Roy E. Ritzmann Professor of Biology Professor of Neurosciences DeGrace Hall, Room 220 rer3@po.cwru.edu 216-368-3554
Research Interests	Courses		Lab Personnel	Publications

Research Interests

Dr. Ritzmann's research is aimed at determining how animals move through the kinds of complex terrain found in natural settings. That is, if an animal wants to get from point A to point B but there are barriers and obstacles in between those points, how does it alter movements to climb over, tunnel under, or go around those objects? We have focused upon insect systems and in particular the cockroach, because they are very agile animals, yet they provide several technical advantages for the kinds of questions that we ask. We use a combination of techniques. First of all we record body and leg movments with high-speed video systems that records at 250 - 1000 frames per second. From these records we can establish the movements of each leg joint in three dimensions with remarkable precision. We can also correlate those movements with electrical activity recorded from nerves or muscles or from individual neurons. The neuromuscular arrangement of insects uses relatively few motor neurons for whole muscles. Indeed, in some cases a large muscle is innervated by only two distinctly different motor neurons. Where this occurs, electromyograms (EMGs) can provide detailed information about individually identified motor neurons.

Currently we are examining three questions. 1. What sensors do cockroaches use to evaluate barrier and how is that evaluation process being carried out. 2. How does the cockroach's brain process that sensory information and generate the necessary changes in movement to get around barriers? 3. How is the information in the higher neural centers used by motor control centers in the thoracic ganglia to alter leg movements and ultimately solve the problems posed by the barriers.

While our studies are aimed at understanding locomotion in complex terrain, the data are also provided to members of Dr. Roger Quinn's Biorobotics laboratory. There it is used in efforts to design and build hexapod robots. Currently the Biorobotics group at CWRU is developing two lines of robotic devices. One is a large vehicle modeled closely after the joints of the cockroach that are essential for agile walking and climbing. The other is a much simpler device that uses biologically inspired principles derived from our insect studies, but implements them in abstract form on a simpler mechanical platform. We have also recently begun a project that uses motor activity recorded from a moving cockroach to control the movement of a robotic leg that was modeled after the front leg of the same species of cockroach. Movies of many of these and other robots can be viewed at the Biorobotics web site (http://biorobots.cwru.edu).

Courses

·        BIOL 216 – Organisms and Ecosystems

·        BIOL 374/474 – Neurobiology of Behavior

Lab Personnel

Senior Research Personnel

      Alan J. Pollack

      Dr. Angela Ridgel

Current Graduate Students

      Laiyong Mu

      Blythe Alexander

Former Graduate Students

      Dr. Martha Tobias

      Dr. Michelle Murrain

      Dr. Janet Casagrand

      Dr. Songhai Chai

      Dr. Andrew Tryba

      Dr. Scott Nye

      Ms. Lynda Dieckman

      Mr. Daniel Greenblatt

      Dr. Paul Schaefer

Selected Publications