Neurons (travers)

Question 1

Glial cells comprise ___ % of cells in the CNS.

Answer 1

90

Question 2

Schwann cells (in the PNS) and Oligodendrocytes (in the CNS) do what?

Answer 2

provide myelination

Question 3

What is a microglia?

Answer 3

It is a macrophage like cell

Question 4

What does an astrocyte do?

Answer 4

It regulates extracellular fluid
Helps form blood brain barrier
Provides neurons with glucose

Question 5

A Schwann cell and an oligodendrocyte contribute to how many axons?

Answer 5

Schwann cell- one axon- many schwann cells per axon

Oligodendrocyte- contributes to many axons

Question 6

Neurons and microglia interact with each other. What does the neuron do in this relationship?

Answer 6

Neurons keep microglia unreactive

Neuronal injury releases ATP, inducing motility

Question 7

Neurons and microglia interact with each other. What does the microglial cell do in this relationship?

Answer 7

Microglia are involved in pruning unused dendrites

Make physical contact with healthy neurons

Question 8

T/F, proteins and other material can be transported through an axon?

Answer 8

True

Question 9

What facilitates anterograde axonal transport?

Answer 9

Microtubules run the length of the axon
Kinesin proteins (motor protein) attached to the microtubule hold and help transport secretory vesicles with necessary material

Question 10

What is and what facilitates retrograde transport?

Answer 10

It is transport from the axon to the cell body.
It is facilitate by dyneins- motor proteins-
Viruses also use this

Question 11

Tell me about herpes simplex 1

Answer 11

1. Easily transmitted via oral contact
2. Up to 75% infection in adult population but usually asymptomatic
3. Virus transmitted retrogradely where it remains latent in trigeminal ganglion
4. During latency, virus is transcriptionally quiet
5. In infants virus can go beyond ganglia and cause encephalitis
6. Can be activated by fever, sun, cold, trauma or stress
7. Transmitted anterogradely to peripheral tissue, lips, palate causing painful blisters

Question 12

In the CNS, what happens to damaged neurons?

Answer 12

They don’t regenerate
Axons sprout but don’t reach targets
Scar formation prevents axons from reaching targets
Astrocytes make chondroitin sulfate proteoglycans that inhibit neuron growth

Question 13

In the PNS, what happens to damage neurons?

Answer 13

Functional recovery can take place depending on severity

tooth extraction can cause nerve injury

Question 14

T/F, anterograde degeneration always involves terminal degeneration?

Answer 14

True!

Question 15

What is chromatolysis?

Answer 15

It is associated with protein synthesis- cell body swells, eccentric nucleus

Question 16

If a nerve cell is damage in the PNS, what do Schwann cells do?

Answer 16

They proliferate and produce laminin for substrate for the regenerating axons
Schwann cells secrete NGF (nerve growth factor)
NGF is transported to the ganglion cell body

Question 17

What does NGF do?

Answer 17

It regulates the gene expression and promises sprouting

Question 18

NGF travels via retrograde or anterograde transport?

Answer 18

Retrograde

Question 19

T/F adjacent axons can sprout and go to the target of a degenerating axon terminal?

Answer 19

True!

Question 20

Collateral sprouting is great.

Answer 20

Indeed

Question 21

T/F Reinnervation does not occur humans.

Answer 21

True

Question 22

In order for synaptic vesicles to release their contents, what two molecules are vital?

Answer 22

Calcium and synaptotagmin

Question 23

With the post synaptic potential, what is temporal summation? What is spacial summation?

Answer 23

Temporal summation is where the PSP’s are close enough together in time to be additive.
Spatial summation is where two different impulses come at the same time, but at different places- also additive

Question 24

What is a classic neurotransmitter?

Answer 24

Released from presynaptic terminal due to the arrival of an action potential- it functions in rapid communication and it acts on postsynaptic cells to produce an excitatory or inhibitory post synaptic potential

Question 25

What is a neuromodulator?

Answer 25

Often co-released with neurotransmitters. May act to postsynaptically amplify or dampen current synaptic activity Can act on the presynaptic cell to alter synthesis, release, or uptake of neurotransmitters Actions can involve changes in protein synthesis or enzyme activity, so it can be a lot slower, taking minutes or days

Question 26

Tell me about acetylcholine.

Answer 26

It is synthesized from choline and acetyl Co-enzyme A by choline acetyltransferase in synaptic terminal Its action is stopped by diffusion & degradation (by acetylcholinesterase) Choline re-uptake by presynaptic neuron

Question 27

What are some neurons that release Ach?

