JPJ_Glassware

I was just sent this "proof" that marijuana is too dangerous to legalize...

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The effects of cannabinoids on the brain
by
Ameri A
Department of Pharmacy and
Pharmacology of Natural Compounds,
University of Ulm, Germany.
Prog Neurobiol 1999 Jul; 58(4):315-48



Cannabinoids have a long history of consumption for recreational and
medical reasons. The primary active constituent of the hemp plant
Cannabis sativa is delta9-tetrahydrocannabinol (delta9-THC). In humans,
psychoactive cannabinoids produce euphoria, enhancement of sensory
perception, tachycardia, antinociception, difficulties in concentration
and impairment of memory. The cognitive deficiencies seem to persist after
withdrawal. The toxicity of marijuana has been underestimated for a long
time, since recent findings revealed delta9-THC-induced cell death with
shrinkage of neurons and DNA fragmentation in the hippocampus.

The acute effects of cannabinoids as well as the development of tolerance
are mediated by G protein-coupled cannabinoid receptors. The CB1 receptor
and its splice variant CB1A, are found predominantly in the brain with
highest densities in the hippocampus, cerebellum and striatum. The CB2
receptor is found predominantly in the spleen and in haemopoietic cells
and has only 44% overall nucleotide sequence identity with the CB1 receptor.
The existence of this receptor provided the molecular basis for the
immunosuppressive actions of marijuana.

The CB1 receptor mediates inhibition of adenylate cyclase, inhibition
of N- and P/Q-type calcium channels, stimulation of potassium channels,
and activation of mitogen-activated protein kinase. The CB2 receptor mediates
inhibition of adenylate cyclase and activation of mitogen-activated protein
kinase. The discovery of endogenous cannabinoid receptor ligands, anandamide
(N-arachidonylethanolamine) and 2-arachidonylglycerol made the notion of a
central cannabinoid neuromodulatory system plausible. Anandamide is released
from neurons upon depolarization through a mechanism that requires calcium-
dependent cleavage from a phospholipid precursor in neuronal membranes. The
release of anandamide is followed by rapid uptake into the plasma and
hydrolysis by fatty-acid amidohydrolase. The psychoactive cannabinoids
increase the activity of dopaminergic neurons in the ventral tegmental
area-mesolimbic pathway. Since these dopaminergic circuits are known to
play a pivotal role in mediating the reinforcing (rewarding) effects of the
most drugs of abuse, the enhanced dopaminergic drive elicited by the
cannabinoids is thought to underlie the reinforcing and abuse properties of
marijuana. Thus, cannabinoids share a final common neuronal action with other
major drugs of abuse such as morphine, ethanol and nicotine in producing
facilitation of the mesolimbic dopamine system.
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Is it just me, or does this thing seem a bit suspect? Hearing the old "pot kills brain cells" line in the first at the end of the first paragraph just doesn't inspire confidence in me...

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"The Partnership for a Drug-Free America; please, make me laugh and gag at the same time with that title. Partnership? They're a lobbying arm for the liquor and prescription drug industry. They don't want an America free of drugs; they want an America free of the drugs that are their competition. Prozac doesn't want to go up against Marijuana; it will lose." - Bill Maher, Be More Cynical.