Development of the brain Flashcards
What is proliferation?
The production of new cells.
What are stem cells?
Cells that stay in place and divide, while others migrate.
How do human neurons differ from chimpanzee neurons in proliferation?
Human neurons continue proliferating longer.
What is migration in brain development?
Primitive cells move with guidance from immunoglobulins and chemokines.
What happens if there’s a chemical deficit during migration?
Can cause smaller brain size and intellectual impairment.
What is cell differentiation?
Cells become neurons and form dendrites, axons, and synapses.
What determines neuron function?
When and where they developed.
What is synaptogenesis?
The formation of synapses; continues throughout life.
What is myelination?
Glia form insulation (myelin) around axons.
What did Cajal believe about new neurons?
Brain forms neurons only during early development.
What are exceptions to Cajal’s belief?
Olfactory receptors and some neurons in the hippocampus.
How was new neuron growth detected in adults?
By using radioactive carbon (¹⁴C) in tissues.
What did Paul Weiss’s experiments suggest?
Nerves attach randomly and send various messages (incorrect).
What did Roger Sperry demonstrate with newts?
Axons find their correct targets using surface molecules.
What guides axon pathfinding?
Cell surface molecules that attract or repel.
What is Neural Darwinism?
Neurons compete for targets; appropriate synapses are kept.
What determines which synapses survive?
Their usefulness and input patterns.
What did Rita Levi-Montalcini discover?
Axons survive based on access to nerve growth factor (NGF).
What is NGF?
A neurotrophin from muscles that supports neuron survival.
What happens if a neuron doesn’t get enough NGF?
It undergoes apoptosis (cell death).
What are other important neurotrophins?
Brain-derived neurotrophic factor (BDNF) and others.
What can impair fetal brain development?
Fever, malnutrition, BPA, iron deficiency, thyroid issues, lead.
What is fetal alcohol syndrome?
Caused by maternal alcohol use; leads to cognitive and physical impairments.
What behavioral effect can maternal stress have?
Alters mother’s behavior, affecting child’s behavior.
