Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuroscience > Neuronal Cell Biology > Flashcards

Neuronal Cell Biology Flashcards

1
Q

give brief overview of the cerebral cortex

A

senses perception, voluntary movements, learning, memory, thinking, emotion and consciousness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what brain regions are are evolutionary conserved?

A

pituitary. spinal cord. medulla. hypothalamus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what happens as you move up the brain?

A

get more complex

  • cerebellum = highest neuron density
  • cerebral cortex = higher thought
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

give a brief overview of the cerebellum.

A

muscle tone, balance, coordination of voluntary movement, motor learning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

where would you find the brain areas that are evolutionary ancient?

A

the structures at the bottom
all animals have them
need for basic function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is white matter?

A

higher lipid content

contents mainly axons with myelin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is grey matter?

A

contains the cell bodies which have less lipid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how are grey and white matter connected?

A

tracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is an example of function due to a neural circuit?

A

reflex e.g. knee jerk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the knee jerk reflex?

A
  • stimulation of peripheral sensors
  • initiates receptors
  • trigger action potentials
  • travels on the afferent axons on sensory neurons
  • stimulates motor neurons through synapses
  • action potentials travel through efferent axons
  • gives rise to muscle contraction and behavioral response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what did ramon y cajal do?

A
  • used a stain to visualise neurons

- golgi stain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does the silver chromate stain do?

A
  • when labelled doesnt label all of the neurons

- can see whats happening in the tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how can you use genetic engineering to show pathways?

A

use a promoter to drive a reporter gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how can we use a promoter to drive a reporter gene?

A
  • cell type specific
  • select a promoter to the neuron
  • can track GFP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe the process of genetic engineering using a reporter protein

A
  • reporter protein that codes for a visible protein
  • inserted into the genome
  • under control of a cell type specifci promoter
  • reporter expressed only in those cell types
  • reveals the cell bodies/axons/dndrites of cells that express the gene
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the 2 key points about neuron morphology?

A
  1. high degree of polarity

2. electrically excitable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

describe dendrites

A
  • provide the input

- more dendrites then axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

describe axons

A
  • provides the ouput

- can be branched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are spiny neurons?

A

dendritic spines, use neurotransmitter glutamate, excitatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are non-spiny neurons?

A

use NT gabba, inhibitory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are glia?

A
  • provide support to neurons

- not electrically excitable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the different types of glia?

A

astrocytes, oligodendrocytes, microglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are astrocytes?

A

most common, star like shape, involved in the blood brain barrier (BBB)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are oligodendrocytes?

A

schwann cells in peripheral nervous system, ensheath the axons with myelin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what are microglia?

A

innate immune cells in the central nervous system (CNS), macrophages, activate when theres a problem, become highly motile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is neuronal polarity underpinned by?

A

the neuronal cytokseleton: microtubules, neurofilaments, microfilament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what does a restriction at the cell body do?

A

only allows certain proteins in the axon. selective filter at the axon entrance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what can be useful markers?

A

specific cytoskeletal isoforms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is highly expressed in the axon?

A

tau

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is the problem with axonal transport?

A

synapse can be mm or m away from the cell body

31
Q

what experiment did Weiss and Hiscoe do?

A
  • exposed the nerve on cats
  • tied a twine, restricted axons
  • started to bulge, proteins etc get trapped
  • suggests active transport
32
Q

what do you need to transport materials?

A

motor proteins

33
Q

how are mitochondria made?

A

mitochodnrial polypeptides are synthesised and imported in the cell body

34
Q

how are synaptic vesicles made?

A

Synaptic vesicle polypeptides are synthesised and processed in the ER and Golgi

35
Q

how are mitochondria and synaptic vesicles transported?

A
  • Loaded onto kinesin molecules
  • transported to synaptic terminus where they are used
  • used bodies are transported back to the cell body
36
Q

in what direction is there movement along the axon?

A

bidirectional

37
Q

what is anterograde transport?

A

away from the cell body

38
Q

what is retrograde transport?

A

too the cell body

39
Q

what is the resting membrane potential?

A
  • electrical potential recorded at rest
  • expressed relative to the outside
  • between -60 - 70 mV
40
Q

how does the lipid bilayer play a role?

A
  • impermeable to ions so they have to move through ion channels
  • move through Na/K ATPase ump
41
Q

describe ion movement in neurons

A
  • membrane highly permeable to K+ ions
42
Q

what is the Nernst potential?

