Epigenetics: Significance of the gene-environment interface for brain development

TitleEpigenetics: Significance of the gene-environment interface for brain development
Publication TypeBook Chapter
AuthorsKeverne, E. B.
Brain development in humans extends over a very lengthy time period, initially in utero and subsequently embracing attachment interactions with the mother, social interactions with peers, and the emotional turmoil of puberty. Puberty is a period of development when those cortical regions concerned with forward planning and emotional control undergo synaptic pruning and reorganization of connection strengths. Each of these life phases is developmentally important in shaping and being shaped by the maternal and social environments. Although genetics forms the scaffold for brain development, the detail of connectivities is determined by the kind of environment in which the brain functions. The brain, more than any other organ, is a product of gene-environment interaction. The in utero environment is the most protected of environments and has evolved strong maternal-fetal coadaptations. The fetal placenta hormonally interfaces with and regulates the mother’s brain (hypothalamus) at a time when these same parts of the fetal brain (hypothalamus) are themselves developing. This transgenerational coordinated development is under the control of epigenetically regulated imprinted genes. Since the maternal hypothalamus controls all aspects of care and provisioning, offspring in receipt of such quality care will themselves be both genetically and epigenetically predisposed to good mothering of the next generation. However, impairments at the placental level caused by stress, toxins, or poor nutrition may impact adversely on the developing hypothalamus, and hence mothering of the next generation. A peaceful, secure environment is thus of paramount importance to a mother for securing a successful pregnancy and for the security of well-being in raising her offspring. Further, we need to take into account how events experienced in utero also shape the outcome of future generations, since epigenetic reprogramming of future oocytes (matrilineal contribution to grandchild) occurs at the earliest (epiblast) stages of in utero ovarian development. The postnatal formative years of the brain are strongly influenced by mother-infant interactions. The brain’s mechanisms for reward that subserve mother-infant-mother (p.66) affiliation subsequently extend to the reward process of social interaction later in life. Throughout the first two decades of development, functional contacts are made across the brain’s billions of neurons, involving trillions of synapses such that no two brains are the same, not even those of genetically identical twins. Since consolidation of neural connectivities is activity dependent, the environments that generate this activity determine the functional details of these structural connections. Our brains are very much a product of the pre- and postnatal niche in which they develop and survive.
Title Epigenetics: Significance of the gene-environment interface for brain development
Publication Title Pathways to peace: The transformative power of children and families
Publication Type Book Chapter
Published Year 2014
Publisher MIT Press
Authors E.B. Keverne
Section 5
Grant List
-

JOIN THE CONVERSATION

For breaking news and to stay connected, follow us on social media. Sign up to get our E-News delivered straight to your inbox.