Assessing neurotoxicity authoritatively
April 9, 2004 10:37 PM Subscribe
BioMeFites, what's the authoritative process on assessing neurotoxicity of any substance, in general? [more inside]
I wrote a similar post at Straight Dope boards. It's a loooong post. Someone read it and tell me if I can post it here. You can help with the specific and supplementary points raised in that post. But, just the question above, will also do.
I wrote a similar post at Straight Dope boards. It's a loooong post. Someone read it and tell me if I can post it here. You can help with the specific and supplementary points raised in that post. But, just the question above, will also do.
Response by poster: Well, that doesn't help. The whole point of my post is to know what's the current consensus on authoritative assay of neurotoxicity. Given that you have Ricaurte saying* that process A is conclusive and accurate, O'Callaghan saying another process is accurate. And these two processes lead to opposite conclusions, or atleast not matching conclusions. Now, I'm not in the bio/medical field, so I don't trust myself to comprehensively spot errors of reasoning or methodology. If I have to personally research into that, I might as well take up medical school.
I was hoping that MeFi with 17,000 members would have atleast 200 members with relevant experience. Of whom, hopefully, 3-7 chance upon this post. Same for the post at the Straight Dope.
You did mention something about meta-analyses. Is there a way to locate the most recent representative meta-analyses of neurotoxicity detection?
*Read the linked Straight Dope post.
posted by Gyan at 11:44 PM on April 9, 2004
I was hoping that MeFi with 17,000 members would have atleast 200 members with relevant experience. Of whom, hopefully, 3-7 chance upon this post. Same for the post at the Straight Dope.
You did mention something about meta-analyses. Is there a way to locate the most recent representative meta-analyses of neurotoxicity detection?
*Read the linked Straight Dope post.
posted by Gyan at 11:44 PM on April 9, 2004
I seem to remember reading an article saying that the only study linking MDMA to brain damage was flawed because the drug they actually used on the rats was something like crystal meth (!) and not MDMA (oops). But I don't have a link for you.
As far as personal anecdotes, while I don't think MDMA is chemically addictive, I have known some people who seem to be permantenly "e-tarded".
posted by falconred at 1:21 AM on April 10, 2004
As far as personal anecdotes, while I don't think MDMA is chemically addictive, I have known some people who seem to be permantenly "e-tarded".
posted by falconred at 1:21 AM on April 10, 2004
Gyan: To reference your post on the Straight Dope boards, Ricaurte (who said "Everyone in the field has accepted [MDMA] is a neurotoxin") was the researcher that later admitted that he gave the test animals amphetamines instead of MDMA. As a result, his test data is worthless. At the moment, there is no conclusive (or even compelling) evidence that recreational doses of MDMA cause neurotoxicity.
falconred: The problem with anecdotal evidence like that is that there's no control group. Most people who do a lot of MDMA also tend to smoke pot, go to raves, do impure/contaminated/mislabelled drugs etc. They live a certain lifestyle, and without a group of people to check against who live the exact same lifestyle (raves, pot, etc.) but don't do E, there's no way to be sure that it's MDMA that causes the problems, and not some other factor (or a combination of MDMA and other factors).
posted by Jairus at 5:29 AM on April 10, 2004
falconred: The problem with anecdotal evidence like that is that there's no control group. Most people who do a lot of MDMA also tend to smoke pot, go to raves, do impure/contaminated/mislabelled drugs etc. They live a certain lifestyle, and without a group of people to check against who live the exact same lifestyle (raves, pot, etc.) but don't do E, there's no way to be sure that it's MDMA that causes the problems, and not some other factor (or a combination of MDMA and other factors).
posted by Jairus at 5:29 AM on April 10, 2004
I don't know if there's one single method. The problem is that "neurotoxicity" isn't just one thing. There's probably a couple dozen different types of damage that can be done to the central nervous system. For each one there's a different test.
For animal studies (say, for research into compounds which are being considered for human pharmaceutical testing) I believe the procedure is to give the drug to the test animal for a while, kill it, slice up its brain and look at the slices under a microscope. Have a pathologist compare the tissue to a control group. Even then, my understanding is they'll use several different stains to look for different things. Of course, this method can't be used on humans.
You might also be interested in this article, which looks like it gives a more recent (2003) review of the state of knowledge of neurotoxicity of MDMA. (Abstract only; it's $30 to see the full article, unless you're at an institution which already has an electronic subscription to Brain Research Reviews. But if you're interested, I'd check with the librarians at your local public library--they may be able to get the article for you for less. Or, if you're near a major university--especially one with a medical school--check to see if their library has a subscription.)
posted by DevilsAdvocate at 5:56 AM on April 10, 2004
For animal studies (say, for research into compounds which are being considered for human pharmaceutical testing) I believe the procedure is to give the drug to the test animal for a while, kill it, slice up its brain and look at the slices under a microscope. Have a pathologist compare the tissue to a control group. Even then, my understanding is they'll use several different stains to look for different things. Of course, this method can't be used on humans.
You might also be interested in this article, which looks like it gives a more recent (2003) review of the state of knowledge of neurotoxicity of MDMA. (Abstract only; it's $30 to see the full article, unless you're at an institution which already has an electronic subscription to Brain Research Reviews. But if you're interested, I'd check with the librarians at your local public library--they may be able to get the article for you for less. Or, if you're near a major university--especially one with a medical school--check to see if their library has a subscription.)
posted by DevilsAdvocate at 5:56 AM on April 10, 2004
i (briefly) looked through the article that devilsadvocate linked to; seems to be pretty thorough. i'd make it available to all except for the whole copyright thing - hesitant to just post it on a website and say download away (given that elsevier, the publisher, is on the cusp of publishing something i wrote i don't want to risk pissing them off). if anyone really wants a copy and can't get it locally, send me an email (in my profile) and i'll forward the pdf to you.
posted by caution live frogs at 10:51 AM on April 10, 2004
posted by caution live frogs at 10:51 AM on April 10, 2004
Response by poster: DevilsAdvocate: The monograph referenced in my SD post, covers that. The author in the introduction (and in the rest) compares gliosis with the other methods. Neurotoxicity is defined as "...damages or destroys nerve tissue". I take that to mean actual physical damage, as opposed to cognitive deficits (even if permanent and ultimately due to physical damage).
posted by Gyan at 11:47 AM on April 10, 2004
posted by Gyan at 11:47 AM on April 10, 2004
This thread is closed to new comments.
posted by gramcracker at 11:29 PM on April 9, 2004