- or holometabolous insects and during evolution. They may be very conserved in different species, or they may have undergone interesting adaptive changes.