Related Experiment Video
Updated: Jul 22, 2026

Eye Tracking, Cortisol, and a Sleep vs. Wake Consolidation Delay: Combining Methods to Uncover an Interactive Effect of Sleep and Cortisol on Memory
Published on: June 18, 2014
Orexins (hypocretins) and adrenal function
O Jöhren1, N Brüggemann, P Dominiak
1Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany. joehren@uni-luebeck.de
Abstract:
The recently discovered neuropeptides orexin A and B regulate feeding behavior, neuroendocrine and autonomic functions, and sleep-wakefulness by central mechanisms. The expression of orexins and orexin receptors in various peripheral organs and the presence of orexin A in blood indicate the existence of a peripheral orexin system. In rat and human adrenal glands, both OX (1) and OX (2) receptor subtypes have been described with a predominant expression of OX (2) receptors in the adrenal cortex. In male rats, adrenocortical OX (2) receptors are much higher expressed than in female rats. Various experimental data demonstrate a stimulatory effect of orexins on the secretion of adrenocortical steroids, mainly on glucocorticoids. Some results also suggest the regulation of catecholamine synthesis and release by orexins. Whether the gender-dependent expression of adrenocortical OX (2) receptors has functional correlates awaits future clarification. As plasma orexin appears to rise during hunger and hypoglycemia, orexins may link adrenal functions with energy homeostasis.
Related Concept Videos
Hypothalamic-Pituitary Axis
Sleep-Wake Cycles
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
Anatomy of the Adrenal Glands
These glands possess a distinctive yellow tinge due to the stored cholesterol and fatty acids required for hormone synthesis. They are encased in a fibrous capsule and cushioned by fat.
The adrenal gland comprises two distinct regions...
Hormones of the Adrenal Glands
The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone...
Major Hormones and Their Functions
Oxytocin, produced in the hypothalamus and released by the pituitary gland, plays a role in social bonding, childbirth, and lactation.
Cushing Syndrome II: Pathophysiology

