Posted by linkadge on October 5, 2007, at 8:38:57
In reply to Re: Which drugs are the most neuroprotective?, posted by zana on October 4, 2007, at 19:51:26
Yes lithium can be bad for the kidneys, but it is a highly neuroprotective substnace.
Lithium goes beyond neuroprotection to actual neuroregeneration. Lithium enhances the activity of a substance called BCL-2 which actually promotes regeneration of axons. Lithium is neurotrophic thorought the brain, not just the hippocampus.
But lithium does not have the kind of pep that antidepressants do. Its one of those drugs that people take religiously for heuristic values.
Its one of those drugs that you take for 5 years and you look back and notice that you have a better brain. I found it very difficult to tollerate, but I am still toying with the idea of perhaps a low dose longer term.Some more recent work of Dr. Manjii on bipolar, suggests that even subtheraptutic doses can massivly increase the level of the BCL-2 protein, so it is his assumption that even very low doses my have some protective effect on disease progression.
All the anticonvulstants have *some* degree of neuroprotective capacity, but some of these studies results are disease dependant. The are generally neuroprotective via simply modulation of neurotransmitter release. They do not employ the activation of the cellular survival genes like lithium does ie BDNF/BCL-2
Antidepressants have mixed ability to be neuroprotective. They are highly neuroprotective in models of Huntingtons (which is a disease who's primary source of neurdegeneration is abnormal glutamate regulation) Ie all the SSRI's and SNRI's generally show a dramatic and medication specific ability to slow the progression of Huntintons. Actually, in this regard, antidepressants are a bit better than lithium which also has some application. This is suggestive of a glutamate modulating effect of the antidepressants. The SSRI's indirectly will lower glutamate release in certain brain regions.
If the SSRI's were neurotoxic, its not likely that the mechanism is glutamate neurotoxicity otherwise they would be as bad for Huntingtons as MSG is, which they are not.The notion that SSRI's cause brain dammage is somewhat more speculative, but is probably a result of mechanisms such as overstimulation of receptors, or neuroanatomical changes due to continually reduced dopaminergic neurotransmission.
I don't know if there is a difinitive model of antidepressant induced neurotoxicity. Most studies demonstrating such changes tend to use doses far in excess of the human dose range.
Linkadge
poster:linkadge
thread:786887
URL: http://www.dr-bob.org/babble/20070929/msgs/787015.html