Posted by Sarah T. on March 21, 2005, at 2:01:40
In reply to Re: Medications and sleep, specifically REM sleep » Sarah T., posted by SLS on March 19, 2005, at 8:19:44
> > > > Is it global throughout the brain or regionally specific? I imagine the visual cortex in the occipital lobes are exempt.
I will have to do more reading on this to answer you as thoroughly as I'd like. From what I know now, I believe that it is regionally specific. For example, most, but not all, of the body's motorneurons are inactive during REM sleep, so the neurotransmitters affecting those particular motorneurons are not released at that time; however, there are other motor neurons, such as the motor neurons controlling the muscles around the eyes, that are very active during REM and, therefore, the neurotransmitters activating those motorneurons are being released during REM sleep.
> > >> Sleep deprivation allows me to feel improved for the first half of the day after. Of course, I pay for this the following day.
I wonder whether sleep-deprivation-induced improvement is as short-lived for others who experience some improvement. It makes sense that you might feel a bit better because if several neurotransmitters are not released during REM, and you're not experiencing REM because you haven't slept, then you won't have the decline in neurotransmitter levels that occurs during REM. That also makes me wonder whether I have too much of a decline in NT levels during REM sleep. I tend to feel pretty awful in the morning, and I feel better as the day progresses. Perhaps I experience too much of a decline, so it takes longer to build up to a therapeutic concentration of neurotransmitters.
> > > > REM sleep might not be as important as once thought. Perhaps it is more a marker of neuronal activity than a participant. It is a fact that antidepressants downregulate certain receptors. This might be because the exposure to neurotransmitter is elevated enough and chronic enough to elicit the second messenger system and gene transcription events to a degree that would not be suppressed by REM sleep anyway. This could explain the efficacy of trimipramine, mirtazapine, bupropion, and nefazodone. These drugs do not suppress REM sleep and sometimes increase it. Have you tried any of these?
Hmmm. Thank you for mentioning those. I did take bupropion for a long time. I had terrible insomnia on it. I have tried the other medicines only briefly. I will probably try trimipramine again some day.
As for the importance of REM sleep, just a few weeks ago, I came across an article by an ophthalmologist who believes that the purpose of REM sleep is to oxygenate the cornea. The aqueous humor needs to circulate in order to bring oxygen from the blood vessels in the iris back to the cornea. When the eyelids are closed, circulation in the aqueous humor stops unless the eyes are moving. The ophthalmologist believes this explains why periods of REM get longer as the night progresses.
> > > Consolidation of memory and LPT can occur in the absence of REM sleep.
>Yes, I am coming across more articles indicating that REM sleep is not necessary for memory consolidation. Dolphins have almost no REM sleep, yet they learn very well.
> >> Were you depressed in school? I had to drop out of college when I could no longer read, learn, and remember. These things became problematic when my depression worsened. I was naive to antidepressants at the time.
>I think I've probably been depressed most of my life, but I didn't really become aware of it until I was in my mid to late twenties. In other words, I felt bad, but I didn't place a diagnostic label on those feelings until many years later.
>
> I think your hypothesis regarding your own illness might be correct. I am less responsive now to those medications that had once been effective and at that time suppressed dreaming and produced discontinuation dreaming rebound. These same drugs do not work or suppress dreaming. I would assume that dreaming had been a marker of REM sleep. However, dreaming and REM are not mutually inclusive. You can dream without REM and have REM without dreaming. How do you know that you do not experience a suppression of REM sleep?
>Yes, dreaming can occur during non-REM sleep as well. A few months ago, I read about a woman who lost the ability to dream after she had a stroke deep in the back part of the brain, around the posterior communicating artery. Her vision was also affected temporarily. Her dreams did not return for at least a year, and they were never again as frequent, vivid or intense as they had been before the stroke. In spite of losing the ability to dream, her REM sleep was absolutely normal. This led the researchers to confirm what they'd already suspected: that REM and dreaming are controlled by different brain systems.
How do I know that I do not experience suppression of REM sleep? I don't know that for a fact. I just know that when I've been on medicines that are known to suppress REM, I don't do well. I don't feel as if I've slept. On most AD's, I don't feel rested or refreshed after sleeping. I feel as if I've been unconscious, but not asleep.
Now, speaking of sleep, I think I'd better get some. To be continued. . .
poster:Sarah T.
thread:472726
URL: http://www.dr-bob.org/babble/20050317/msgs/473450.html