Roy Ritzmann - US grants

Neural systems are organized to assimilate large amounts of sensory information and utilize it in making choices that result in meaningful behaviors. How such choices are made is central to understanding the function of any of these systems, whether they be complex processing centers such as the mammalian visual system or more simple invertebrate motor control systems. Several escape systems have served as useful models for studying this problem, because of various technical advantages which they offer. Although the neurons that make up an escape system must quickly process large amounts of sensory information in order to identify and react to a potential threat, the complete cellular analysis of the underlying circuitry is a very real possibility. The experiments described in this proposal are designed to take advantage of a particularly useful escape system, that of the american cockroach. The advantages of this system as a model include numerous large identifiable cells, (including the giant interneurons), and a resultant behavior that while reasonably complex is sufficiently predictable to allow extensive quantification. The recent discovery of a group of large thoracic interneurons that are post-synaptic to the giant interneurons means that a complete understanding of the decision making processes at the cellular level may now be possible. Our specific aims are to: (1) determine the manner in which directional sensory information carried in the giant interneurons is deciphered and used to control the directional escape movements, (2) determine the differences between two separate input pathways (the dorsal and ventral giant interneurons) and how one pathway is chosen over the other, and (3) determine the manner in which sensory information from thoracic appendages is used to influence the escape circuitry. All of these objectives will be pursued using intracellular analysis and dye injection techniques. Our hope is that these studies will generate principles regarding the manner in which nervous systems process sensory information and make meaningful decisions important to specific behaviors. Such principles may ultimately be generalized to more complex vertebrate systems which must solve similar problems.

This award provides funds to the Department of Biology at Case Western Reserve University to develop a modern laboratory course in neurobiology for undergraduates. The course will include an introduction to the major concepts and techniques of modern neuroscience. Specifically, it will demonstrate (1) the biophysical properties of the membranes of nerve cells using the techniques of patch clamping, (2) the chemical properties of nerve cells using the techniques of immunocytochemistry, and (3) the electrical properties of nerve cells and their connections using the techniques of electrophysiology. This laboratory will form a central part of a "track" in neurobiology which is currently being implemented by the Department of Biology. It is one of a series of tracks which will involve leading researchers, state-of-the-art equipment, and opportunities for research projects, will attract larger numbers of undergraduates, including women and minorities, into the sciences. Neurobiology is especially effective in drawing students into scientific research because of its focus on the cellular basis of animal land human behavior, and its clinical relevance. The grantee is matching the award with non-Federal sources.

This Integrative Graduate Education and Research Training (IGERT) award supports the establishment of a multidisciplinary graduate training program of education and research merging four existing research groups into a new entity with broad technical expertise yet still sharing a focus on Neuro-mechanical systems. Each existing group has a history of collaboration between various engineering fields and the biological sciences. However, meaningful interactions only came after considerable effort to overcome barriers. The training program will provide a formal process to help graduate students proceed through that process quickly and efficiently. Students in the training program will participate in cross-disciplinary courses and rotate through laboratories in all four fields. A multidisciplinary seminar featuring extended visits from leaders in each field will draw students together. Funds will permit travel to scientific meetings and workshops in each field. A common computer facility and office area will maintain interactions beyond the classroom. Internships in clinical and industrial settings will also be available as options. We have also planned an aggressive recruitment program emphasizing institutions committed to training students in underrepresented groups. Our trainees will graduate with appropriate tools and background necessary to work efficiently in teams. We believe that such an experience will pay great dividends to both the students and the disciplines in which they choose to work.

IGERT is an NSF-wide program intended to facilitate the establishment of innovative, research-based graduate programs that will train a diverse group of scientists and engineers to be well-prepared to take advantage of a broad spectrum of career options. IGERT provides doctoral institutions with an opportunity to develop new, well-focussed multidisciplinary graduate programs that transcend organizational boundaries and unite faculty from several departments or institutions to establish a highly interactive, collaborative environment for both training and research. In this second year of the program, awards are being made to twenty-one institutions for programs that collectively span all areas of science and engineering supported by NSF. This specific award is supported by funds from the Directorates for Biological Sciences, for Engineering, for Computer and Information Science and Engineering, and for Education and Human Resources.

