Psycho EXAM 3

Narcolepsy (cont'd)

Seems to run in families although no gene has been identified. Caused by lack of hypothalamic cells that produce and release orexin. • Treatments? • Ritalin • SSRIs • Why not increase Orexin?

Thoughts...........

Strong sociocultural influence........... • Develops during adolescence. • Many women have a difficult relationship with food,...one wrought with guilt, pleasure, shame and secrecy.

2.Hypovolemic thirst:

a thirst resulting from loss of fluids due to bleeding or sweating • Fixed concentration of solutes in the body is a set point - 0.15 M (molar) in mammals

Night terrors

are experiences of intense anxiety from which a person awakens screaming in terror. - Usually occurs in NREM sleep.

• Coma:

extended period of unconsciousness characterized by low brain activity that remains fairly steady - Person shows little response to stimuli

Poikilothermic (ectothermic):

idea that the body temperature matches that of the environment - Amphibians, reptiles, and most fish - The organism lacks the internal, physiological mechanisms of temperature regulation - Temperature regulation is accomplished via choosing locations in the environment - Although known as "cold-blooded," organism is cold only if environment is cold

Social jet lag

may occur when sleep routines are disrupted during weekends. • After a succession of 5-hour nights, we accumulate a sleep debt that cannot be satisfied by one long sleep. • In a 2013 Gallup poll, 40 % of Americans reported getting 6 hours or less sleep per night (Jones, 2013).

• Brain death:

no sign of brain activity and no response to any stimulus

• "Sleep talking"

occurs during both REM and NREM sleep.

Minimally conscious state:

one stage higher than a vegetative state marked by occasional brief periods of purposeful action and limited speech comprehension

• Vegetative state:

person alternates between periods of sleep and moderate arousal but no awareness of surrounding - Some autonomic arousal to painful stimulus - No purposeful activity/response to speech

Jet lag

refers to the disruption of the circadian rhythms due to crossing time zones. • Stems from a mismatch of the internal circadian clock and external time. • Characterized by sleepiness during the day, sleeplessness at night, and impaired concentration.

1.Osmotic thirst:

results from eating salty foods

"Sleep-walking"

runs in families, mostly occurs in young children, and occurs mostly in stage 3 or 4 sleep.

• Homeothermic (endothermic):

use of internal physiological mechanisms to maintain an almost constant body temperature • Characteristic of mammals and birds • Requires energy and fuel • Sweating and panting decrease temperature • Increasing temperature is accomplished via shivering, decreasing blood flow to the skin, and fluffing out fur to increase insulation

• (Are there)Universally desired characteristics ??:

• 1) kindness, loyalty, understanding (not looks) • 2) similarity • 3) conscientiousness (reliable, practical organized) • 4) emotional stability • 5) the belief that relationships take work

What about men?

• 5-10% of the anorexics are men • Who? • career-related: i.e. Jockeys, boxing,.... • 35% of those who suffer from bingeeating (overeating) disorder are men • More likely to abuse muscle-enhancing drugs than to avoid food - WHY??

Orexin

• Additional pathway from paraventricular nucleus - Cells in the lateral hypothalamus release orexin • Orexin increases animals' persistence in seeking food - Influences response to incentives and reinforcement in general

Females—FSH and LH

• After the end of a menstrual period: • Anterior pituitary releases folliclestimulating hormone (FSH) • FSH promotes growth of follicle in the ovary • Follicle nurtures the ovum and produces estrogen • Towards the middle of the menstrual cycle, the follicle builds up receptors to FSH • As a result, the follicle produces increasing amounts of estradiol • Increased estradiol causes the anterior pituitary to increase release of FSH and luteinizing hormone (LH) • FSH and LH cause the follicle to release an ovum • The remnants of the follicle release the hormone progesterone • Prepares the uterus for implantation of a fertilized ovum • (progesterone) Inhibits the further release of LH

Endogenous Circadian Rhythms

• All animals produce endogenous circadian rhythms, internal mechanisms that operate on an approximately 24-hour cycle: • Sleep cycle • Frequency of eating and drinking • Body temperature • Secretion of hormones • Urination • Sensitivity to drugs (due to changes in body temp etc)

Allostasis

• Allostasis refers to the adaptive way in which the body anticipates needs depending on the situation • Helps the body avoid errors instead of just correcting them • E.g ?? • See danger......"fight or flight" ....prepares you

