SRI International Research on Sleep and Wakefulness Featured in "Neurobiology Select" Series of the Journal Cell

MENLO PARK, CA--(Marketwire - May 07, 2009) - SRI International, an independent, nonprofit research and development organization, announced today that two recent papers co-authored by SRI researchers have been highlighted in the "Neurobiology Select" section of Cell, a scientific journal. Each month, the editors of Cell identify noteworthy recent papers in neurobiology. SRI-authored publications about sleep and wakefulness are highlighted in the May 1st issue.

"The recently published studies describe new insights into what controls the sleep/wake cycle," said Thomas Kilduff, senior director of Neurobiology at SRI International, and an author on both papers. "These studies may help explain what goes wrong with our sleep as we age and, in an extreme case, in the sleep disorder narcolepsy."

SRI's research published March 25, 2009 in the Journal of Neuroscience focused on new discoveries into the brain signals that control sleep and wakefulness. The studies provide evidence that thyrotropin-releasing hormone (TRH), known to promote wakefulness, does so by acting on hypocretin/orexin-producing neurons in the lateral hypothalamic area of the brain. Since hypocretin cells provide the brain with wake-promoting signals, scientists are now working on ways to adjust these signals.

The second paper, published March 17, 2009 in the Proceedings of the National Academy of Sciences in collaboration with scientists at Kanazawa University (Japan), the University of Basel (Switzerland), and the University of Texas Southwestern Medical Center, focused on the importance of gamma-aminobutryric acid (GABA), a major neurotransmitter in the central nervous system. Previous research has shown that degeneration of hypocretin neurons occurs in narcolepsy. The researchers were able to determine the consequences of keeping the hypocretin cells intact while selectively eliminating one of the receptors for GABA, the GABAB receptor, from these cells.

GABAB receptors were targeted because previous work by the SRI International-Kanazawa University team indicated that these receptors were particularly important for control of hypocretin cells. Elimination of GABAB receptors from hypocretin cells resulted in an inability to sustain a long period of wakefulness or of sleep, similar to what occurs in narcoleptics and in elderly people.

"This research may lead to greater understanding about disrupted sleep patterns, particularly in the elderly. The results lead us to question whether there is a loss of GABAB receptors on hypocretin neurons as we age," Kilduff said.

The sleep/wake rhythm changes with age, when seniors need to nap during the day and nighttime sleep is often disrupted. Similarly, inability to stay awake or asleep for extended periods of time is a primary symptom of narcolepsy. Patients suffering from narcolepsy are unable to stay awake for more than 3-4 hours without having to take a nap, yet only get about 8 hours of sleep per day.

Although it is not currently possible to selectively target a drug to a specific cell type in the nervous system, such as only to the hypocretin cells, greater understanding of the control of these cells by substances such as TRH and GABA may lead to the development of improved drugs for the treatment of sleep/wake disorders.

The work conducted at SRI described in these studies was supported by the National Institute of Aging and the National Institute of Mental Health.

About SRI's Biosciences Division

SRI International's Biosciences Division teams with pharmaceutical and biotechnology companies, academia, foundations, and government agencies to solve important problems in global health. SRI Biosciences conducts basic research, drug discovery, and drug development, including contract research. SRI has all of the resources necessary to take R&D programs from "idea to IND"™ -- from initial discovery to investigational new drug applications to start human clinical trials -- and specializes in cancer, immunology and inflammation, infectious disease, and neuroscience research. To date, SRI has helped advance more than 100 drugs into clinical trials, including a number of its own discoveries, several of which have reached the market. SRI is also working at the nexus of science and technology to create new technology platforms for the next generation of drug discovery and development in areas such as diagnostics, drug delivery, medical devices, and systems biology.

About SRI International

Silicon Valley-based SRI International (www.sri.com) is one of the world's leading independent research and technology development organizations. SRI, which was founded by Stanford University as Stanford Research Institute in 1946 and became independent in 1970, has been meeting the strategic needs of clients and partners for more than 60 years. Perhaps best known for its invention of the computer mouse and interactive computing, SRI has also been responsible for major advances in networking and communications, robotics, drug discovery and development, advanced materials, atmospheric research, education research, economic development, national security, and more. The nonprofit institute performs sponsored research and development for government agencies, businesses, and foundations. SRI also licenses its technologies, forms strategic alliances, and creates spin-off companies. In 2008, SRI's consolidated revenues, including its wholly owned for-profit subsidiary, Sarnoff Corporation, were approximately $490 million.