Researchers reverse the negative effects of adolescent marijuana use

September 12, 2017, University of Western Ontario
Steven Laviolette and Justine Renard in their lab at Western University. Credit: Schulich Medicine & Dentistry, Western University

Researchers at Western University have found a way to use pharmaceuticals to reverse the negative psychiatric effects of THC, the psychoactive chemical found in marijuana. Chronic adolescent marijuana use has previously been linked to the development of psychiatric diseases, such as schizophrenia, in adulthood. But until now, researchers were unsure of what exactly was happening in the brain to cause this to occur.

"What is important about this study is that not only have we identified a specific mechanism in the prefrontal cortex for some of the mental health risks associated with adolescent use, but we have also identified a mechanism to reverse those risks," said Steven Laviolette, professor at Western's Schulich School of Medicine & Dentistry.

In a study published online today in Scientific Reports the researchers demonstrate that adolescent THC exposure modulates the activity of a neurotransmitter called GABA in the region of the brain. The team, led by Laviolette and post-doctoral fellow Justine Renard, looked specifically at GABA because of its previously shown clinical association with .

"GABA is an and plays a crucial role in regulating the excitatory activity in the frontal cortex, so if you have less GABA, your neuronal systems become hyperactive leading to behavioural changes consistent with schizophrenia," said Renard.

The study showed that the reduction of GABA as a result of THC exposure in adolescence caused the neurons in adulthood to not only be hyperactive in this part of the brain, but also to be out of synch with each other, demonstrated by abnormal oscillations called 'gamma' waves. This loss of GABA in the cortex caused a corresponding hyperactive state in the brain's dopamine system, which is commonly observed in schizophrenia.

By using drugs to activate GABA in a rat model of schizophrenia, the team was able to reverse the neuronal and behavioural effects of the THC and eliminate the schizophrenia-like symptoms.

Laviolette says this finding is especially important given the impending legalization of marijuana in Canada. "What this could mean is that if you are going to be using marijuana, in a recreational or medicinal way, you can potentially combine it with compounds that boost GABA to block the negative effects of THC."

The research team says the next steps will examine how combinations of cannabinoid chemicals with compounds that can boost the brains GABA system may serve as more effective and safer treatments for a variety of disorders, such as addiction, depression and anxiety.

Explore further: New findings reverse hypothesis of GABA neurodevelopment in schizophrenia

More information: Justine Renard et al, Adolescent THC Exposure Causes Enduring Prefrontal Cortical Disruption of GABAergic Inhibition and Dysregulation of Sub-Cortical Dopamine Function, Scientific Reports (2017). DOI: 10.1038/s41598-017-11645-8

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Spaced out Engineer
1 / 5 (1) Sep 12, 2017
Or you could grab a beer with that blunt. Perhaps this study explains why there were hashish assassins who would kill for hash only to waste it on Yogic traditions (Yoga releases GABA). To know thyself, dosage make the poison, but the wound is of the flesh, never the mind.

This also could explain why cardiovascular activity helps schizophrenia. GABA maybe requisite neurotransmitter when activating those noise reducing analog circuits the muscles utilize. You know, so you don't just epileptic grand mal out. Just temporal lobe up in Brodin of the iron forge!!! For VALHALLA!

Seriously though kids eat fish twice a week and lift for memory. Run for neural genesis and maybe your parents won't have to pump you full of amphetamines to compensate for being behind a desk all day. 20-30 is peek hormone profile for men. Don't miss it.
rodkeh
not rated yet Sep 12, 2017
aa
Anonym
5 / 5 (1) Sep 13, 2017
Having vanquished the bogeyman of adolescent pot use, the researchers announced they will now seek a cure for homosexuality.

Seriously, they've put the cart before the horse, albeit with a nice chemistry based yoke:No one has shown that THC causes psychosis in anybody. There is a countervailing theory that schizoids use pot to self-medicate. Tens of millions of teens have smoked marijuana over the past 50 years; any significant (as opposed to merely statistical) link between pot use and psychosis would have been discovered long ago to all those NIDA researchers whose lifelong quest has been to demonstrate the downside, in any, to marijuana.



Nanook
not rated yet Sep 17, 2017
Obviously, you missed Reefer Madness.
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