The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science

by Norman Doidge

But there is another possible cause. It has recently been discovered that early childhood trauma causes massive plastic change in the hippocampus, shrinking it so that new, long-term explicit memories cannot form. Animals removed from their mothers let out desperate cries, then enter a turned-off state—as Spitz’s infants did—and release a stress hormone called “glucocorticoid.” Glucocorticoids kill cells in the hippocampus so that it cannot make the synaptic connections in neural networks that make learning and explicit long-term memory possible. These early stresses predispose these motherless animals to stress-related illness for the rest of their lives. When they undergo long separations, the gene to initiate production of glucocorticoids gets turned on and stays on for extended periods. Trauma in infancy appears to lead to a supersensitization—a plastic alteration—of the brain neurons that regulate glucocorticoids. Recent research in humans shows that adult survivors of childhood abuse also show signs of glucocorticoid supersensitivity lasting into adulthood.

many anxiety laden individuals may suffer this