Becoming Stressed: Does the Age Matter? Reviewing the Neurobiological and Socio-Affective Effects of Stress throughout the Lifespan.

Aroa Mañas-Ojeda,Francisco E Olucha-Bordonau,Francisco Ros-Bernal,Esther Castillo-Gómez

doi:10.3390/ijms21165819

Abstract

Social and affective relations occur at every stage of our lives. Impairments in the quality of this “social world” can be exceptionally detrimental and lead to psychopathology or pathological behavior, including schizophrenia, autism spectrum disorder, affective disorders, social phobia or violence, among other things. Exposure to highly stressful or traumatic events, depending on the stage of life in which stress exposure occurs, could severely affect limbic structures, including the amygdala, and lead to alterations in social and affective behaviors. This review summarizes recent findings from stress research and provides an overview of its age-dependent effects on the structure and function of the amygdala, which includes molecular and cellular changes, and how they can trigger deviant social and affective behaviors. It is important to highlight that discoveries in this field may represent a breakthrough both for medical science and for society, as they may help in the development of new therapeutic approaches and prevention strategies in neuropsychiatric disorders and pathological behaviors.

Highlights

Human beings are a highly social species
As a process orchestrated by the brain, the stress response varies across the lifespan
The studies in humans and animal models reviewed here reveal that, while deficits in sociability and social interaction/communication are shared consequences of stress exposure across all stages of life, depression- and anxiety-like symptoms are more variable among age periods, and aggression is just documented as a consequence of peripubertal period

Summary

Introduction

Human beings are a highly social species. This does not make us special, since all mammals exhibit some degree of social behavior, such as cooperation, affiliation or aggression, that allows us to survive and thrive. Social neglect is one of the important factors that can elicit this pathological aggression, especially when it occurs in early life [5,10,24], the underlying neural bases of such phenomenon remain poorly understood In this regard, experimental animal models devoid of human cultural connotations constitute a valuable tool for studying anti-social behaviors and affective impairments related to stress. Alterations in this brain region have been found in many neuropsychiatric and behavioral disorders, including schizophrenia, ASD, major depression and social phobia, among others [2,25,27,28] These studies in humans and animal models, together with classic studies based on amygdaloid lesions in nonhuman primates, have positioned the amygdala at the center of the socio-affective brain [27]. As the development of the circadian clock begins in the prenatal period, continuous light exposure during gestation decreased mobility and exploratory activity in the

Stress Exposure during Late Childhood and Adolescence

Stress Exposure during Adulthood

Stress Exposure during Old Age

Conclusions