A new study has investigated the long thought correlation between intelligence and genes. Previously, the volume of the brain’s grey matter (the cells responsible for mental processing) has been shown to be inheritable as well as the amount of white matter, the connections between these cells. Now, the quality of these connections; the strength of myelin sheath (a fatty layer responsible for lining nerve impulse channels) has been shown to be somewhat hereditary.
In the study, a special type of MRT imaging called HARDI, mapped the diffusion of water through myelin sheathed impulse channels (white matter). The ‘mind maps’ of 23 sets of identical and 23 sets of fraternal twins were compared to evaluate correlations of fluid velocity and hence nerve impulse speed. As identical twins share the same genes and fraternal twins share about half, differences in the mind maps of twins proposed certain genetic influences on brain power.
Genes were shown to influence myelin integrity in many areas of the brain known to be correlated with intelligence, such as the corpus callosum which is responsible for inter-hemisphere interaction and the parietal lobes which are largely involved in visual processing and logical thinking. Correlations between myelin sheath strength in these areas of the brain and performance on IQ tests were also seen to be positive.
The findings are particularly integral for researchers studying the genetic basis for disorders such as autism, multiple sclerosis and attention deficit disorder which are linked to degraded myelin strength. By sequencing genes that promote myelin sheath integrity and identifying the proteins that they code for, more effective treatments for such disorders could be developed.
By Peter Bowstead (42064365)
Photo: An MRI of brain activity.
Article Website: http://www.newscientist.com/article/mg20126993.300-highspeed-brains-are-in-the-genes.html
In the study, a special type of MRT imaging called HARDI, mapped the diffusion of water through myelin sheathed impulse channels (white matter). The ‘mind maps’ of 23 sets of identical and 23 sets of fraternal twins were compared to evaluate correlations of fluid velocity and hence nerve impulse speed. As identical twins share the same genes and fraternal twins share about half, differences in the mind maps of twins proposed certain genetic influences on brain power.
Genes were shown to influence myelin integrity in many areas of the brain known to be correlated with intelligence, such as the corpus callosum which is responsible for inter-hemisphere interaction and the parietal lobes which are largely involved in visual processing and logical thinking. Correlations between myelin sheath strength in these areas of the brain and performance on IQ tests were also seen to be positive.
The findings are particularly integral for researchers studying the genetic basis for disorders such as autism, multiple sclerosis and attention deficit disorder which are linked to degraded myelin strength. By sequencing genes that promote myelin sheath integrity and identifying the proteins that they code for, more effective treatments for such disorders could be developed.
By Peter Bowstead (42064365)
Photo: An MRI of brain activity.
Article Website: http://www.newscientist.com/article/mg20126993.300-highspeed-brains-are-in-the-genes.html
