Love, Sex, and Aggression Exam 1

Berthold's study

- first formal study of endocrinology

- roosters, usually mate w hens, attack other roosters, crow, larger and distinctive look

- capons (castrated prior to adulthood), no mating w hens, less aggressive, don't crow, smaller

-1849

- tried reimplanting the testes into the abdominal cavity and the male developed normally

- tried transplanting another hens testes and the male developed normally

- concluded that testes are transplantable, transplatable testes can function and produce sperm, testes function is not directed by nerves (bc nerves were cut and didn't regenerate and they were put back in a totally different spot)

- when transplanted they regained access to blood supply, showed that they were a secretory blood-born product coming from the testes

what are hormones

- organic chemical messenger

- released from endocrine cells and glands

- travels through the bloodstream

- any cell receiving blood can potentially receive a hormonal message

- interact w target cells from a distance

- need a receptor, sufficient numbers of those receptors must be present for a hormone to exert any effect

- cause a biological response (activate cellular pathways, gene expression, protein synthesis, etc.)

neural transport

- much shorter distance relative to hormonal

behavior affects hormones and hormones affect behavior

- bidirectional relationship

how can hormones affect behavior

- hormones can make environmental cues more salient

- alter speed of neural processing or high processes like motivation or attention

- might affect the vocal organ, like development

how can behavior affect hormones

- when you lose, testosterone goes down

- when you win, testosterone goes up (physically win/lose or mentally)

- social factors - domincan males during dice tournaments show elevated testosterone only when defeating outsiders, not friends

- observing a competition can cause changes too

- women's testosterone levels increase after sex more than after exercise

- eating and sleeping increase/decrease some hormones

ways to measure hormone levels

- immunassays (radioimmunoessays and enzyme immunoassays)

- imminohisochemistry

- blots

- in situ hybridization

- brain imaging (fMRI)

Radioimmunoassay (RIAa)

- used to measure hormone levels

- uses antibodies and purified radiolabeled ligands

- can measure how much is left after they compete for receptor slots

Enzyme Immunoassay (EIA)

- uses the principle of competitve binding of an antibody to its antigen to determine the presence or quanity of a biological substance such as a hormone

pregnancy test example

- HCG is whats measured

- signals during pregnancy, eps early on

- reacts w antibodies, binds with another antibody, color appears

- control shows that the reaction worked

Immunohistochemistry (IHC)

- uses antibodies to label hormones or receptors in teh brain or other tissues

blots

used to determine whether a specific protein or nucleic acid is present in a tissue sample

- southern blot - DNA

- northern blot - RNA

- western blot - Protein

in situ hybridization

- used to identify cells or tissues producing RNA molecules that encode a specific protein (such as a hormone)

- advantage over blots is that it tells us if a protein is bring produced in that tissue, not just present

- can be quantified

brain imaging (fMRI)

- detects neural activity changes during specific tasks or conditions, aka measures function

- detects changes in the ratio of oxyhemoglobin to deoxyhemoglobin. when brain regions increase activity, there is an increase in oxygenated blood leading to a net increase in signal

ablation and replacement

- ablation: the removal of the suspected source of the hormone

1) a gland beleives to produce a hormone that affects a behavior is surgically removed

2) the effects of that removal are observed

3) the hormone is replaced

4) have the consequences of the ablation been reversed by replacement?

pharmacological techniques

- usually involves introducing a chemical agent that can stimulate or inhibit hormone action

- agonist: binds to the receptor of a hormone and miics the action of that hormone

antagonist: binds to the receptor of a hormone but does not activate it

routes of administration for hormones

- peripherally through injection

- centrally through cannulation

- vein or artery catheterization

- pills, patches, gels, injections

optogenetics

- control over the activity of neurons, can silence or cause them to fire

- engineered microbial opsins that repsond to specific wavelengths of light

- channelrhodopsin-2 (ChR2) - non-specific cation channel, derived from green algae, activated by blue light, excitatory

- Halorhodopsin (NpHR) - chloride pump (moves Cl- into the cell), derived from the halobacterium, activated by yellow light, inhibitory

Genetic Manipulations

- knock out (KO) - engineered so that a specific gene has been deactivated

- transgenic - engineered so that there is an overexpression of a specific gene

- CRISPR/Cas9 - a gene editing tool that alters DNA sequences to modify gene function

endocrinology

the scientific study of the endocrine glands and their associated hormones

intracrine mediation

regulate intracellular events, doesn't leave the cell

autocrine mediation

leaves cell and reenters, feed back to influence the same cell that secreted them

paracrine mediation

cells secrete chemicals that affect adjacent cells

ectocrine mediation

ectocrine substances such as pheromones are released into the environment by individuals to communicate with others

