Sleep Helps Memory.   Of Mice and Men: Sleep Torture

By Les Porter

Are you a [hu]Man or a Mouse?  [This includes [wo]men too!]

Do you Forget!  (Perish the thought!)

Do you get enough sleep?  (How much sleep is enough sleep?)

If they won't let you sleep! how can you remember anything?

WHO are They?

Do you sleep-torture yourself?  Are you a cog in the system of profit and wage slavery, or a bit of debris?  That is one question you might have to answer yourself.  It will depend on your ideas of the "real world" or the world you are told by the financial system that you inhabit. Where is this sick pyramid they use to control you  located? 

Come on!  Why can't you remember anything?

This memory thing is part of the limbic system components--and one clear piece of the sleep torture treatment and memory was learned recently.

The Hippocampus is a part of the "Limbic System" and the limbic system reminds me of the Intel approach to chips.  The limbic system seems like a bunch of evolutionary "add-ons."  Intel adds another chip while the old Motorola approach was to write more powerful software and address the problems with a global view in stead of hardware.  Think of this part of evolution as new hardware.

Mice and Men -- as well as all other mammals, all reptiles, and of course the long gone dinosaurs, share brain structure that even we late newcomers are not at all conscious of "operating" -- and in many ways whose operation lies totally beyound our control.  Yes, we are talking old, primitive, sub-brain parts.  Such ancient brain capabilities came into existence long, long ago and are part of what we now call the "limbic" system.  Heck.  Where do you think your brain came from -- and how long has it taken your current model, the one you're driving,  to come into existence?  Will next-year's model be better?   Thinking about a trade-in?  Unlike your computer,  this model of brain changes, oh, so slowly.  It's architecture is so very old.

By old, I mean it existed in animals well before the evolution of either reptiles or mammals -- and continues to underlie all brain development in every brain of every species that enjoys the ability to "fight or flee," to "remember what has happened before," to experience "complex" course changing emotions, and even to get excited sexually, or collect a harem of mates.  The Limbic System is possibly older than 450,000,000 years and was built to perform functions that we are "possibly" in the early part of this century, going to begin to understand.

Physically, the Limbic System in humans is a relatively small part of the brain. In us, physically, it is relatively tiny compared to the mass of the cerebellum and cerebrum.  It is "primitive" in the sense that it came into existence so long ago, that it was mostly already developed and ready for reptiles, the dinosaurs, and mammals to build upon it.  In earlier animals with "smaller" overall brainsize, it is a major part of the brain of that life form.  In "higher" larger brained animals it acts as an intercessionary component or even in some functional aspects as an orchestrator, organizing or influencing the rest of the brain as a predominant undercurrent, or subtle manager of the architecture.  Does it have intelligence?  Not really.  But it sure forms the chassis for intelligence and the structure of the higher brain.  The limbic system, and the components there of are a long-used extant methodology living things have found to be reasonably successful for survival.  The hippcampus deep within the brain between the next set of "add-ons" is attached to both the higher and lower nervous system components.  Sitting above the brainstem, as a seeming "add-on" it was recognized by Paul Broca, the famous French doctor, anatomist and anthropologist.  Because of the historical behaviors of humans when parts of the human brain containing the limbic system components were damaged, the limbic system has long been recognized as the seat of emotions, the location of quick fight/flight responses, and the primary architect and engineer of memory, especially converting what is short-term memory to long-term memory.

The limbic system is actually quite complex and if you were a computer architecture designer you might consider them ancilliary parts, or if a software engineer attempting to come up with the perfect robot, you would likely engineer all of these components into the "instructions for operation" as well as using their messages and hardware and its hardwiring to carry messages within your robot..

http://upload.wikimedia.org/wikipedia/commons/thumb/b/bc/Constudoverbrain.png/439px-Constudoverbrain.png
Image: Wikipedia   entire brain, indicating proportions and locations.
 

Different authorities and experts describe different parts of the human and mammalian brain being part of the Limbic System.

Cingulate gyrus
Amygdala
Thalamus
Hypothalamus
Hippocampus
Pituitary gland

In the recent report in a letter to Nature,the hippocampus is what was studied. 

