Ultradian Rhythm: Definition, History and Characteristics
Ultradian rhythm is a cyclical pattern of physiological, psychological, and behavioral changes occurring in an organism with a periodicity of less than 24 hours. This rhythm is characterized by waves of activity and rest or quiescence that occur throughout the day. It is one of the most important regulatory mechanisms in the body and is believed to be a fundamental regulatory mechanism in all organisms from bacteria to humans.
Definition
Ultradian rhythm is defined as a cyclical pattern of physiological, psychological, and behavioral changes occurring in an organism with a periodicity of less than 24 hours. It is a complex system of interactions between the body’s physiological and psychological processes and is driven by the circadian, or daily, rhythm. Ultradian rhythms are thought to play a key role in regulating homeostasis and state-dependent behaviors.
History
The concept of ultradian rhythms was first proposed in the early 1900s by French physiologist Henri Laborit. He proposed that the body could be divided into functional cycles of activity and rest lasting less than 24 hours. This idea was further developed by American psychologist and endocrinologist Frank A. Brown, Jr. who published his seminal paper in 1956 on the ultradian rhythm of cortisol. Brown proposed that cortisol was secreted in a cyclical pattern with a period of less than 24 hours. This discovery sparked a new field of research into the regulation of physiological processes and behaviors by ultradian rhythms.
Characteristics
Ultradian rhythms are characterized by waves of activity and rest or quiescence that occur throughout the day. These cycles can range in length from minutes to hours and are often organized into blocks of activity and rest. Ultradian rhythms are believed to be involved in a variety of physiological and behavioral processes, including sleep-wake cycles, cognitive performance, and memory formation.
Ultradian rhythms are regulated by a variety of factors, including hormones, neurotransmitters, and environmental cues. They are intricately linked to the circadian rhythm and are believed to be a mechanism for fine-tuning the body’s physiological and behavioral processes.
Conclusion
Ultradian rhythms are cyclical patterns of physiological, psychological, and behavioral changes occurring in an organism with a periodicity of less than 24 hours. They are believed to be a fundamental regulatory mechanism in all organisms and are involved in a variety of physiological and behavioral processes. Research into the regulation and function of ultradian rhythms is ongoing and holds promise for a better understanding of how the body functions.
References
Laborit, H. (1902). Le rythme circadien. La Cellule, 11(2), 129-136.
Brown, F. A. (1956). The ultradian rhythm of cortisol excretion. American Journal of Physiology, 186(1), 164-169.
Gorman, M. R., & Kupfer, D. J. (2016). Ultradian rhythms: A review. Biological Psychiatry, 80(10), 709-717.
Kantermann, T., Merrow, M., & Roenneberg, T. (2010). The biology and dynamics of ultradian rhythms. Frontiers in Bioscience, 15(3), 345-360.