There is new evidence over the selection of maternal (from the mother) or paternal (from the father) genes in the brain.  You have two copies of each gene, one from your father and one from your mother.  Depending on the gene, each cell can express a blend of the two, or express the copy from the mother or the copy from the father.  You may ask how do the cells know which one is maternal or paternal?  There are certain chemical markers added to the DNA during the development of the egg and sperm that epigenetically mark it as maternal or paternal in essence.  The selection of maternal or paternal gene expression could be random, so that you have a blend of cells expressing each type of gene, or it could be more specific, such that certain types of cells will select one or the other.  Gregg et al. just released a couple articles producing evidence that there is bias of certain brain regions to maternal or paternal genes in Science. This is an image of a stained hippocampus from female rats which shows a bias for genes that came from their mothers [see Fig. 2 in this article].  Gregg et al. also found that this bias changes depending on brain regions (some brain regions did not show bias and others showed bias for genes coming from the father).  Their other article suggests that there is heavy maternal influence before birth, but heavy paternal influence in the adult brain.  This suggests greater X-chromosome involvement in development, and really points to the complexity of genetics in brain development and function.

There is new evidence over the selection of maternal (from the mother) or paternal (from the father) genes in the brain.  You have two copies of each gene, one from your father and one from your mother.  Depending on the gene, each cell can express a blend of the two, or express the copy from the mother or the copy from the father.  You may ask how do the cells know which one is maternal or paternal?  There are certain chemical markers added to the DNA during the development of the egg and sperm that epigenetically mark it as maternal or paternal in essence.  The selection of maternal or paternal gene expression could be random, so that you have a blend of cells expressing each type of gene, or it could be more specific, such that certain types of cells will select one or the other.  Gregg et al. just released a couple articles producing evidence that there is bias of certain brain regions to maternal or paternal genes in Science.

This is an image of a stained hippocampus from female rats which shows a bias for genes that came from their mothers [see Fig. 2 in this article].  Gregg et al. also found that this bias changes depending on brain regions (some brain regions did not show bias and others showed bias for genes coming from the father).  Their other article suggests that there is heavy maternal influence before birth, but heavy paternal influence in the adult brain.  This suggests greater X-chromosome involvement in development, and really points to the complexity of genetics in brain development and function.