Neurobiologia do Estresse Crônico e Contágio do Estresse
Neurobiologia do Estresse Crônico e Contágio do Estresse
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DOI: https://doi.org/10.22533/at.ed.172112613014
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Palavras-chave: Estresse crônico; Carga alostática, Eixo HPA; Estresse contagioso; Neurofisiologia.
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Keywords: Chronic Stress; Allostatic Load; HPA Axis; Stress Contagion; Neurophysiology
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Abstract: This chapter addresses the main neurobiological mechanisms involved in the response to chronic stress, with emphasis on physiological adaptation processes, neuroendocrine systems, and neural circuits responsible for emotional regulation. Initially, the effects of prolonged exposure to stress on the organism are discussed, highlighting the sustained activation of stress-response systems and its consequences for physiological homeostasis. Next, the concepts of allostasis and allostatic load are presented, which describe the adaptive processes mobilized by the organism in response to environmental challenges and the physiological wear resulting from chronic exposure to stressors. The chapter also explores the functioning of the hypothalamic–pituitary–adrenal (HPA) axis, the main neuroendocrine system responsible for coordinating the stress response, as well as the mechanisms of hormonal regulation mediated by mineralocorticoid and glucocorticoid receptors. In addition, processes associated with HPA axis dysregulation are discussed, including neuroinflammation, microglial activation, and interactions with the gut–brain axis. The chapter also addresses the main neural structures and circuits involved in the stress response, highlighting the hippocampus, amygdala, and prefrontal cortex, emphasizing how prolonged exposure to stress can promote structural and functional alterations in these regions and contribute to emotional and cognitive changes associated with stress-related disorders. Finally, recent evidence is discussed indicating that physiological and behavioral responses to stress can also be triggered indirectly through cohabitation with stressed individuals, a phenomenon known as stress contagion. In this context, studies are presented that investigate how social interactions and cohabitation with stress-exposed conspecifics can modulate neuroendocrine and behavioral responses, expanding the understanding of stress as a process influenced not only by direct stressors but also by the social environment.
- Lisiê Valéria Paz
- Helena Rodrigues Horta
- Andressa Mayer
- Mariáh Cecília Graeff Buchele
- Isabelle Canal Rodrigues
- Léder Leal Xavier