Biological Psychology - Hunger and Eating

Hypothalamic nuclei regulating hunger

Lateral hypothalamus (LH) and arcuate AgRP/NPY neurons promote hunger.

Hypothalamic nuclei regulating satiety

Ventromedial hypothalamus (VMH), paraventricular nucleus (PVN), and arcuate POMC/CART neurons promote satiety.

Hypothalamic nuclei regulating both hunger and satiety

Arcuate nucleus contains both hunger (AgRP/NPY) and satiety (POMC/CART) neurons.

Neurotransmitters of hunger pathway

NPY, AgRP, orexin; activated by ghrelin.

Neurotransmitters of satiety pathway

POMC, α-MSH, CART; activated by leptin, insulin, CCK, PYY.

Ghrelin function

Hunger signal from stomach that activates NPY/AgRP neurons.

Satiety signals

Leptin, insulin, PYY, and CCK increase with food intake and fat storage.

Defects in leptin signaling

Leptin deficiency or resistance prevents satiety → overeating → obesity.

Non-homeostatic influences on eating

Social cues, stress, habits, palatability, culture, time of day, portion size.

Mesolimbic pathway and eating

VTA → NAcc dopamine increases motivation to eat; sensitivity may be altered in obesity.

Brain regions influencing eating

PFC (control), amygdala (emotional eating), hippocampus (memory), insula (taste).