Testosterone example

- leydig cell produced T

- it goes through the bloodstream to muscle tissue (endocrine)

- it goes to sertoli cell, nearby (paracrine)

features of the endocrine system

- endocrine glands or cells are ductless

- endocrine glands have a rich blood supply

- hormones are secreted into the bloodstream

- hormones travel in the blood to virtually every cell

- hormone receptors are specific binding sites embedded in the cell membrane that interact with a particular hormone

endocrine deficiency despite high hormone levels

- occurs when receptors are insufficient or unresponsive

- two causes

1) clinical conditions, genetic mutations in receptors or type II diabetes insulin resistance

2) receptor downregulation due to high hormone concentrations

endocrine excess to elevated receptor numbers

- if target tissues have more receptors than usual, a normal or elevated hormone level can produce exaggerated effects

hypothalamus

control of hormone secretions

pinal gland

reproductive maturation, body rhythms, melatonin production

pituitary gland

anterior pituitary

- hormone secretion by thyroid, adrenal cortex, and gonads

posterior pituitary gland

- water balance, salt balance

thyroid

growth and development, metabolic rate

adrenal glands

adrenal cortex

- salt and carbohydrate metabolism, inflammatory reactions

adrenal medulla

- emotional arousal and stress response

pancreas main purpose

sugar metabolism

gut

digestion and appetite control

gonads

body development, maintenance of reproductive organs in adults

what are the 4 classes of hormones

protein and peptide hormones

steroid hormones

monoamines

other lipid-based hormones (not true hormones)

protein and peptide hormones general

- made of amino acid building blocks

- longer chain: protein hormone

- shorter chain: peptide hormone

- metabolism is reported as biological half-life (time for concentration to reduce by 50%)

what are the types of protein and peptide hormones

- hypothalamic hormones

- pituitary hormones

- thyroid and parathyroid hormones

- pancreatic hormones

- gastrointestinal hormones

hypothalamic hormones

- neurosecretory cells: function as an endocrine gland but similar to conventional neuron

- neurohormones: released by NSCs into blood vessels in the pituitary rather than into a synapse

hypothalamus releasing hormones

thyrotropin-releasing hormone (TRH): stimulates the release of thyroid-stimulating hormone (TSH)

growth hormone-releasing hormone (GHRH): also called somatocrinin, provokes growth hormone release

gonadotropin releasing hormone (GnRH): regulares follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

Corticotropin-releeasing hormone (CRH) - stimulates release of adrenocorticotropic hormone (ACTH)

hypothalamus inhibiting hormones

- somatostatin (GHIH): reduces growth hormone secretion

- gonadotropin-inhibitory hormone (GnIH): inhibits release of GnRH and gonadotropins

other hypothalamic hormones

- dopamine (DA)

- prolactin inhibitory hormone (PIH)

- Hypocretin and orexin: wakefulness and sleep

pituitary general

- grows out of the bottom of the hypothalamus

- hypothalamus controls the anterior pituitary, then the anterior pituitary control the posterior pituitary

anterior pituitary hormones

- derived from the soft tissue of the upper palate

- the anterior pituitary regulates other endocrine glands (master gland)

- protein hormones (called tropic hormones)

- topic hormones affect the secretion of other hormones from their target glands

how does the hypothalamus control the anterior pituitary gland

- the hypophyseal portal system

- axon terminals of hypothalamic neurons release neurohormones near capillaries that give rise to portal vessels

- neurohormones from the portal vessels stimulate or inhibit the release of hormones from anterior pituitary cells

- anterior pituitary hormones leave the gland vis the blood

anterior pituitary hormones

- luteinizing hormone (LH)

- follicle-stimulating hormone (FSH): stimulate steroid hormone production and gamete maturation in the gonads

- thyroid-stimulating hormone (TSH): regulates thyrid

- growth hormone (GH): stimulates somatic growth, regulate production of somatomedins (insulin-like growth factors)

growth hormone

- secreted in pulsatile fashin

- GHRH, SWS, exercise, fasting and stress promote secretion secretion

- IGF-1 mainly liver but also local tissue

anterior pituitary prolaction

- named after role in promoting lactation but also has hundreds of functions known across species

reproduction

growth and development

water and electrolyte balance

maintenance of integumentary structure

NO prolactin-releasing hormone, more general affects

POMC

- POMC (pro-opiomelanocortin) is a precursor protein synthesized in the anterior pituitary, cleaved into the following proteins

