Body map proto-organization in newborn macaques

• Published in: Proceedings of the National Academy of Sciences - PNAS 2019-12, Vol.116 (49), p.24861-24871
• Main Authors: Arcaro, Michael J., Schade, Peter F., Livingstone, Margaret S.
• Format: Article
• Language: English
• Subjects: Animals; Biological Sciences; Birth; Brain; Brain Mapping; Cerebral Cortex - anatomy & histology; Cerebral Cortex - diagnostic imaging; Cerebral Cortex - growth & development; Cerebral Cortex - physiology; Cortex (somatosensory); Cross-modal; Early experience; Female; Fingers - physiology; Functional magnetic resonance imaging; Macaca mulatta - anatomy & histology; Macaca mulatta - growth & development; Macaca mulatta - physiology; Magnetic Resonance Imaging; Male; Monkeys; Motor Neurons; Motor systems; Neural Pathways - physiology; Neuronal Plasticity; Representations; Scaffolding; Sensory Receptor Cells; Somatosensory Cortex - anatomy & histology; Somatosensory Cortex - diagnostic imaging; Somatosensory Cortex - growth & development; Somatosensory Cortex - physiology; Topography; Touch - physiology; Touch Perception - physiology
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1912636116

Topographic sensory maps are a prominent feature of the adult primate brain. Here, we asked whether topographic representations of the body are present at birth. Using functional MRI (fMRI), we find that the newborn somatomotor system, spanning frontoparietal cortex and subcortex, comprises multiple topographic representations of the body. The organization of these large-scale body maps was indistinguishable from those in older monkeys. Finer-scale differentiation of individual fingers increased over the first 2 y, suggesting that topographic representations are refined during early development. Last, we found that somatomotor representations were unchanged in 2 visually impaired monkeys who relied on touch for interacting with their environment, demonstrating that massive shifts in early sensory experience in an otherwise anatomically intact brain are insufficient for driving cross-modal plasticity. We propose that a topographic scaffolding is present at birth that both directs and constrains experience-driven modifications throughout somatosensory and motor systems.