Dr. Peter Hasenhütl
Center for Neural Circuits and Behaviour
University of Oxford
Dr. Hasenhütl is a postdoctoral fellow in the lab of Gero Miesenböck
at the University of Oxford, where he investigates (i) neuronal
dynamics underlying decision-making, and (ii) the representation of
sleep need in the experimentally-tractable brain of Drosophila
melanogaster. Before joining the Miesenböck lab, Peter completed
the M.D.-Ph.D. Program of the Medical University of Vienna, where
he studied ligand recognition and substrate transport by the serotonin and dopamine transporters.
Programm
Network oscillations as a shared dynamical feature of sleep homeostasis
When faced with the same problem, evolutionarily-distant nervous systems can arrive at surprisingly similar solutions. Sleep homeostasis serves a vital computational function, suggesting that also here, shared dynamical features can be found and abstracted from species-specific implementational details. Indeed, neurons projecting to the dorsal fan-shaped body (dFBNs) of Drosophila encode sleep pressure through oscillations similar to those in the brains of sleeping mammals, but which differ fundamentally in their implementation. The dFBN ensemble contains highly rhythmic cells whose membrane voltages oscillate at 0.2–2 Hz. These dynamics, whose optogenetic replay promotes sleep, rely on direct interhemispheric competition causing the two hemispheres to oscillate in antiphase. The dynamics of this half-centre oscillator persist in awake flies, but increase their power with sleep need. This is mediated through an increase in excitability and by homeostatic depression of their output synapses, as shown structurally, functionally, and through a parsimonious computational model. I will conclude by discussing how the sophisticated toolkit for molecular interventions in the Drosophila brain can be
utilized to answer important mechanistic questions on the cellular, circuit and behavioural levels.
Host: Tibor Harkany
Center for Brain Research
Medical University of Vienna
Spitalgasse 4
A-1090 Vienna, Austria