What is the Origin of Ghrelin Orexin Axis?

This conceptual axis emerged from independent discoveries: Ghrelin was identified as a potent growth hormone secretagogue and appetite stimulant, while Orexin peptides were found to be central regulators of arousal and energy balance in the hypothalamus. The clinical recognition of their profound functional interplay, particularly in conditions like narcolepsy and obesity, forms the basis of this axis.

What is the Mechanism of Ghrelin Orexin Axis?

Ghrelin, secreted from the stomach when fasting, acts on the hypothalamus to stimulate Orexin neurons, which in turn promote wakefulness and a strong feeding drive. This dual action ensures that the organism is alert and highly motivated to seek food when energy stores are perceived as low, thereby linking metabolic signals to essential cognitive and behavioral states through direct neuropeptide signaling.

Ghrelin Orexin Axis ∞ Area

Ghrelin Orexin Axis

Meaning

A neuroendocrine signaling pathway that integrates peripheral energy status with central nervous system arousal and feeding behavior, primarily involving the gut-derived hormone Ghrelin and the hypothalamic neuropeptides Orexin, also known as Hypocretin. This axis plays a crucial, integrated role in the homeostatic regulation of hunger, satiety, and the promotion of sustained wakefulness. Clinical modulation of this axis is key for metabolic health.