Term
| What are the two main hypothalamin structures involved in feeding behavior? |
|
Definition
paraventricular nucleus (PVN)
Arcuate Nucleus (ARC) |
|
|
Term
| What are the main stimulatory and inhibitory monoamines that are involved in feeding behavior |
|
Definition
stimulatory- NE
Inhibitory- 5-HT |
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Term
| the effects of NE in the PVN are mediated by ___ receptors |
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Definition
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Term
| Upon activation of alpha-2 receptors, how does food preference change and how does general feeding behavior change. |
|
Definition
| activation of apha-2 receptors specifically increases consumption of carbs and increases meal size and duration (but not frequency) |
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Term
| How does activation of alpha-1 receptors in the PVN affect feeding behavior |
|
Definition
|
|
Term
| How doe direct infusion of 5-HT into PVN affect food intake? |
|
Definition
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|
Term
| a drug that causes loss of appetite is called _____. |
|
Definition
|
|
Term
| by what mechanism does fenfluramine function as an anoretic? |
|
Definition
a serotonergic drug:
indirect agonist
promotes release of serotonin
inhibits reuptake of serotonin |
|
|
Term
| how does fenfluramine affect feeding behavior |
|
Definition
increases feeling of satiety
decreases meal size: decreases rate and duration of feeding and total food intake |
|
|
Term
| how does phentermine affect feeding behavior |
|
Definition
|
|
Term
| by what mechanism does phentermine function as an anoretic? |
|
Definition
| phentermine is a stimulant, and acts at catecholamine (NE/DA) sites |
|
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Term
| what is the problem with using the fenfluramine/phentermine combination? |
|
Definition
| high doses of fenfluramine is damaging to 5-HT axonal terminals, and PHEN may exacerbate this FEN-induced neurotoxicity |
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|
Term
| how does serotonergic activity modify food intake? |
|
Definition
| increased serotonergic activity decreases food intake |
|
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Term
| will you have higher brain serotonin after high protein or high carbohydrate meal? Why? |
|
Definition
high protein meal has lots of serotonin but lots of other large neutral amino acids which compete for the same transporter to get to the brain.
high carb meal causes insulin release which causes uptake of amino acids into muscle- depletion of other LNAAs allows greater uptake of tryptophan (5-HT precursor) |
|
|
Term
| how is serotonin regulation and anorexia related? |
|
Definition
increased serotonin decreases feeding. anorexics express genetic variant for several 5-HT receptors, lower effective binding in cortical areas.
it is suggested that anorexics starve themselves to decrease 5-HT neuronal activity to secrease dysphoria |
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|
Term
| Name three CNS neuropeptides involved in feeding |
|
Definition
Neuropeptide Y
POMC peptides (MSHs)
Agouti Related Peptide (AgRP) |
|
|
Term
| ____ is the most powerful appetite stimulant known |
|
Definition
|
|
Term
| What kind of receptors are NPY receptors, what happens when they are activated? |
|
Definition
NPY receptors are G-protein coupled receptors
activation of receptors inhibits Ca2+ influx |
|
|
Term
| what is the receptor for MSH (POMC active peptide)? |
|
Definition
|
|
Term
| how does activation of melanocortin receptor affect feeding behavior |
|
Definition
| activation of melanocortin receptors inhibits feeding |
|
|
Term
| what is the most common genetic obesity syndrome? |
|
Definition
MC4R deficiency
-the receptor for MSH, which when activated inhibits feeding behavior |
|
|
Term
| how does agouti-related peptide (AgRP) effect feeding behavior |
|
Definition
| endogeneous inhibitor of melanocortin receptors, which increases feeding behavior |
|
|
Term
| where is ghrelin synthesized? |
|
Definition
|
|
Term
| how do ghrelin levels fluctuate with food intake and food deprivation |
|
Definition
levels decrease with food intake
levels increase with food deprivation |
|
|
Term
| how does Prader-Willi syndrome affect feeding behavior? what is a proposed bio basis? |
|
Definition
ghrelin levels are severly increased
patients exhibit voracious appetites and are profoundly obese |
|
|
Term
where in the hypothalamus are Ghrelin receptor expressed?
on what neurons are ghrelin receptors present? how does ghrelin affect these neurons?
how does their activation affect feeding behavior? |
|
Definition
Ghrelin receptors are expressed in ARC on NPY neurons
Ghrelin activates NPY neurons and induces feeding behavior |
|
|
Term
| where is leptin synthesized |
|
Definition
|
|
Term
| how do leptin levels fluctuate with food intake or food deprivation? |
|
Definition
leptin levels increase with food intake
levels decrease with food deprivation |
|
|
Term
| how does leptin affect feeding behavior? |
|
Definition
leptin inhibits feeding
leptin is a long-term regulator of body weight and appetite |
|
|
Term
| how does leptin effect the neurons in the hypothalamus |
|
Definition
leptin activates POMC neurons
leptin NPY neurons |
|
|
Term
| where is Peptide YY (PYY) expressed? |
|
Definition
|
|
Term
| what modulates the amount of PYY that is released? |
|
Definition
| PYY is released in relation to caloric content |
|
|
Term
| how does PYY affect feeding behavior? |
|
Definition
|
|
Term
| where is CCK synthesized? |
|
Definition
|
|
Term
|
Definition
| when food is present in the small intestine |
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