http://www.lifescience.net/publications ... ly-suppre/Teenagers who regularly smoke cannabis suffer long lasting brain damage and are in much greater danger of developing schizophrenia.
American researchers say the drug is particularly dangerous for a group of people who have a genetic susceptibility to the mental health disorder - and it could be the trigger for it. Asaf Keller, of the University of Maryland School of Medicine, said the results highlight the dangers of teenagers smoking cannabis during their formative years.
The study, published in the journal Neuropsychopharmacology, exposed young mice to the active ingredient in marijuana for 20 days. It found that their brain activity was impaired, with the damage continuing into adulthood. The past 20 years has seen major controversy about the long-term effects of marijuana, with experts divided over its long-term effects on teenagers.
Previous research has shown that children who started using marijuana before the age of 16 are at greater risk of permanent brain damage, and have a significantly higher incidence of psychiatric disorders. ‘Adolescence is the critical period during which marijuana use can be damaging,’ said the study's lead author, Sylvina Mullins Raver, a PhD candidate at the University of Maryland School of Medicine. ‘We wanted to identify the biological underpinnings and determine whether there is a real, permanent health risk to marijuana use.’ The scientists began by examining cortical oscillations in mice. Cortical oscillations are patterns of the activity of neurons in the brain and are believed to underlie the brain's various functions.
These oscillations are very abnormal in schizophrenia and in other psychiatric disorders.
The scientists exposed young mice to very low doses of the active ingredient in marijuana for 20 days, and then allowed them to return to their siblings and develop normally. ‘In the adult mice exposed to marijuana ingredients in adolescence, we found that cortical oscillations were grossly altered, and they exhibited impaired cognitive abilities,’ said Raver. ‘We also found impaired cognitive behavioural performance in those mice. The striking finding is that, even though the mice were exposed to very low drug doses, and only for a brief period during adolescence, their brain abnormalities persisted into adulthood.’
The scientists repeated the experiment, this time giving marijuana to adult mice that had never been exposed to the drug before.
Previous research has shown that children who started using marijuana before the age of 16 are at greater risk of permanent brain damage, and have a significantly higher incidence of psychiatric disorders. ‘Adolescence is the critical period during which marijuana use can be damaging,’ said the study's lead author, Sylvina Mullins Raver, a PhD candidate at the University of Maryland School of Medicine.
‘We wanted to identify the biological underpinnings and determine whether there is a real, permanent health risk to marijuana use.’ The scientists began by examining cortical oscillations in mice. Cortical oscillations are patterns of the activity of neurons in the brain and are believed to underlie the brain's various functions.
These oscillations are very abnormal in schizophrenia and in other psychiatric disorders.
The scientists exposed young mice to very low doses of the active ingredient in marijuana for 20 days, and then allowed them to return to their siblings and develop normally.
‘In the adult mice exposed to marijuana ingredients in adolescence, we found that cortical oscillations were grossly altered, and they exhibited impaired cognitive abilities,’ said Raver.
‘We also found impaired cognitive behavioural performance in those mice. The striking finding is that, even though the mice were exposed to very low drug doses, and only for a brief period during adolescence, their brain abnormalities persisted into adulthood.’ The scientists repeated the experiment, this time giving marijuana to adult mice that had never been exposed to the drug before.
According to the research team, there is a group of people who have a genetic susceptibility to developing schizophrenia. Adding weed to the mix during adolescence could be the trigger that causes it to develop, permanently impairing brain function and cognition Their cortical oscillations and ability to perform cognitive tasks remained normal, indicating that it was only drug exposure during the critical teenage years that impaired brain activity.
‘We found that the frontal cortex is much more affected by the drugs during adolescence,’ said Keller. ‘This is the area of the brain controls executive functions such as planning and impulse control. It is also the area most affected in schizophrenia.’ Keller now wants to know whether the effects can be reversed. ‘We are hoping we will learn more about schizophrenia and other psychiatric disorders, which are complicated conditions,’ he said.
‘These cognitive symptoms are not affected by medication, but they might be affected by controlling these cortical oscillations.’
Best named researcher ever!!
Best named researcher ever!!
“If you trust in yourself, and believe in your dreams, and follow your star. . . you'll still get beaten by people who spent their time working hard and learning things and weren't so lazy.”
Re: Best named researcher ever!!
All that for a name?
Yer a Raver...
Yer a Raver...
Sometimes it seems as though one has to cross the line just to figger out where it is
Re: Best named researcher ever!!
What was the dosage and the strength of the compound administered to the subjects?Abstract
Regular marijuana use during adolescence, but not adulthood, may permanently impair cognition and increase the risk for psychiatric diseases, such as schizophrenia. Cortical oscillations are integral for cognitive processes and are abnormal in patients with schizophrenia. We test the hypothesis that adolescence is a sensitive period because of the active development of cortical oscillations and neuromodulatory systems that underlie them. The endocannabinoid (eCB) system upon which marijuana acts is one such system. Here we test the prediction that adolescent cannabinoid exposure alters cortical oscillations in adults. Using in vitro local field potential (LFP), in vivo electrocorticogram (ECoG) recordings, and cognitive behavioral testing in adult mice, we demonstrate that chronic adolescent, but not adult, cannabinoid exposure suppresses pharmacologically evoked cortical oscillations and impairs working memory performance in adults. The later-maturing prefrontal cortex is more sensitive to adolescent exposure than the earlier-maturing, primary somatosensory cortex. These data establish a link between chronic adolescent cannabinoid exposure and alterations in adult cortical network activity that underlie cognitive processes.Neuropsychopharmacology accepted article preview online, 4 July 2013. doi:10.1038/npp.2013.164.
Not disputing the findings, just an interesting study.
Although a little abstract for the layperson.
Your collective inability to acknowledge this obvious truth makes you all look like fools.
yrs,
rubato