{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

NE101 Lecture Notes

Goal can we learn something about how value is

Info iconThis preview shows pages 12–14. Sign up to view the full content.

View Full Document Right Arrow Icon
Goal” can we learn something about how “value” is encoded in the brain? October 26, 2012: Basic Endocrinology All forms of chemical communication share basic similarities signaling cell → signal → receptor → target molecule → response Hormones – chemical messengers secreted by cells in one part of the organism and affecting cells in a distant part of the organism In animals, it is usually through the circulatory system Chemical communication is classified largely by distance of effect Endocrine vs, neural communication Endocrine long distance action (m) signals broadcast through bloodstream to almost all cells slow (s – min) analogue (graded) no conscious control Neural very localized (nm) signals travel along defined routes between specific cells 9neural networks) very rapid (ms)
Background image of page 12

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
digital (all or nothing) some conscious control Modes of hormone action Steroid hormones usually enter cell, interact directly with transcription factors to affect gene expression persist longer in bloodstream, have longer-term effects Protein and amine hormones bind to receptors on cell surface, effects mediated inside the cell by second messengers shorter lived effects (broken down/internalized rapidly) Neuroendocrine communication 1. Hormones of the HPA (hypothalamus, pituitary, adrenal) Axis HPA Axis functionally integrated system composed of CNS and endocrine structures final products (glucocorticoids such as cortisol in humans are important modulators of stress response and serve as negative feedback for rest of HPA axis Stress → hypothalamus puts out CRH → anterior pituitary puts out ACTH → adrenal glands put out glucocorticoids (cortisol) → less ACTH & CRH are put out in response stress response: mobilized energy resources (increases blood sugar, facilitates protein and/or at metabolism), inhibits immune, digestive, and reproductive function Hypothalamus Diencephalic origin Main point of integration between the CNS and endocrine system. Not protected by blood-brain barrier thus can be affected by blood-born ligands. Contains many neurosecretory (neuroendocrine) cells action potentials and synapses but release hormones interact with pituitary Pituitary Gland Posterior pituitary Hormones (e.g. oxytocin and vasopression/ADH ) released directly from hypothalamic neurosecretory cells into bloodstream. Anterior pituitary Hypothalamic releasing hormones (e.g., CRH ) released into portal vessels by neurosecretory cells. Induce pituitary endocrine cells to release their own hormones (e.g., ACTH ) into bloodstream. Case Study: Hormonal Modulation of Behavior – Oxytocin/Vasopressin and Affiliative Behavior Oxytocin and vasopressin Close structural similarity (probably evolved from common ancestor via gene duplication).
Background image of page 13
Image of page 14
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}