High on Memory

At first glance – or puff – marijuana might seem like a less-than-ideal candidate for boosting memory. But if you’re an aging lab rat at the Ohio State University department of psychology, your experience will suggest otherwise. Researchers here recently showed (pdf) that stimulating the brain’s endocannabinoid receptors, which are responsible for the marijuana high, may actually reduce the natural memory loss of old age.

So, would puffing away at the illegal drug allow you to skirt memory problems later in life? Probably not, because typical recreational doses are too large, said Yannick Marchalant, the lead author of the study. “If you consume it every day,” he noted, “you’re going to impair your memory one way or another.”

To work around this problem, the researchers used a synthetic drug that mimics the effects of marijuana’s main psychoactive ingredient, but at doses too small to produce the high. In a new study presented at the Society for Neuroscience’s recent annual meeting in Washington, D.C., the scientists revealed that the treated rat brains showed less of the inflammation that usually afflicts old brains. Surprisingly, the brains had also sprouted new nerve cells in an area essential to memory formation.

Both neuron loss and inflammation are common findings in diseases like Alzheimer’s and Parkinson’s, and the researchers hope their findings can be used to develop preventive medicine for these conditions. But young and healthy people are unlikely to benefit from the drug – cautioned Marchalant: “Without disease, it’s just another recreational drug.”

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