RSS Feeds

Earth Science

Space Science

Life Science

Fields of Scientific Study

Nanotechnology

Cancer

Definitions of The Fields of Scientific Study

Sleep and sedation controlled in same brain centre, say scientists

August 25, 2002

Undergoing anaesthesia may be more like falling asleep than we once thought, according to new research from Imperial College London and Harvard Medical School, USA.

Researchers report today in the journal Nature Neuroscience how two of the most widely used anaesthetics, pentobarbital and propofol induce sleep by mimicking the natural process of falling into a deep sleep.

Using behavioural studies and molecular imaging techniques in rats, the team of basic scientists and clinicians found that the sleep-inducing action of anaesthetics is localised to a small area of the brain, the tuberomammillary nucleus (TMN), part of the hypothalamic region that controls other fundamental processes such as breathing and temperature regulation.

The team showed that the anaesthetics produce their sedative effect by locking on to a specific type of neurotransmitter receptor in the TMN called GABA-A.

GABA-A receptors have an inhibitory action, hence when anaesthetic molecules bind to them they stop the nerve cells from sending electrical signals to other neurons.

"The sleep-inducing action of general anaesthetics occurs by hijacking one pathway in the brain responsible for promoting deep sleep," said Professor Nick Franks of Imperial College London.

"The TMN region of the brain is part of a key switching mechanism in the sleep/wake cycle. When stimulated, it sends excitatory signals to other parts of the brain telling the body to be awake. TMN neurons are pharmacologically inhibited by the negative action of the anaesthetics binding to the GABA-A receptor - leading to a sleep induced state," said Professor Franks.

"Although not all anaesthetics exert their sedative effect using GABA-A receptors, the research is significant because it indicates that the sleep-inducing effect of anaesthetics acts on specific areas of the brain," he added.

Professor Mervyn Maze, Head of the Department of Anaesthetics and Intensive Care at Imperial College London and senior author of the study said that their new understanding of how anaesthetics induce sleep could lead to new anaesthetics providing a better recovery for patients.

"Individuals need a prolonged period of deep sleep to gain its restorative benefits. Patients recovering from surgery and those in intensive care often suffer from sleep-deprivation. Our research might lead to the design of anaesthetics that mimic non-REM sleep more accurately, reducing post-operative fatigue," said Professor Maze.

The research was supported by the Medical Research Council (UK), the Westminster Medical Trust (UK) and the National Institutes of Health (USA).

Imperial College, University of London

Science Research Departments

	Scientific Explorer's Mind Blowing Science Kit for Young Scientists by Scientific Explorer Mind blowing experiments to delight and educate young scientists! Erupt a color changing volcano. Mix up magic ooze with a mind of its own. Play with sand that never gets wet. Mix safe chemicals and watch colors change before your eyes. You'll amaze yourself and your friends as you explore the science behind these truly remarkable reactions.
	The Everything Kids' Science Experiments Book: Boil Ice, Float Water, Measure Gravity-Challenge the World Around You! (Everything Kids Series) by Tom Robinson (Author) Science has never been so easy - or so much fun! With The Everything Kids' Science Experiments Book, all you need to do is gather a few household items and you can recreate dozens of mind-blowing, kid-tested science experiments. High school science teach Tom Robinson shows you how to expand your scientific horizons - from biology to chemistry to physics to outer space. You'll discover answers to questions like: Is it possible to blow up a balloon without actually blowing into it? What is inside coins? Can a magnet ever be "turned off"? Do toilets always flush in the same direction? Can a swimming pool be cleaned with just the breath of one person? Get ready to enter the laboratory and learn how to conduct cool experiments, understand scientific terms...
	Scientific Explorer's Disgusting Science - A Kit for Studying the Science of Revolting Things by Scientific Explorer Grow your own friendly germs and fuzzy molds. Mix up a batch of coagulating fake blood. Even make a stinky intestine. learn the science behind unmentionable bodily functions while doing some truly NASTY Experiments. Ages 8+
	The Science Book: Everything You Need to Know About the World and How It Works (National Geographic) by National Geographic (Author), Marshall Brain (Foreword) A delight for the casual reader, yet so complete and wide-ranging that science buffs and students will welcome it, The Science Book encapsulates centuries of scientific thought in one richly illustrated volume. Natural phenomena, revolutionary inventions, and the most up-to-date investigations are explained in detailed text, and 2,000 vivid illustrationsincluding 3-D graphics and pictogramsmake the information even more accessible and amazing to discover. The Science Book offers both a general overview of topics for the browsing reader and more specific information for those seeking deeper insight into a particular subject. Six major sections, ranging from the universe and planet Earth to biology, chemistry, physics, and mathematics, encompass everything from microscopic life...
	Scientific Explorer's The Magic Science Wizard's Kit by Scientific Explorer Cast real smoke from your fingertips, make a wizard wand, and whip up color-changing potions in your test tube laboratory. Also included are laminated cards with wizard facts, an instruction booklet with 11 activities, lab equipment, and mysterious wizard powders that will mix together to mystify you!
	Scientific Explorer's Tasty Science Chemistry in the Kitchen Kit by Scientific Explorer Who knew science could taste so good? With this kit, you’ll whip up cupcakes, cookies, candy, and more—all in the name of science! Learn what makes cakes rise, candy crystallize, and more real chemistry happen in the kitchen. Tasty Science is packed with ingredients, recipes, activity cards, a test tube laboratory, and lots more to explore the science of taste.
	The Complete Book of Science, Grades 5-6 by School Specialty Publishing (Author) The Complete Book of Science for grades 5 to 6 teaches children important science skills! Children complete a variety of exercises that help them develop a number of skills in this 352 page workbook. Including a complete answer key this workbook features a user-friendly format perfect for browsing, research, and review. Over 4 million in print! The best-selling Complete Book series offers a full complement of instruction, activities, and information about a single topic or subject area. Containing over 30 titles and encompassing preschool to grade 8 this series helps children succeed in every subject area! ...
	Magic School Bus Journey into the Human Body Science Kit by Young Scientist Club The Magic School Bus and Ms. Frizzle take Young Scientists on a wild ride into the human body with these breathtaking experiments. Young Scientists bend bones, make joints, map taste buds, expand lungs, build a stethoscope, measure lung capacities and heart rates, perform the iodine starch test, spin glitter, simulate synovial fluid, create a human body poster, and much, much more! This exciting kit includes a life-size poster with eight sheets of body part stickers. So put on your seat belts, students, and get ready to discover The Human Body!
	Scientific Explorer's Glow in the Dark Fun Lab Science Kit by Scientific Explorer You will love setting up your own Glow in the Dark Fun Lab. Create a light wand, make your own glow stick, and even generate a human-powered light.
	What Is the World Made Of? All About Solids, Liquids, and Gases (Let's-Read-and-Find-Out Science, Stage 2) by Kathleen Weidner Zoehfeld (Author), Paul Meisel (Author) Did you ever walk through a wall? Drink a glass of blocks? Have you ever played with a lemonade doll, or put on milk for socks? This latest addition to the Let's-Read-and-Find-Out Science series introduces the youngest readers to an important science concept: the differences between solids, liquids, and gases. Any child who wants to know why he can't walk through a wall will enjoy Kathleen Zoehfeld's simple text and Paul Meisel's playful illustrations.