At approximately day 1

Invaginations of mesenchymal epithelial tissue, then blood vessels, forms the choroid plexus; choroid plexus continues to develop until birth.

Duration: 31 weeks

Reference [PubMed Link]

Dziegielewska KM, Ek J, Habgood MD, Saunders NR. 2001. Development of the choroid plexus. Microscopy Research and Technique 52(1):5-20.

At approximately day 1

Neurogenesis of hippocampus, through week 35.9.

Duration: 28 weeks

Reference [PubMed Link]

Bayer SA, Altman J, Russo RJ, Zhang X. 1993. Timetables of neurogenesis in the human brain based on experimentally determined patterns in the rat. Neurotoxicology 14(1):83-144.