Alpha Waves and Stage 1 sleep

• Alpha waves are present when one begins a state of relaxation. (drowsy) • Stage 1 (NREM-1) sleep is when sleep has just begun. • the EEG is dominated by irregular, jagged, low voltage waves. (Theta waves) • brain activity begins to decline. • Light sleep, claims to be awake • May see fleeting images

External Factors controlling Hunger/Eating

• Aspects of the food itself • Flavor • Appearance and smell • Eating habits involving times, places, kinds of food you're used to can affect food choices - Includes cultural differences in eating customs • Food cues can trigger eating as well, even when a person does not physically need food - Includes sight, smell, past associations • Social rules and cultural traditions - Food culture (learning influence)

Activating Effects of Sex Hormones

• At any time in life, sex hormones exert activating effects to temporarily modify behavior • Behavior can also influence hormone secretion • Oxytocin - Important for reproductive behavior - Stimulates uterine contractions during delivery and mammary glands in releasing milk

Falling in love..........

• Attractiveness across cultures • Let's consider what is attractive.... • (Are there)Universally desired characteristics ??:

Eating Disorders-weight gain

• Availability of tasty, high calorie foods makes animals (and people) obese, and they find other rewards less rewarding • Psychological distress does not cause weight gain • A high-fat diet before birth can result in the offspring being born with a larger than average lateral hypothalamus

Satiety signals

• Axons from the satiety-sensitive cells of the arcuate nucleus deliver an excitatory message to the paraventricular nucleus • (Note: leptin and glucose also signal satiety) • Causes release of melanocortins • Melanocortin: chemical important in limiting food intake • Deficiencies of this receptor lead to overeating • Nicotine also stimulates the satiety neurons in the arcuate nucleus • Cigarette smoking decreases appetite • Distention of the intestine triggers neurons to release the neurotransmitter CCK • CCK= Cholecystokinin • =hormone released from the duodenum that constricts the sphincter muscle between stomach and duodenum • Causes stomach to 'fill up' more quickly • Limits meal size • Short-term effects

Biological Perspectives on Dreaming

• Biological research on dreaming is complicated by the fact that subjects often cannot accurately remember what was dreamt • Two biological theories of dreaming include: • The activation-synthesis hypothesis • The neurocognitive hypothesis

Females—Birth Control Pills

• Birth control pills prevent pregnancy by interfering with the usual feedback cycle between the ovaries and pituitary • The combination-pill contains estrogen and progesterone • Prevents the surge of FSH and LH that would release an ovum • Thickens the mucus of the cervix • More difficult for sperm to reach the egg • Prevents egg from implanting in uterus

Brain Mechanisms

• Body temperature regulation is predominantly dependent upon areas in the preoptic area/ anterior hypothalamus (POA/AH) • POA/AH receives input from temperature receptors throughout the body - Heating the POA/AH leads to panting or sweating; cooling leads to shivering - Receives input from the immune system

What Men and Women seek in a mate.......

• Both men and women prefer a romantic partner that is healthy, intelligent, honest, and physically attractive • Women prefer partners who are likely to be good providers - Evolutionary explanation: • Choosing a father who is likely to be a good provider aids the woman while she is pregnant or caring for a small child

Androgens and Estrogens

• Categories of chemicals, not chemicals themselves • Androgens - Group of primarily male hormones - Testosterone is the most widely known • Estrogens • Most common is estradiol • Progesterone -Prepares the uterus for the implantation of a fertilized ovum -Promotes the maintenance of pregnancy

Brain Mechanisms of Wakefulness and Arousal—GABA and Acetylcholine

• Cells of the basal forebrain release the inhibitory neurotransmitter GABA • Inhibition provided by GABA is essential for sleep • Other axons from the basal forebrain release acetylcholine, which is excitatory and increases arousal

Sleep

• Characterized by a moderate decrease in brain activity and decreased response to stimuli • Sleep differs from the following states: • Coma, vegetative state, minimally conscious state, and brain death

Morning People and Evening People??

