Again, asking for my friend dds, I learn that:
The effects of cannabinoids on the brain
Abstract
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.
https://pubmed.ncbi.nlm.nih.gov/10368032/and
A well-known 2012 study from New Zealand evaluated marijuana use and cognitive ability in more than 1,000 individuals over a 38-year period.
The researchers reported an association between ongoing marijuana use and cognitive decline.
In particular, they found that:
People who started using marijuana heavily as adolescents and continued as adults lost an average of six to eight IQ points by the time they reached midlife.
Among the group above, people who stopped using marijuana as adults didn’t regain lost IQ points.
People who started using marijuana heavily as adults didn’t experience any IQ loss.
This study had a significant impact for a few reasons.
First, it was among the first large, longitudinal (long-term) studies to assess marijuana use and cognitive functioning.
Next, the results suggest that marijuana use during adolescence may have an irreversible effect on adolescent brain development. Some additional research supports this conclusion.
https://www.healthline.com/health/does-weed-kill-brain-cells#effects-on-iqand one more:
After getting high on cannabis, you might have trouble focusing on a task or remembering things you usually don’t forget. Chronic marijuana use can make matters worse. You might develop ongoing memory loss or suffer from perpetually poor concentration. Weed can even affect the motor skills involved in driving a vehicle.
https://harmonyplace.com/blog/marijuana ... our-brain/