Gravity dependence of waves in the retinal spreading depression and in gel type Belousov–Zhabotinsky systems

In this study the influence of gravity on the velocity of propagating waves in excitable media was investigated in the retinal spreading depression (SD) and in gels of the Belousov–Zhabotinsky (BZ) reaction. It is assumed that in both systems diffusion and convection is small. Compared with liquids, convection in a gel should be absent or should be a much less efficient mode of heat and mass transport. Diffusion, though present in a gel, is slower than in a liquid. Nevertheless in both systems gravity dependent effects were found, including even effects in the case of when the g-vector is oriented perpendicular to the plane in which the waves propagate.