It is a bit more complex than old time ideas of nervous system signal transmission by Acetycholine and Cholinesterase.   There are a lot more "olines" and "esterases" now-a-days.  The "-esterases" are the chemical "erasers" that reset or allow the initial chemical triggers to be rebuilt for the next nerve data transmission.  They can be corrupted and neuro toxins in various venoms act to interfere in normal resets. That can kill you, not just mess up your sleep-tortured memory as learned by the team reporting in Nature.

upload.wikimedia.org/wikipedia/commons/9/99/Hippocampus.gif

Image animation from Wikipedia.  Hippocampus, part of the limbic system

 
There is a report in Nature, where you can read the conclusions of this 16-member team.    These scientists are a16-member team of "sleep-torturers" and have determined that the chemistry destroyed by their torture of mice is likely the same for men or other mammals -- and if you sleep-torture mice you can learn about what happens in humans who are also sleep-tortured.  The reason scientists like mice is that these relatives of ours [which as you might note  also includes "rats."] appear to have all the inesacapable consequences of mammalian biochemistry, and the same chassis -- the limbic system's functions.

A strengthening of long-term potentiation represents the ability to form a memory you can "remember" for a long time.  By experimenting with the molecule cyclic adenosine monophosphate [cAMP] the found that sleep deprived mice -- and probably all other sleep deprived mammals -- did not have as much available cAMP as well rested mice.  This cAMP is the messenger stuff of memory.  So what happens to it in sleep-torture? 

What occurs is that sleep deprivation produces an excess of another enzyme, a Phosphodiesterase [PDE4A5] enzyme that effectively dissembles the cAMP molecules that underlie the hard memory creation and reinforcement.  The PDE4A5 subverts successful attempts to transmit memory chemicals signals by destroying the messenger -- actually destroying the cAMP molecules..

The researchers then tried to use a bit of chemistry to disrupt the PDE4A5 created by the sleep deprivation by using Rolipram -- a concoction that prevents formation of the cAMP memory-eater PDE4A5. (and other PDE4's]

See Wikipedia's bit on Rolipram: link
en.wikipedia.org/wiki/Rolipram

See this link for a quick read about the Nature report!

sciencenow.sciencemag.org/cgi/content/full/2009/1021/1
Why Sleepyheads Forget By Michael Torrice, ScienceNOW Daily News
21 October 2009
 
The report itself is here:www.nature.com/nature/journal/v461/n7267/abs/nature08488.html

"Sleep deprivation impairs cAMP signalling in the hippocampus"

Christopher G. Vecsey[1,2,] George S. Baillie[3,] Devan Jaganath[2,] Robbert Havekes[2,] Andrew Daniels[2], Mathieu Wimmer[1,2,] Ted Huang[1,2,] Kim M. Brown[3,] Xiang-Yao Li[4,] Giannina Descalzi[4], Susan S. Kim[4,] Tao Chen[4,] Yu-Ze Shang[4,] Min Zhuo[4,] Miles D. Houslay[3] & Ted Abel[2]

   [1.] Neuroscience Graduate Group,
   [2.] Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
   [3.] Neuroscience and Molecular Pharmacology, Wolfson and Davidson Buildings, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
   [4.] Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada

 
Millions of people regularly obtain insufficient sleep. Given the effect of sleep deprivation on our lives, understanding the cellular and molecular pathways affected by sleep deprivation is clearly of social and clinical importance. One of the major effects of sleep deprivation on the brain is to produce memory deficits in learning models that are dependent on the hippocampus. Here we have identified a molecular mechanism by which brief sleep deprivation alters hippocampal function. Sleep deprivation selectively impaired 3', 5'-cyclic AMP (cAMP)- and protein kinase A (PKA)-dependent forms of synaptic plasticity in the mouse hippocampus, reduced cAMP signalling, and increased activity and protein levels of phosphodiesterase 4 (PDE4), an enzyme that degrades cAMP. Treatment of mice with phosphodiesterase inhibitors rescued the sleep-deprivation-induced deficits in cAMP signalling, synaptic plasticity and hippocampus-dependent memory. These findings demonstrate that brief sleep deprivation disrupts hippocampal function by interfering with cAMP signalling through increased PDE4 activity. Thus, drugs that enhance cAMP signalling may provide a new therapeutic approach to counteract the cognitive effects of sleep deprivation.

-------------

Will you remember who sleep-tortures you?

Or if you torture yourself? Will you remember?