Answer:
Condensation. I believe. No promise if that's right though.
The hear makes sure that oxygen taken in by the lungs gets to the brain.
Although in many regions of the brain—particularly those that give rise to nuclear cell groups—neurons migrate without the benefit of glial guides, migration along radial glial fibers is always seen in regions where cells are organized into layers, like the cerebral cortex, hippocampus, and cerebellum.
