Food Intake Regulation Flashcards
Where are the neuronal control centers for feeding and satiety?
Hypothalamus
What are the main neuronal control center nuclei in the hypothalamus that control feeding and satiety behaviors?
Arcuate nucleus
Paraventricular nucleus
In general, neurons from ______ are sent to synapse to neurons in _______
Arcuate nucleus neurons are sent to synapse to neurons in the paraventricular nucleus
What pathway tries to decrease food intake and increase energy expenditure?
Anorexigenic pathway
What pathway tries to increase food intake and decrease energy expenditure?
Orexigenic pathway
For the anorexigenic pathway, what type of neurons are used in the arcuate nucleus?
Pro-opiomelanocortin (POMC) neurons
What do POMC neurons release at their synapse?
Alpha-MSH
POMC neurons release Alpha-MSH to what receptor?
MCR-4
For the orexigenic pathway, what type of neurons are used in the arcuate nucleus?
AGRP/NPY neurons
What do AGRP/NPY neurons release at their synapse?
Neuropeptide Y (NPY) OR AGRP
Neuropeptide Y (NPY) binds to what receptor?
Y1R
AGRP binds to what receptor?
It is an ANTAGONIST for MCR-4
The anorexigenic pathway and the orexigenic pathway try to antagonize each other. Explain the ways they do so.
- POMC neurons can release Alpha-MSH to NPY/AGRP neurons
- NPY/AGRP neurons can release NPY to POMC neurons
- AGRP can try to bind the MCR-4 receptor at the paraventricular neurons so that POMC neurons cannot have Alpha-MSH bind them
- Stimuli that activate one pathway will also try and inhibit the other pathway
What kind of stimuli will activate the Anorexigenic pathway?
Leptin
Insulin
CCK
What kind of stimuli will activate the Orexigenic pathway?
Ghrelin
If the Anorexigenic pathway is activated, what is the end result?
Decreased food intake
If the orexigenic pathway is activated, what is the end result?
Increased food intake
Describe the Anorexigenic pathway
- Leptin, Insulin, CCK activate POMC neuron in the arcuate nucleus
- POMC neuron travels to the paraventricular nucleus
- POMC releases Alpha-MSH
- Alpha-MSH binds to MCR-4 receptor
- Paraventricular neuron signals for decreased food intake
Describe the Orexigenic pathway
- Ghrelin activates NPY/AGRP neuron in the arcuate nucleus
- NPY/AGRP neuron travels to the paraventricular nucleus
- NPY/AGRP releases NPY (neuropeptide Y)
- NPY binds to Y1R receptor
- Paraventricular neuron signals for increased food intake
What are 4 GENETIC causes of obesity?
- Prader-willi syndrome
- Leptin deficiency
- POMC neuron deficiency
- MCR-4 mutation