Genetics

Question 1

ALS

Answer 1

Alteration of SOD1 GENE that fights DNA damage in neurons

Question 2

Microcephaly

Answer 2

Alteration to ASPM GENE which makes proteins needed for producing new CNS neurons, particularly during development

Question 3

Brain weight at birth

Answer 3

350 grams

Question 4

Brain begins to form…

Answer 4

2 weeks gestation

Question 5

Brain weight at 1 year

Answer 5

1000 grams

Question 6

Adult brain weight

Answer 6

1200 grams

Question 7

Proliferation

Answer 7

Production of new cells

Question 8

Determination

Answer 8

Deciding which type of neuron a given stem cell will become

Question 9

Diffrentiation

Answer 9

Cell develops into a neuron forming dendrites,soma, axon and synapses

Question 10

Synaptogenesis

Answer 10

Formation of synapses

Question 11

Myelination

Answer 11

Process thru which glial cells produce insulating fatty sheaths around the axons

Question 12

Many nerve cells…

Answer 12

Migrate to other areas of the PNS while some remain in CNS

Question 13

How do axons find their way from CNS to appropriate part of the body?

Answer 13

They follow a chemical gradient to determine their target area. They connect with areas of the body that have a similar chemical makeup.

Question 14

Neural Darwinism

Answer 14

Principal that the human NS starts off with more neurons and synapses than necessary and thru a selection process, most successful are kept and others r discarded.

Question 15

How pathfinding happen in PNS

Answer 15

1. When neuron forms a synapse on a muscle, the muscle delivers a protein called nerve growth factor (NGF) a neutrophin promoting the growth of that neuronal connection.
2. If axon doesn’t receive NGF, it gets message that not needed and kills itself thru apoptosis
3. Enables CNS to match number of axons to number of receiving cells and kill off unnecessary neurons.

Question 16

Things NOT DEVELOPED by early infancy

Answer 16

1. Olfactory cells - exposed to toxic chemicals in environment and receptors die. They’re replaced by dividing are, cells in the nose.
2. Hippocampus + BG- they replace appx 2% neurons per year; responsible for new learning

Question 17

CNS = what develops first

Answer 17

Primary sensory areas- hearing, vision, touch etc.

Question 18

CNS- what takes longer

Answer 18

Prefrontal cortex and other cortical areas. Thru adolescence

Question 19

Why adolescence more impulsive and pleasure-seeking? (2)

Answer 19

1. Immaturity of prefrontal cortex
2. Brains response to rewards increases during adolescence

Question 20

Roper v Simmons

Answer 20

Lmaisa 18 y.o. Can’t be executed

Question 21

Closed head injury

Answer 21

1. Rotational forces drive the brain tissue against inside of skull
2. Blood clots form and interrupt blood flow to brain

Question 22

Ischemia

Answer 22

Blood clot or obstruction of artery leading neurons to be deprived of oxygen and glucose

Question 23

Hemorrhage

Answer 23

Ruptured artery causes neurons to be flooded w excess blood, oxygen, calcium, and other chemicals.

Question 24

Edema

Answer 24

Accumulation of fluid in the brain and Impairment of NAK pump leading to build up of sodium inside neuron. This causes glutamate to be released by neuron, leading to overstimulation and damage of neurons and synapses.

Question 25

Diaschisis

Answer 25

Decreased activity of surviving neurons after damage to other neurons

Question 26

Early treatment for strokes

Answer 26

Tissue plasminogen activator - breaks up blood clots

Question 27

Long term recovery

Answer 27

1. Regrowth of axons- damaged axons can grow back in PNS but not CNS
2. Denervation supersensitivity- when a section of synapses get damaged the remaining synapses become more responsive and more easily stimulated to compensate for decreased input. Can lead to strengthening of desirable connections but also increased sensitivity to pain.
3. Collateral sprouting- after a neuron loses input from a damaged neuron, it secretes neurotrophins that induce other nearby axons to form new branches and take over vacant synapses. If the sprouting axons convey info similar to those they replace, this can be very helpful to functional recovery. However, if they convey different information, further interruption of behavior can result.