Brainscape's Knowledge GenomeTM

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


See full index

Clinical Neuroscience > Cellular Physiology Of The Brain > Flashcards

Cellular Physiology Of The Brain Flashcards

1
Q

List 4 roles of Astrocytes

A
  • Help to provide nutrition for neurones via Glucose-lactate shuttle
  • Uptake of neurotransmitter to keep concentration low
  • Maintain ionic environment via K+ buffering
  • Help to form blood brain barrier
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Can neurones store or produce glycogen?

A

No

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

How do astrocytes provide nutrition to neurones

A
  1. Produce lactate from blood glucose (which is 1st converted to Glycogen and Pyruate in the cell)
  2. Lactate transported to neuron via Glucose-lactate shuttle
  3. Lactate converted to Pyruvate in neurone and used to make ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name a toxic neurotransmitter that can be taken up by astrocytes

A

Glutamate

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

List the features of K+ buffering by Astrocytes

A
  • Astrocytes have a RMP even more (-ve) than that of neurones
  • Na-K ATPase and NKCC2 channels involved
  • Astrocytes are connected to each other, so ions can move between them
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Compare Microglia in resting and activated phases

These cells can act as APCs

A

Resting: Dendritic with long projections

Activated/ Phagocytic: Compact with disappearance of dendrites

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

Describe 3 structural features of the Blood Brain Barrier

A
  • Tight junctions between endothelial cells of capillaries
  • Basement membrane around capillaries
  • End feet of astrocyte processes surrounding capillaries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the meaning of the CNS being immune privileged

A
  • No inflammation tolerated due to rigidity of skull (would lead to damage/ compression of vessels -> neuron damage)
  • Microglia act as Antigen Presenting Cells to T cells
  • T cells enter CNS through Blood Brain barrier
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

List the 4 main sections of a neurone

A
  • Cell soma
  • Axon

Dendrites and Terminals, which often synapse with each other

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

Describe neurotransmitter release briefly

A
  • Depolarisation causes opening of VGCCs

- Ca diffuses in and causes release of vesicles containing neurotransmitter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

List the 3 chemical classes of neurotransmitters in the CNS

A
  • Amino acids
  • Biogenic amines
  • Peptides (Encephalin, Dynorphin, Somatostatin, CCK, Neuropeptide Y)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which chemical class do the following neurotransmitters belong to?

  • Glutamate
  • GABA
  • Glycine

Are they inhibitory or excitatory?

A

All are amino acid neurotransmitters

Glutamate- Excitatory
GABA and Glycine- Inhibitory

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

List 5 Biogenic Amines

A
  • ACh
  • Dopamine
  • NA
  • Histamine
  • Serotonin (5-HT)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Over 70% of CNS synapses involve the use of which neurotransmitter?

A

Glutamate (The major excitatory neurotransmitter)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Compare the 2 classes of Glutamate receptors

A

Ionotropic: Contain an integral ion channel that opens upon activation, leading to depolarisation

Metabotropic: a GPCR linked to either;
- Changes in IP3 and Ca mobilisation
OR
- Adenylyl Cyclase inhibition and reduced cAMP levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Compare the 3 types of Ionotropic Glutamate receptors

A

AMPA Receptors: Permeable to Na and K ions

Kainate receptors: Permeable to Na and K ions

NMDA receptors: Permeable to Na, K and CA ions

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

Describe the role of the 2 types of Ionotropic Glutamate receptors present in Glutamatergic synapses

A
  • AMPA receptros mediate the initial depolarization

- NMDA receptors are permeable to Ca

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

In order for Ca to flow through NMDA receptors what are 2 things required?

What chemical acts on these receptors as a co-agonist?

A
  • Cell must be depolarised
  • Glutamate must bind

Glycine

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

Glutamate receptors have a role in learning and memory.

What can NMDA receptor activation cause?

What does strong, high frequency stimulation cause?

A

Up-regulation of AMPA receptors

Long Term Potentiation, LTP (Ca entry through NMDA receptors is important for this)

20
Q

What can excess Ca entry through NMDA receptors cause?

A

Excitotoxicity (too much glutamate) as Ca is toxic in high Intracellular concentrations

21
Q

Name the main inhibitory neurotransmitters in the;

  • Brain
  • Brainstem
  • Spinal Cord
A

Brain: GABA

Brainstem and Spinal Cord: Glycine

22
Q

Describe briefly how binding to GABAa and Glycine receptors cause Hyper-polarisation leading to an IPSP

A
  • Both receptors have integral Cl- channels
  • These channels open and Cl- diffuses in
  • Inside of neuron is now more negative-> reduced firing of APs
23
Q

Compare GABAa and GABAb receptors

A

GABAa: Ligand gated receptors

GABAb: GPCRs, have a modulatory role

24
Q

Name 2 types of drugs that act on GABAa receptors

How do they affect the receptors?

