At approximately day 1

Secondary brain vesicles form: forebrain into diencephalon and telencephalon; hindbrain into myelencephalon and metenchephalon.

Reference

Evans OB, Hutchins JB. 1997. Development of the Nervous System. Chapter 5 In: Haines DE, ed. Fundamental Neuroscience. New York: Churchill Livingstone.

At approximately day 1

Diencephalon develops into epithalamus, thalamus, and hypothalamus, as well as the optic cup (which develops into the optic nerve and retina).

Duration: 1 week

Reference

Evans OB, Hutchins JB. 1997. Development of the Nervous System. Chapter 5 In: Haines DE, ed. Fundamental Neuroscience. New York: Churchill Livingstone.

At approximately day 1

Main structures of the forebrain develop; facial structures develop from mesoderm.

Duration: 4 weeks

Reference

Evans OB, Hutchins JB. 1997. Development of the Nervous System. Chapter 5 In: Haines DE, ed. Fundamental Neuroscience. New York: Churchill Livingstone.

At approximately day 1

Cerebral hemispheres develop into cerebral cortex, subcortical white matter, olfactory bulb/tract, basal gaglia, amygdala, and hippocampus.

Duration: 5 weeks

Reference

Evans OB, Hutchins JB. 1997. Development of the Nervous System. Chapter 5 In: Haines DE, ed. Fundamental Neuroscience. New York: Churchill Livingstone.

At approximately day 1

The pontine flexure divides the hindbrain into the myelencephalon (medulla) and metencephalon (pons and cerebellum) sections.

Reference

Moore KL, Persaud TVN. 1998. The Developing Human: Clinically Oriented Embryology. 6th ed. Philadelphia: WB Saunders Co.

At approximately day 1

Embryonic cerebrospinal fluid begins to form.

Duration: 1 week

Reference

Moore KL, Persaud TVN. 1998. The Developing Human: Clinically Oriented Embryology. 6th ed. Philadelphia: WB Saunders Co.

At approximately day 1

Forebrain (prosencephalon) divides into the telencephalon and diencephalon.

Reference

Larsen WJ. 1997. Human Embryology. New York: Churchill Livingstone Inc.

At approximately day 3

Neurogenesis of cerebellum, through week 40.

Duration: 35 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.

At approximately day 3

Neurogenesis of piriform cortex and septum, through week 9.9.

Duration: 4 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.

At approximately day 6

Neurogenesis of thalamus (through week 9.9), neocortex (through week 14.9) and striatum (through week 18.9).

Duration: 9 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.

At approximately day 6

Neurogenesis limbic cortex, through week 14.9.

Duration: 9 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.

At approximately day 7

Brain stem cranial nerve association nuclei are all distinguishable.

Duration: 1 week

Reference

Larsen WJ. 1997. Human Embryology. New York: Churchill Livingstone Inc.