• Cycles can differ between people and lead to different patterns of wakefulness and alertness • Change as a function of age • Young children are morning people • Adolescents are often night people • As an adult, it partially depends upon genetics

Evolutionary Interpretations of Mating Behavior

• Darwin's theory of evolution: • Individuals whose genes help them survive will produce more children, and the next generation will have more of these genes • Sexual selection: genes that make an individual more appealing to the opposite sex will increase the probability of reproduction • Must be balanced between attractiveness and survival

Sexual Differentiation

• Depends mostly on the level of testosterone during a sensitive period • The human sensitive period for genital formation occurs during the first trimester of pregnancy • At first, the external genitals of males and females look the same

Weight Loss

• Dieting by itself not considered reliably effective • Most people do not stick to diet for long • Lifestyle changes including increased exercise essential • Some drugs are effective in weight loss • Gastric bypass surgery • Weight-loss is often difficult and specialists rarely agree. • Successful treatments include change of lifestyle, increased exercise and decreased eating. • Some appetite-suppressant drugs such as fenfluramine and phentermine block reuptake of certain neurotransmitters to produce brain effects similar to that of a completed meal.*NOTE: side effects

Digestion and Food

• Digestive system function • Break down food into smaller molecules that the cells can use • Digestion begins in the mouth - Enzymes in saliva break down carbohydrates • Hydrochloric acid and enzymes in the stomach digest proteins

Males—Effects of Neurotransmitters

• Dopamine stimulation of D1 and D5 receptors is associated with sexual arousal -Facilitates erection of the penis and sexually receptive postures in females (Lordosis in rats) • Higher concentrations of dopamine stimulate D2 receptors and lead to orgasm • Neurotransmitter serotonin decreases sexual activity by blocking dopamine release

The Stomach and Intestines— Duodenum

• Duodenum - Part of the small intestine - Site of initial absorption of significant amounts of nutrients • Distention of the duodenum can also produce feelings of satiety • The duodenum also releases the hormone cholecystokinin (CCK), which helps to regulate hunger

Brain Activity in REM Sleep

• During REM sleep: • Activity increases in the pons and the limbic system • Activity decreases in the primary visual cortex, the motor cortex, and the dorsolateral prefrontal cortex • REM sleep is also associated with a distinctive pattern of high-amplitude electrical potentials known as PGO waves • Waves of neural activity are detected first in the pons, then in the lateral geniculate of the hypothalamus, and then the occipital cortex • REM deprivation results in a high density of PGO waves during uninterrupted sleep • Cells in the pons send messages to the spinal cord, which inhibits motor neurons that control the body's large muscles - Prevents motor movement during REM sleep • REM is also regulated by serotonin and acetylcholine • Drugs that stimulate acetylcholine receptors quickly move people to REM • Serotonin interrupts REM

Anorexia Nervosa

• Eating disorder characterized by a refusal to eat enough to maintain a healthy body weight • Most have an exaggerated fear of getting fat • Many also engage in excessive exercise • May have altered dopamine levels—cause versus effect? • New hypothesis for treatment—adjust temperature levels -keep them warm to 'prevent' the need to 'over exercise' (text pg 316) • European trials showed ¾ of patients fully recovered

Bulimia Nervosa

• Eating disorder in which people alternate between extreme dieting and binges of overeating • Some force vomiting after eating • Associated with increased release of ghrelin and alterations of several other hormones and transmitters • Resembles drug addiction

Digestion and Food Selection— The Intestines

• Enzymes in the small intestine digest proteins, fats, and carbohydrates - Digested food absorbs into the bloodstream • The large intestine absorbs water and minerals - Lubricates the remaining materials to pass as feces

Organizing Effects of Sex Hormones—Estrogens

• Estradiol and other estrogens do not modify male anatomy - They do modify various internal structures, including the prostate gland • The absence of sex hormones generally leads to female-looking external genitalia • Females lacking estradiol during early life do not develop normal sexual behavior

The Lateral Hypothalamus (LH)

• Feeding-related functions of the lateral hypothalamus - Controls insulin secretion - Alters taste responsiveness • Stimulation of the lateral hypothalamus increases the drive to eat - Damage to this area causes aversion to food

Organizing Effects of Sex Hormones—Androgens

• Female rats exposed to testosterone during sensitive periods become partly masculinized in anatomy and behavior - Clitoris grows larger than normal - Sexual behavior becomes masculinized • If a male rat lacks androgen receptors or is castrated, it develops female-like anatomy and behavior

Sleep and the Inhibition of Brain Activity

• Functions of the inhibitory neurotransmitter GABA are also important for: • Decreasing the temperature and metabolic rate • Decreasing the stimulation of neurons

