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By manipulating a single protein found in the brains of mice, researchers can wipe out a mouse’s specific, traumatic memory without damaging brain cells, a new study reports. While the process is nowhere near ready for testing in humans, researchers say it does raise the possibility of novel treatments for post-traumatic stress disorder and other mental health conditions. “While memories are great teachers and obviously crucial for survival and adaptation, selectively removing incapacitating memories, such as traumatic war memories or an unwanted fear, could help many people live better lives,” said [lead researcher] Joe Tsien [Telegraph].

Humans have the same so-called “memory molecule” in our brains, and the announcement is certain to prompt speculation that sci-fi scenarios of memory erasure are almost upon us. The concept was the premise of the popular 2004 film Eternal Sunshine of the Spotless Mind, in which two former lovers pay a “memory-erasure” service to expunge the unhappy affair from their minds [HealthDay News].

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A small study has found that the brains of men and women are wired differently in a region that is related to speech, memory, and hearing. Researchers studied the brain tissue from four men and four women who were all having a small portion of their brains excised as a treatment for epilepsy. They found that in the brain region called the temporal neocortex, men have a higher density of synapses, which are the connection points between brain cells.

For many years, scientists have searched for structural variations between men’s and women’s brains to explain psychological studies showing that, overall, the sexes think and act differently. Past studies found differences in brain mass and neuron density, but “they were hyped and untrustworthy,” [neuroscientist Edward] Jones says. This study is meticulously detailed, he notes. It is the first to show gender differences on such a fine scale — at the synapse [Science News].

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Researchers have gotten an amazingly close look at the human brain’s methods of short-term memory formation and recollection. A new study has examined the activity of individual brain cells, and found that the same neurons that fire when a person gets their first look at something fire again when they recall it.

Scientists at the University of California, Los Angeles, (U.C.L.A.) showed 13 volunteers—epilepsy patients with therapeutic electrodes implanted in their brains—several five- to 10-second clips from videos such as The Simpsons. The researchers found that a small sample comprising some 50 neurons in the hippocampus and entorhinal cortex (memory centers in the brain) fired in distinctive repeatable patterns that differed for each clip [Scientific American]. A few minutes later, when researchers asked the volunteers to think back to the film clips and say what came to mind, the neurons fired in the same distinct patterns when they mentioned each clip.

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By disrupting the memories of cocaine-addicted lab rats, researchers were able to keep the rats from seeking out a fix for up to a month. Researchers say the new study points the way towards possible drug therapies for human addicts, because memory is one of the main reasons why drug addicts who have gone sober suddenly find themselves jumping off the wagon. Environmental cues like visiting a place where you were high can make you remember the drug and weaken your resistance to taking it again [io9].

In the experiment, psychologists taught rats to associate a flashing light with the delivery of cocaine to their cages, making the light a “drug-associated memory.” Then researchers gave half the addicted rats a dose of a drug that interferes with proteins called NMDA-type glutamate receptors in rat brains. Previous work on addiction and post-traumatic stress has shown that these proteins—which are found on the surface of brain cells—are essential to memory formation. The receptors are also crucial to reconsolidating a memory—moving it from its storage area in long-term memory to brain regions that handle short-term memory [Scientific American].

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Climatologists predict that the African continent will grow drier and drier as global warming brings more droughts. But whether elephants herds can survive might depend on their oldest members.

In a study published in Biology Letters, Charles Foley of the Wildlife Conservation Society studied how three family groups of elephants responded to a severe African drought in 1993. In a nine-month period 16 out of 81 elephant calves in three study groups died, a mortality rate of 20 per cent. The normal mortality rate of calves during non-drought years is only two per cent [Telegraph].

Two groups left the area during the drought, migrating to places with more water, and lost only five calves between them, compared to 11 for the group that stayed. Foley found that the groups that left contained older females than the remaining group, which was perhaps the key to their success: [T]he older females may have been able to draw on memories of an earlier severe drought from 1958 to 1961, and how the elephants survived it [The Press Association]. The third group, meanwhile, lost many of its females during plagues of poaching in the 1970s and 1980s. As such, its leader was only 33, too young to remember the the late 1950s drought.

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British researchers have found that giving nicotine to lab rats boosts their concentration and memory, and say that the findings could point the way towards pharmaceuticals that could treat the symptoms of Alzheimer’s and dementia. This benefit may be linked to the effect nicotine has on addicted smokers: The “boost” in concentration that smokers experience from cigarettes could help sufferers fight the mental decline associated with dementia, studies suggest [Telegraph].

Researchers are definitely not suggesting that elderly people take up smoking or start wearing nicotine patches in an attempt to ward off dementia, as the negative health effects would far outweigh any benefits. Lead researcher Professor Ian Stolerman said: “Nicotine, like many other drugs, has multiple effects, some of which are harmful, whereas others may be beneficial. It may be possible for medicinal chemists to devise compounds that provide some of the beneficial effects of nicotine while cutting out the toxic effects” [BBC News].

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The “good” cholesterol that is found in olive oil and avocados has been portrayed as a good fairy lately based on its association with healthy hearts, but a new study may give people another reason to chow down on guacamole. A broad study of people in their 50s and 60s revealed that low levels of good cholesterol are linked to poor memory, which may be an early indicator of dementia and Alzheimer’s.

The results, reported in a journal [subscription required] published by the American Heart Association, showed that 60-year-olds with low levels of good cholesterol were 53 percent more likely to have memory problems. However, other researchers point out that the study did not prove causation, and said the study did not yet support larger diet trials aiming to boost levels [BBC News].

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The onset of dementia in an aging relative can be a devastating thing to watch, as memory and cognition slowly degrade. But a new study suggests one easy thing you can do to help hold back the fog: Turn on bright lights, and keep them on all day.

The study in the Journal of the American Medical Association [subscription required] suggests that this simple intervention may boost a patients’ cognition by reinforcing the body’s circadian clock, the sleep-wake cycle that can be modulated by daylight. When the circadian rhythms are disrupted (as in a case of jet-lag), the brain releases hormones and other agents that can affect cognition.

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