1 / 30

Hormonal Control of Behavior

Hormonal Control of Behavior. Lecture 22. Chemical Control of Brain. Point-to-point control closed-circuit synapse fast, short-lived, local ~. Chemical Control of Brain. Diffuse control widespread control slower, longer lasting Diffuse modulatory systems Neuroendocrine system ~.

fletcher-hampton
Download Presentation

Hormonal Control of Behavior

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hormonal Control of Behavior Lecture 22

  2. Chemical Control of Brain • Point-to-point control • closed-circuit • synapse • fast, short-lived, local ~

  3. Chemical Control of Brain • Diffuse control • widespread control • slower, longer lasting • Diffuse modulatory systems • Neuroendocrine system ~

  4. Hormones & Behavior? • Responses to a changing environment detect stimulus  make response • Effectors • muscles • glands • Autonomic N.S. • Homeostasis ~

  5. 2 Types of Glands • Exocrine • ducts • sweat, tears, etc. • Endocrine • ductless • hormones • released into blood ~

  6. Neurohormones • Interact with nervous system • Chemical message • Neurotransmitters (NTs) • Hormones • Pheromones • What’s the difference? ~

  7. Neurohormones • Similarities • chemical messengers • act at receptors • influence behavior • Differences • medium • distance traveled • time course ~

  8. Neurohormone Properties • Neurons release molecules into blood • Long distances • Slower • Longer lasting effects • Widespread ~

  9. Function • Developmental • sex differentiation • testosterone, estradiol • Regulatory • Insulin, CCK, etc. • Vasopressin, Oxytocin ~

  10. Types of Neurohormones • Amino acid-derived hormones • e.g. epinephrine • released from adrenal medulla • Protein & Peptide Hormones • Bind to membrane receptors • Activate the 2nd messenger system ~

  11. Types of Neurohormones • Steroid Hormones • Derived from cholesterol • Soluble in lipids • Bind to cytoplasmic receptors • regulates gene expression • e.g. sex hormones ~

  12. Neuroendocrine System • Brain • Hypothalamus • Releasing Hormones • Pituitary gland • Anterior: tropic hormones • Posterior: neurohormones • Glands - Hormones ~

  13. Pituitary Gland • 2 parts • different developmental origins • Anterior pituitary (adenohypophysis) • no axons from hypothalamus • parvocellular neurosecretory cells • portal system • Posterior pituitary (neurohypophysis) • axons from hypothalamus • magnocellular secretory cells ~

  14. G Hypothalamus Pituitary Stalk Pituitary hypophysis Posterior Pituitary- Neurohypophysis Anterior Pituitary- Adenohypophysis

  15. Supraoptic nucleus PVN Posterior Pituitary

  16. Posterior Pituitary: Neurohormones • Magnocellular neurosecretory cells • Supraoptic & Paraventricular Nuclei • Neurons fire  Neurohormones released • Transported down axons • to posterior pituitary • Peptide Neurohormones • Oxytocin • Vasopressin ~

  17. Oxytocin • Induces uterine contractions • child birth • orgasm during sex • Triggers lactation • “letdown reflex” • triggered by touch, sight, sound ~

  18. Antidiuretic Hormone (ADH) • AKA: Vasopressin • Responds to ¯blood pressure • Induces vasoconstriction • Promotes water retention • Kidney: Renin release • Angiotensin I  Angiotensin II • to kidneys & subfornical organ ~

  19. Subfornical Organ • Subfornical organ - SFO • Dorsal 3d ventricle • lacks blood-brain barrier • A II receptors • Output to • Supraoptic & paraventricular nuclei • ADH release • lateral hypothalamus (LH) • thirst  drinking behavior ~

  20. SFO Hypothalamus A II LH PVN & SON ADH Thirst Kidneys

  21. ADH (Vasopressin) • Alcohol suppresses ADH release • Damage  diabetes insipidus • Symptoms • copius urination • intense thirst ~

  22. Anterior Hypothalamus • Primordial tissue from roof of mouth • No axons from hypothalamus • Parvocellular neurosecretory cells • Releasing hormones • triggers release of tropic hormones • Tropic hormones  various glands gonads adrenal • mammary thyroid ~

  23. Hypothalamopituitary Portal System • Portal Systems • Capillary beds • Connected by a vein • e.g. hepatic portal vein • Hypothalamus  Anterior Pituitary ~

  24. PVN RH G

  25. G TH TH TH TH TH PVN RH

  26. Cortisol Regulation • Adrenal glands • medulla: NE & E • cortex: cortisol • Regulation of cortisol • steroid • fight/flight & immunosuppression • stress response • Receptors widely distributed ~

  27. Cortisol Regulation • Hypothalamus • Corticotropin-releasing hormone (CRH) • Anterior pituitary • Adrenocorticotropin (ACTH) • Adrenal cortex • Cortisol • Negative feedback to hypothalamus • cortisol inhibits own release ~

  28. Sex Hormones • Hypothalamus • Gonadotropin-releasing hormone - GRH • isolated from pig hypothalami • Anterior Pituitary - • Gonadotropins • Follicle stimulating hormone - FSH • Lutenizing hormone - LH ~

  29. Gonadotropins: Target Cells • Gonads • Testes - • Androgens -Testosterone • Ovaries - • Estrogens • Estradiol and Progesterone ~

  30. Gonadotropin Release Patterns • Sex differences • FSH & LH both sexes • Males  steady • Females • cyclical • Transplant male pituitary into female? ~

More Related