Juvenile experience and learning modulate the functional maturation of thebrain: Relevance for the genesis and therapy of mental disorders

This article summarizes experimental data that indicate how juvenile experi ence and learning events modulate the functional maturation of the brain, s haping thereby the neuronal substrate for the development of intellectual a nd socio-emotional abilities. The fact that early experience occurs during early postnatal brain development, i.e. phases of elevated neuronal and syn aptic plasticity, results in an,,imprinting" of synaptic connectivity and n eural circuitry in the infant brain. Results from experimental research in animal models support the hypothesis that impoverished intellectual stimula tion and disturbance of the socio-emotional environment during early childh ood may disturb the formation of functional brain pathways, in particular o f the limbic circuits, which play a major role in emotion and learning. Suc h defective brain systems, representing neurofunctional ,,scars" in the bra in, may be the neuronal basis of a variety of mental disorders and clinical symptoms caused by early stressful psychosocial environment. Ultimately, t he goal will be to apply the knowledge gained to the development of biologi cal and psychosocial intervention strategies by utilizing remaining plastic ity of the adult human brain aimed at promoting human health, decreasing su sceptibility and increasing resistance to disease.