2. Neurodevelopment across life Flashcards
(24 cards)
What are the three prenatal stages? (Neurodevelopment B&B)
- Germinal stage
- Embryonic stage
- Fetal stage
At what age is the germinal stage? (Neurodevelopment B&B)
1-2 weeks
At what age is the embryonic stage? (Neurodevelopment B&B)
3-8 weeks
At what age is the fetal stage? (Neurodevelopment B&B)
9-38 weeks
What happens in the germinal stage? (Neurodevelopment B&B)
- Egg and sperm nuclei fuse to form zygote
- Zygote divides through cleavage process to form morula
- Morula divide to form blastocyst
- Implantation to the uterus
What happens at the embryonic stage? (Neurodevelopment B&B)
- Cell development forms three stages layers: ectoderm, mesoderm and endoderm
- Ectoderm folds to form neural tube (eventually becomes CNS)
What happens at the fetal stage? (Neurodevelopment B&B)
- Fertilization occurs and the embryo becomes a fetus
- Structures grow and develop
What are the 6 processes of neurodevelopment? (Neurodevelopment B&B)
- Cell birth/proliferation
- Migration
- Differentiation/maturation
- Synaptogenesis
- Cell death/synaptic pruning
- Myelination
What is the process of cell birth/proliferation? (Neurodevelopment B&B)
- Neural tube lined with stem cells
- Inner stem cells form progenitor cells (neuroblast or glioblast)
- New cells mitigate out of the ventricular zone
What is the process of migration? (Neurodevelopment B&B)
- Primitive neurons express genes allowing them to become a particular cell
- They form an axon and dendrites (allowing them to take shape)
What is the process of differentiation/maturation? (Neurodevelopment B&B)
- Dendritic development (branching and spinal growth)
- Immature cells (stem cells) acquire characteristics of implantation region
What is the process of synaptogenesis? (Neurodevelopment B&B)
- Begins after neurons have differentiated
- Growing end of the axon is the growth cone
- Growth cone develops extensions called filopodia
What is the process of cell death/synaptic pruning? (Neurodevelopment B&B)
- Proteins secreted by target cells promote survival (survival signals)
- No survival signal = cell death (apoptosis)
- To avoid apoptosis, neurotrophins and active communication is needed
What is the process of myelination? (Neurodevelopment B&B)
Speeds up transition of neuronal impulses
What does a neuroblast form? (Neurodevelopment B&B)
Neurons
What does a glioblast form? (Neurodevelopment B&B)
Glia
What is synaptogenesis? (Neurodevelopment B&B)
Formation of synapses between neurons
What is synaptic pruning? (Neurodevelopment B&B)
New connections forming between neurons and discarding old ones
What is apoptosis? (Neurodevelopment B&B)
Cell death
What is myelination? (Neurodevelopment B&B)
Process where glia produce a fatty sheath that covers the axons of neurons
What is spinal bifida? (Neurodevelopment B&B)
The failure to close the neural fold at the level of the spinal cord, which can lead to paralysis or limb deformities
What are the characteristics of fetal alcohol syndrome? (Neurodevelopment B&B)
- Brain abnormalities
- Mental retardation
- Facial abnormalities
What are the causes of fetal alcohol syndrome? (Neurodevelopment B&B)
- Alcohol consumption through pregnancy
- Alcohol interferes with proliferation, migration and differentiation
- Enhances apoptosis
What can cause schizophrenic symptoms in the offspring during pregnancy? (Neurodevelopment B&B)
- Activation of the mothers immune system
- Prenatal maturation
- Substance abuse
- Complications i.e. anoxia