Legged locomotion evolved as the most effective form of movement through difficult environments. Although much research has focused upon control of basic leg movements, it is an animal's capacity to re-direct these movements around unpredicted barriers that makes legged locomotion particularly successful. Upon encountering an obstacle, an animal must evaluate the object with its sensors, then use that information to effectively turn or climb over the barrier. In this project Dr. Ritzmann will examine how insect nervous systems control these movements. He will target specific brain regions with a range of techniques with increasing precision. These techniques include various recording and stimulation procedures combined with high-speed video analysis of behavior. They will allow Dr. Ritzmann to examine just how sensory information is used to generate descending commands that ultimately alter leg movements and, thereby, allow the animal to deal with barriers.
Dr. Ritzmann's project will have wide ranging impacts. The issues of movement through complex terrain confront virtually all legged animals, and similar control systems must be present. In vertebrates, control occurs through interactions between motor regions of the brain, such as the cerebellum, and local circuits in the spinal cord. Nevertheless, the basic control problem is the same as that found in insects, yet insects provide significant technical advantages for the experiments that he will pursue. The control issues must also be solved by robots as they traverse complex and unpredictable terrain. Indeed, failure to deal with such problems limited success of search vehicles in the World Trade Center tragedy. In other projects, Dr. Ritzmann collaborates with engineers in Dr. Roger Quinn's Biorobotics laboratory to develop advanced robotic vehicles based upon biological control that can perform dangerous missions with little supervision. Results from Dr. Ritzmann's project have tremendous potential for improving the designs of these vehicles.

Animals as simple as cockroaches and slugs and as complex as humans all possess similar ways to control how they walk, crawl, swim or fly through earth's many complex environments. Engineers have turned to these natural systems for inspiration in developing robots, hoping to attain the same ease of movement and ability to adapt to any environment on earth (or off of it). The goals of animal motion studies and robotics are clearly complementary and benefit greatly from extended interaction. Although many meetings have limited sessions dedicated to such discussions, the International Symposium on Adaptive Motion in Animals and Machines (AMAM) is uniquely dedicated to intense week long interaction among engineers and biologists. The funds from this proposal will be used to bring young U.S. scientists and engineers (especially female and underrepresented minorities) to AMAM 2008 this June 1-6 at Case Western Reserve University in Cleveland, Ohio. Funds will also be used to support web-based distribution of the meeting to members of the international community and educators who cannot attend the meeting in person. The potential impacts of this meeting include: 1) use of robots as hardware models to promote a greater understanding of how animals (including humans) control their movement through their complex worlds, 2) creation of new walking, crawling, swimming and flying robots that more closely capture properties of animals, and 3) introduction of young developing scientists and engineers to an area of research that relies heavily on collaboration of people with many different skills from many different areas for success. The ultimate goal of this work is to provide highly functional robotic devices to serve human needs, such as search and rescue, environmental monitoring, surveying and many others, as well as greater understanding of animal movement.

This project will examine neural circuits that make up a unique region of the insect brain called the central complex. This large midline brain region is made up of several subunits that each has a columnar anatomy. The repeating units that make up these columns provide a unique opportunity for understanding the underlying neural circuitry. They appear to be involved in processing large amounts of sensory information, then using it to influence movement. A range of electrophysiological techniques will be used to examine how central complex circuits process mechanical information arising from antennal stimulation as well as visual cues. In conjunction with behavioral techniques, central complex processing will be related to actual movements. The results are critical to the understanding of how brain systems influence more immediate local reflex circuits that directly control leg movements in walking, turning and climbing which in insects are found in thoracic ganglia. They will complement recent advances in motor control stemming from neurogenetic techniques from several other laboratories. Indeed, because similar interactions between higher brain systems and local reflexes exist in virtually all legged animals, including vertebrates, the results will have wide ranging neurobiological impact. Moreover, the PI has a long-term commitment to bringing knowledge of biological systems to the design of legged robots. As such, the project should also lead to more advanced robots that can move autonomously through tortuous terrain with less direction from a driver. The project will continue a successful record of training both graduate and undergraduate students. Students will have the opportunity to work directly with senior laboratory personnel on the project and a larger number of students will take part in a novel capstone course that brings together undergraduate biologists and engineers on semester-long projects related to this research.

