Research

The waggle dance

Aside from humans, honeybees are the only known species that convey spatial information to conspecifics by using a symbolic communication. The waggle dance takes place on vertical combs inside the hive. The waggle dance is composed of a waggle run in which the bee laterally oscillates her abdomen, followed by a return run. With the waggle dance, the dancing bee communicates distance and direction to a profitable food source (indicated here as three flowers). The waggle run direction relative to the gravity axis is consistent. Notably, this angle matches with the angle between the communicated food source and the solar azimuth. The waggle run duration increases with the flower distance.

Using the waggle dance to study spatial memory

The waggle dance gives us a unique glimpse into the bee's spatial mind. The dancing bee retrieves spatial memory which she has previously acquired during her foraging trip, while recruits acquire spatial memory. This means, we can determine the time points of spatial memory acquisition and retrieval. With behavioral and neurophysiological experiments, we aim to unravel the neural mechanisms of spatial memory by using the waggle dance to access the bee's spatial memory.

Waggle dance recorded and tracked by Leonie Kollek

This project will be conducted in collaboration with Dr. Jaqueline Degen (University of Würzburg, Germany).

Using a flight simulator to study spatial memory

Bees trained to a feeder often pilot between the hive and the feeder. Neural recordings from freely flying insects are not feasible with current state-of-the-art techniques. Contrastingly, brain recordings from tethered flying insects are feasible. We will present a tethered flying bee visual stimuli that are relevant for estimating the flight distance and flight direction. First, we want to test behaviorally whether such a reduced stimulus condition is sufficient for the bee to head into the direction of the feeder.

For the long term, we will present a virtual reality of the bee's natural habitat in which the tethered bee can orient. To this end, we will monitor wing movements online with DeepLabCut live to track the bee's intended steering in real-time. Later, the flight simulator will be combined with tetrode recordings from the central brain of tethered flying bees.

This project will be conducted in collaboration with Prof. Karin Nordström (Flinders University, Australia) and Prof. Tim Landgraf (Freie Universität Berlin, Germany).

Distance coding

To measure the waggle run duration, recruits can integrate acoustic pulses that are emitted by the dancing bee at a constant rate duing the waggle run. When flying, bees estimate their traveled distance by integrating visual optic flow (movement of the visual surroundings induced by self-motion). This means that the bees use two different modalities (auditory and visual stimuli) to process distance information. With intracellular recordings followed by tracer injections, we aim to dissect the neural circuit that integrates waggle-dance related acoustic signals with optic flow information processed in the central brain.

Visualization of a TN neuron that is discussed to play a role in flight distance estimation. (C) insectbrain database data from Stone et al. 2017

This project will be conducted in collaboration with Prof. Hiroyuki Ai (Fukuoka University, Japan) and Prof. Keram Pfeiffer (University of Würzburg).

Studying landmark coding during place learning

By designing different laboratory mazes, we study visual place learning in freely-walking honeybees. By manipulating the visual scene, we study how honeybees use and store visual landmarks.

Studying spatial coding in freely moving bees

With neural recordings from freely walking honeybees, we study how space is represented in the insect brain. In contrast to the recordings conducted in the flight simulator, the honeybees can here freely interact with objects and feeders that are locally dispersed.