Lecture 3 Flashcards Preview

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Flashcards in Lecture 3 Deck (21):
1

What is the soma? Name main features.

Soma = nerve cell body
1. Nucleus
2. Stacks of rER = Nissl bodies
3. Tons of mitochondria

2

What is the role of dendrites? Name main features.

Expands cell surface area for synaptic input
1. Spines - active structures that change as you learn things
2. No nuclei, BUT mitochondria & rER

3

What are the characteristics of a chemical excitatory synapse?

ROUND vesicles
Asymmetric pre/post synaptic densities - probably denser post synaptic

4

What are the characteristics of a chemical inhibitory synapse?

Flat vesicles
Symmetrical pre/post synaptic densities

5

Describe an electrical synapse.

Pre and post synaptic sides are connected by gap junctions
NO vesicles
Flow of positive ions depolarize neighboring cells

6

Name the 3 classifications of synapse. (Hint: has to do with where 2 neurons are connected.)

Axodendritic
Axosomatic
Axoaxonic

7

How does the Nissl stain work?

Anulin dye taken up by acidic things
Aka nucleic acids --> ribosomes
Therefore will see Nissl bodies (in neuron cell bodies) because ribosome dense
Don't see axons

8

What stain do you use to visualize myelin?

Weigert stain
Myelin stain black - white matter is black!
Axon in the middle of myelin is white in cross section

9

What is a neurofibrillar stain?

Stains the axon black
Myelin are white
Opposite of Weigert stain

10

What is the principle behind the Golgi stain?

Neurons like gold and silver stains
Show dendritic trees

11

What is the principle immunocytochemisty?

Antigen-antibody reactions so you can visualize nerve cells
Target the specific NT for the neuron you are examining

12

Describe the 4 features of a retinal ganglion cell.

Multipolar = 1 axon, many dendrites (what you think of)
Sensory
Relay
On/off center

13

Describe characteristics of neo-cortical neurons. (6 layers)

Multipolar
Both relay (out of the layers) and interneurons present
Pyramidal and stellate shapes

14

What are the 2 types of axoplasmic transport?

Axoplasmic transport is transport inside the axon via microtubules
Anterograde = away from soma
Retrograde = towards soma

15

What 2 proteins are important for axon transport? Name their directionality.

Kinesin - anterograde
Dynein - retrograde
Both use ATP to move along microtubules

16

What cell myelinates the PNS?

Schwann cells
Wraps 1 axon at a time

17

What cell myelinates the CNS?

Oligiodendrocytes
Wraps more than 1 axon at a time

18

What are astrocytes? Name the 2 main types and general characteristics.

= stellate cell bodies + many radiating processes
Fibrous - fewer processes that go long distances
Protoplasmic - many short, branched processes
Role: BBB, metabolic support, NT balance

19

What are microglia?

Small cells + delicate processes
Respond to injury - proliferate and remove debris in neuro tissue

20

What is Wallerian degeneration? Can it be overcome?

= distal axon will die if cut away from cell body
Anterograde regeneration = axon will attempt to sprout or regenerate the cut axon if near an oligodendrocyte/Schwarnn

21

What is chromatolysis?

Retrograde degeneration = if no cell body attached, the cut away axon degenerates because no nutrients
- Nissl substance breaks down
- Eccentric nucleus
- Protein synthesis changes to make materials for growth
Process is reversible in PNS if neuron survives