This project will examine neural circuits that make up a unique region of the insect brain, called the central complex, and will study its role in guiding the insect as it turns to move around barriers. This large midline brain region appears to be involved in processing large amounts of sensory information, then using it to influence movement. The Ritzmann laboratory will employ a range of electrophysiological and behavioral techniques to examine how central complex circuits process mechanical and visual information from antennae and eyes and to identify the neurons that perform these functions. Regions of the central complex will then be reversibly inactivated with local anesthetics to examine their effects on behavior. The results are critical to our understanding of how brain systems influence complex movements. They will complement recent advances in motor control stemming from neurogenetic techniques from several other laboratories. Indeed, because similar interactions between higher brain systems and local reflexes exist in virtually all legged animals, including vertebrates, the results will have wide ranging neurobiological impact. Moreover, the PI has a long-term commitment to bringing knowledge of biological systems to the design of legged robots. As such, the project should also lead to more advanced robots that can move autonomously through tortuous terrain with less direction from a driver. The project will continue the PI?s successful record of training both graduate and undergraduate students and extend this opportunity to pre-college students. Undergraduate and pre-college students will have the opportunity to work directly with graduate students and other senior laboratory personnel on the project under the direct guidance of Dr. Ritzmann. This arrangement generates a unique opportunity for novices to experience research while providing mentorship experience for the senior personnel.

Animal behavior is affected by an individual's internal conditions. For example, as animals feed, their strategies for acquiring food changes. The impact of food odors has a very different effect on a hungry person than one who has just had a large meal. This project brings together laboratories from the Case Western Reserve University Biology department and the Cleveland Museum of Natural History to examine changes in hunting strategy that occur as praying mantises feed. The biology laboratory will examine changes in brain systems that control movement as the insect feeds or receives injections of hormones associated with feeding. Insects provide advantages for monitoring brain activity for long feeding periods. Results will demonstrate how brain systems that are altered by hormones associated with feeding affect hunting and will increase our general understanding of the mechanisms by which hormonal changes alter animal behavior. The museum laboratory will expand the study to a wider range of praying mantis species. The project also has a unique educational component. Project related material will be developed into new high- and middle-school teaching modules for the Cleveland Museum of Natural History's award winning distance learning program, which has reached thousands of students in 48 states. These programs align with Ohio's New Learning Standards. Modules will be offered for free for the duration of the project and 3 subsequent years.

The project focuses on the highly structured central complex insect brain region that has received much recent attention. Numerous forms of sensory information coupled with motor effects and the presence of behaviorally relevant neuromodulators imply an important role for the central complex in behavioral adaptation. Yet, no study has brought all these components together to demonstrate how these brain circuits generate context dependent adjustments in natural behavior. This project seeks do that by relating changes in praying mantis hunt strategies to central complex activity patterns recorded by multi-channel tetrode implants as the hunt takes place in one generalist and two specialist praying mantis species. Tetrode wires will be implanted in the insect's central complex. Then after recovery the subject will be moved to an arena where it hunts either live prey (cockroach nymphs) or artificial prey (moving dots on a computer screen that makes up the floor of the arena). The artificial stimulus allows repeated trials to provide quantitative data on neural activity associated with hunting. Neural and behavioral changes will be documented as physiological state is modified by feeding or insulin injection. Comparative studies will clarify how evolution acts on brain structures to shape behavior for specific niches. Successful completion will be transformative both in our understanding of the central complex's role in behavioral adjustment and, more generally, in defining mechanisms by which brain regions in all animals can alter adaptive behavior, thereby establishing the praying mantis as a new general model for behavioral selection.