A new study examining the effects of THC on the brain found that the cannabinoid increased markers associated with cell proliferation while reducing signs of inflammation in female rats, with some effects influenced by estrogen levels. The study involved 16 rats divided into four groups receiving THC, estradiol benzoate, a combination of the two or a vehicle control. These included Ki-67, which is associated with cell proliferation; doublecortin and PSA-NCAM, markers associated with neurogenesis; CB1 cannabinoid receptors; and the inflammatory markers COX-2 and TNF-α. THC significantly increased Ki-67 immunoreactivity, indicating greater cell proliferation. “These findings indicate that THC influences markers associated with hippocampal cell proliferation, neurogenesis, cannabinoid signaling and inflammation in female rats, and that some of these effects depend on estradiol status”, concludes the study.