Stefan Dahlhoff (Postdoc)

Animal behavior needs to be flexible and adaptive to changes in the environment, but behavioral decisions also need to take changing internal demands into account. Environmental factors such as incoming predators can trigger escape behaviors, for example, while internal demands, like hunger, can increase food-searching behavior. To achieve appropriate behavioral selection under various, complex conditions, multiple sensory inputs must be received and integrated by neuronal circuits in the brain in a context-dependent manner. 

Stefan is studying this context-dependent integration of sensory stimuli by neural circuits and the resulting behavioral responses. He is focusing on descending neurons, which play a major role in eliciting behaviors by controlling and modulating activity pattens in motor networks of the ventral nerve cord (the analogue to the vertebrate spinal cord). In certain behaviors, such as landing, these neurons are gated by the behavioral state of the fly. If the fly is in a state where landing is inappropriate the neurons controlling landing are decoupled from visual stimuli thereby preventing undesired behavioral responses. To elucidate whether state-dependent modulation of descending neurons is a general mechanism mediating action selection, and how this modulation is achieved, Stefan uses in vivo whole-cell patch clamp recordings combined with optogenetic tools and behavioral analysis. 

Stefan holds a B.Sc in Applied Biology from the University of Applied Sciences Bonn Rhein-Sieg and a M.Sc in Life and Medical Sciences from the University Bonn. He did his PhD in the group of Prof. Kittel at the Institute of Animal Physiology. His thesis focused on metabotropic mechanosensation in chordotonal organs of Drosophila larvae.

Prof. Dr. Tanja Godenschwege (Visiting Scientist)

Tanja is a visiting Professor from Florida Atlantic University. We’re collaborating on a project that investigates the role of G protein-coupled receptors in regulating neuronal activity which, according to Tanja, makes us finally do ‘proper mechanistic neuroscience’. Apart from sharing her expertise on sub-cellular signaling pathways, Tanja helps us push our fly game.

Fathima Mukthar Iqbal (PhD Student)

Fathima’s interest lies in studying the neural circuits underlying the plethora of behaviours displayed by animals. She is especially fascinated by how different complex behaviours are adapted to changes in the environment. 

The fact that the basic units of the brain are separate, discrete cells was still debatable in the late nineteenth century, although vast advances had already been made in understanding many other physiological aspects of our body. What makes the brain so difficult to decipher is its anatomical and functional complexity. One approach to understanding the functional principles of the organ that determines who we are and how we perceive and interact with the world is to study numerically simpler brains, which are nonetheless capable of producing and controlling complex behaviours.

Currently, Fathima is studying the descending pathways that convey information about the environment from sensory organs and central brain circuits to lower motor centers in flies, with a focus on how these descending pathways control and execute locomotion. At present, she is building different setups and standardizing protocols that will allow her to optogenetically manipulate various descending neurons to study more closely the flexible control of locomotion in flies and she is in absolute awe of it. Once our protocols and setups are established, Fathima’s experiments will help us develop a better understanding of how descending pathways modify and direct the ongoing behaviour.

Fathima hails from the southern part of India. She holds a bachelor’s degree in Botany and Biotechnology from Mahatma Gandhi University, Kerala and a master’s degree in Biotechnology from the Cochin University of Science and Technology. As part of her master’s thesis, she worked on developing a new method to probe exclusively the post-ingestive nutrient sensing in flies using liposomes with Dr Gaurav Das, NCCS, Pune and Dr Sneha Bajpe, Symbiosis International, Pune. She continued the work at the NCCS with the same group before moving to Würzburg to embark on her PhD project.

P.S: Fathima considers reading literary fiction as her sport and was delighted to find out about the big library on the campus in Würzburg. Recently, she has also re-invented her interest in gaming.

Federico Milani (PhD Student)

One of the most complicated and intriguing objects known to humanity can be found right inside our own head: the human brain. Despite the fact that humans have been fascinated with their brain for centuries, even simple nervous systems, like those of a worm or a fly, remain beyond our grasp. In the last decades, a huge effort has been made to advance our knowledge about the nervous system, but we are still a long way from being able to claim that we ‘understand’ the brain. Studying the brain remains challenging because the experiments we can carry out with the available techniques focus either on single neurons with a high level of precision, or on larger networks and brain areas at the price of losing information about sub-threshold neuronal dynamics. Unfortunately, most of the functions of the nervous system arise from global network activity, but we cannot record all the neurons with high precision at the same time. In this situation, computational models come to our aid, allowing us to develop an insight into the properties of neural networks at a global level, which are difficult or impossible to measure with empirical approaches. These data can then be exploited to ­design better experiments and to create new, improved hypotheses about network functions.

Modulatory neurons are key to understanding complex neural networks since they enable flexible, adaptive processing of external sensory cues and internal state signals. Since the complexity of these systems is quite high, Federico’s goal is to develop a computational model to understand how the ensemble of neuromodulators acts together to mediate flexible sensorimotor processing and adjust the metabolism of flies to ever-changing external and internal demands. To this end, Feffo is combining patch-clamp recordings from modulatory neurons and sensorimotor pathways with Hodgkin-Huxley type modeling approaches. 

Federico holds a Bachelor’s degree in Natural Sciences and a Master’s degree in Neurobiology from La Sapienza-University of Rome, Italy. He also attended a one-year master course at the Advanced School in Artificial Intelligence (AS-AI) held by the Institute of Cognitive Sciences and Technologies, National Research Council (CNR-ISTC) of Rome. Thus, he acquired the necessary skills to complete his MSc thesis in computational neuroscience under the supervision of Dr. Gianluca Baldassarre in the same institute (CNR-ISTC).