Inhibitory Transmitters from Hunger sensitive cells

• GABA • Neuropeptide Y (NPY) • Agouti-related peptide (AgRP) • NPY and AgRP block the satiety action of the paraventricular nucleus and provoke overeating

The Suprachiasmatic Nucleus (SCN) and the Circadian Rhythm

• Generates circadian rhythms in a genetically controlled, unlearned manner • Single cell extracted from the SCN and raised in tissue culture continues to produce action potentials in a rhythmic pattern • Various cells communicate with each other to sharpen the circadian rhythm

Sex Differences in Childhood Behavior—Prenatal Hormones

• Girls born to women with high testosterone levels while pregnant show a slightly elevated preference for typical boys' toys • Boys born to women with high phthalate (found in perfumes, food packaging, etc.) levels while pregnant showed more interest in typical girls' toys • Toy preferences are a result of both prenatal hormones and child-rearing experiences

Glucose, Insulin, and Glucagon

• Glucose - Main product of digestion - Important source of energy for the body - Main fuel used by the brain - Excess glucose enters the liver and fat cells • Insulin = pancreatic hormone that enables glucose to enter the cell • Glucagon = pancreatic hormone that stimulates the liver to convert stored glycogen to glucose • Both insulin and glucagon regulate the flow of glucose into cells

Parental Behavior—Hormonal Changes

• Hormonal changes prepare a female mammal to provide milk - And to prepare her to care for young • Prolactin - Necessary for milk production - Enables mother to eat more than usual - Responsible for some maternal behavior • Vasopressin - Hormone synthesized by the hypothalamus - Secreted by the posterior pituitary gland - Associated with social behavior in many species - Facilitates olfactory recognition • Mice (and humans) can adopt normal maternal behavior without the hormonal changes of going through pregnancy

Genes and Sex Differences

• Hormones do not account for all the biological differences between males and females • Genes on the X and Y chromosomes also produce sex differences • At least three genes on the Y chromosome are active in specific brain areas • At least one gene on the X chromosome is active only in the female brain

Parental Behavior—Hormones and the Quality of Care

• Hormones play initial role in quality of maternal care - Experience replaces hormonal influences as hormone levels decline • Correlation exists between father's hormones and level of interaction with their child • Fathers with lower testosterone and higher prolactin levels spent most time playing with and caring for child

Mechanisms of Water Regulation

• Human mechanisms of water regulation vary depending on circumstances • Water can be conserved by: • Excreting concentrated urine • Decreasing sweat • Most often, water regulation is accomplished by drinking more water than we need and excreting the rest • Vasopressin is a hormone released by the posterior pituitary • Raises blood pressure by constricting blood vessels • Helps to compensate for decreased water volume • Also known as an antidiuretic hormone (ADH) • Enables the kidneys to reabsorb water and excrete highly concentrated urine

Hunger sensitive signals

• Hunger sensitive cells receive input from taste pathway and from GHRELIN • Ghrelin - Released by the stomach - Triggers stomach contractions - Neurotransmitter released in the brain - Acts on the hypothalamus to increase appetite

Treatment for sleep disorders, jet lag, insomnia etc...

• Identify 'stress' factors • Utilize knowledge of circadian rhythms • Have a routine • Jet lag : stay in the sun • Don't sleep...... • Exercise • Avoid caffeine/nicotine at night • Avoid/Turn off any source of "night lights" • OTC Sleep aids: Mild insomnia • Tylenol PM, Advil PM, .....diphenhydramine--- • Like anti-histamine , causes drowsiness • May Not get good sleep..... • PRESCRIPTIONS: • Selective GABA medications (inhibitory neurotransmitter) • Ambien, Lunesta, Sonata • Rapid onset • Side effects: memory disturbance, hallucinations, confusional arousal ( "extreme" sleep walking) • Latest: Ramelteon - acts on sleep wake cycle - bind to melatonin receptors -2018= BELSOMRA-OREXIN

Insulin Levels

• If insulin level stays constantly high: - Body continues rapidly moving blood glucose into the cells long after a meal - Blood glucose drops and hunger increases in spite of high insulin levels - Food is rapidly deposited as fat and glycogen - Causes weight gain

Females—Pregnancy

• If woman is pregnant, estradiol and progesterone levels increase gradually throughout pregnancy • If not, levels of both decline, and uterine lining is cast off (menstruation) • High levels of estradiol and progesterone produce heightened activity in the serotonin receptor - Causes nausea associated with pregnancy

