Prosencephalon

• The procencephalon differentiates into the diencephalon and telencephalon
• The diencephalon develops the optic cups and stalks, pituitary, epithalamus, thalamus and hypothalamus
• The diencephalon consist of a roof plate, floor plate and two alar plates
• The basal plates are lacking in the diencephalon
• The ependymal roof plate becomes the epithalamus, which gives rise to the choroid plexus of the third ventricle. Its most caudal part develops into the pineal gland or epiphysis, which secretes melatonin.
• The alar plates, which form the lateral walls of the diencephalon, are divided into a dorsal and a ventral portion by a deep groove, the hypothalamic sulcus.
• The large thalamic swelling, dorsal to this groove, gives rise to the thalamus. The thalamus serves as a relay center, processing information from subcortical structures before passing it to the cerebral cortex.
• The hypothalamic swelling ventral to the hypothalamic sulcus differentiates into the nuclei of the hypothalamus, which is prominently involved in the control of visceral activities such as heart rate and pituitary secretion.
• The infundibulum develops from the diencephalon
• The infundibulum grows ventrally towards the stomodeum
• The Rathke's pouch consist of ectodermal cells which loses connection to the stomodeum in the 8 week.
• The infundibulum gives rise to the posterior pituitary, called pars nervosa or neurohypophysis
• The Rathk'es pouch gives rise to the anterior pituitary, called pars distalis or adenohypophysis, also gives rise to pars tuberalis and pars intermedia
• Eyes are developed from the diencephalon
• The future eyes first appear during the fourth week as lateral grooves in the presumptive forebrain, the optic sulci
• Once the neural tube is closed, the grooves form the optic vesicles. The vesicles are connected to the third ventricle through a hollow optic stalk. The overlying surface ectoderm is induced to form a thick lens placode as soon as the optic vesicle touches the ectoderm.
• While the optic vesicle invaginates further to become a double-walled, goblet-shaped optic cup, the lens placode invaginates into the optic cups. The invagination of the lens placode leads to the formation of the lens pit, an indentation that is visible on the outside of the embryo. 
• By the end of the fifth week, the lens placode pinches off of the surface ectoderm and forms a hollow lens vesicle that is enclosed by the optic cup.
• The double walls of the cup differentiate into the pigment (outer) and neural (inner) layers of the retina
• The retina layers: outer = pigment, inner = neural
•  Meanwhile, the posterior cells of the lens vesicle start to elongate anteriorly and form long primary lens fibers. By the end of the seventh week, the lens fibers have reached the anterior wall of the lens vesicle: a solid lens has formed.  
• The telencephalon consist of highly modified derivatives of the alar plates and roof plate. The floor plate remains
• In the telencephalon basal plates are lacking
• The lamina terminalis represents the zone of the closure of the anterior neuropore.
• The early telencephalon consists of two bilateral telencephalic vesicles and a median wall called the lamina terminalis
• telencephalic vesicles expand en will become cerebral hemispheres
• Lateral ventricles are an diverticulum of the primitive ventricle of the telencephalon
• The choroid fissue is groove formed from the ependymal roof that is attached to the roof of the diencephalon
• The interventricular foramen is an opening between each lateral ventricle and third ventricle
• The pallium gives rise tot the cerbral cortex, commissures, olfactory bulbs, - tracts and hippocampus.
• The subpallium gives rise to the corpus striatum
• The cortex consists of gray matter that surrounds white matter
• Gray matter = neural cell bodies
• white matter = axons
• The cerbal cortex is initially smooth, but begins in week 18 tot aquire the patter of grooves (sulci) and concolutions (gyri)
• The central sulcus separates the motor areas of the cortex (rostral to the central sulcus) from the sensory areas of the cortex (caudal to the central sulcus)
• The hippocampus is involved memory retention, spatial memory, survival behavior and olfaction (smell perception).
• The cerebral commissures are three bundles of nerve fibers that connect corresponding areas, all formed in the lamina terminalis
• The corpus callosum is the most important connection between the right and left halves of the adult brain
• The subpallium differentiates into the corpus striatum