Effects of different gravity conditions on self organizing biological systems

The effects of different gravity conditions on the retinal Spreading Depression (rSD) were investigated. The rSD, an excitation depression wave in retinal tissue is used as an example of self organization and pattern formation in the central nervous system (CNS). The properties of such phenomena depend critically on the parameters of the system, small changes in the system can thus induce significant changes in the propagation properties of the SD. Gravity is a small but permanently stimulus on earth, absence of gravity and amplification respectively may have severe consequences for the function of the brain as an excitable medium. Microgravity experiments were performed on a TEXUS sounding rocket mission (5 min μg) and two DLR parabolic flight missions (20 s μg), hypergravity experiments were performed in the centrifuge in the lab. In this presentation we summarize the effects of altered gravity conditions on different parameters of the rSD. The results are discussed also in their relation to other earlier experiments with propagating action potentials under different gravity conditions. For both self organized biological systems a gravity dependence could be shown.