A

membrane potential at which there is no net flow of that particular ion from one side to the other
- ion is in equilibrium

43
Q

what is the Nernst potential equation?

A

Ek= RT/zF ln⁡〖[K]out/[K]in〗

44
Q

what is the concept of a current clamp

A

inject a known quantity of current into the cell which alters the neuronal membrane potential

45
Q

what does the current clamp measure?

A

measure the Vm response

46
Q

how does the current clamp work

A
  • 2 microelectrodes
  • one measures the membrane potential
  • one injects current
47
Q

what happens if you inject positive current in a current clamp?

A
  • increases positivity, depolarize slightly

- above the threshold will trigger an action potential

48
Q

what is the concept of a voltage clamp?

A
  • measuring ion channel activity

- control the membrane voltage whilst measuring the current and injecting a metered amount to keep at a desired level

49
Q

what do we measure in the voltage clamp?

A

measuring the current - equal and opposite to the current through the ion channels

50
Q

describe the process of the voltage clamp

A
  • internal electrodes measure the membrane potential - connected to a voltage clamp and a voltage clamp amplifier
  • compares the Vm to command voltage
  • if Vm is different an electrode injects current into the axon
51
Q

where is the recording electrode in voltage clamp?

A

in the axon

52
Q

where is the reference electrode in voltage clamp?

A

in the surrounding saline solution

53
Q

what is the command voltage?

A

we set the membrane voltage

54
Q

what is the patch clamp technique?

A
  • smaller neurons
  • pipette forms a high resistant seal on the membrane
  • apply suction
  • results in brief currents
  • when the channels are open the trace goes down
55
Q

what is the whole patch clamp technique?

A
  • seal pipette to neuron
  • apply more suction so the membrane ruptures
  • pipette in phase with the cell
  • voltage is that of the whole membrane
56
Q

how can properties of one type of channel be studied with whole cell patch clamp technique?

A

can be studied by blocker other types with toxins/drugs/chemicals

57
Q

describe the activation gate of Na+ channels?

A

fast kinetics, closed at resting potential, open in response to depolarisation

58
Q

describe the inactivation gate of Na+ channels?

A

slow kinetics, open at resting potential, closes in response to depolarization

59
Q

describe the activation gate of K+ channels?

A

slow kinetics, closed at resting potential, open in response to depolarization

60
Q

describe the inactivation gate of K+ channels?

A

not present

61
Q

what happens when there are changed concentrations of extracellular Na+?

A
  • amplitude and rise of action potential decreased
  • action potential –> changed shape
  • no matter what happens to Na+ the resting potential stays around the same
62
Q

describe the K+ ion channel?

A
  • voltage gated

- tetrameric (4 subunits)

63
Q

describe the Na+ ion channel

A
  • monomeric

- one large protein that folds itself

64
Q

what is meant by voltage gated?

A
  • activation gate –> both open in response to depolarisation
  • have a voltage sensor
65
Q

what is the role of the transmembrane helix S4

A
  • senses change
  • twists via a conformational change and opens
  • positively charged residues in S4 cause it to rotate
66
Q

describe inactiavation

A
  1. closed resting - no Na+
  2. opens - Na+ flows in
  3. inactivated - second gate shuts, pore opens but no Na+ can get through
  4. closed inacitvated - membrane repolarise, activation gate closes and inactivation gate opens again
67
Q

when is inactivation triggered?

A

when the channel is open

68
Q

which is the more activated state?

A

inacitvation state is more energetically stable than the activated state

69
Q

what is the inactivation gate?

A
  • large intracellular loop on the channel protein

- contains amino acid motif (IFM) which blocks the pore

70
Q

what is the Hodgkins and Huxleys model?

A

Rest –> activation gates closed
- depolarisation = Na+ channels open, influx, further depolarisation, K+ channels open, K+ flows out
- depolarisation slows down
reprolarisation - inactivation gate opens again and activation gate shuts

71
Q

describe how TTX toxin modulates the Na+ channel?

A
  • puffafish neurotoxin

- sticks into the pore of the channel blocking it

72
Q

how would BTX and ScTX modulate the Na+ channel?

A

dont block - change how it operates - too much sodium as the channels are kept open

73
Q

what can mutations in the channels caust?

A

epilepsy

Neuroscience (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions