The effects of Δ9-tetrahydrocannabinol on the dopamine system

Δ(9)-tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis, is a pressing concern to global mental health. Patterns of use are changing drastically due to legalisation, availability of synthetic analogues (‘spice’), cannavaping and aggrandizements in the purported therapeutic effects of cannabis. Many of THC’s reinforcing effects are mediated by the dopamine system. Due to complex cannabinoid-dopamine interactions there is conflicting evidence from human and animal research fields. Acute THC causes increased dopamine release and neuron activity, whilst long-term use is associated with blunting of the dopamine system. Future research must examine the long-term and developmental dopaminergic effects of the drug

Additional observations about Phaseolus rotundatus (Fabaceae), an endemic bean species from western Mexico

Further information is presented about Phaseolus rotundatus, a new bean species for western Mexico, where it appears to be endemic and endangered, with very few populations reported to date, and all outside current protected areas. The differences between P. rotundatus and P. marechalii (both of Phaseolus section Paniculati Freytag), the closest taxon with which it can be confused, are highlighted to confirm the validity of the former taxon