Brain Mechanisms—The Immune System

• Immune system delivers prostaglandins and histamines - Causes shivering, increased metabolism, and fever • POA/AH is not the only brain area involved in temperature regulation - Primary area for controlling sweating or shivering

Glucose/Calorie signaling

• Important in regulation of feeding and satiety • Fructose - sugar that does not increase insulin or leptin • Less accurate predictor of satiety • Saccharin? (Swithers and Davidson, 2008) • Naturally sweetened vs. Saccharin • Which group gained more weight?? • Saccharin group- why?? • "lost ability to predict calorie intake and more likely to overeat" & less active

Sleep Deprivation

• In humans: Severe sleep deprivation hurts virtually all aspects of functioning, especially complex tasks • Contributes to traffic & workplace accidents • Irritable, out of sorts, unable to concentrate • Extreme: Slurred speech, decreased mental ability, paranoia, hallucinations

Females—The Menstrual Cycle

• In women, the hypothalamus and pituitary interact with the ovaries to produce the menstrual cycle • The menstrual cycle -Periodic variation in hormones and fertility over the course of about 28 days

Brain Mechanisms: the Arcuate nucleus and Paraventricular hypothalamus

• Information from all parts of the body regarding hunger impinge onto the arcuate nucleus • Output from the arcuate nucleus goes to the paraventricular nucleus (PVN) of the hypothalamus • The PVN inhibits the Lateral Hypothalamus (LH) • Note: LH is involved with eating (food consumption) • Hence PVN is involved with satiety • The arcuate nucleus is a part of the hypothalamus containing two sets of neurons • Neurons sensitive to hunger signals • Neurons sensitive to satiety signals

Sleep disorders

• Insomnia is a sleep disorder associated with inadequate sleep. • Caused by a number of factors including noise, stress, pain medication. • Can also be the result of disorders such as epilepsy, Parkinson's disease, depression, anxiety or other psychiatric conditions. • Dependence on sleeping pills and shifts in the circadian rhythms can also result in insomnia

The Suprachiasmatic Nucleus (SCN) and the Retinohypothalamic Path

• Light resets the SCN via a small branch of the optic nerve called the retino-hypothalamic path • Travels directly from the retina to the SCN • The retinohypothalamic path comes from a special population of ganglion cells that have their own photopigment called melanopsin • The cells respond directly to light and do not require any input from the rods or cones

Weight loss aids?

• MANY weight loss aids available • What about Sugar Substitutes? • Fructose? • Saccharin?

The Advantages of Constant High Body Temperature

• Mammals have a constant temperature of 37˚C (98˚F) • Muscle activity benefits from being as warm as possible • Ready for vigorous activity • So why not go higher if warmer is better? • Requires even more energy. • Proteins in the body break their bonds and lose their useful properties at higher temperatures • Reproductive cells require cooler temperatures

The Lateral Hypothalamus and Axons

• Many axons containing dopamine pass through the lateral hypothalamus • Axon functions: • Affect the taste sensation and salivation response to tastes • Cause cortical cells to increase response to taste, smell, or sight of food • Increase pituitary gland's hormone secretion that increase insulin secretion • Control digestive secretions

Mechanisms of circadian rhythms

• Mechanisms of the circadian rhythms include the following: • The Suprachiasmatic nucleus (SCN) • Genes that produce certain proteins • Melatonin levels

Interest in Multiple Mates

• Men are more likely to seek multiple sex partners, especially for short-term encounters • Evolutionary explanation • Two methods for success in spreading a man's genes • Loyal to one woman and devoting energies toward helping in child rearing • Mate with many women and hope some can raise babies without help • Women can also gain from having multiple sexual partners -Multiple mates increase resources available to her child and herself • No direct evidence suggests that specific genes influence whether people prefer single or multiple mates

What Men and Women seek in a mate.......

• Men tend to prefer a young partner - Evolutionary explanation: • Preference exists because younger women remain fertile longer than older women • Men remain fertile well into old age so preference for a young mate for women is not as pronounced

Sleep Disorders.....

