Genes and your Hippocampi

ENIGMA researchers reported noticing genetic differences in the hippocampus (there are two of them). The name hippocampus reportedly came from the fact that the shape of these little brain organs resemble that of a sea horse. They are linked to memory formation and organization (the hippocampi, not sea horses!)  A gene sequence called rs7294919 on chromosome #12 reportedly has been linked with variations in hippocampus volume: Every instance of a genetic variant called a T-allele in this region was linked to lower hippocampus volume equivalent to 3.9 years of aging. (DNA is made up of four bases—A, C, T and G.) The location on the chromosome (a threadlike structure that holds a DNA molecule) occurred between genes associated with the regulation of cell death and with cellular brain development and the cleaning up of proteins, including tau, which becomes defective in Alzheimer's disease.