Marijuana may help Alzheimer's patients, new Spanish study shows

• New clues about Alzheimer's disease have emerged from a Spanish study of marijuana.
• The drug's active ingredients --- cannabinoids help prevent brain problems seen in Alzheimer's, say the scientists.
• There is no cure for Alzheimer's disease, which progressively damages brain areas involved in memory, judgment, language and behavior.
• Alzheimer's disease is the most common form of mental decline, or dementia (search), in older adults.
• Instead, the researchers focused on human brain tissue samples and conducted cannabinoid experiments on rats.
• The findings showed that "cannabinoids work both to prevent inflammation and to protect the brain," says researcher Maria de Ceballos in a news release.
• Their results appear in the Feb. 23 edition of The Journal of Neuroscience.
• The researchers studied human brain tissue samples, some of which were from deceased Alzheimer's patients and some from normal brain tissue.
• Plaques are protein clumps that are seen outside brain cells, and they have been shown to activate inflammation seen in brain tissue of Alzheimer's disease patients.
• Besides the typical plaques seen with Alzheimer's disease, the brain tissues taken from Alzheimer's patients also had many fewer cannabinoid receptors.
• The researchers also injected rats with a protein called beta-amyloid, which gave the rats an Alzheimer's-like brain condition.
• After two months, the rats were tested for learning, memory, and mental functions.
• The researchers tried to train them to find a platform in a tank of water.
• By the fifth day, the rats that received the cannabinoid injections were able to find the platform on their own.
• "Our results indicate that cannabinoid receptors are important in the pathology of Alzheimer's disease and that cannabinoids succeed in preventing the neurodegenerative process occurring in the disease," write the researchers in the journal.