Chapter 5

Question 1

Proliferation

Answer 1

Growth and development of neurons step 1: the production of new cells / neurons in the brain primarily occurring early in life

Question 2

migration

Answer 2

Growth and development of neurons step 2: movement of the newly formed neurons and glia to their eventual locations guided by immunoglobulins and chemokines - some move quickly, some not until adult hood; movement can be radial, tangential or both

Question 3

differentiation

Answer 3

Growth and development of neurons step 3: the process of axon and dendrite formation; migrating neurons tow axon so tip remains at target or axon grows toward target, dendrites grow at destination

Question 4

myelination

Answer 4

Growth and development of neurons step 4: glia produce insulating fatty sheaths that excellerate transmission and continue to grow gradually for decades

Question 5

synaptogenesis

Answer 5

Growth and development of neurons step 5: formation of synapses begin before birth and continue throughout life as neurons form new synapses and discard old synapses

Question 6

Stem Cells

Answer 6

undifferentiated cells found in the interior of the brain and generate “daughter cells” which can transform into glia or neurons

Question 7

chemical gradient

Answer 7

growing axons follow a path of cell surface molecules and a chemical gradient (navigate by attraction and repulsion) and connect to cells with same concentration as them

Question 8

neural darwinism

Answer 8

selection process of neural connections - successful axon connections and combinations survive while the others fail to sustain active synapses

Question 9

Nerve Growth Factor

Answer 9

a type of neurotrophin released by muscles that promotes the survival and growth of axons

Question 10

Neurotrophin

Answer 10

a chemical that promotes the survival and activity of neurons (eg NGF)

Question 11

BDNF

Answer 11

Brain Derived Neurotrophic Factor (a neuroptrophin)

Question 12

Apoptosis

Answer 12

programmed mechanism of cell death (often as a result of lack of NGF) as compared to necrosis (death by injury/toxic substances)

Question 13

Fetal Alcohol Syndrome

Answer 13

a condition marked by hyperactivity, implusiveness, difficulty maintaining attention, varying degrees of mental retardation, motor problems, heart defects, and facial abnormalaties (occurs when fetus is exposed to alchohol during pregnancy)

Question 14

Focal Hand Dystonia

Answer 14

musician’s cramp, a condition in which the reorganization of the brain goes too far, causes musician to become clumsy, fatigue easily and make involuntary movements due to overlapping signals

Question 15

Antisaccade Task

Answer 15

looking away from a powerful attention-getter

Question 16

Stroke (Cerebrovasular accident)

Answer 16

is temporary loss of blood flow to the brain; ischemic - resulting from a blood clot or obstruction of an artery, neurons lose their oxygen and glucose supply or hemmorhagic - resulting from a ruptured artery. Neurons are flooded with excess blood, calcium, oxygen, and other chemicals; both types cause edema

Question 17

Edema

Answer 17

the accumulation of fluid in the brain resulting in increased pressure on the brain and increasing the probability of further strokes

Question 18

Tissue Plasminogen Activator (tPA)

Answer 18

a drug that breaks up blood clots and can reduce the effects of an ischemic strokes (administered preferably within 3 hrs)

Question 19

Penumbra

Answer 19

region that surrounds the immediate damage

Question 20

What methods have researches found to save cells in the penumbra?

Answer 20

blocking glutamate synapses and opening potassium channels; cooling the brain to 34-35 degrees

Question 21

Diaschisis

Answer 21

decreased activity of surviving neurons after damage to other neurons

Question 22

Collateral Sprouts

Answer 22

after a cell loses input from an axon it secretes neurotrophins that induce other axons to form new branches and take over vacant synapses (esp in 1st 2 weeks)

Question 23

Denervation Supersensitivity (Receptor Supersensitivity)

Answer 23

the heightened sensitivity of a neuron to a neurotransmitter after the destruction of an incoming axon (helps compensate for decreased input)

Question 24

Phantom Limb

Answer 24

continued sensation in an amputated body part

Question 25

Deafferenated Limb

Answer 25

limbs that have lost their afferent sensory input (sensory neurons can’t communicate with CNS)