The two-hit stress model predicts that exposure to stress at two different time-points in life may increase or decrease the risk of developing stress-related disorders later in life. Most studies... Show moreThe two-hit stress model predicts that exposure to stress at two different time-points in life may increase or decrease the risk of developing stress-related disorders later in life. Most studies based on the two-hit stress model have investigated early postnatal stress as the first hit with adult stress as the second hit. Adolescence, however, represents another highly sensitive developmental window during which exposure to stressful events may affect programming outcomes following exposure to stress in adulthood. Here, we discuss the programming effects of different types of stressors (social and nonsocial) occurring during adolescence (first hit) and how such stressors affect the responsiveness toward an additional stressor occurring during adulthood (second hit) in rodents. We then provide a comprehensive overview of the potential mechanisms underlying interindividual and sex differences in the resilience/susceptibility to developing stress-related disorders later in life when stress is experienced in two different life stages. Show less
In contrast to classical conditioning of physiological responses such as immune responses and drug effects, only a limited number of studies investigated classical conditioning of endocrine... Show moreIn contrast to classical conditioning of physiological responses such as immune responses and drug effects, only a limited number of studies investigated classical conditioning of endocrine responses. The present paper is the first systematic review that integrates evidence from animal and human trials regarding the possibility to condition the endocrine responses. Twenty-six animal and eight human studies were included in the review. We demonstrated that there is accumulating evidence that classical conditioning processes are able to influence specific endocrine responses, such as cortocosterone/cortisol and insulin, while more limited evidence exists for other hormones. Animal and human studies were generally consistent in their findings; however, the limited number of human studies makes it difficult to generalize and translate the results of animal research to humans. Next to methodological recommendations for future studies, we suggest several ways how classically conditioned endocrine responses can be used in clinical practice. Show less
In contrast to classical conditioning of physiological responses such as immune responses and drug effects, only a limited number of studies investigated classical conditioning of endocrine... Show moreIn contrast to classical conditioning of physiological responses such as immune responses and drug effects, only a limited number of studies investigated classical conditioning of endocrine responses. The present paper is the first systematic review that integrates evidence from animal and human trials regarding the possibility to condition the endocrine responses. Twenty-six animal and eight human studies were included in the review. We demonstrated that there is accumulating evidence that classical conditioning processes are able to influence specific endocrine responses, such as cortocosterone/cortisol and insulin, while more limited evidence exists for other hormones. Animal and human studies were generally consistent in their findings; however, the limited number of human studies makes it difficult to generalize and translate the results of animal research to humans. Next to methodological recommendations for future studies, we suggest several ways how classically conditioned endocrine responses can be used in clinical practice. Show less
The brain is of bewildering complexity and numerous genes and signaling molecules have been described that affect the architecture and functioning of specific neuronal circuits. Recent evidence... Show moreThe brain is of bewildering complexity and numerous genes and signaling molecules have been described that affect the architecture and functioning of specific neuronal circuits. Recent evidence from genome analysis revealed the existence of a large group of novel RNA molecules with unexpected properties. One such group is called microRNAs, which are small 21-23 nucleotides RNA molecules that are transcribed by the genome. However, they are not translated into proteins but rather control translation of coding mRNA. Particularly in the brain, numerous different microRNAs are expressed in a cell type specific fashion both during development and in adulthood. Aberrant microRNA expression has been implicated in several human diseases including CNS diseases. The aim of this review is to emphasize their role in the development of the brain and their function. In addition, we highlight recent findings on the evolution of mammalian microRNAs and their effect on steroid signaling in the brain. (C) 2009 Elsevier Inc. All rights reserved. Show less
