Evolution and physiology of neural oxygen sensing

Area of Science:

• Evolutionary biology
• Physiology
• Neuroscience

Background:

• Atmospheric oxygen (O2) levels have profoundly shaped animal physiology and evolution.
• The development of aerobic respiration and increasing O2 concentrations spurred the evolution of specialized organ systems for O2 transport.
• Cardiorespiratory function in animals has evolved in response to global O2 variations throughout geological periods.

Purpose of the Study:

• To explore the concept that regulating oxygen homeostasis is a fundamental role of the nervous system.
• To review the physiology of the peripheral chemoreflex and its evolutionary significance.
• To discuss the role of hypoxia and the peripheral chemoreflex in the context of cardiovascular and respiratory diseases.

Main Methods:

• This review synthesizes existing research on evolutionary physiology and neuroscience.
• It focuses on the peripheral chemoreflex pathways, including glomus cells and brainstem regions.
• The review examines the integrative effects of chemoreflex activation and its evolutionary importance.

Main Results:

• Oxygen transportation systems are regulated by brain mechanisms that sense O2 availability.
• The peripheral chemoreflex is the primary system in vertebrates for sensing oxygen and responding to hypoxia.
• This system is crucial for regulating autonomic and respiratory responses, ensuring survival during hypoxic challenges.

Conclusions:

• Regulating oxygen homeostasis appears to be an ancient and primordial function of the nervous system.
• The peripheral chemoreflex system is essential for the survival of complex vertebrates.
• Understanding the evolutionary context of hypoxia and the peripheral chemoreflex is vital for addressing cardiovascular and respiratory diseases.