Mice with ‘human brain genes’ have better memories

The Tweet: “Scientists once spliced human brain genes with lab mice and were able to produce smarter mice.”

Genetically modifying a gene in the brain of mice makes them better at learning routes in a maze, scientists have found. The gene in question is FOXP2, which in humans is responsible for speech and language proficiency. The researchers, a collaboration of MIT and European scientists, were investigating the role this important gene plays in human learning.

So how were these mice ‘smarter’? The mice were trained to find chocolate in a maze using either visual landmarks in the form of lab equipment visible from the maze or by feeling textures on the floor. For regular mice it took 11 days of training for them to learn the route to the chocolate, and for the genetically modified mice it took 7 days.

The researchers suggested that this was because the modification in the Foxp2 gene increased cognitive flexibility in the mice, allowing them to switch between two types of learning more easily. Navigation using landmarks calls upon our conscious memory to find our way: we are aware of our surroundings and use this to work out a route, compared to unconscious memory which is used to navigate with textiles. Humans don’t normally navigate using touch, so the researchers likened the ability of the mice to navigate the maze unconsciously to our ability to walk routes that are familiar to us, paying little attention to where we are going. But, when we are unsure of our route we snap back into consciousness and look for landmarks to fill the gaps. This requires cognitive flexibility to segue between the two easily.

“This really is an important brick in the wall saying that the form of the gene that might have allowed us to speak may have something to do with a special kind of learning, which takes us from having to make conscious associations in order to act to a nearly automatic-pilot way of acting based on the cues around us,” study co-author Ann Graybiel, said in a written statement.

The researchers next removed either the landmarks or textiles to see what would happen. When either  were removed leaving only one source of recognition, both mice fared equally. For mice without the modified Foxp2 gene segueing was more difficult but when there was only one source of recognition both mice were on a level playing field. The human gene didn’t improve the navigation ability of the mice, only their ability to be flexible when remembering a route.

These mice were smarter in the sense that cognitive flexibility allowed them to better use their memories and learn routes more efficiently. Being able to adapt and improvise when problem solving is definitely a quality of more sophisticated thinkers. However, this research tells us more about the way humans learn than it does about mouse cognitive abilities.

Image credit: tambako (Flickr)
This post was first published on The Untweetable Truth (12/11/2014)

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