People suffering with memory loss could be a step closer to treatment after doctors discovered a drug that boosts the part of the brain responsible for storing and processing memories.
A single oral dose of methylene blue was shown to cause an increased MRI-based response in brain areas that control short-term memory and attention.
Methylene blue is used to treat methemoglobinemia - a blood disorder in which oxygen is unable to release itself effectively to tissue - and as a surgical stain.
Animal studies have shown a single low dose of methylene blue enhances long-term contextual memory. This is the conscious recall of the source and context of a specific memory. It has also been linked with improving so-called "extinction" memory, a process in which a person's memory that is triggered by a certain song, or smell, for example fades over time.
"Although the memory-enhancing effects of methylene blue were shown in rodents in the 1970s, the underlying neuronal changes in the brain responsible for memory improvement and the effects of methylene blue on short-term memory and sustained-attention tasks have not been investigated," said study author Timothy Duong from the University of Texas. "Our team decided to conduct the first multi-modal MRI study of methylene blue in humans."
A total of 26 healthy participants, aged between 22 and 62, took part in a placebo clinical trial. Each underwent functional MRI (fMRI) scans before and one hour after either taking a low-dose of methylene blue or a placebo drug.
The results showed methylene blue increased response in a region of the brain known as the bilateral insular cortex. This area is found deep within the brain and is associated with emotional responses.
The fMRI results also showed an increased response during short-term memory tasks involving the brain's prefrontal cortex, which controls processing of memories, the parietal lobe, responsible for processing sensory information, and the occipital cortex, the brain's visual processing centre.
In addition, methylene blue was linked to a 7 per cent increase in correct responses during memory retrieval.
The findings suggest methylene blue can regulate certain brain networks related to sustained attention and short-term memory after just a single dose.
"This work certainly provides a foundation for future trials of methylene blue in healthy ageing, cognitive impairment, dementia and other conditions that might benefit from drug-induced memory enhancement," Dr Duong said.
The results are published in the journal Radiology.
This article was originally published by WIRED UK