- Adrenocorticotropic (ACTH) - stimulates the adrenal glands to secrete corticosteroids

- Melanocyte-stimulating hormone (MSH) - regulates skin color in some vertebrates (as well as sexual function and appetite)

- B-endorphin - endogenous opioid

posterior pituitary hormones general

- neural origin is in the base of the brain

- hypothalamic neurohormones get released into the posterior pituitary

- acts as a reservoir for oxytocin and vasopressin

- 75% volume is from axons

- 25% is made up of glial cells called pituicytes

- provide structure, balance, extracellular fluid, and mediate the secretion of oxytocin and vasopressin

how to think of AP and PP

- AP: production facotory

- PP: storage warehouse

oxytocin

- the love hormone

- released by the PP

- uterine contractions (receptors for it increase around birth)

- milk ejection let down

vasopressin

Also known as antidiuretic hormone (ADH) and Arginine vasopressin (AVP)

controls of the body osmotic balance

high plasma osmolarity - ADH release

acts on receptors in kidneys to increase water reabsorption

also blood pressure regulation

alcohol decreases ADH

thyroid and parathyroid

- high cascularized H shapped organ

- consists of many follicles which produce the thyroid hormones

- needs iodine to function

- stores in large quanities in collids inside follicles

C-cell and parathyroid hormones

- C-cells are endocrine cells in the thyroid that secrete the hormone calcitonin(CT)

- CT lowers blood calcium levels but inhibiting therelease of Ca from the bone

- parathyroid secretes parathyroid hormone (PTH), which increases blood calcium levels and inhibits phosphate resorption from the kidneys

- both CT and PTH are regulated by blood calcium levels with no anterior pituitary involvement

pancreas in general

- exocrine and endocrine functions

- endocrine tissue is called the islets of Langerhans

- Innervated by the vagus nerve, stimulates insulin release

pancreatic hormones

b cells produce insulin

- highly concerved

- only hormone to reduce blood sugar levels

- receptors found throughout the body and brain

- take blood glucose into cell or store in muscle as glycogen

a cells produce glucagon

- first acts in the liver to stimulate glycogenolysis (breaking down glycogen into glucose)

-acts in opposition to insulin by increasing blood glucose levels

delta cells release somatostatin

- inhibits release of insulin and glucagon locally

PP/F cells release pancreatic polypeptides

- released by protein, fasting, exercise, hypoglycemia

- PP treatment suppressed appetite and food intake

- may modulate exocrine secretions

e cells release ghrelin

- released from stomach

- stimulates appetite

gastrointestinal hormones general

- secretin, cholecystokinin (CCK), and ghrelin

- goals:

coordinate digestion and absorption

regulate gastric emptying and motility

signal nutrient arrival to the pancreas and brain

secretin

- discovered by william bayliss and ernest sterling

- denervated jejunum loop in dogs, when perfused with acid there were secretions from the pancreas and when acid was added to the blood there were no secretions

- proved that when acidic food enters from the stomach, duodenal mucous cells release secretin which travel to the pancreas and release biocarbonate from exocrine cells

- also stimulates peptin release, insulin release, renal function and inhibits GI tract movement

CCk

- release of digestive enzymes from the pancreatic exocrine cells

- contraction of gallbladder and release of bile

ghrelin

- peptide made in endocrine cells in the stomach

- stimulates release of GHRH

- treated mice show increase food intake and fat deposition

- humans ate 30% more after ghrelin treatment

- levels peak before food intake

glucagon-like peptide-1

- peptide made in endocrine cells in the intestines

- stimulates release of insulin

- decreases glucagon release

- slows gastric empyting

- increases satiety

gonadal functions

- produce gametes

- production of hormones

testes

- seminiferous tubules: where sperm is made

- sertoli cells have heads of nearly mature sperm embedded for nourishment and produce inhibin and activin

- leydig cells produce steriod hormones

ovaries

- follicles, each one contains a developing ovum

- theca cells produce steroid hormones

- grunulose cells - produce inhibin and activin

- corpus luteum: endocrine structure that forms from the remnants of an ovarion follicle following ovulation, secretes progestin and relaxin

