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Orexin System: The Key for a Healthy Life
Sergio Chieffi1, Marco Carotenuto2, Vincenzo Monda1
1Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetic and Sport Medicine, Università degli Studi della Campania "Luigi Vanvitelli"Naples, Italy.
Frontiers in Physiology
|June 17, 2017
Summary
Orexin neuropeptides regulate wakefulness, feeding, and mood. Orexin deficiency causes narcolepsy, obesity, and deficits in learning and memory, highlighting their vital physiological roles.
Area of Science:
- Neuroscience
- Endocrinology
- Physiology
Background:
- Orexin-A/hypocretin-1 and orexin-B/hypocretin-2 are neuropeptides synthesized in the lateral hypothalamus.
- Orexin neurons regulate critical functions like sleep-wake states, feeding, energy homeostasis, cognition, and mood.
Purpose of the Study:
- To investigate the multifaceted roles of orexinergic system in physiological regulation.
- To explore the link between orexin system dysfunction and pathological conditions such as narcolepsy and obesity.
Main Methods:
- Review of existing literature on orexin neuron synthesis, signaling, and function.
- Analysis of studies on orexin deficiency in animal models related to narcolepsy, obesity, and cognitive function.
Main Results:
- Orexin neuron loss is implicated in narcolepsy, emphasizing their role in wakefulness.
- Orexin deficiency in animal models leads to obesity due to reduced physical activity and energy imbalance, despite lower caloric intake.
- Orexinergic signaling influences cognition and mood, with deficiency causing learning/memory deficits and depression.
Conclusions:
- The orexinergic system is crucial for maintaining wakefulness, energy balance, and emotional regulation.
- Dysfunction of the orexin system is associated with narcolepsy, obesity, and mood/cognitive impairments.
- Orexin signaling plays a significant role in promoting obesity resistance through physical activity and energy expenditure.
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