Area preoptica is located on the border of the basal forebrain. The area is located in front of the hypothalamus region proper, immediately below the commissura anterior and above the optic nerve corset. It is often included in the hypothalamus anteriora/supraoptic part (this is despite the fact that the area of foetal development does not originate from the diencephalon but is part of the telencephalon).
The region includes six core areas:
1/ Nucleus preopticus medianus (midline preopticus nucleus, dorsally in the midline).
2+3/ Nucleus preopticus medialis (inner preopticus nucleus, one right and one left)
4+5/ Nucleus preopticus lateralis (outer preopticus nucleus, one right and one left)
6/ Nucleus preopticus periventricularis