Some drugs interfere with neurotransmitters in the brain. These 'mind-altering' drugs change our interpretation of the world, our behaviour, and our mood. For example, cannabinoids come from the plant Cannabis sativa, and affect neurones releasing acetylcholine, noradrenaline and dopamine work. LSD (D-lysergic acid diethylamide) is a combination of an artificial acid and a natural molecule found in the fungus Claviceps purpurea (Ergot). LSD mimics serotonin action in the brain, which seems to explain its hallucinogenic effects.