Are there any studies that indicate a greater susceptability to
Parkinson's disease(presumably a result of dopaminergic injury) on the
part of former or current amphetamine abusers?
"John H." <johnh at faraway.xxx> wrote in message news:<3ed201dd at dnews.tpgi.com.au>...
> "Gene Haywood" <gehayw at hotmail.com> wrote in message
> news:bd56540c.0305252014.27f49b70 at posting.google.com...> > Where neurons are not killed outright, to what extent is neuronal
> > damage caused by amphetamines reversible?
>> Interesting question. However, the main neurons damaged by amphetamines are
> probably dopaminergic, and neurogenesis of these cells is probably very
> limited if at all. Additionally, I have noted a study in the Journal of
> Neurochemistry showing that dopaminergic neurons can be damaged and
> dysfunctional but remain alive. This raises questions regarding typical
> means of determining CNS damage from various agents. Recovery will be
> contingent upon age, dietary status, general health, mtDNA damage a very
> strong candidate for ongoing dysfunction as mtDNA much more suspectible to
> ROS damage than nuclear DNA. Interestingly, EPA administration to aged rats
> produced marked improvements in hippocampal LTP(probably via reduced
> presence of il 1 which is strongly implicated in age associated cognitive
> impairment and many others) and another study where alpha lipoic acid
> (generates protective gene transcription) and acetyl l carnitine (improves
> transport across mitochondrial membrane), also provided marked enhancement
> of cognition in rats.
>> As to the studies showing mild short term amphetamine doses causing lasting
> damage, I'm inclined to view these with suspicion. Remember all those peer
> reviewed studies about the neurological horrors of marijuana? Turns out that
> cannabinoids are amongst the most powerful neuroprotective agents
> available(Hampson et al, PNAS, July 7, 1998) and a recent study by Fried
> published in the Canadian Medical Journal claimed that post M use former
> chronic light smokers had increased iq (5.8pts) and even ongoing light
> smokers showing slightly higher iqs while current heavy smokers had slightly
> reduced iq but upon cessation had slightly increased iq (2.1 I think).
> Significantly, Fried did a series of longitudinal prospective studies on
> children whose mothers smoked during pregnancy and established deficits in
> these children, so he is hardly pushing the M barrow. However, another
> longitudinal study by Solwicj and Hall in Aus found that the most
> significant impairment from ongoing M smoking was in the academic realm ....
> Confused? Join the club.
>> MDMA purportedly causes permanent serotonergic dysfunction but I have noted
> studies in rats and one with women where after about 12 months the deficits
> vanished. I vaguely recall some primate studies showing that serotonergic
> neurons being replaced by news after loss. Sounds strange I know, but hey
> until a few years ago we all thought there were no new brain cells in the
> adult brain and now we're finding them in olfactory bulb, dentate gyrus,
> spinal cord, and probably quite a few other places. The most startling
> example I saw was a primate study which tracked the migration of new neurons
> to damaged areas, this taking some two weeks.
>> In general it seems to depend on the individual, diet, genes, lifestyle, may
> all play important roles in determining rate of recovery. Incidentally, the
> famous mathematican, Paul Erdos, used a type of amphetamine for many years
> and it didn't appear to do him any harm. On the other hand, if you've ever
> seen speed psychosis, you soon have little doubt that serious damage has
> occurred. As a general rule, amphetamines are very bloody dangerous when
> used for extended periods or in heavy doses. Those bloody MAOs ... . Try L
>> In perspective, depression, chronic stress, also cause organic damage to the
> brain. As does chronically low folate, omega 3's ... . I think if occasional
> drug use was as dangerous as some would like us to believe then there'd be a
> lot more sick puppies around. When looking at these studies, look very
> carefully at the degree of deficit.
>>>> John H.