In 1936 an exploitation film directed by Louis Gasnier called Reefer Madness was made in an attempt to teach parents about the dangers of cannabis use. It told of fictional highschool students experimenting with the drug and their tragic and utterly ridiculous demise (e.g. manslaughter, rape, suicide). I'm pretty sure the majority of us now know that smoking marijuana will not cause someone to go on a murderous rampage or off themselves just because they're high. However, recent studies have found that cannabis use does have some negative effects on long-term memory.
Puighermanal and her colleagues investigated the possible involvement of the mTOR pathway in the cognitive impairments produced by cannabinoid agonists. mTOR is a type of enzyme that regulates multiple cellular processes such as neural development and long-term modification of synaptic strength. Administering acute amounts of THC (3 or 10 mg per body weight) to mice, they found modulation of the mTOR/p70S6K signaling cascade in the hippocampus and measurable deficits in long-term memory on an object and context recognition test. However, lower doses did not produce any significant effects.
The authors explain that CB1R activation by exogenous or endogenous cannabinoids can trigger the activation of the mTOR pathway and protein synthesis in the hippocampus through a glutamatergic mechanism which underly the long-term memory impairment. They conclude by pointing out the serious drawbacks of cannabis consumption (i.e. amnesic effects) and believe that their findings would be useful for the development of new therapeutic strategies leading to the prevention of negative side effects of cannabis use. C'mon guys, lets get crackin'!
The film ends with the ominous warning "TELL YOUR CHILDREN" in large text. Yes friends, tell your children...that is...if you can remember to. ::cues overly dramatic music::
Puighermanal, E., Marsicano, G., Busquets-Garcia, A., Lutz, B., Maldonado, R., & Ozaita, A. (2009). Cannabinoid modulation of hippocampal long-term memory is mediated by mTOR signaling Nature Neuroscience, 12 (9), 1152-1158 DOI: 10.1038/nn.2369