Spacelab Mission D-2 Experiment STATEX "Gravity Perception and Neuronal Plasticity". Comparative Investigations of Near Weightlessness Effects on the Development and Function of the Gravity Perceiving System of Two Waterliving Vertebrates (Xenopus laevis daudin, Oreochromis mossambicus)

Aboard the German-Spacelab-Mission D-2 the joint project "Gravity Perception and Neuronal Plasticity (STATEX II)" (Universities Stuttgart and Ulm, German Aerospace Research Establishment DLR) was performed. STATEX is for STATolith EXperiment. Objects were growing tadpoles of the South African Toad (Xenopus laevis D.) and a juvenile cichlid fish (Oreochromis mossambicus). The paper presents first results of the DLR research prgram and is therefore focused to the frog experiments. The results of the joint spaceflight project shall give a broader base for the understanding of how enviromental stimuli (e.g. linear accelerations) affect the development and funciton of the gravity perceiving systems in these two vertebrates also as models for the respective human vestibulum. Results of expe- riments in hyper-g (up to 5 g), weightlessness simulation (Fast- rotating-clinostat) and parabolic flights are discussed and compared