NeurophysiologyUrb
Brain neuroplasticity in physiological and pathological conditions
Neuroplasticity is an “umbrella term” referring to the complex, multifaceted physiological processes that mediate the ongoing structural and functional modifications occurring, at various time- and size-scales, in the ever-changing immature and adult brain, and that represent the basis for fundamental neurocognitive behavioral functions. On the other hand, maladaptive neuroplasticity plays a role in the pathophysiology of neurological dysfunctions. The hippocampal formation, an important brain structure involved in cognitive functions and in affectivity, appears to be particularly affected by plastic processes throughout the lifespan of mammalians, including humans. Among the most remarkable forms of neural plasticity is the ability of the hippocampus to continuously generate functional neurons during adulthood, a process known as adult hippocampal neurogenesis, which is integral for the hippocampus functions. Besides structural plasticity, hippocampus is able to exhibit the form of functional synaptic plasticity known as long-term potentiation, which is widely believed to be one of the main neural mechanisms by which memory is stored in the brain. Therefore, the extended restructuring and functional remodeling of the hippocampus, according to experiential stimuli and diverse endogenous and exogenous factors, may confer important adaptive plasticity. On the other hand, the perpetual capacity for structural changes might render the hippocampus particularly sensitive to perturbations that may have adverse consequences on hippocampal function. Indeed, hippocampus is a vulnerable structure impaired by events, such as stroke, head trauma and epilepsy, and it is susceptible to damage during aging and repeated stress. Plastic changes triggered by intense and prolonged negative stimuli could be responsible for disease progression; this aspect of neural plasticity could be referred to as maladaptive. In this context, the increasingly in-depth knowledge of neurobiological correlates underlying dysfunctional brain plasticity would allow to correct the mechanisms behind the pathology.