Shining a light on embryonic development of the brain

The ability of birds to integrate information learnt separately from each half of their brain depends on the experiences of the embryo, reports a paper published in Nature Communications this week. Specialization of the brain, where the left and right hemispheres perform different functions, is thought to have evolutionary advantages, however, hemispheric cooperation is also important for optimal information processing. Martina Manns and Juliane Roemling studied hemispheric cooperation in birds - who have a visual system that develops asymmetrically in the brain in response to light stimulation. By presenting the right or left eye of the birds with different colour pairings, they show that they are able to integrate information learnt separately by the right or left hemisphere to solve a difficult puzzle. They note that the efficiency of cooperation between the two hemispheres depends on the development of this specialization, based on the experiences of the embryo. For example, when the embryos were kept in the dark, they could not discriminate between colour pairings that required the combination of information learnt separately from each eye / hemisphere, in contrast to embryos grown in light. These findings further our understanding of how the brain has evolved to perform different tasks.