Our skin acts as the protective barrier between our internal body systems and the outside world. Its ability to perceive touch sensations gives our brains a wealth of information about the environment around us, such as temperature, pain, and pressure. Without our sense of touch, it would be very hard to get around in this world.
But, what stimulates the sense of touch in the brain, still puzzles scientists. The development of a sense of touch has been studied by scientists for many years, but how it develops is still unclear. Prior research has shown that once it has developed, it exists as a sort of map imprinted on the cerebral cortex.
Some have suggested that a basic map is created in the brain before birth and data points for it are added as newborns develop—sensory input from various body parts is simply added to the map. But now, that view might have to change, as the team in Spain reports evidence that suggests the map is already in place by the time a baby is born.
In a new study by the scientists at the Institute of Neurosciences of Alicante of the ISIC in Spain have discovered that the sense of touch arises in the brain before birth—at least in mice. The study highlights the embryonic stages of the development of the brain in mice and what they learned from it.
Scientists conducted the study on mice to better understand how the sense of touch might develop because mice have what are known as cortical barrels—regions within the cortical layer that are visibly darker when stained. They also studied brain slices at various stages of development to monitor cortical barrel development, and also studied brain waves that have previously been identified as those associated with sensory processing.
The results suggest that the sensory map created to process the sense of touch was built while the mice were still embryos. This map developed because of signals traveling to cerebral cortex by the thalamus, which also plays a major role in relaying synaptic information throughout the life of the mouse.
The researchers suggest that it is likely the same process occurs in humans because “the organization of the cortex is conserved evolutionarily between species.”
The study is published in the journal Science.