Related Experiment Video
Updated: Mar 11, 2026

09:29
Author Spotlight: Hypothalamic Neural Mechanism Insights
Published on: August 4, 2023
4.9K
Orexin/Hypocretin Signaling.
1Biochemistry and Cell Biology, Department of Veterinary Biosciences, University of Helsinki, POB 66, FIN-00014, Helsinki, Finland. jyrki.kukkonen@helsinki.fi.
Current Topics in Behavioral Neurosciences
|December 3, 2016
Summary
Orexin peptide signaling through OX1 and OX2 receptors shows diverse cellular responses. This diversity is observed across various cell types and species, highlighting complex signaling pathways.
Area of Science:
- Neuroscience
- Molecular Biology
- Endocrinology
Background:
- Orexin peptides (orexin-A and orexin-B) mediate their effects via two G-protein-coupled receptors (GPCRs): OX1 and OX2.
- Previous research has explored orexin signaling in various endogenous and heterologous cell systems, including neurons and other cell types.
Purpose of the Study:
- To present orexin signaling on cellular and molecular levels.
- To discuss receptor signaling pathways across different tissues, cell types, and species.
Main Methods:
- Investigation of orexin signaling in diverse endogenously orexin receptor-expressing cells (neurons and others).
- Analysis of orexin signaling in recombinant cells expressing OX1 and OX2 receptors.
- Comparative analysis of signaling pathways across different biological contexts.
Main Results:
- Findings indicate partially convergent signaling patterns across different cell systems.
- Evidence suggests significant cellular background-specific signaling, contributing to overall diversity.
- A general picture of high diversity in orexin receptor signaling is presented.
Conclusions:
- Orexin receptor signaling exhibits inherent complexity and diversity.
- Understanding these diverse pathways is crucial for elucidating orexin's physiological roles.
Related Concept Videos
Sleep-Wake Cycles
3.1K
Sleep is an essential physiological process vital to maintaining overall well-being. The reticular activating system (RAS), a network of neurons in the brainstem, regulates wakefulness and sleep. While it may seem passive, sleep consists of distinct cycles, each with its unique characteristics and functions. Two key sleep phases are non-rapid eye movement (NREM) and rapid eye movement (REM).
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
3.1K
Regulation of Food Intake
3.0K
Short-term regulation of food intake primarily involves neural signals from the gastrointestinal (GI) tract, blood nutrient levels, and GI tract hormones. Communication between the gut and brain via vagal nerve fibers plays a significant role in evaluating the contents of the gut. Clinical studies have shown that protein ingestion produces a more prolonged response in these nerve fibers compared to an equivalent amount of glucose. Additionally, the activation of stretch receptors caused by GI...
3.0K
Narcolepsy
694
Narcolepsy is a chronic sleep disorder characterized by pervasive, uncontrolled sleepiness and other sleep disturbances. One of its hallmark symptoms is an abrupt transition to REM sleep upon falling asleep, which causes symptoms typically associated with this phase to occur unexpectedly during wakefulness. These include the following symptoms, which typically last from a minute or two to half an hour.
694
Diencephalon: Hypothalamus and Coordination
4.9K
The hypothalamus is a small yet highly complex and essential brain region that plays a crucial role in regulating various bodily functions. Anatomically, it is located at the base of the brain, just above the brainstem and below the thalamus, forming part of the limbic system.
The hypothalamus interacts with other brain regions, including the pituitary gland, through a direct physical connection called the hypothalamic-pituitary axis. The hypothalamus receives somatic and visceral inputs and...
The hypothalamus interacts with other brain regions, including the pituitary gland, through a direct physical connection called the hypothalamic-pituitary axis. The hypothalamus receives somatic and visceral inputs and...
4.9K
Circadian Rhythms and Gene Regulation
4.7K
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent...
4.7K
Parasympathetic Signaling
3.6K
Parasympathetic signaling plays a crucial role in regulating various physiological processes. It involves the release of acetylcholine (ACh) by parasympathetic neurons, which can have localized and short-lived effects. The majority of ACh released is rapidly inactivated at the synapse by the enzyme acetylcholinesterase (AChE), which hydrolyzes Ach into choline and acetate. Additionally, the tissue cholinesterase deactivates any ACh diffusing into the surrounding tissues.
The effects of...
The effects of...
3.6K

