Brainscape's Knowledge GenomeTM

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


See full index

Synaptic plasticity and cognition > Leptin > Flashcards

Leptin Flashcards

1
Q

Where is leptin made?

A

Primarily made and secreted by white adipose tissue

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

What is the function of leptin?

A

Regulates energy homeostasis via its actions in the hypothalamus

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

What gene produces the leptin receptor?

A

The diabetes (db) gene

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

What receptor family does leptin belong to?

A

Class I cytokine receptor family

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

Where in the brain is leptin receptor expression high?

A

High levels of OB-Rb expressed in specific hypothalamic nuclei High levels of OB-Rb mRNA/protein also expressed in cerebellum, hippocampus, brain stem and amygdala

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

How does leptin get into the brain?

A

Via a saturable transport system Leptin also reaches the brain via the CSF

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

Where are short OB-R isoforms expressed in the brain?

A

On brain microvessels These isoforms bind and internalise leptin

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

What does leptin do to hippocampal synaptic plasticity?

A

It causes LTP (instead of STP without the presence of leptin)

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

What does leptin do to NMDA receptors?

A

Enhances them which mediates synaptic transmission

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

What effect does leptin have on NMDA induced calcium influx?

A

Leptin increases the NMDA induced calcium influx

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

What is the function of NR2 subunits?

A

They determine biophysics and pharmacology of NMDAR

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

Which NMDA receptor subunits predominate in the hippocampus?

A

NR2A and NR2B

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

Where are NR2A and NR2B expressed respectively?

A

NR2A is synaptic whereas NR2B is expressed extrasynaptically

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

Leptin has the capacity to enhance NMDA receptor mediated currents but what is required for this to occur?

A

Leptin receptors are required

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

Which substances are involved in leptin modulation of NMDAR function?

A

PI3-kinase and MAPK

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

What do specific C-terminal regions determine in AMPAR complexes?

A

They determine the trafficking properties of AMPAR complexes

17
Q

Cytoplasmic C-terminal tails are key for regulating AMPAR function. What is the difference in tails between GluA1 and 4 compared to GluA2 and 3?

A

GluA1 and 4 have long tails, GluA2 and 3 have short tails

18
Q

What effect does leptin have on GluA1 surface expression?

A

Increases GluA1 surface expression

19
Q

Which AMPA receptor subunits are predominant in the hippocampus?

A

GluA1 and GluA2

20
Q

What is the difference between GluA1 and GluA2 in terms of calcium permeability?

A

GluA1 = calcium permeable GluA2 = calcium impermeable

21
Q

What does this diagram show?

A

Leptin promotes GluA1 trafficking to synapses - increased GluA1 with leptin treatment compared to control image

22
Q

What is the function of PI3K?

A

It converts PIP2 to PIP3 which then activates downstream targets

23
Q

Leptin activates a kinase and inhibits a phosphatase. What kinase and what phosphatase does leptin act upon?

A

Leptin activates PI3 kinase and inhibits PTEN

24
Q

What effect does leptin have on BpV?

A

Leptin occludes the effects of BpV on synaptic strength

25
Q

How does leptin increase GluA1 expression and PIP3 levels?

A

Via inhibition of PTEN

26
Q

How does leptin increase excitatory synaptic strength?

A

By increasing GluA1 surface expression

27
Q

How does leptin facilitate hippocampal LTP?

A

By enhancing NMDAR function

28
Q

What underlies trafficking of GluR1 to CA1 synapses in the hippocampus?

A

Leptin inhibition of PTEN underlies trafficking of GluR1 to CA1 synapses

29
Q

What does leptin insensitivity do to LTP and LTD in rodent models?

A

Leptin insensitive rodents display impaired hippocampal LTP and LTD

30
Q

Diabetics often display cognitive impairments, why might this be?

A

Obesity is a common risk factor for type 2 diabetes Obesity involves leptin resistance so type 2 diabetics may be potentially leptin insensitive which impairs LTP and LTD, leading to cognitive decline such as Alzheimer’s

31
Q

What evidence is there to back up the use of leptin as a therapeutic target in AD?

A

Circulating leptin levels are lower in AD patients Leptin decreases amyloid beta levels in transgenic mice with elevated beta amyloid levels Leptin improves memory in a mouse model of beta amyloid toxicity

32
Q

What effect does amyloid beta have on AMPAR internalisation?

A

Amyloid beta promotes AMPAR internalisation

33
Q

What effect does leptin have on amyloid beta induced AMPAR internalisation?

A

Leptin prevents amyloid beta induced internalisation of AMPA receptors

Synaptic plasticity and cognition (5 decks)

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