CH 3.3 (PSYCHOPHARM)

Hormones

Are secreted by the endocrine glands; circulate in the bloodstream

Target cells contain

Hormone specific receptors

endocrine system

System consists of multiple layers

Works more slowly BUT longer effect than cell communication

Adrenal gland

Derived from nervous system tissue

TWO pyramid shaped organs on top of the kidneys; produce hormones and regulate body functions

• adrenal medulla

• Adrenal cortex

Adrenal medulla

Secretes epinephrine (EPI) and norepinephrine (NE) Monoamines

Chromaffin cells secrete specialized neuroendocrine cells

Adrenal cortex

Secretes glucocorticoids (steroid hormones)

Gonads

Sexually reproductive organs

• Testies

• Ovaries

Testies

Found in males; release testosterone

Ovaries

Found in females; secrete estrogen and progesterone

Islets of Langerhands

In pancreas

• secrete insulin and glucagon (peptide hormones)

• Regulation of glucose

Thyroid gland

Secretes thyroxine (T4) and triiodothyronine (T3)

• regulates energy metabolism

• Both made from a tyrosine (precursor for DA, NE, EPI)

Pineal gland

Secretes melatonin

• controls sleep and other rhythms

• Synthesized from Serotonin (SE)

Pituitary gland

Secretes hormones that control other glands

Anterior pituitary

Secretes stimulation hormones

• TSH, ACTH, FSH, LH, GH, & PRL

• Connected to hypothalamus via blood vessels

Hypothalamus

Secretes releasing hormones to trigger secretion of stimulating hormones by the anterior pituitary

• shared blood supply

• Responds by releasing matching hormones

Hypothalamic releasing hormones

Released by neurons in the median eminence

• blood vessels in pituitary Stalk carry their to A. Pituitary

Thyrotropin-releasing hormone (TRH) stimulates

TSH

Corticotrophin releasing hormone (CRH) stimulates

ACTH (stress)

Gonadotrophin releasing hormone (GnRH) stimulates

FSH and LH

Vasopressin (VP) and Oxytocin (OT)

Synthesized in the hypothalamus by neurons whose axons reach the posterior pituitary gland

• communication is neural

• AP in hypothalamus = release of OT

Synthesized by specialized secretory neurons (magnocellular neurons) in paraventricular and supraoptic nuclei

Brain areas recieving input are part of social behavioral neural network

Pathways are sexually dimorphic; influenced by gonadal steroids

Vasopressin

Antidiuretic hormone- regulates water retention in kidneys

Function as NT

Neurons from the paraventricular nucleus

Oxytocin

Stimulates uterine contractions during childbirth; triggers milk letdown from breasts

Function as NT

Neurons from the paraventricular nucleus

Research: influenced social behaviors (empathy, trust, etc); potential in ameliorating the social deficits of autism

Mechanism of hormone action

1. Peptide hormone acts through metabotrophic receptors

   1. OT/VP activate PI second messengers → activate PKC

Insulin

Reciprocate phosphorylate BY using tyrosine kinase receptors

Steroid and thyroid hormones

Operate through intracellular receptors in cell nucleus’s function as transcription factors

• fat soluble

• Penetrates cell

• Drugs that are fat soluble = more effective

• ACTIVATES GENE = long lasting effect

Neurotransmitter system has been altered

Because pituitary hormones are controlled by neurotransmitters in the brain, the endocrine system can reveal if a _______

Pharmacology: hormones

• drugs can adversely alter endocrine function

• Hormones may alter behavioral responses to drugs

  • Hormones sometimes have psychoactive properties