PhD Research

I've recently completed my graduate studies in biology at the University of Washington and am now a postdoc in the Daniel Lab.

My main research interest lies in how animals respond to cues from their environment and how they use this information to successfully navigate through space.

Moth flight control

For my PhD research, I built a flight arena for the large hawkmoth Manduca sexta, in which I can test how mechanosensory and visual inputs are integrated to provide a moth with a reliable flight control system. The setup is very much inspired by the Rock'n'Roll arena in Michael Dickinson's lab at Caltech. See the embedded video below for an animated schematic of what a moth experiences during an experiment.

Moths show very strong abdominal flexion responses that are elicited both by pure visual, as well as pure mechanical rotations. My recent publication (Hinterwirth and Daniel, 2010) describes how the insect's antennae mediate a flexion response of the abdomen when a moth is rotated in space mechanically. This movement of the abdomen (by changing the center of mass with respect to the center of lift) could be used as a brake for rotations of the animal in the pitch axis.

The following video shows how the abdominal angle changes when the moth is watching a periodic, oscillating grating.

Multisensory integration happens at many levels

Animal sensors are often influenced by each other. I have recently started exploring how visual motion might affect mechanosensory organs situated at the base of a moth's antennae. In the next video below, an isolated head of a moth is placed in a visual arena and presented with an oscillating grating. At the same time, I'm recording EMG signals from a tiny muscle at the base of an antenna. As you can see in the evolving traces shown in the video (and hear in the audio), the muscle firing rate is clearly modulated by the up-and-down movement of the pattern. This shows that circuits contained within the head are able to modulate antennal muscle firing, and by extension, antennal position.

The effect of a visual stimulus on antennal position can be more directly visualized by just filming a moth's head from the side with a high-speed video camera. Below is a sample video, in which the moth's head is fixed, and it is forced to watch a strong visual stimulus oscillating around it's pitch axis.

Notice how the antennae move up and down with the same frequency as the visual stimulus. This can be quantified by measuring the antennal angle for each frame and plotting it against the stimulus, as shown in the lower traces in this video. (The visual stimulus is stronger than in the example above, so it's easier to see the antennal movement. It also means the legs of the moth react when the moth "thinks" it's falling, i.e. when the visual stimulus moves upwards.)