Comprehensive Study Notes on Hypothalamic Regulation of Hunger and Satiety

Vocabulary terms and definitions related to the neural and hormonal mechanisms of hunger and satiety regulation as described in the lecture notes.

Anorectic Neurons

Hypothalamic neurons that release $\alpha$-melanocyte-stimulating hormone ($\alpha$-MSH) and cocaine- and amphetamine-regulated transcript (CART) to inhibit food intake.

Orexigenic Neurons

Hypothalamic neurons that release neuropeptide Y (NPY) and agouti-related peptide (AgRP) to promote hunger and food intake.

Alpha-melanocyte-stimulating hormone ($\alpha$-MSH)

An anorectic peptide that projects to the paraventricular nucleus (PVN) and lateral hypothalamic area (LHA) to promote energy expenditure.

CART

Cocaine- and amphetamine-regulated transcript; a satiety signal activated by leptin and insulin to inhibit food intake.

NPY

Neuropeptide Y; an orexigenic peptide that stimulates appetite and inhibits the activity of anorectic neurons when energy stores are low.

AgRP

Agouti-related peptide; a hunger signal that works in opposition to satiety signals to increase feeding behavior.

Leptin

A hormone that activates satiety-signaling neurons and inhibits hunger-signaling neurons to maintain energy balance.

Insulin

A hormone that, along with leptin, acts on the arcuate nucleus to trigger physiological responses that inhibit feeding.

GLP-1

Glucagon-like peptide-1; released from intestinal cells post-eating, it acts on the Nucleus of the Tractus Solitarius (NTS) and hypothalamus to inhibit appetite.

CCK

Cholecystokinin; a gastrointestinal signal indicating fullness that acts on the vagus nerve to reduce meal size and frequency.

MCH

Melanin-concentrating hormone; a hypothalamic peptide that stimulates feeding behavior and promotes appetite.

Orexins (Hypocretins)

Peptides produced in the hypothalamus that increase appetite and promote wakefulness.

Arcuate nucleus

The site of transduction in the hypothalamus that integrates humoral signals like leptin or insulin to regulate energy intake.

PVN

Paraventricular nucleus; a target for anorectic neuron projections that promotes the suppression of appetite.

LHA

Lateral hypothalamic area; an area that receives projections from anorectic neurons to increase energy expenditure.

Humoral Response (Hunger)

A physiological response triggered by decreased leptin or insulin leading to decreased secretion of TSH and ACTH.

Viscero-motor Response (Satiety)

A response to increased satiety signals involving increased sympathetic activity and decreased parasympathetic activity.

Somatic Motor Response (Satiety)

The inhibition of feeding behavior through the activation of anorectic peptides like $\alpha$-MSH and CART.

Medial preoptic area

The hypothalamic region that mediates thermal signals to adjust sympathetic and parasympathetic output.