Amygdalo-Hypothalamic Pathways Mediate Stress-Induced ACTH (Adrenocorticotropic Hormone) Release.

摘要

The research goals of this project are to determine the anatomical pathways and neurotransmitters that participate in the neuroendocrine response to stressors. We have focused our study on the amygdala which is composed of a heterogeneous group of nuclei and is part of the limbic system. Studies are designed to determine which corticotropin releasing cells of the hypothalamus are innervated by the amygdala, to identify the neurotransmitters that influence corticotropin releasing cells, and to determine the role of the amygdala in release of ACTH and related 'stress' hormones to different psychological and physical stressors. Studies have been completed that identify the anatomical connection between the amygdala and ACTH releasing cells of the hypothalamus. The results show that the central nucleus of the amygdala and the bed nucleus of the stria terminalis are directly linked to cells which control anterior pituitary release of ACTH and thus can modulate the release of corticosterone release from the adrenal glands. Studies have also been completed that demonstrate that destruction of cells in the central amygdala blunt the plasma increases corticosterone and renin which normally increase in response to stress. In addition, studies have demonstrated that central injections of thyrotropin releasing hormone (TRF) cause the release of ACTH, probably mediated through excitation of corticotropin releasing factor neurons of the hypothalamus. (SDW)