Deck 3: Development, Degeneration and Recovery of the Nervous System

Question 1

Which of the following statements about human brain development is correct?

A) Cells which will go on to produce those that form the foetal brain are not identifiable until week 3 after fertilisation of the egg.
B) Differential gene expression is only observed once cells begin to undergo differentiation into mature neurons.
C) Glial cells are not produced until mature neurons have been produced.
D) The cellular and molecular processes that underpin early human brain development are unique to humans.

Answer 1

A

Question 2

Neural induction is the process where ______.

A) a region of the ectoderm forms the neural plate
B) neurons first start to fire action potentials
C) the basic structural plan of the brain is visible
D) the first structurally mature neurons are identifiable

Answer 2

A

Question 3

Which of the following statements about the process of neurulation is correct?

A) All the cells involved express the same genes.
B) Any error in this process is incompatible with life.
C) It is complete by about 4 weeks after fertilisation of the egg.
D) It is only involved in formation of the spinal cord.

Answer 3

C

Question 4

In the context of brain development, differentiation refers to the process of ______.

A) expression of a subset of the cell's genes as appropriate to the cell's function
B) initiating action potential firing
C) massive expansion in cell numbers
D) the movement of cells to the anterior end of the embryo

Question 5

A teratogen is ______.

A) a substance released by a presynaptic cell when it reaches its target neurons to induce synapse formation
B) a substance that interrupts proliferation or migration of cells during brain development
C) the name for a form of glial cell that acts as scaffolding during development
D) the general name for a gene involved in development which is mutated

Question 6

Which of the following statements about axon guidance is correct?

A) It is an evolutionarily recent process.
B) It occurs whilst the immature neurons are migrating to their final destination.
C) It relies on glia to produce a physical track for the axons to follow.
D) The growth cone expresses receptors that allow it to interact with specific substances in the environment.

Question 7

For accurate synaptogenesis, which of the following does NOT have to occur?

A) exchange of signals between pre- and postsynaptic neurons
B) firing of action potentials in the postsynaptic neuron
C) presynaptic axons being guided to the correct target
D) retraction of some synapses

Question 8

The purpose of synaptic remodelling during early brain development is thought to ______.

A) cause the parent neuron to die, thus saving resources
B) enable fully formed circuits to be present in the brain at birth
C) ensure that the brain is not too big for the head to pass through the birth canal
D) remove dysfunctional synapses

Question 9

Which of the following statements about the fully-formed brain is correct?

A) All neurons that are born during development can be found in the brain of a newborn.
B) Axons that were unable to locate the correct target cells can induce changes in the gene expression of their parent neuron.
C) Synapse formation can be influenced by the individual's experience in their early years.
D) Synapse formation is complete by the late teenage years.

Question 10

Myelination occurs ______.

A) as soon as neurons are born during the proliferation phase
B) for some considerable period of time postnatally
C) once all synapse formation has ceased
D) while axons are extending towards their targets

Question 11

The brain is thought to be at its maximum size at about the age of 20 because ______.

A) all synaptic formation ceases at this age
B) at this age the brain has its maximum number of neurons, synapses and myelinated axons
C) neurons are only produced to replace ones that have died
D) the skull cannot expand to house a bigger brain

Question 12

Which of the following statements about neurodegeneration is correct?

A) It is caused by a genetic mutation.
B) It only involves retraction of synapses.
C) It always results in loss of discrete neuron populations.
D) The deficits produced will be determined by the location of the degeneration.

Question 13

Which of the following statements about Parkinson's disease is correct?

A) Environmental factors impact on the likelihood of someone developing the disease.
B) It is a monogenetic condition.
C) It results in the mass death of neurons by necrosis.
D) The primary pathological feature is loss of synapses in the cortex.

Question 14

Huntington's disease ______.

A) is a monogenetic condition
B) occurs following exposure of an individual to environmental heavy metals
C) produces different symptoms in different people due to the random loss of neurons
D) results in death of neurons throughout the brain by necrosis

Question 15

Functional recovery following neuronal damage in the nervous system is ______.

A) impossible in the central nervous system because the cell bodies die
B) inhibited in the peripheral nervous system due to the actions of the glia
C) limited in the central nervous system because the glia suppress axon regrowth
D) only possible in the peripheral nervous system because no new neurons can be born in the postnatal brain

Question 16

To increase the chances of neuronal repair in the adult central nervous system, we could ______.

A) enhance the activity of growth cones
B) induce neuronal proliferation in the ventricular zone
C) inhibit the glial processes that suppress regeneration
D) remove all microglia

Question 17

Stem cells are required for neurogenesis because ______.

A) they are able to inhibit glial activity in the brain
B) they are found in regions of the brain that are often damaged
C) they can act to guide the migrating immature neurons
D) they have the potential to divide to form new stem cells and immature neurons

Question 18

The neurogenic capacity of the adult human brain ______.

A) is extensive, but the neurons produced are unable to form functional connections
B) is related to the age of the individual
C) is responsible for producing brain tumours
D) is sufficient to account for the relatively low incidence of human neurodegenerative disease

Question 19

Evidence for neurogenesis in adult brains can be obtained by ______.

A) looking for evidence of incorporation of a marker into DNA
B) measuring brain size
C) observing any signs of functional recovery following neurodegeneration
D) recording electrical activity form individual neurons

Question 20

Which of the following statements about our ability to increase the neurogenic capacity of the brain is correct?

A) It will not solve the problem of neuronal loss because the new neurons also need to be functional.
B) It will only be important for situations where neurons die due to apoptosis.
C) It will only produce functional recovery in the brains of young children.
D) We will also need to find ways to increase the capacity of the brain to produce glia.

Question 21

Give an overview of the processes that occur in early embryonic brain development.

Question 22

Discuss how the processes of neuronal proliferation and migration are involved in brain development and, using examples, explain how disruption to these processes may result in dysfunction.

Question 23

Discuss how the potential for synaptic change contributes to brain function and the potential for dysfunction both during development but also in adulthood.

Question 24

Neurodegenerative diseases are devastating for the individual and their carers. What is the potential for preventing, halting or even reversing these conditions?

Question 25

Experimental evidence suggests that neuronal repair and replacement leading to functional recovery is possible in the peripheral nervous system. Discuss the extent to which the same is true for the central nervous system, explaining why any differences might arise.