00:00Welcome to 2 Minute Neuroscience, where I simplistically explain neuroscience topics in 2 minutes or less.
00:04In this installment, I will discuss early neural development.
00:08The development of the nervous system begins at around the third week of embryonic development,
00:12when an area of the ectoderm, or the outer tissue layer of the embryo, thickens and forms what is known
00:17as the neural plate.
00:18This plate begins to fold inward, forming a groove called the neural groove.
00:23The sides of the neural groove, known as the neural folds, begin to come together.
00:27At the end of the third week, the folds will begin to fuse together.
00:31By the end of the fourth week, they have completely fused together to form the neural tube,
00:35which will eventually become the brain and the spinal cord.
00:38As the neural tube closes, bulges and bends begin to appear, and they gradually become more noticeable.
00:43During the fourth week, there are three of these bulges present.
00:46They are called the primary vesicles.
00:48They are the prosencephalon, which will eventually form the cerebrum,
00:52the mesencephalon, which will eventually become the midbrain,
00:55and the rhombencephalon, which will eventually become the rest of the brainstem and the cerebellum.
01:00The end of the neural tube will form the spinal cord.
01:04As the brain continues to develop, two of these vesicles further subdivide to form secondary vesicles.
01:10The prosencephalon forms the telencephalon and the diencephalon.
01:13The telencephalon will become the cerebral hemispheres.
01:16The diencephalon will eventually consist of the thalamus, hypothalamus, and other structures.
01:20The mesencephalon does not subdivide any further, and will become the midbrain.
01:25The robencephalon will subdivide into the metencephalon and the myelencephalon.
01:28The metencephalon will become the pons in the cerebellum, and the myelencephalon will become the medulla.
01:34The spinal cord will still form from the end of the neural tube.
01:38Next, the neural tube will continue to develop to look more like the brain.
01:42The telencephalon will grow more rapidly than other parts of the tube,
01:45and by 11 weeks, the brain will have a similar shape as to what it will at birth.
01:50Although it will continue to develop after birth,
01:52the brain at birth is structurally similar to a fully developed brain.
01:55After birth, the first time we're
01:59creating an anal tube.
01:59You