Call us toll-free

Quick academic help

Don't let the stress of school get you down! Have your essay written by a professional writer before the deadline arrives.

Calculate the price

Pages:

275 Words

$19,50

Glucocorticoid Hypothesis of Brain Aging and its ..

The glucocorticoid hypothesis of cognitive decline in aging. Stress increases pituitary release of corticotropin, which causes the adrenal gland to produce more glucocorticoids. Long‐term exposure to these stress hormones increases neuronal vulnerability to aging, extrinsic injuries, and disease, causing hippocampal deterioration and eventual cognitive decline.

The Neuroendocrinology of Stress and Aging: The Glucocorticoid Cascade Hypothesis Robert M

The original glucocorticoid (GC) hypothesis of brain aging and Alzheimer’s disease proposed that chronic exposure to GCs promotes hippocampal aging and AD. This proposition arose from a study correlating increasing plasma corticosterone with hippocampal astrocyte reactivity in aging rats. Numerous subsequent studies have found evidence consistent with this hypothesis, in animal models and in humans. However, several results emerged that were inconsistent with the hypothesis, highlighting the need for a more definitive test with a broader panel of biomarkers. We used microarray analyses to identify a panel of hippocampal gene expression changes that were aging-dependent, and also corticosterone-dependent. These data enabled us to test a key prediction of the GC hypothesis, namely, that the expression of most target biomarkers of brain aging should be regulated in the same direction (increased or decreased) by both GCs and aging. This prediction was decisively contradicted, as a majority of biomarker genes were regulated in opposite directions by aging and GCs, particularly inflammatory and astrocyte-specific genes. Thus, the initial hypothesis of simple positive cooperativity between GCs and aging must be rejected. Instead, our microarray data suggest that in the brain GCs and aging interact in more complex ways that depend on the cell type. Therefore, we propose a new version of the GC-brain aging hypothesis; its main premise is that aging selectively increases GC efficacy in some cell types (e.g., neurons), enhancing catabolic processes, whereas aging selectively decreases GC efficacy in other cell types (e.g., astrocytes), weakening GC anti-inflammatory activity. We also propose that changes in GC efficacy might be mediated in part by cell type specific shifts in the antagonistic balance between GC and insulin actions, which may be of relevance for Alzheimer’s disease pathogenesis.

stress and aging: the glucocorticoid cascade hypothesis.

The glucocorticoid hypothesis of cognitive decline in aging. Stress increases pituitary release of corticotropin, which causes the adrenal gland to produce more glucocorticoids. Long‐term exposure to these stress hormones increases neuronal vulnerability to aging, extrinsic injuries, and disease, causing hippocampal deterioration and eventual cognitive decline.

and Aging: The Glucocorticoid Cascade Hypothesis ..

Order now
  • UNMATCHED QUALITY

    As soon as we have completed your work, it will be proofread and given a thorough scan for plagiarism.

  • STRICT PRIVACY

    Our clients' personal information is kept confidential, so rest assured that no one will find out about our cooperation.

  • COMPLETE ORIGINALITY

    We write everything from scratch. You'll be sure to receive a plagiarism-free paper every time you place an order.

  • ON-TIME DELIVERY

    We will complete your paper on time, giving you total peace of mind with every assignment you entrust us with.

  • FREE CORRECTIONS

    Want something changed in your paper? Request as many revisions as you want until you're completely satisfied with the outcome.

  • 24/7 SUPPORT

    We're always here to help you solve any possible issue. Feel free to give us a call or write a message in chat.

Order now
  • You submit your order instructions

  • We assign an appropriate expert

  • The expert takes care of your task

  • We send it to you upon completion

Order now
  • 37 684

    Delivered orders

  • 763

    Professional writers

  • 311

    Writers online

  • 4.8/5

    Average quality score

Order now
  • Kim

    "I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."

  • Paul

    "Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."

  • Ellen

    "Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."

  • Joyce

    "Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."

  • Albert

    "Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."

  • Mary

    "Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."

Ready to tackle your homework?

Place an order