Chapter 8 Flashcards
(37 cards)
What is the overall plan of the human brain in terms of individual variation?
The basic plan of the brain is virtually identical from person to person and similar across all mammals.
What primarily determines the brain’s development?
It is largely genetically determined, but electrical activity in early life influences fine details.
What scientific advancement has significantly advanced our understanding of brain development?
The genetic/genomic revolution.
What does the genome provide in development?
A set of instructions for making body organs—not a blueprint.
How is brain formation compared to paper folding?
A small set of instructions (like folds) can generate a complex structure, like the brain.
How many genes are involved in orchestrating development?
About 40,000.
Why is the fruit fly important in neuroscience?
Many genes important for human nervous system development were first discovered in Drosophila.
What makes zebrafish useful in studying brain development?
Their transparent embryos allow cell tracking under a microscope.
What advantage do mice offer in brain development research?
They breed quickly and have a fully sequenced genome.
Why use frogs and chicks?
Their large embryos are ideal for microsurgery, despite limited genetic tools.
What is the first major step in brain development?
Cell division.
What is cell differentiation?
When cells stop dividing and become specific types (e.g., neurons or glia).
What is pattern formation?
The spatial organization of neurons during development.
What happens during week 3 of gestation?
The neural plate forms and begins patterning into the brain and spinal cord.
What structure does the neural plate become?
The neural tube.
What does the front of the neural plate form?
The brain.
What does the rear of the neural plate form?
The spinal cord.
What causes the brain’s regions to form?
Local gene expression in parts of the neural tube.
What happens if the neural tube fails to close at the bottom?
Spina bifida.
What happens if it fails to close at the top?
Anencephaly (no organized brain forms).
What is the main idea behind patterning in the nervous system?
Cells determine their position using axes (front-back and top-bottom).
How do cells “measure” position?
Via gradients of signal molecules secreted from polarizing regions.
What is Sonic hedgehog?
A signaling molecule secreted from the floor plate of the neural tube.
How does Sonic hedgehog guide development?
It affects gene expression based on its concentration, influencing neuron type.
