Scientists at the University of Pittsburgh School of Medicine and Pittsburgh's Veterans Affairs Medical Center have identified a new area of the primate brain that evolved to enable the use of tools and other small, fine motor skills.Most animals' primary motor cortex of the brain controls all movements indirectly via the pathways through the spinal cord. However, in human and higher primate brains researchers discovered another area located just outside the motor cortex that consists of specialized corticomotoneuronal cells. These cells control spinal cord motor neurons directly, specifically the neurons responsible for muscle movement in the shoulder, arm and hand.
The spinal neural structure is much the same in most vertebrates, but these corticomotoneuronal cells permit human and other primates brains to bypass the limitations imposed by greater spinal cord pathways and control these muscles directly. This allows the development of fine motor control necessary for the use of tools, throwing a ball or playing musical instruments.
Also discovered in this study is that these corticomotoneuronal cells are not present at birth but instead develop during the first months of life and become mature at about two years of age. The growth and progress of an infant's early motor skills is due to the establishment of these connections.
These results were published recently in an online edition of the Proceedings of the National Academy of Sciences.
Photo: LiveScience
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A link to the pnas main page won't help at all if we don't have the researchers names or the title of the study!
Many stories are reported online ahead of appearing in print journals, which may lag news and blog reports by months. Names and titles may not be known at the time of the post.
A link is always provided back to the original online news item.
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