Dr. Sander Liessem (Postdoc)

Locomotion needs to be adjusted to ever-changing environmental and internal demands. For example, animals need to respond to obstacles or conspecifics in their path and integrate a range of sensory information to navigate them, for instance by walking around the obstacle or waiting for the conspecific to pass. To this end, information from diverse and distinct sensory modalities, such as vision or mechanosensation, is integrated by brain circuits, and converges onto a relatively small population of descending neurons. These “output neurons” of the brain communicate with motor centers in the ventral nerve cord, where they control various behaviors, such as curve walking or stopping, an thus adapt motor programs to cope with changes in the environment. To deliver insights into fundamental principles facilitating this sensorimotor flexibility, Sander is combining various techniques such as whole-cell patch clamp recordings, optogenetics, and behavioral analysis.

After finishing his Bachelor’s thesis at the Max Planck Institute for Neurological Research, Sander pursued his postgraduate studies at the University of Cologne where he qualified for the Fast-Track Masters/Doctoral program. He earned his PhD in neurobiology in Ansgar Büschges’ and Reinhard Predel’s Labs. His thesis focused on the identification and role of neuropeptides in insect motor control.

Rituja Bisen (PhD Student)

Rituja has always been intrigued by the complexity of the brain: How does the state of mind affect our behavior? What are the neural mechanisms underlying decision making? What is the role of the environment in shaping our behavior? To answer some of these questions in her PhD project, Rituja is investigating how sensory inputs and internal states are integrated to shape the activity of neuronal networks in the Drosophila brain. Currently, she is spending most of her time befriending fruit flies and convincing them that it makes absolute sense to expose their brains to her, so that she can access their neurons and perform patch-clamp recordings.

Rituja holds a B.Sc in Biochemistry, Genetics and Biotechnology from Bangalore University, India and an MRes in Tissue Engineering and Regenerative Medicine from the University of Manchester, UK. Later, she moved to Germany to pursue her postgraduate studies and obtained a Masters in Molecular and Developmental Stem Cell Biology from Ruhr University Bochum. She carried out her master‘s thesis titled, “Effect of BAP1 mutations on DNA methylation pattern in human iPSCs” in Dr. Steenpaß’s lab at the Institute of Human Genetics, Essen.

Dr. Jan M. Ache (PI)

To ensure survival in an ever-changing, complex world, animal behavior needs to be flexible and adaptive. Nervous systems have evolved to enable behavioral responses to a wide variety of sensory stimuli, but the adequate behavioral response to a given stimulus is highly context-dependent, and behavioral or internal states accordingly affect sensorimotor processing. For example, locomotion modulates responses of visual neurons, and hunger increases food-searching behavior and shifts taste preferences. Despite their ubiquitous importance, the neural mechanisms enabling context-dependent sensorimotor flexibility are not well understood. The Ache Lab for Sensorimotor Flexibility aims to discover fundamental principles of motor control, in particular with regard to sensorimotor flexibility, by leveraging the power of neurogenetics, electron microscopy-based circuit reconstruction, and in-vivo patch-clamp recordings in behaving Drosophila.

Photorealistic painting of Jan by the talented (Mar)Tina Held.

Dr. Martina Held (Postdoc)

To initiate and control adaptive, context-dependent behavior instantaneously the brain needs to process and integrate a barrage of inputs from various sources with extremely high speed and accuracy. These inputs include complex, multimodal sensory cues from the environment, such as the visual scenery, or an odor plume, as well as intrinsic feedback about the animal’s state. Intrinsic feedback is mediated, for example, by ascending neurons which provide information about the state of the locomotor system. In order to generate appropriate behavioral responses to all this information impinging on the brain simultaneously, a relatively small number of descending neurons, which elicit and control locomotion responses, receives input from numerous sensory processing neurons. So far, the neuronal pathways underlying this process and their connectivity patterns remain largely unknown.

Therefore, Martina’s main research interest lies in the neuronal translation of sensory input to behavioral output, in particular in internal feedback loops that enable state-dependent responses of the system. By combining visual stimulation with two-photon calcium imaging in behaving fruit flies and optogenetic manipulation techniques, Martina is investigating the neuronal processes in populations of neurons that are involved in multimodal integration. In addition to imaging populations of neurons, she acquires data on the single cell level via patch clamp recordings. Comparing findings from single cells to population data will help us understand the neuronal processes underlying context-dependent action selection. 

Martina holds a BSc. in Biology and an MSc. in Organismic Biology from the University of Marburg. As a PhD student, she moved to Würzburg with the lab of Keram Pfeiffer, where she worked in the Department for neuroethology. During her PhD, Martina spent 10 months at HHMI’s Janelia Research Campus as a visiting scientist. She earned her PhD in neurobiology from the University of Marburg with her thesis focusing on anatomical and physiological investigations of the sky-compass system in honeybees and desert locusts.

Dr. Alex S. Chockley (Postdoc)

Alex’s main research interests lie in how animals select behaviors and movements from the entire repertoire available to them at any time. The neural pathways for all behaviors that an animal can perform are always present, yet the nervous system successfully and reliably “selects” those that are most appropriate given the context. This involves an intricate interplay between sensory information, originating both externally and internally, and the state of the animal. Alex is curious to find which of these myriad, dynamic sensory and state signals are most relevant for the elicitation of certain behaviors and how these signals influence the underlying neuronal circuitry.

A native of the United States, Alex moved to Germany to pursue his graduate education in Neuroscience after receiving his B.S. in Zoology from Michigan State University.  He earned an M.Sc. in neurosciences from the University of Bonn, after which he moved on to do a Ph.D. at the University of Cologne. His dissertation work in the Büschges Lab focused on sensorimotor integration between leg proprioceptive signals and locomotor networks.