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Sense of direction is represented in the brains of newborn rats before they have explored their environment, according to new research by scientists at UCL.
Published in the journal Science, the results of a new study reveal that the brain’s ways of representing sense of place and orientation appear extremely early in the animal’s development – within two weeks of being born - and seemingly independently of any experience of the world.
Scientists also found that the representation of directional orientation, i.e. which way the rat is facing, is already at adult levels as soon as it can be measured in newborn rats. Sense of place is also present, but improves with age, with representations of distance appearing a few days
later.
Dr Francesca Cacucci, UCL Institute of Behavioural Neuroscience, and one of the authors of the paper said: “The question of how we acquire knowledge of the outside world and form our sense of place in it is one that has challenged both scientists and philosophers for
centuries.”
“This work clarifies the processes involved for the first time, and shows that the concept of space is something that develops very early – most likely within the first two weeks of being born, and is unlikely to have been
learnt.”
In the study, scientists monitored the activation, or ‘firing’, of three different types of neurons in the brains of rats, specifically in an area of the brain called the hippocampus. As the hippocampus in humans plays a crucial role in long-term memory for events and spatial navigation, understanding its development tells us to what extent our ability to remember (and find our way) depends on innate factors and
learning.
In the newborn rats studied in this research, directional neurons were the first to develop, allowing the brain to understand which way the animal is facing. Place cells, which identify location, are the next to develop, improving slowly as the hippocampus matures. The last to develop are neurons called ‘grid’ cells that are associated with the brain’s representation of distance, i.e., measuring how far the animal has
moved.
“We want to know how early each of these three types of spatial cell develop and in what order. This will provide us with clues about how the system gets wired up”, said Dr Thomas Wills, UCL Department of Developmental and Cell Biology and author of the
paper.
The notion of a pre-wired spatial framework has been around for some time but lacked empirical
support.
“Given that we have found that some aspects of the spatial representation come into play so early, within two weeks of birth, we think that space could be a sense that is developed independently of any experience: providing a conceptual framework for experience of the world, a view first advocated by the 18th century philosopher Immanuel Kant,” added Professor O’Keefe, another author from the UCL Department of Developmental and Cell
Biology.
Source
http://www.ucl.ac.uk
(MDN)
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