- stroma: connective tissue

gonadal hormones

- mullerian inhibitory hormone (testes): inhibits the mullerian duct system which gives ruse to female accessory sex organs

- inhibin (ovaries and testes): feeds back to block FSH release from anterior pituitary and inhibit aromatase

- activin (ovaries and testes): stimulates FSH release, and stimulates aromatase activity in ovaries

- relaxin: produced by the corpora lutea at the end of pregnancy to relax pelvic ligaments in prep for labor

placental hormones

- temporary endocrine organ maintains respiratory, nutritional function for the fetus

- human chorionic gonadotropin (HCG): placental hormones similar to prolactin and GnRH, some supplemental ones (CC, CT

- chorionic somatomammotropin (CS) initiates onset of maternal behavior

adipokine hormones

leptin

- protein secreted from adipose cells

- induced energy expenditure and inhibits food intake

- blood concentrations increase following eal in concert with insulin release

adiponectin

- peptide secreted from adipose cells

- expression of mRNA is decreased in obese mice and humans

- treatment w adiponectin reduces blood glucose and insulin resistance

steriod hormones

- fat soluble hormones derived from cholesterol

- primarily produced in brain gonads and adrenals

- not stored in cell so it can be hours between signal for production and release

- can't be stored in vesicles

prohormones

- act as a hormone and convert into a different hormone

progestins

- pregnenolone is a progestin and a precurser to all other steroid hormones

- named for their pro-gestational actions in maintaining pregnancy

- in mammals involved in maintaining pregnancy and the initiation and cessation of mating

where are mineralocorticoids produced

zona glomerulosa of adrenal cortex (SALT)

example: aldosterone

where are glucocorticoids produced

Zona fasciculata of the adrenal cortex (SUGAR)

example: cortisol

where are androgens produced

zona reticularis of the adrenal cortex (SEX)

example: DHEA, androstenedione

corticoids

- pregnenolone make sprogesterone makes corticoids

- glucocorticoids are involved in carbohydrate metabolism and stress

- ex: corticosterone - reptiles, birds, some mamals secrete it and mice

- ex: cortisol: primary GC for humans, primates, and bony fish

- mineralocorticoids like aldosterone mediate ion exchange and water metabolism

androgens

- pregnenolone becomes androgens

- androstenedione and DHEA are weak

- testosterone

5a and b-dihydrotestosterone are strong and derived from testosterone

roles for androgens

- speratogenesis

- maintain accessory sex organs

- male secondary sex traits

- morphological effects

- behaviors

- metabolism

- ovarian function, cardiac health, bone metabolism, muscle mass

estrogens

androgens become estrogens

enzyme called aromatase converts androgens to estrogen

ovaries produce androgens

17b estradiol

estriol

estrone

roles for estrogens

initiate formation of corpora lutea

affect the genital tract

mammalian female secondary sex characters

sexual behavior

maternal aggression

water metabolism

calcium metabolism

libido, erectile disfunction, spermatogenesis

neurosteroids

made in both CNS and PNS

predominantly in glial cells

modulate neurotransmitter receptors

adrenal medullary monoamine hormones

- prepare the body for action

- catecholamines, like epinephrine, norepinephrine and dopamine

- stress, exercise, low temps, anxiety, hemorrhage drive release

- increaed HR and cardiac output

- vasoconstriction of arteries and veins

- dilation of skeletal and liver blood vessels

- increased glycolysis

- increased blood glucagon and decreased insulin

- all derived from tyrosine

thyroid hormones pr

- T3: increases basal metabolic rate

- T4: primary hormone secreted from the thyroid

- made from tyrosine

- fat soluble and need a carrier protein to travel through the blood, like a steroid hormone

functions of thyroid hormones

- metabolism: heat production, adapts to changing temps, glucose movement

- growth and differentiation

- reproduction

prostaglandins

- not strictl a hormone, paracrine factor

- found in seminal fluid and cause contraction or relaxation of the uterus

-

receptors for protein/peptide and monoamine hormones

- bind to surface level receptors

- G proteins second messagers

receptors for steroid hormones and thyroid hormones

- can interact w membrane receptors

- diffuse through the membrane

regulation of receptor concentrations

- up regulation: high concentration of hormone increases # of receptors

- down reg opposite

called homospecific priming

heterospecific is when the concentration of one hormone can increase or decrease the number of receptors for a different hormone