What is the Origin of Orexigenic Signal Amplification?

The term is a compound derived from the Greek orexis (appetite or desire) and genes (producing), meaning "appetite-producing." "Amplification" denotes a pathological increase in the signal's magnitude or effect. This concept is central to the neuroendocrinology of feeding behavior, specifically pointing to dysregulation in the hypothalamic feeding centers.

What is the Mechanism of Orexigenic Signal Amplification?

This phenomenon often involves a sustained increase in the secretion of the peptide hormone ghrelin from the stomach, which acts on the hypothalamus to stimulate the Agouti-related peptide (AgRP) and Neuropeptide Y (NPY) neurons, powerfully driving hunger. Concurrently, a state of leptin resistance can diminish the opposing satiety signal, leading to a net effect of amplified orexigenic drive. This chronic stimulation overcomes normal behavioral control, promoting hyperphagia.

Orexigenic Signal Amplification ∞ Area

Orexigenic Signal Amplification

Meaning

A pathological increase in the strength or frequency of neuroendocrine signals that stimulate appetite and promote food-seeking behavior, leading to a persistent state of hunger and increased caloric intake. This amplification often results from hormonal dysregulation, such as elevated ghrelin levels or reduced sensitivity to satiety hormones, contributing significantly to weight gain and the development of obesity. It represents a clinical imbalance favoring energy intake over energy expenditure.