• Narcolepsy is a sleep disorder characterized by frequent periods of sleepiness. • Four main symptoms include: • Gradual or sudden attack of sleepiness. • Occasional cataplexy - muscle weakness triggered by strong emotions. • Sleep paralysis- inability to move while asleep or waking up. • Hypnagogic hallucinations- dreamlike experiences the person has difficulty distinguishing from reality. • Periodic limb movement disorder is the repeated involuntary* movement of the legs and arms while sleeping. • Legs kick once every 20 to 30 seconds for periods of minutes to hours. • Usually occurs during NREM sleep. • * not restless leg syndrome • REM behavior disorder is associated with vigorous movement during REM sleep. • Usually associated with acting out dreams. • Occurs mostly in the elderly and in older men with brain diseases such as Parkinson's. • Associated with damage to the pons (inhibit the spinal neurons that control large muscle movements).

Leptin: the wonder weight loss peptide??

• Not! • Most people who needed to lose weight were already obese (i.e. high fat cell content) • More likely not sensitive to leptin • High levels could lead to diabetes and other medical problems • Conclusion: High levels of leptin do not necessarily decrease hunger. • *Although introduction of leptin to those who genetically cannot produce leptin has helped • THE BIGGEST LOSER (2016-In the news) • LONG TERM STUDY ...losing a Key Hormone • "how hard the body fights back against weight loss". • Regained weight • Slower metabolism • constantly battled hunger, cravings and binges. why? • Start of show: normal levels of leptin • End of show: they had almost NO LEPTIN • = feel hungry all the time!!! • After show: leptin returned but half of normal • "What was surprising was what a coordinated effect it is," Dr. Proietto said. "The body puts multiple mechanisms in place to get you back to your weight. The only way to maintain weight loss is to be hungry all the time. We desperately need agents that will suppress hunger and that are safe with long-term use."

The flip side...............

• Obesity • = excessive body fat (based on height) • Obesity considered a disease in the United States • STATISTICS: More than 78 million adults (or 35.7%) and more than 12.5 million children (or 16.9%) in the U.S. are classified as obese. • Obesity is officially defined as having body fat above 32% for women, 25% for men, 30% for girls and 25% for boys. • calculate your BMI. Note: 1foot - 12inches • Interpretation: A BMI of 30 or more is considered obese and a BMI between 25 to 29.9 is considered overweight.

The flip side............Obesity

• Obesity can also be a function of genes interacting with changes in the environment. - Example: Diet changes of Native American Pimas of Arizona and Mexico. • Obesity has become common in the United States and has increased sharply since the 1970's. - Attributed to life-style changes, increased fast-food restaurants, increased portion sizes, and high use of fructose in foods. • What causes obesity, a condition of excessive body fat? • Biological and psychological factors contribute, including set point, eating habits, stress levels • Genetics ?? • Obese gene : increased eating, decreased metabolic rate

Organizing Effects of Sex Hormones

• Occur at sensitive periods of development (before birth and at puberty in humans) • Determine whether the brain and body will develop male or female characteristics • Activating effects of sex hormones -Occur at any time of life and temporarily activate a particular response • Examples: pregnancy, menstruation • Distinction between the activating and organizing effects of hormone is not absolute • Hormones early in life can exert temporary effects • During puberty, hormones can also induce long-lasting structural changes

Short- and Long-Term Regulation of Feeding

• Oral factors - The desire to taste and chew are also motivating factors in hunger and satiety - Chewing gum from 4500 B.C. discovered • Sham feeding experiments • Everything an animal eats leaks out of a tube connected to the stomach or esophagus • Do not reliably produce satiety • E.g. this means taste/chewing does not make

FYI.....

• Orthorexia nervosa: - an obsession with eating foods that one considers healthy. - a medical condition in which the sufferer systematically avoids specific foods in the belief that they are harmful. • Body dysmorphic disorder (BDD) - BDD is a body-image disorder characterized by persistent and intrusive preoccupations with an imagined or slight defect in one's appearance.

Medial Areas of the Hypothalamus

• Output from the ventromedial hypothalamus (VMH) inhibits feeding • Damage to this nucleus leads to overeating and weight gain • Rats eat normal sized meals but eat more frequently • Increased stomach motility—stomach empties faster than normal

Type I Diabetes

• Pancreas does not produce insulin • insulin levels remain constantly low, but blood glucose levels are high • People eat more food than normal, but excrete the glucose unused and lose weight • Treatment: insulin injected or infused with a pump Treatment?

