is higher than that of the more posterior ganglia. In addition, inhibitory interneurons in the lamprey project 14-20 segments caudally but have short rostral projections. Sensory feedback may be important for appropriately responding to perturbations, but seems to be less important for the maintenance of appropriate phase relations. Robotics Based on biologically hypothesized connections of the central pattern generator in the salamander, a robotic system has been created which exhibits the same characteristics of the actual animal. Electrophysiology studies have shown that stimulation of the mesencephalic locomotor region (MLR) located in the brain of the salamander produce different gaits, swimming or walking, depending on intensity level. Similarly, the CPG model in the robot can exhibit walking at low levels of tonic drive and swimming at high levels of tonic drive. The model is based on the four assumptions that: Tonic stimulation of the body CPG produces spontaneous traveling waves. When the limb CPG is activated it overrides the body CPG. The strength of the coupling from the limb to the body CPG is stronger than that from body to limb. Limb oscillators saturate and stop oscillating at higher tonic drives. Limb oscillators have lower intrinsic frequencies than body CPGs at the same tonic drive. This model encompasses the basic features of salamander locomotion. See also Animal locomotion Aquatic locomotion Locomotion in space Locomotive Robot locomotion Terrestrial locomotion References External links Biologically Inspired Robotics Group @ EPFL Center for Biologically Inspired Design at Georgia Tech Functional Morphology and Biomechanics Laboratory, Brown University Peristalsis Robot Snake Locomotion Research for this Wikipedia entry was conducted as a part of a Locomotion Neuromechanics course (APPH 6232) offered in the School of Applied Physiology at Georgia Tech Animal locomotion Wave mechanics