French Tolerance Study 2/09

[beachguy in thongs]

Chronic treatment with Delta(9)-tetrahydrocannabinol impairs spatial memory and reduces zif268 expression in the mouse forebrain.
Boucher AA, Vivier L, Metna-Laurent M, Brayda-Bruno L, Mons N, Arnold JC, Micheau J.

CNIC, Université de Bordeaux, CNRS UMR, Talence, France.

Few studies have investigated the effects of chronic cannabinoid exposure on memory performance and whether tolerance occurs to cannabinoid-induced memory impairment. Here, we studied the effects of repeated exposure to Delta-tetrahydrocannabinol (THC: 1 mg/kg) on spatial memory and zif268 expression in mice. One group of animals was not pretreated with THC, whereas another group was injected with 13 daily injections of THC before memory testing in the Morris water maze. Both groups were administered with THC throughout the memory-testing phase of the experiment. THC decreased spatial memory and reversal learning, even in animals that received the THC pretreatment and were tolerant to the locomotor suppressant effects of the drug. Zif268 immunoreactivity was reduced in the CA3 of the hippocampus and in the prefrontal cortex only in non-pretreated animals, indicating that although tolerance to the effects of THC on neuronal activity was evident, cannabinoid-induced memory impairment in these animals persisted even after 24 days of exposure. This study shows that after extended administration of THC, its spatial memory-impairing effects are resistant to tolerance.

Behav Pharmacol. 2009 Feb;20(1):45-55.

[painretreat]

O.K.! :stoned::stoned: :jointsmile: PR

[the image reaper]

I can dig that, the last mouse I talked to, couldn't remember where he hid his cheese ... dumbass stoner mouse :jointsmile:

[thcbongman]

That's a nice study.

Basically the more you smoke, the more resistant you become to forgetting stuff. Makes sense.

[Coelho]

Basically the more you smoke, the more resistant you become to forgetting stuff.

I didnt understand this way... i did understand that the more you smoke the more resistent to the THC effects you get (tolerance), but the memory impairing effects remains the same, regardless the level of tolerance. So we keep forgetting, no matter how tolerant to THC we are.


THC decreased spatial memory and reversal learning, even in animals that (...) were tolerant to the (...) effects of the drug.


This study shows that after extended administration of THC, its (THC´s) spatial memory-impairing effects are resistant to tolerance.

My personal experience tends to confirm it... i have a reasonably high tolerance, in fact my highs last much less than they used to, and are also far less intense, and yet my memory remains almost as bad as it became after i started to smoke... :jointsmile:

[midlifecrisis]

Did someone mention cheese....I love cheese.

I think it's great that the French did a study on the effects cheese has on memory.......:wtf:

[beachguy in thongs]

It mentions that the cheese will still knock you on your butt, no matter how long you smoke it. :rastasmoke:

[jsdinosaur]

I'm curious as to whether or not these effects are persistent after a long period of abstinence, and whether or not they are actually present in humans.

Have any reliable studies been done on the effects on memory in humans that someone could refer me to?

[Coelho]

Have any reliable studies been done on the effects on memory in humans that someone could refer me to?

I think i did read something about this... somewhere... but i cant remember where... :D

[thcbongman]

I didnt understand this way... i did understand that the more you smoke the more resistent to the THC effects you get (tolerance), but the memory impairing effects remains the same, regardless the level of tolerance. So we keep forgetting, no matter how tolerant to THC we are.





My personal experience tends to confirm it... i have a reasonably high tolerance, in fact my highs last much less than they used to, and are also far less intense, and yet my memory remains almost as bad as it became after i started to smoke... :jointsmile:

But if you were more resistant of the effects of THC, wouldn't you also become more resistant to the impairing effects on memory as well? Like when you first smoke, you feel more burnt-out, but as you smoke more, you feel the effects of the burnout less. Why wouldn't it be the same with memory impairment.

I mean I feel like I have a good memory overall and that cannabis hasn't impaired it, only in the short-term when high.

[Coelho]

But if you were more resistant of the effects of THC, wouldn't you also become more resistant to the impairing effects on memory as well? Like when you first smoke, you feel more burnt-out, but as you smoke more, you feel the effects of the burnout less. Why wouldn't it be the same with memory impairment.


I agree with you, and i think everybody else would too, because it is the most reasonable thing.
But the findings of the study are exactly that, despite of what everybody used to think, there is no build of tolerance for the memory impairment . Probably this unexpected effect was what motivated them to write the article.


I mean I feel like I have a good memory overall and that cannabis hasn't impaired it, only in the short-term when high.

Exactly... its like the article says, the mice were injected with THC before having the test, so they were pretty high and thus were having too much fun to care about finding the way out a maze... :jointsmile:

[thedeadone]

first the bastages get these unsuspecting participents, and get them really,
really loaded.Then the sonsabitches hide thier munchies from them.:hippy:

[denialisback]

That's a nice study.

Basically the more you smoke, the more resistant you become to forgetting stuff. Makes sense.

not quite, the study is saying that in the mice that were pre-treated there was a lower immunoreaction - i.e. the brain protects itself less..

Thus indicating long term exposure to THC decreases the neurological immuno ability of mice to supress the THC from affecting memory..

Quite an interesting study indeed. I would have expected the opposite too thcbongman :-)


Odd.

Peace,
denial

[thcbongman]

not quite, the study is saying that in the mice that were pre-treated there was a lower immunoreaction - i.e. the brain protects itself less..

Thus indicating long term exposure to THC decreases the neurological immuno ability of mice to supress the THC from affecting memory..

Quite an interesting study indeed. I would have expected the opposite too thcbongman :-)


Odd.

Peace,
denial

It's actually states the opposite.


Zif268 immunoreactivity was reduced in the CA3 of the hippocampus and in the prefrontal cortex only in non-pretreated animals, indicating that although tolerance to the effects of THC on neuronal activity was evident, cannabinoid-induced memory impairment in these animals persisted even after 24 days of exposure.

Which is why I don't understand the conclusion:


This study shows that after extended administration of THC, its spatial memory-impairing effects are resistant to tolerance.

[denialisback]

This study shows that after extended administration of THC, its spatial memory-impairing effects are resistant to tolerance.

It's saying that memory impaired effects via THC were observed to be resistant to the immunotolerance of the subjects of the experiment, in this case the prefrontal of mice.

i.e. THC shows resistance to immunotolerance in the trials even after 24 days of continuous exposure

Peace,
denial

[thcbongman]

Ah I see now.

Thanks for the clarification.

[denialisback]

Ah I see now.

Thanks for the clarification.

no worries it confused me too at first, was unexpected here too :thumbsup:

yes, very.. but then again it is still only mice..


You actually had me second guessing myself, lol, well done ;- ) that can only be a good thing!


Peace,
Denial

[Purple Banana]

Mmm... I'm eating cheese as I read this. Ever read that stupid book "Who Moved My Cheese?" it's supposed to apply as a metaphor to business and work in general, but it's so stupid!

Mice have completely different brains than us... Though the study has some applications to human brains, it's not 100% correct... I've been smoking for about 6 years, about 3 times a week, and my memory is just as sharp, if not sharper than it had been before I smoked!

I'm an outlier!

:stoned:

[beachguy in thongs]

You can be tolerant to the locomotor suppressant effects, of THC, but, you can't build tolerance to spatial memory and reversal learning. Cannabidiol makes up 40%* of the plant. I figured that it's the key ingredient to offset all the ill effects.

*-heard that, somewhere