Can’t sleep? Can’t think clearly? Feel depressed? It may not be what you think.
“The bacteria residing inside of you outnumber your own cells 10:1 and affect sleep, cognition, mood, brain temperature, appetite, and many additional brain functions. Yet we lack an understanding of how they do it,” explained James Krueger, PhD, MDHC, Regents Professor at the WSU College of Veterinary Medicine, Department of Integrative Physiology and Neuroscience.
With a $1 million grant from the W. M. Keck Foundation, Krueger and colleagues at Washington State University and the University of Massachusetts Amherst (UMA) will explore whether variations in brain levels of bacterial fragments can account for life’s sleep/wake and 24-hour cycles, known as circadian rhythms.
The sleep research is led by Krueger and the circadian rhythm portion of the project is led by Associate Professor Ilia Karatsoreos, PhD, at UMA, who was formerly at WSU and a co-investigator on the study.
The award builds on nearly 40 years of cutting-edge sleep research. In the early 1980s, Krueger isolated a sleep-promoting molecule from brains of sleep deprived rabbits and from human urine. Its chemical structure was a muramyl peptide – a building block component of bacterial cell walls.
At the time of the discovery, it was difficult to measure small amounts of muramyl peptides. As a result, determination of the brain’s muramyl peptide levels and whether they correlated with sleep-wake cycles or with circadian rhythms was shelved. Now, improved measurement technologies and the W. M. Keck Foundation funding enables this work to be done.
Further, WSU researchers will determine if sleep loss results in increased levels of muramyl peptides in the brain; a predicted result based on the 1980’s work.
The UMA researchers will use models of simulated jet lag, a way to transiently disrupt our circadian (daily) rhythms. Disruption of these rhythms is associated with multiple changes including sleep, cognition, and body temperature. They will determine if muramyl peptide levels in the brain correlate with such changes.
“When jetlagged, many of the normal bodily functions are out of synchrony with each other. This is a consequence of altering circadian rhythms,” Karatsoreos said. “By looking for changes of bacterial products in the brain, we anticipate we will discover new approaches to treat jet lag, and possibly the desynchrony of physiological functions that occurs with old age.”
A third goal of the W. M. Keck funded work will be to determine how brain muramyl peptides elicit sleep. “Our minds are an outcome of a bacteria/human symbiosis,” Krueger said. “Expanding this concept by determination of how such disparate species talk to each other will transform our views of cognition, psychiatric disorders, consciousness including sleep, and our understanding of what it means to be human.”
Based in Los Angeles, the W. M. Keck Foundation was established in 1954 by the late W. M. Keck, founder of the Superior Oil Company. The Foundation’s grant making is focused primarily on pioneering efforts in the areas of medical research, science and engineering and undergraduate education. The Foundation also maintains a Southern California Grant Program that provides support for the Los Angeles community, with a special emphasis on children and youth. For more information, please visit www. wmkeck.org.
- Laura Lockard, WSU College of Veterinary Medicine, 206-861-6884, firstname.lastname@example.org