Leptin Flashcards
How do neurotransmitters/modulators affect LTP?
Change either
- the threshold for LTP
- magnitude of LTP
- duration of LTP
What is leptin?
A 16 kDa protein that acts as an endocrine hormone
Which gene encodes for leptin?
Ob gene
What is leptin mostly made by?
White adipose tissue
What is the amount of circulating leptin proportional to?
Body weight
What is the main role of leptin?
To regulate energy homeostasis
Which gene encodes of the leptin receptor?
db gene
diabetes gene
Which receptor superfamily is leptin a member of?
Class I cytokine receptor superfamily
Name the leptin receptor (ObR) isoforms
ObR a-f
Which is thought to be the most competent signalling ObR isoform?
ObR(b)
Has lotsa tyrosine residues
Phosphorylation of WHAT occurs at the C terminal of the leptin receptor?
Tyrosine reside phosphorylation by JAK
What occurs after JAK activation?
STAT3 activation
What is the main function of the JAK-STAT pathway?
Regulate gene transcription
What other pathways does ObR binding activate?
RAS > RAF signalling
PI3K
Where are high levels of Ob-R mRNA expressed?
Hippocampus
Cerebellum
Brainstem
Amygdala
What is the main route for leptin into the brain?
Via a sturable transport system regulated by triglycerides and other factors
Where do shorter ObR isoforms get expressed in the brain?
On brain microvessels
Which other route does leptin take into the brain?
via CSF
How can we see where leptin is in the hippocampus?
Fix and permeablise them then 4% paraformaldehyde and 0.1% Triton X-100
Insert primary Ab and secondary Ab
Visual with laser scanning confocal microscope
Which antibodies are used to in the immunocytochemical determination of leptin location?
Primary - polyclonal goat anti-Ob-R
Secondary - Alexa 488 conjugated donkey anti-goat