Posted by SLS on September 23, 2001, at 19:06:45
In reply to Re: Monominergic theories could be horse hockey, posted by jay on September 23, 2001, at 8:12:56
Hi Jay.
continued...Regarding the mechanisms of action of antidepressants:
> > > You will have to look at the book for sources, but he mentions that within one day of starting anti-depressants, both THE neurochemical *and* receptor changes occur...
> > He is wrong.
> >
> > It is well documented that the turnover rate of neurotransmitter receptors along the cell membrane is approximately two weeks - just about the time it takes for downregulation to occur in response to antidepressants - just about the time it takes for someone to respond to these antidepressants. Whether or not some types of receptors are changed in some way immediately, it is indisputable that changes in the binding characteristics of many monoamine receptors (NE beta-1, NE alpha-1, NE alpha-2, 5-HT1a, 5-HT2, etc.) and the behavior of many postsynaptic second-messenger events are latent and associated with the chronic, but not acute, administration of antidepressant drugs.> Well, that is your view. Read Peter Whybrow's "A Mood Apart" for discussion on the immediate changes of receptor sensitivity after a.d. administration. You are talking about the *complete* process of regulation, but that is old news.
It really has little to do with any view. Although it may be old news, it is quite well established news. I think it is still relevant and important when describing the biological events known to occur when the brain is exposed to many antidepressants.
This is why I reacted to you the way I did: I know this is going to sound picayune, but your use of the word "the" in your original post infers that the receptor changes responsible for the clinical effects of antidepressants occur immediately. I doubt this is true. I capitalized your use of the word "the" that I found so critical to the meaning of your sentence as I it quoted above. No hard feelings, I hope.
> More questions than answers.
Unfortunately.
I wish they'd find the answers before the day my brain becomes part of the NIH archives.
What precisely are the immediate changes that Peter Whybrow describes to occur with receptors? In what ways does he feel these changes participate in the way antidepressants produce their therapeutic effects? I would like to learn more about it. I probably won't buy his book right away, but I would be very interested to know what are the things in it that you find most salient. How does he go about treating difficult cases?
Thanks.
> Why do some a.d.'s work, that don't even touch NT levels?
Which ones in particular? I know trimipramine is a bit of a black sheep. I think iprindole might fit into that category, but I'd have to check on that. For that matter, Wellbutrin probably belongs in this category as well.
If I remember correctly - and it's been a long time - I think some experiments showed that there are actually some receptor changes that occur latently in laboratory animals (poor things) in response to a single dose of an antidepressant. In other words, you take one dose of imipramine, and two weeks later, changes in receptor function appear. Like I said, it's been a long time, but it is entirely conceivable that things like this can occur.
Sincerely,
Scott
poster:SLS
thread:79238
URL: http://www.dr-bob.org/babble/20010917/msgs/79405.html