The CRF hypothesis and stress

CRF is synthesized in the hypothalamus and elicits the release of adrenocorticotropic hormone (ACTH) from the pituitary. CRF was isolated from sheep hypothalamus and its structure as a 41-amino-acid peptide determined.96 The hypothalamic paraventricular nucleus (PVN) is the major region in the brain of CRF-containing cell bodies and through axonal projections to the capillaries of the median eminence can secrete CRF directly into the portal system where it acts at the pituitary to regulate ACTH secretion into the circulation. The principal role of ACTH is to stimulate the release of cortisol from the adrenal gland, thus completing the HPA axis, a primary component of the neuroendocrine response to stress. Similarly, projections from the PVN to the lower brainstem and spinal cord have been demonstrated to regulate autonomic function and help to further mediate the behavioral responses to stress. High densities of CRF-containing neurons are localized in particular to prefrontal, cingulate, and insular areas and appear to regulate behavioral actions of the peptide. Above and beyond its direct role in mediating HPA activity, the extrahypothalamic anatomical distribution of CRF suggests that this neuroactive peptide is localized in discrete brain regions that are thought to regulate mood and stress-related behaviors.89 Administration of CRF into the locus coeruleus initiates stress responses accompanied by increases in catecholamine turnover and activity in the frontal cortex suggesting that the peptide produces anxiety-related behavior by increasing the activity of the noradrenergic system.89 Such studies implicate CRF and related peptides in the mechanisms through which various stressors can alter behavior.89

Getting to Know Anxiety

Getting to Know Anxiety

Stop Letting Anxiety Rule Your Life And Take Back The Control You Desire Right Now! You don't have to keep letting your anxiety disorder run your life. You can take back your inner power and change your life for the better starting today! In order to have control of a thing, you first must understand it. And that is what this handy little guide will help you do. Understand this illness for what it is. And, what it isn't.

Get My Free Ebook


Post a comment