New Study Shows How Being Attentive Strengthens Our Memory

Helen Holmes October 01, 2012

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One cannot understand mental disorders without first understanding the basic mechanisms of the brain – this is what the researchers from the Massachusetts Institute of Technology suggest in their new study. There, they illustrated how giving attention stimulates the brain to help us remember visual stimuli.

Overlooked cells strengthen neural response to visual stimuli

The team identified a neural circuit that is activated when a person is paying close attention to a visual stimulus. Those cells, called astrocytes, are stimulated by the brain through neurotransmitters acetylcholine. When a person pays more attention, the nucleus basalis, a structure found behind the eyes and deep within the brain, fuels the release of acetylcholine which in turn targets the astrocytes, enhancing one’s memory of certain visual stimulus.

Astrocytes has long been believed to play a supporting role in certain cognitive functions particularly in neural processing but it is unknown how it exactly works and for what purpose. According to Mriganka Sur, senior study author and a professor of Neuroscience at the university, these star-shaped cells have been named 150 years ago but their function remained to be a mystery.

How paying attention helps one remember things

The researchers conducted an experiment on mice to study how exactly the astrocytes react to visual stimuli. The goal was to test how far the mice can remember several visual patterns which were composed of parallel lines arranged in various directions. During the presentation of one of the visual patterns, the researchers stimulated the nucleus basalis to release acetylcholine.

They saw a sudden increase in the calcium levels in the astrocytes which indicated high activity in the said neural circuit. When they showed the same pattern to the mice, Sur and his team noticed a much stronger response in the neurons of the subjects, particularly in the visual cortex. Meaning, the mice remembered such particular pattern more than the rest. The activity lasted for 10 minutes. After which, the subjects’ neurons returned to their normal visual response levels.

As a control for the study, the researchers performed the same experiment in another group of mice, but this time, they disabled the astrocytes in the subjects’ brains. They found no increase in the neural response of mice even if the nucleus basalis released acetylcholine.

The study sheds more light on the critical role of the astrocytes, and how it can be used as basis for the development of new treatments for various mental disorders, particularly memory loss.

It is an established fact that people with Alzheimer’s have low levels of acetylcholine. This is why they are usually provided with a drug that prevents the decline of the said neurotransmitters. In future studies, the researchers are planning to investigate how astrocytes are affected by Alzheimer’s disease.

 

Source of this article:

How attention helps you remember, Massachusetts Institute of technology