PNB 2XB3 - Neural Development
Spina bifida - ✔️✔️neural tube fails to close caudally
- risk factor: insufficient folate (vitamin B9) consumption during pregnancy - needed for
production of DNA and RNA and for mitosis
- exposed nerves can result in infection, affect bladder and bowel function, and
paralysis
Day 20 of gestation - ✔️✔️neural groove develops; part of the mesoderm becomes
somites which become bones
Pluripo Endoderm - ✔️✔️lung, gut, and liver (inside layer)
tent - ✔️✔️potential to become any type of cell
Neuroectoderm - ✔️✔️in the ectoderm; becomes the nervous system
(Embryonic) Stem Cells - ✔️✔️precursors to all types of cells
Ectoderm - ✔️✔️brain and skin (outer layer)
Mesoderm - ✔️✔️muscle, blood, bone, cartilage (middle layer)
Germline - ✔️✔️sperm and eggs
Mitosis - ✔️✔️process of one cell dividing in two
Day 18 of gestation - ✔️✔️neural plate develops
Neurulation - ✔️✔️formation of the neural tube that becomes the nervous system
Floorplate - ✔️✔️the midline part of the neural tube (lines the neural tube)
Day 22 of gestation - ✔️✔️development of the neural tube
Roofplate - ✔️✔️closes the tube and lines it with the floorplate; facilitates differentiation
of cells
Day 24 of gestation - ✔️✔️beginnings of the CNS (neural tube), PNS (neural crest),
skeleton and axial muscles (somites)
, Spina bifida occulta - ✔️✔️more mild form of spina bifida where nerves don't protrude
through skin - often no symptoms
Anencephaly - ✔️✔️neural tube fails to close rostrally
- risk factor: insufficient folate consumption during pregnancy
- most of the brain doesn't form - baby typically doesn't live long after birth
Symmetrical division - ✔️✔️makes 2 neural stem cells
Cell migration - ✔️✔️the directed movement of a single cell or multiple cells in
response to a mechanical/chemical signal
- in embryo develop - used to develop different parts of the body
- in adult organisms - used for tissue and wound repair, homeostasis, immune
responses to infection
X-Linked Lissencephaly - ✔️✔️- cell migration disorder where the whole brain or parts
of the brain appear smooth
- symptoms: eating or swallowing difficulty, seizures, intellectual impairment
- x-linked chromosome gene - mutation of doublecortin (DCX) - affects males more than
females
- in males - migration of all neurons is affected
- in females - some neurons stop migrating early - results in layers of neurons
misplaced in the white cortical matter, appearance of two cortices
Growth cones - ✔️✔️- make axons grow
- advance at speeds of 0.5-2 mm/day
- have Ca++ ion channels - intracellular [Ca++] regulates growth cone extension
Chemoattractants - ✔️✔️attract certain growth cones to keep them growing in a certain
direction
Chemorepellents - ✔️✔️repel certain growth cones to keep axons growing in a certain
direction
Axon guidance factors - repellents - ✔️✔️- some guidance molecules repel axons by
having high concentrations of some ions
- i.e. nephrin and slit are long-range repellents
- short-range repellents are based on things that are attached
Contact attractants/repellents - ✔️✔️guidance molecules that attract or repel without
concentration gradients - have to touch the molecule to be attracted/repelled (i.e.
ephrins are contact repellents)
Spina bifida - ✔️✔️neural tube fails to close caudally
- risk factor: insufficient folate (vitamin B9) consumption during pregnancy - needed for
production of DNA and RNA and for mitosis
- exposed nerves can result in infection, affect bladder and bowel function, and
paralysis
Day 20 of gestation - ✔️✔️neural groove develops; part of the mesoderm becomes
somites which become bones
Pluripo Endoderm - ✔️✔️lung, gut, and liver (inside layer)
tent - ✔️✔️potential to become any type of cell
Neuroectoderm - ✔️✔️in the ectoderm; becomes the nervous system
(Embryonic) Stem Cells - ✔️✔️precursors to all types of cells
Ectoderm - ✔️✔️brain and skin (outer layer)
Mesoderm - ✔️✔️muscle, blood, bone, cartilage (middle layer)
Germline - ✔️✔️sperm and eggs
Mitosis - ✔️✔️process of one cell dividing in two
Day 18 of gestation - ✔️✔️neural plate develops
Neurulation - ✔️✔️formation of the neural tube that becomes the nervous system
Floorplate - ✔️✔️the midline part of the neural tube (lines the neural tube)
Day 22 of gestation - ✔️✔️development of the neural tube
Roofplate - ✔️✔️closes the tube and lines it with the floorplate; facilitates differentiation
of cells
Day 24 of gestation - ✔️✔️beginnings of the CNS (neural tube), PNS (neural crest),
skeleton and axial muscles (somites)
, Spina bifida occulta - ✔️✔️more mild form of spina bifida where nerves don't protrude
through skin - often no symptoms
Anencephaly - ✔️✔️neural tube fails to close rostrally
- risk factor: insufficient folate consumption during pregnancy
- most of the brain doesn't form - baby typically doesn't live long after birth
Symmetrical division - ✔️✔️makes 2 neural stem cells
Cell migration - ✔️✔️the directed movement of a single cell or multiple cells in
response to a mechanical/chemical signal
- in embryo develop - used to develop different parts of the body
- in adult organisms - used for tissue and wound repair, homeostasis, immune
responses to infection
X-Linked Lissencephaly - ✔️✔️- cell migration disorder where the whole brain or parts
of the brain appear smooth
- symptoms: eating or swallowing difficulty, seizures, intellectual impairment
- x-linked chromosome gene - mutation of doublecortin (DCX) - affects males more than
females
- in males - migration of all neurons is affected
- in females - some neurons stop migrating early - results in layers of neurons
misplaced in the white cortical matter, appearance of two cortices
Growth cones - ✔️✔️- make axons grow
- advance at speeds of 0.5-2 mm/day
- have Ca++ ion channels - intracellular [Ca++] regulates growth cone extension
Chemoattractants - ✔️✔️attract certain growth cones to keep them growing in a certain
direction
Chemorepellents - ✔️✔️repel certain growth cones to keep axons growing in a certain
direction
Axon guidance factors - repellents - ✔️✔️- some guidance molecules repel axons by
having high concentrations of some ions
- i.e. nephrin and slit are long-range repellents
- short-range repellents are based on things that are attached
Contact attractants/repellents - ✔️✔️guidance molecules that attract or repel without
concentration gradients - have to touch the molecule to be attracted/repelled (i.e.
ephrins are contact repellents)
