Us humans do have a rather big brain in comparison to our bodies and most other living creatures. However, regarding the dimensions our thinking can reach, and all the different capabilities of our brain, it suddenly can also seem sort of small from another perspective. That point of view emphasizes its complexity and importance at the same time. The brain works closely with our spinal cord. Together, they form the central nervous system, which is responsible for transforming sensory information about the external world into appropriate motor responses, among other things. The brain and spinal cord work together in controlling physical movements, like walking, and other interaction with our environment. 

When focusing on the neuronal control of locomotion, our goal is to comprehend the principles enabling adaptive walking, including every single step of this process. To research and gain a better understanding of the descending control of walking, we utilize the model organism Drosophila melanogaster. Their well-known genome and the availability of numerous genetic tools make Drosophila very efficient to work with. While the brain contains most of the circuits filtering and processing sensory inputs, motor commands are generated by circuits in the Ventral Nerve Cord – the fly’s version of the spinal cord. Hence, sensorimotor transformation requires a series of connections. The first important link is represented by interneurons, which can be viewed as a reception and transmission center in the brain. They receive input from different sources and transmit to certain recipients, for example different populations of Descending Neurons. Descending Neurons then enable the communication between the brain and the ventral nerve cord – a critical bottleneck. In the ventral nerve cord, the information reaches motor neurons that ultimately synapse onto muscles and generate coordinated movements. 

I am particularly interested in the role of brain interneurons in this process. To identify the particular function of a given neuron, we optogenetically activate them and quantify resulting changes in behavioral output. Thus, we can pick apart neuronal circuits controlling locomotion one neuron at a time. Already very early in my biology studies, I became fascinated with understanding fundamental principles of walking behavior and its origins. For my bachelor’s thesis, I joined the sensorimotor flexibility lab to identify brain interneurons involved in controlling locomotor circuits in detail. To accomplish this, I use patch clamp recordings to characterize the activity patterns of identified neurons that are part of the neuronal architecture controlling adaptive locomotion.