Delta 9 Tetrahydrocannabinol is the primary psychoactive
constituent of Cannibis sativa, and is bound to two cannabinoid receptors: CB1 receptors, located primarily in the brain, and CB2 receptors, located primarily in the periphery (Wiley & Martin 2002). A cannabinoid is defined as a substance that has
pharmacological properties that resemble those of delta 9 THC i.e. " a drug that binds to CB1 and /or CB2 receptors in vitro and produces a profile of in vivo effects in the tetrad model" (Wiley 2002). THC inhibits the function of the enzyme adenylate cyclase which is involved in the transmission of pain messages. While there are over 60 cannibinoids identified in the plant Cannabis sativa, Delta 9 tetrahydrocannabinol is the primary mood altering psychoactive agent in marijuana. Marijuana effects acetylcholine synthesis and turnover in the limbic region of the brain and in the cerebellum. (Harwood 2005)
Eldreth, Matochik Cadet, and Bolla (2004) used PET 15 and a modified version of the Stroop task to determine if 25 day
abstinent heavy marijuana users experienced persistent deficits in executive cognitive functioning and brain activity. The
performance on a modified version of the Stroop task and brain activity was compared between 25 day abstinent, heavy users, and a matched comparison group. The 25 day abstinent users showed no deficits in performance on the modified version of the Stroop task when compared to the comparison group. They also found that despite the lack of performance differences, the anterior
cingulated cortex and the left lateral prefrontal cortex had hyperactivity in the hippocampus bilaterally, when compared to the comparison group. The results suggested that users display
persistent metabolic alterations in brain regions responsible for executive cognitive functioning. (Eldreth, Matochik, Cadet, & Bolla 2004).
When performing the Stoop task, marijuana users were found to...