Single Cell Recordings

​To unravel how compass information is encoded in the brain, we study the insect brain electrophysiologically. To observe the activity of single neurons, we perform intracellular recordings using sharp electrodes. To study if the neurons encode specific orientation cues that we tested behaviorally, we simulate the skylight cues, such as polarized light, or the sun, during recording. In addition to skylight cues, we can also present wind and magentic signals, as well as terrestrial landmark and optic low cues to the insects. After recording, we inject a tracer into the neuron to identify the neuron anatomically and reveal in which brain area the neuron branches.

Left: A tethered Monarch butterfly with an implanted tetrode in its brains (photo: M.J. Beetz)

MultiChannel Tetrode Recordings

We are also monitoring the activity of neurons in the brain using extracellular multichannel tetrode recordings. This has the advantage that we can study the activity of neurons over several hours. In addition, we can perform simultaneous recordings from a population of neurons. Such recordings also allow to perform brain recordings in actively navigating insect.s For instance, we can perform these recordings while a dung beetle is rollling a dung ball in an arena or while a butterfly is tethered to a mounting rod at the center of a flight simulator while presenting simulated orientation cues to the insect.