Regulation of Energy

Question 1

Arcuate nucleus

Answer 1

contains first order neurons that promote either food intake (NPY/AgRP) or satiety (POMC/CART)

POMC gives rise to alpha-MSH

Question 2

Paraventricular Nucleus

Answer 2

Innervated by arcuate nucleus neurons
House MCR - melanacortin receptors
House NPYR - Neuropeptide Y receptor

Question 3

Lateral Hypothalamus

Answer 3

Hunger center - expresses MCH and orexins - eating

Question 4

Ventromedial Nucleus

Answer 4

Satiety center

Question 5

Knock out of POMC gene?

Answer 5

This will fuck with alpha-melanocyte stimulating hormone

Alpha-MSH lowers intake and increases expenditure –> so getting rid of it will lead to weight gain

Question 6

Knock out of NPY gene?

Answer 6

Neuropeptide Y is a hunger hormone - increases intake and decreases expenditure –> knocking out will lead to weight loss

Question 7

Loss of function in MCR

Answer 7

If melanocortin receptor cannot be stimulated, and its stimulation leads to decreased intake and increased expenditure - then we will have weight gain

Question 8

Grehlin

Answer 8

peptide hormone secreted from stomach that induces feeding

Receptors in arcuate nucleus - food intake
Activates NPYR/AgRP neurons
Stimulats anabolic pathway

Question 9

CCK

Answer 9

Released from duodenum in response to food - stimulates POMC/CART pathway –> alpha-MSH –> decreased intake / increased expenditure

Question 10

PYY

Answer 10

Released from L cells in distal ileum - acts by INHIBITING NPY/AgRP neurons
Inhibits anabolic pathway

Question 11

GLP-1

Answer 11

Released from ileum - reduces food intake

Inhibits anabolic pathway

Question 12

Insulin

Answer 12

Levels correlate with body fat content -
Stimulates POMC/CART
Inhibits NPY/AgRP

Question 13

Leptin

Answer 13

Released from fat- more fat - more leptin
activates POMC/CART - catabolic
inhibits NPY/AgRP - anabolic

Question 14

Leptin in obesity?

Answer 14

Obese prone have much higher leptin but don’t seem to have lower hunger - leptin resistant?

Question 15

Grehlin in OP vs OR

Answer 15

Slightly higher in OR

Question 16

PYY in OP vs OR

Answer 16

Slightly higher in OR

Question 17

Non-homeostatic regulation of energy intake

Answer 17

Internal 
Reward/craving/thought/restraint/attention/ learned behaviors 
External
Environment - sight/smell/taste
availability 
social 
time cues

Question 18

When hungry
Hedonic foods compared to basic objects
fMRI we see

Answer 18

increased:
attention 
reward 
motivation 
memory 
especially in fluffly

Question 19

Obese resistant vs obese prone brain activity pre and post meal?

Answer 19

OR have slightly higher signals pre-feed that remit post-feed

OP signals don’t remit post-feed

Question 20

As we saw fMRI brain reward/motivation/attention signals in obese prone do not remit post-feed
WHAT can help?

Answer 20

EXERCISE :)

Question 21

Homeostatic regulation

Answer 21

Adiposity
Metabolites
Gut Peptides
Gastric distension

All talk to the hypothalamus

Question 22

Non homeostatic regulation

Answer 22

Internal and external cues

also talk to the hypothalamus

Prof thinks overrides hypothalamus in obesity

Question 23

Elevated levels of grehlin would do what to NPY and alpha-MSH

Answer 23

NPY is hunger so these would rise

Alpha-MSH is satiety so these would fall