Aging and Development

Question 1

Neurogenesis

Answer 1

Cells of the neural tube divide to create either progenitor or neuron close to neural tube

Question 2

Radial glial cells

Answer 2

Glia that extend from inner to outer surfaces of growing NS like spokes of a wheel

Question 3

Cell migration

Answer 3

Cells that form in the ventricular layer migrate along the surface of radial glial cells

Question 4

Cell adhesion molecules

Answer 4

Protein that guides cell migration and promotes adhesion of developing NS; an example of cell-cell interactions

Question 5

Differentiation

Answer 5

Cells express genes to make proteins that allow them to acquire their specific appearance and function

Question 6

Experimental data of differentiation

Answer 6

The development of different types of neurons seen in early development

Question 7

Induction in differentiation

Answer 7

The influence of neighboring cells on other adjacent cells

Question 8

Example of induction

Answer 8

The notochord releasing dorsalizing or ventralizing hormones which determines whether a neuron is sensory or motor

Question 9

Regulation

Answer 9

A benefit of induction which allows an adaptive response to early cell injury

Question 10

Synaptogenesis

Answer 10

Establishment of synaptic connections as axons and dendrites form

Question 11

Growth cones

Answer 11

Growing tip of an axon or dendrite

Question 12

Filopodia

Answer 12

Fine extensions that extend from growth cone

Question 13

What role do CAM play in synaptogenesis

Answer 13

Filopodia adhere to CAM released by target nerve cells/tissues, and contract to pull the growth cone in a certain direction

Question 14

Chemoattractants and chemorepellants

Answer 14

Chemoattractants attract certain growth cones while chemorepellants do the opposite

Question 15

Why do we have chemorepellants

Answer 15

Some axons need to stay ipsilateral, so chemorepellants can keep them from crossing the midline

Question 16

Chemoaffinity

Answer 16

A theory for synaptogenesis that states that each cell and target cell have matching chemical identities that guide filopodias

Question 17

Death gene

Answer 17

A gene expressed when a cell decides to commit suicide

Question 18

Caspase

Answer 18

An family of protein-dissolving enzymes that regulate apoptosis

Question 19

Diablo

Answer 19

Released by mitochondria in response to high calcium levels

Question 20

What is the process of cell death

Answer 20

1. Increase in [Ca2+] from extra and intracellular sources
2. High levels of calcium reach the mitochondria and release Diablo protein into cell
3. Diablo binds to an apoptosis inhibitor protein
4. Caspases are no longer blocked, which leads to apoptosis

Question 21

BcI-2 proteins

Answer 21

Proteins that block apoptosis

Question 22

Neurotrophic factors

Answer 22

A chemical made by target structure. If a neuron receives enough neurotrophic factor, it will live and otherwise die

Question 23

Nerve growth factor

Answer 23

Affects the growth of neurons in spinal ganglia and ganglia of sympathetic NS

Question 24

Mechanism of neurotrophic factors

Answer 24

• Neurotrophic factors regulate the expression of various genes which affect neuron development
• Neurons that don’t get enough trophic factor go through cell death
• Amount of neurotrophic factor in cell matches target cell which creates synapse

Question 25

Why does the prefrontal cortex develop last

Answer 25

Synapse rearrangement reoccurs caudal to rostrally

Question 26

Monocular deprivation of cats

Answer 26

Light shone in the deprived eye results in no cell response, while light shone in the normal eye results in normal cell response

Question 27

One eye deviation in cats

Answer 27

Cortical cells only respond to stimulation in one eye or the other

Question 28

Hebbian synapses

Answer 28

Synapses that grow stronger or weaker depending on how it drives the postsynaptic cell

Question 29

Where are multimodal cells found

Answer 29

Deep in superior colliculi

Question 30

Two categories of biological theories of aging

Answer 30

Programmed theory and damage/error theory

Question 31

Three theories of programmed aging

Answer 31

Aging by program, gene theory, autoimmune theory

Question 32

Cholinergic dysfunctions

Answer 32

-Decreased ChAT which catalyzes synthesis of ACh
- Decreased cholinergic neurons

Question 33

Function of scopalamine

Answer 33

An ACh antagonist that artificially disrupts cholinergic function in young subjects and creates impairments similar to the elderly

Question 34

Superoxide

Answer 34

When an oxygen radical receives energy

Question 35

Defense against superoxides

Answer 35

Superoxide dismutase breaks down the superoxide into hydrogen peroxide and oxygen

Question 36

Superoxide damage to cell

Answer 36

Can cause DNA damage in the nucleus & mitochondria and cause cell membrane damage

Question 37

Relationship between free radicals and nerve growth factor

Answer 37

Nerve growth factor suppresses free radical activity

Question 38

What causes cell loss

Answer 38

Could be glia, but it’s definitely not neurons

Question 39

Beta amyloid

Answer 39

Protein that accumulates in small areas of the brain that have abnormal patterns

Question 40

Tau tangles

Answer 40

Tau is a protein associated with abnormal spirals within nerve cells

Question 41

What happens with acetylcholine production in Alzheimer’s

Answer 41

Tau tangles and amyloid plates lead to cholinergic neurons to stop producing ACh