Abstract

Contemporary brain research has expanded its field of study from that of pathological processes in relation to nervous and endocrine functions involved, up to the study of the normal relations of these two systems and the behavior. From the psychological perspective, it is important to address the study of the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis is connected to the central nervous system (CNS) and the endocrine system (ES). The HPA axis is a major neuroendocrine system that controls reactions to stress and regulates many body processes, including digestion, the immune system, mood and emotions, sexuality, and energy storage and expenditure. The evidence also informs of the role of HPA axes in neurocognitive changes. The parts of the HPA axis include the hypothalamus, limbic system, the pituitary gland, and the adrenal glands. The two systems work together to adjust the balance of the hormones and the stress response. It is well documented that the disruption of the HPA axes and changes in the neurocognitive and psychological state of individuals produce high levels of stress. This chapter presents an overview of brain structures and neurohormonal agents involved in HPA axes: Limbic System, hypothalamus, regulation of pituitary secretion and relationship with, stress, mode, personality and neurocognition.