*Arnold Berthold in mid 19th century

*Castrated cockerels (Removal and Replacement study)

*Hormones are blood born

*Sexual Behavior (dogs)

*Comparative Approach (uses animals)

*Integrative Approach

How might hormones alter Behavior?

1.) Altering sensory processing

2.) Affecting the CNS

3.) Changing motor output

*Chemical Messenger

*Emitted from a gland

*Acts on distant target

*Blood-borne

*Interacts with specific receptors

*Hormone made by a neuron(neuropeptide)

*Hormone release is PULSATILE (go up and down)

*Neural control center

*Divided into nuclei

*"Releasing hormones" (causes hormones to be released into the blood)

*Hypophyseal Portal System (tiny network of blood vessels

*Connected to hypothalamus via neural and vascular connections

*Anterior and Posterior

*Periphearl hormones alter secretion of hypothalamic and pituitary hormones

*Way to know that the signal has been received

*Pheriphearl hormones causes DECREASES in hypothalamus and pituitary

*Turns self off

*Pheriphearl hormones cause INCREASES in hypothalamus and pituitary

*Amplify signal (ovulation, childbirth)

*Chains of amino acids (relatively large)

*Cannot cross BBB

*Stroed in vesicles

*Activate membrane receptors

*EX. Hypothalamic releasing hormones

*Derived from cholesterol (relatively small)

*Made as needed, released when made

*Enzymes- rate limiting step

*Activate nuclear receptors

*Lipid soluble, pass through BBB

*Alter protein synthesis

*EX. Estrogen and Testosterone

What do the ovaries produce?

*Estrogen

*Progesterone

*Androgens

*Androgens

(testosterone like substances)

1.)Cortex --> *Cortisol & Aldosterone

2.)Medulla --> *Epinephrine

*Trophic hormones

*B-endorphin

*Vasopressin

*Oxytocin

**PROHORMONES: precursors to hormones, made by a cell (POMC)

Hormone Effects:

Autocrine Mediation

Hormone Effects:

Paracrine Mediation

Hormone Effects:

Endocrine Mediation

Hormone Effects:

Ectorcrine Mediation OR Pheromone

Effects of Hormones:

Activational

*Effect observed only when hormones present in system

*Rapid changes in behavior

*EX. Estrogen effects on female sexual behavior

Effects of Hormones:

Organizational

*Developmental

*Permanent change in morphology or behavior

*Visible long after hormone's clearance

*EX. Androgen effects on genital structure in males

*Penile development

*Interest in sex

*Potency

*Sperm production

*In rats, T must be converted to estrogen to stimulate neural sex centers

*In men, this does not seem to be necessary

*Experimental design

*Altered by investigator

*Experimental design

*Measured by investigator

*Experimental design

*Held constant

*"ABA" Design

A: Measure behavior

B: Reomove hormone & measure behavior

A: Replace hormone & measure behavior

*No sex drive

*Would grow very tall

*Done to protect women

*No puberty

*Singers, high pitched voices

*All male

*Observe behavior (ovary intact)--> female sexual receptivity

*Remove ovaries --> sexual receptivity ceases

*Replace estrogen & progesterone --> restore receptivity

*The higher the dose, the greater the effect (anabolic steroids)

*physiological vs. pharmacological effects

*Competitive binding technique

*uses radioactive hormone

*Visualization of cells containing hormones, receptors, enzymes, etc.

*Antibody raised against an amino acid sequence

*EX. Estrogen receptor-alpha containing cells

*EX. CRF staining PVN

*Surgical implantation of indwelling "tube"

GOAL: deliever drugs directly to brain

EX. Delivery of alpha-MSH

*Surgical implantation of cannula and tubing

GOAL: removal of small amounts of extracellular fluid from around neurons for later measurment of hormones/NT's

*EX. Measure neuropeptide release during behavior

GOAL: determine which protein/peptide/enzyme mediates a hormones effects

*Gene "knockouts"

*Create a line of mice that lack a gene for something

EX. estrogen receptor knockout mice

*Genes

*Steroid hormones secretion

*Genital/morphologic sex

*Gonadal sex

*Social structure

*How others see you as male or female

*How you feel inside

*Biologically influenced

Bipotential, primordial gonad:

1)Cortex

2)Medulla

1)Cortex --> ovary

2)Medulla-->testis

Bisexual Internal Genitalia:

1)Wolffian System?

2)Mullerian System?

1) Wolffian System = MALE

2) Mullerian System = FEMALE

1) Defeminization

2) Masculinization

*Induces formation of testis

*Production depends on Y chromosome

*only direct effect of Y chromosome = testicular development

*Peptide from testes --> defeminization

(Regression of Mullerian System)

*5-alpha-reductase (enzyme)

**DHT masculinizes external genitalia