How do we illustrate resilience in biological systems?
Before attempting to explore neurobiological resilience, it is helpful to consider how resilience may be defined more generally. A simple broad definition of resilience in biological systems can be thought of as those factors that contribute to an organism's ability to cope with environmental challenges, thus ensuring survival. Take the structure of a palm tree. The typical tall palm found in tropical paradises has a very thin, flexible trunk, with a limited number of fronds at the very top, and no other branches along the way. Why is this architecture found in tropical palms, but not in trees resident to deciduous forests in cooler climes? In addition to ample heat and sun, the environment in the tropics is usually quite breezy, and this morphological arrangement allows the tree to gently sway in the wind. When violent hurricanes inflict their damage and destruction in these coastal communities, the morphology of the palms allows many of them to withstand the violent winds, not by rigid resistance of the wind, but by a gradual bending. The trees bend, but do not break. In a sense, this can be thought of as the broad definition of resilience – the ability of an organism to cope with environmental tumult by bending, and not breaking. But how do we define this in the context of neurobiology?
An eloquent way of thinking about resilience was put forward by Ann Masten (2012), by suggesting “resilience is the capacity of a dynamic, malleable system to withstand challenges to its stability, viability or development.” [1]. As such, vulnerability may be considered the flipside of resilience. Vulnerable individuals may be those in which the systems of resilience do not function adequately, or in which the challenge is, for some reason, experienced in an amplified way.