Figure 1.

The processes of embryogenesis instructing patterning form a closed-loop control system between the brain and the body. A schematic drawing of a developing Xenopus embryo, representing how the embryonic brain (purple) is receiving instructive inputs from different (distal and proximal) body tissues to help building the right brain parameters (for example, shape and size). We have recently shown that this control operating system is bi-directional. The very early brain itself has, in turn, an instructive role on morphogenesis and patterning of remote tissues, such as peripheral neural network (blue) and somitic myotome (green). This closed-loop between brain and body is the earliest example of scaling and effective communication for self-assembly of complex biological structures.