Drugs of Abuse-Marijuana Information Marijuana Information Marijuana is a green or gray mixture of dried, shredded flowers and leaves of the hemp plant Cannabis sativa . In recent years, it has appeared in blunts. These are cigars that have been emptied of tobacco and re-filled with marijuana, often in combination with another drug, such as crack.
Some users also mix marijuana into foods or use it to brew tea.
Once securely in place, THC kicks off a series of cellular reactions that ultimately lead to the high that users experience when they smoke marijuana. Scientists have found that whether an individ ual has positive or negative sensations after smoking marijuana can be influenced by heredity. A recent study demonstrated that identical male twins were more likely than nonidentical male twins to report similar responses to marijuana use, indicating a genetic basis for their sensations. Health Hazards Effects of Marijuana on the Brain Researchers have found that THC changes the way in which sensory information gets into and is acted on by the hippocampus. This is a component of the brain's limbic system that is crucial for learning, memory, and the integration of sensory experiences with emotions and motivations.