The Sector in neuromythography represents a gross anatomical compartment. These include forebrain, hindbrain, DiMes (the unified diencephalon and midbrain), the ventricles, and neural crest. We separate out the subpallium and pallium from the forebrain as sectors, even though they are considered part of the forebrain (more specifically, outgrowths of the second prosomere hp2).
We also include the ectoderm, endoderm, and mesoderm as containers for body organs, which are included in the model in order for them to participate in the connectivity network with directly-connected brain areas.
Sectors are the top level in the neuromythography brain hierarchy. They contain Zones.