Investigation of Cavity Development in a Cellular Spheroid Depending on the Mechanisms of Active Intercellular Interactions

The problem of the evolution of a cavity formed at the initial moment of time in the central part of a spherical cellular aggregate is solved. The earlier-developed model of a biological medium formed by cells displaying mechanical activity and an extracellular fluid is used in studying the influence of different mechanisms of active intercellular interactions (chaotic and directed nonlocal) on the propagation of a front separating the cellular medium and the fluid. Numerical solutions show that in certain cases characterized by the fluid pressure and the density of the initial cell distribution the chaotical activity of the cells alone is sufficient for increasing the radius of the internal cavity. In other cases, the cavity development is impossible without the participation of the nonlocal mechanism of active interactions between the cells and the outer boundary. In the absence of the interaction between the cells and the outer boundary the nonlocal mechanism of active intercellular interactions does not lead to the cavity growth for any its initial dimensions. The formulation and solution of the problem describe more completely the possible scenarios of the morhogenesis at one of the earlier stages of the embryonic development.