Lecture 48-49: Eating Flashcards
Diagnostic criteria for anorexia nervosa (4)
- Body weight
Diagnostic criteria for bulimia (4)
- Binge eating (loss of control); 2. Purging; 3. Over-concern with body weight; 4. Weight can be normal, high, low
How common are genetic disorders that cause morbid obesity? Name one target for such a mutation
Very rare; leptin/leptin receptor
What is genetic component (%) of obesity risk? Health risk what what BMI?
70%; 35
What is the best obesity “hit” from GWAS studies?
FTO gene (DNA/RNA demethylase); 16% of adults are homozygous for obesity-causing gene
A lesion where causes animals to stop eating (orexigenic region)?
Lateral hypothalamus (LH)
A lesion where causes animals to become obese (anorexigenic region)?
Medial hypothalamus (MH)
Neural circuits involved in feeding (3)
- Hypothalamus (physiological need for food); 2. Mesolimbic DA system (desire for food as rewarding); 3. Cerebral cortex (control)
Which neurobiological system mediates hunger?
Hypothalamus
Which neurobiological system mediates appetite?
Mesolimbic DA system
Which neurobiological system integrates psychological/social factors with feeding behavior?
Cerebral cortex
Leptin increases/decreases food intake. What else does it do? (2)
Decreases; increases energy use and sympathetic tone
What makes leptin? What kind of molecule?
Adipose tissue; small peptide
Leptin does what to orexigenic factors?
Decreases them
Where does leptin produce its effect? What kind of receptor does leptin use? Final effect of signal transduction?
Hypothalamus; protein kinase; TFs
T/F: Leptin levels explain common obesity? Explain.
False! Heavy people DO have higher leptin levels
What is leptin’s primary site of action (structure and nucleus)
Hypothalamus: arcuate nucleus
Leptin inhibits…(2)
Orexigenic factors: Neuropeptide Y (NPY), Agouti-related peptide (AgRP)
Leptin stimulates…(2)
Anorexigenic factors: alpha-Melanocyte-stimulating hormone (a-MSH); CART
Leptin is able to stimulate the hypothalamus because?
Lack of BBB
Arcuate nucleus projects to…
Lateral and medial hypothalamus
Medial hypothalmus factors
Anorexigenic: CRF, TRF
Laterial hypothalmus factors
Orexigenic: MCH
Neuropeptide Y does what?
Neuropeptide Y neurons in arcuate nucleus project
to medial hypothalamus (PVN), where they inhibit anorexigenic peptides (CRF), and to lateral hypothalamus, where they stimulate orexigenic peptides (MCH)