Changes in plasticity across the lifespan: cause of disease and target for intervention

Abstract

We conceptualize brain plasticity as an intrinsic property of the nervous system enabling rapid adaptation in response to changes in an organism's internal and external environment. In prenatal and early postnatal development, plasticity allows for the formation of organized nervous system circuitry and the establishment of functional networks. As the individual is exposed to various sensory stimuli in the environment, brain plasticity allows for functional and structural adaptation and underlies learning and memory. We argue that the mechanisms of plasticity change over the lifespan with different slopes of change in different individuals. These changes play a key role in the clinical phenotype of neurodevelopmental disorders like autism and schizophrenia and neurodegenerative disorders such as Alzheimer's disease. Altered plasticity not only can trigger maladaptive cascades and can be the cause of deficits and disability but also offers opportunities for novel therapeutic interventions. In this chapter, we discuss the importance of brain plasticity across the lifespan and how neuroplasticity-based therapies offer promise for disorders with otherwise limited effective treatment.

Keywords: Alzheimer's disease; aging; autism spectrum disorders; lifespan; plasticity; schizophrenia; transcranial magnetic stimulation.

Figure 1

Schematic representation of the influence of aging on plasticity and cognitive ability.

Figure 2A

Schematic representation of how factors such as expression of certain genes, diseases, brain injury, or behavior can impact the slope of change in plasticity across the lifespan.

Figure 2B

Schematic representation of how degree of plasticity and cognitive ability at any given time in the lifespan is a consequence of both a given individual's starting point and slopes of change.