Thus, an animal must integrate both internal and external cues in order to appropriately alter local systems that re-direct movement. These challenges require changes in leg movements and posture as they execute appropriate maneuvers in the context of ever changing conditions. Overall, our studies suggest that CC circuits may indeed influence the descending commands associated with navigational decisions, thereby making them more context dependent.Īs animals move through their environments, they must negotiate barriers that block their paths toward goals or away from threats. Finally, we are examining these kinds of decisions made in a large arena that more closely matches the conditions under which cockroaches forage. Similar changes were also found in reversible effects of procaine injections in the brain. Electrolytic lesions in restricted regions of the central complex generated site specific behavioral deficits. To further test for a central complex role in these decisions, we examined behavioral effects of brain lesions. Visual and antennal tactile cues are processed within the central complex and, in tethered preparations, several central complex units changed firing rates in tandem with or prior to altered step frequency or turning, while stimulation through the implanted electrodes evoked these same behavioral changes. These multi-sensory behaviors led us to look at the central complex as a center for sensori-motor integration within the insect brain. Similarly, in a T-maze turning is determined by antennal contact but influenced by visual cues. However, ambient light conditions detected by the ocelli can bias that decision. A shelf presents a choice between climbing and tunneling that depends on how the antennae strike the shelf tapping from above yields climbing, while tapping from below causes tunneling. When encountering a large block, the insect uses its antennae to evaluate the object’s height then rears upward accordingly before climbing. In particular, cockroaches use a combination of tactile and visual information to evaluate objects in their path in order to effectively guide their movements in complex terrain. These challenges require directed changes in leg movements and posture performed in the context of ever changing internal and external conditions. 3Mechanical and Aerospace Engineering, Case Western Reserve UniversityA, Cleveland, OH, USĪnimals must routinely deal with barriers as they move through their natural environment. 2Division of Biology, California Institute of Technology, Pasadena, CA, USA.1Department of Biology, Case Western Reserve University, Cleveland, OH, USA.
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