Answer 27

Motor neurons Neurons in nucleus basalis and pons Preganglionic sympathetic and parasympathetic neurons All postganglionic parasympathetic neurons

Question 28

What are acetylcholine receptors?

Answer 28

Muscarinic receptors- mostly found in CNS, but also in salivary glands Nicotinic receptors

Question 29

What is Myasthenia gravis?

Answer 29

It's an autoimmune disorder in which the individual makes antibodies to nicotinic receptors Muscle weakness results.

Question 30

How is M. gravis treated?

Answer 30

Acetylcholininsterase inhibitors

Question 31

Biogenic amines are synthesized from what?

Answer 31

amino acids

Question 32

T/F Catecholamines include dopamine, norepinephrine and epinephrine?

Answer 32

True

Question 33

Catecholamines are original synthesized from which amino acid?

Answer 33

Tyrosine

Question 34

What is the catecholamine life cycle?

Answer 34

1. Synthesis occurs in the presynaptic terminal and stored in vesicles 2. Release is Ca++ dependent 3. Termination of action occurs via enzymatic degradation and presynaptic neuron re-uptake

Question 35

T/F neurons that synthesize catecholamines are found in very limited locations, but the receptors for the ligand are found extensively throughout the CNS?

Answer 35

True

Question 36

What is a possible side effect of people who receive dopamine blocking drugs?

Answer 36

Tardive dyskinesia (think parkinsons shakiness and stuff, except for with you mouth and tongue)

Question 37

Serotonin is synthesized from what amino acid?

Answer 37

Tryptophan- think sleep after eating a whole turkey.. much like this class. I feel like I just ate a whole turkey

Question 38

Histamine is derived from histadine

Answer 38

Yep

Question 39

What are the excitatory amino acids?

Answer 39

Glutamate and aspartate

Question 40

Excitatory amino acids bind what type of receptor?

Answer 40

Ionotropic

Question 41

Tell me about the NMDA receptor

Answer 41

Involved with long term change- functions that last like memory formation or chronic pain Excessive excitation will result in cell death- epilepsy, trauma, stroke Neuron death occurs from Ca concentration reaching toxic levels

Question 42

How is glutamate controlled in the synapse so that overstimulation doesn't occur?

Answer 42

When glutamate is in the synaptic cleft, it is removed by astrocytes. Glutamate is transported into the astrocyte where it is converted into glutamine, which is then released back into extracellular space where the presynaptic terminal takes it up again and makes more glutamine

Question 43

What is excitotoxicity?

Answer 43

It is where excessive excitation leads to cell death- epilepsy, trauma, stroke

Question 44

What factors promote long term potentiation?

Answer 44

The NMDA receptor is phosphorylated (permanent removal of Mg+ block) Calcium entry into the cell via the NMDA receptor leads to the phosphorylation of and increase in the number of AMPA receptors

Question 45

What is long term potentiation?

Answer 45

When a function lasts a long time and synapses are almost continual

Question 46

GABA is a(n) _________ neurotransmitter. GABAa opens which channel? GABAb opens which channel?

Answer 46

inhibitory Cl- K+

Question 47

GABA deficiency is linked to what disease?

Answer 47

Huntington chorea

Question 48

Glycine is a(n) ________ neurotransmitter. | It opens what channel?

Answer 48

inhibitor | Cl-

Question 49

What do peptides do?

Answer 49

They function as neuromodulators

Question 50

Do peptides have a short or long effectiveness? | How is their action terminated?

Answer 50

They can last a long time. | Proteolysis and diffusion stop the action

Question 51

Where are peptides synthesized?

Answer 51

In the soma

Question 52

Nitric oxide (NO) is a liquid/solid/gas? It is/isn't stored in vesicles? It is/isn't freely diffusible across the membrane (no synapse required)?

Answer 52

Gas Isn't stored in vesicles Is freely diffusible

Question 53

T/F- ATP is both an energy source and a neurotransmitter?

Answer 53

True

Question 54

T/F- ATP as a neurotransmitter is usually excitatory.

Answer 54

True

Question 55

What are some possible actions of drugs on a synapse?

Answer 55

Increase transmitter into cleft Block transmitter release Modulate transmitter synthesis Block transmitter repute Block enzymes that metabolize transmitter Bind to postsynaptic ionotropic receptor Bind to the postsynaptic G-protein coupled receptors