A
  • Barbiturates
  • Benzodiazepines

Enhance the response of the receptors to binding by GABA

DO NOT BIND TO THE RECEPTORS THEMSELVES

25
Q

Describe the clinical use of Barbiturates

A
  • Sedative and Anxiolytic effects
  • Sometimes used as anti-epileptic drugs to decrease brain electrical activity)

(Not used due to risk of fatal overdose as well as dependence)

26
Q

Describe the clinical use of Benzodiazepines

A
  • Sedative and Anxiolytic effects

- Used to treat anxiety, insomnia and epilepsy

27
Q

Is ACh mainly excitatory or inhibitory in the CNS?

Why are they often present on PRE-synaptic terminals?

A

Excitatory

To enhance the release of other neurotransmitters

28
Q

List 4 Cholinergic pathways in the CNS

A
  • From Striatum Nigra to Thalamus
  • Local interneurons in Corpus Striatum (Striatal interneurons)
  • From Basal forebrain + Brainstem to Hippocampus + Parts of the Cortex
29
Q

What are 4 things that the Cholinergic CNS pathways are involved in?

A
  • Arousal
  • Learning
  • Memory
  • Motor Control (From SN to Thalamus)
30
Q

Degeneration of cholinergic neurones in what nucleus is associated with Alzheimer’s?

What drugs can be used to alleviate symptoms of this disease?

A

Nucleus basalis

Cholinesterase inhibitors

31
Q

List 3 Dopaminergic CNS pathways

What are they involved in?

A
  • Nigrostriatal pathways (Between SN and Corpus Striatum), involved in in Motor control
  • Mesolimbic and Mesocortical pathways, involved in Mood, Arousal and Reward
32
Q

List 2 conditions associated with dopamine dysfunction

A
  • Parkinson’s

- Schizophrenia

33
Q

Describe the relationship between Parkinson’s and Dopamine

How can Parkinson’s be treated?

A
  • Associated with loss of dopaminergic neurones in Striatal pathway (SN to Corpus Striatum)
  • Levodopa/ L-DOPA, a precursor of Dopamine (Converted to Dopamine by AADC/ DOPA Decarboxylase)
34
Q

Describe the relationship between Schizophrenia and Dopamine

A

Possibly due to excess Dopamine release

35
Q

Why can Amphetamines cause Schizophrenic behaviour?

What kind of drugs can be used as antipsychotics?

A

Release Dopamine and Noradrenaline

Dopamine antagonists at D2 receptors

36
Q

Describe the flow of L-DOPA through the Blood Brain Barrier

A

Freely crosses the BBB via an LNAA (Large Neutral AA transporter)

37
Q

AADC is present in the brain AND in the periphery.

How do we prevent a rise in peripheral dopamine concentration when we treat with L-DOPA?

A

Give Carbidopa;

  • Inhibits AADC
  • Can not cross BBB

Therefore, AADC is only inhibited in the periphery and not in the brain

38
Q

Outline the CNS Noradrenergic pathways

A
  • Cell bodies of neurones containing NA in the Brainstem (Pons and Medulla)
  • Widespread NA release throughout Cortex, HT, Amygdala, Cerebellum
39
Q

Where does most NA in the brain come from?

When are they inactive, when does activity increase?

A
  • Neurones in the Locus Coeruleus
  • Inactive during sleep, Activity increases during behavioural arousal

(Amphetamines increase release of NA and Dopamine, as well as wakefulness)

40
Q

What substance deficiency may depression be associated with?

A

Noradrenaline

41
Q

List 2 functions of the Serotonin pathways in the CNS

A
  • Mood

- Sleep/ wakefulness

42
Q

How do SSRIs help in the treatment of depression and anxiety disorders?

(Selective Serotonin Re-uptake Inhibitors)

A

Inhibit serotonin uptake, so increased concentration of Serotonin present

43
Q

Which Glutamatic receptors are involved in Fast and Slow excitations

A

Fast- Ionotropic

Slow- Metabotropic

44
Q

Which neurotransmitter is produced by the Raphe Nuclei

A

Serotonin (5-HT)

45
Q

Where are Noradrenaline and Dopamine made?

A

NA- Locus Coeruleus

Dopamine- Substantia Nigra

Clinical Neuroscience (19 decks)

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