Sex Differences in the Brain Hypothalamus—Hormone Release

• Parts of the female hypothalamus generate a cyclic pattern of hormone release • The male hypothalamus releases hormones more steadily

Variations in Sexual Behavior

• People vary in frequency of sexual behavior, preferred types of sexual activity, and sexual orientation • Evolutionary explanations are controversial in explaining mating behavior

The Neurocognitive Hypothesis

• Places less emphasis on the pons, PGO waves, or even REM sleep • Suggests that dreams are similar to thinking, just under unusual circumstances • Either internal or external stimulation activates parts of the parietal, occipital, and temporal cortex • Stimulation is combined with recent memories and information from the senses • Most likely activity is suppressed in the following areas: • Motor neurons in primary motor cortex • Neurons in spinal cord • Prefrontal cortex (impair working memory) • Most likely activity is high in the following areas: • Inferior (lower) part of parietal cortex (visual spatial perception) • Hypothalamus and amygdala (emotional)

PMS? Is it real???

• Premenstrual syndrome (PMS) has a wide variety of signs and symptoms, including mood swings, tender breasts, food cravings, fatigue, irritability and depression. It's estimated that as many as 3 of every 4 menstruating women have experienced some form of premenstrual syndrome. (https://www.mayoclinic.org/diseases-conditions/premenstrual-syndrome/symptoms-causes/syc20376780) • The cause of PMS is unknown. • May be related to a change in both sex hormone and serotonin levels at the beginning of the menstrual cycle

Sex and Hormones

• Prenatal sexual differentiation begins with the chromosomes • Female mammal has two X chromosomes and a male has an X and a Y • During an early stage of prenatal development, both male and female have a set of Müllerian ducts and a set of Wolffian ducts, as well as undifferentiated gonads

REM sleep

• Rapid eye movement sleep (REM) are periods characterized by rapid eye movements during sleep. • Also know as paradoxical sleep: why? • is deep sleep in some ways, but light sleep in other ways. • EEG waves are irregular, low-voltage and fast. • Postural muscles of the body are more relaxed than other stages. • Story dream like state, sleep paralysis

Fever

• Reflects an increased body temperature set point, directed by the hypothalamus • Benefits: • Certain bacteria grow less vigorously • Immune system works more vigorously • Fever of above 39˚C (103˚F) does the body more harm than good • Fevers above 41˚C (109˚F) are lifethreatening

The Function of "Good" Sleep

• Repairing /restoring: "Down time" helps repair normal wear and tear on body and brain • Effective learning & memory (strengthening memories) • Good rest = better mental & emotional functioning • Resting muscles • Decreasing metabolism • Performing cellular maintenance in neurons • Reorganizing synapses

Why REM sleep??

• Research is inconclusive regarding the exact functions of REM. • During REM: • The brain may discard useless connections • Learned motor skills may be consolidated.

Males—Sexual Interest

• Research on testosterone levels and sexual interest show direct correlation • Castration generally decreases sexual interest and activity • Low testosterone is not the typical reason for impotence • Usual cause is impaired blood circulation • Viagra® increases Nitric Oxide (NO) which increases blood flow to the penis and brain.

Meal time....

• Right after a meal: • insulin levels rise • Glucose readily enters the cell • Appetite decreases • As time passes (after a meal): • Blood glucose levels fall • Insulin levels drop • Glucose enters cells more slowly • Pancreas releases glucagon • Hunger induced again when glucose is not replenished

Introduction

• Rising levels of sex hormones during puberty activate interest in sexual behavior • Sexual motivation can be regulated by physiology: sex hormones • Sexual reproduction between two individuals increases variation in the gene pool

REVIEW: What happens?

• STIMULATE: • VMH- stop eating • LH-continue eating • DESTROY • VMH-continue eating • LH-stop eating

What Determines a Person's Weight?

• Set point: "Natural" body weight • Weight loss below a person's set point is often regained • Number of fat cells, metabolic rate may contribute to set point • Can be flexible

Weight Loss remedies

• Sibutramine (Meridia)** has replaced fenfluramine and decreases meal size and binge eating by blocking reuptake of serotonin and norepinephrine • **NOTE: NO LONGER available.....cardiovascular risk! • "Orlistat" (Xenical) is drug that prevents the intestines from absorbing up to 30% of fat in the diet. • Non-prescription orlistat is Alli • Gastric bypass surgery is the removal or sewing off of part of the stomach. • Decreased stomach size allows greater distention of the stomach to produce satiety

Sleep and Memory

• Sleep also plays an important role in enhancing learning and strengthening memory • Performance on a newly learned task is often better the next day if adequate sleep is achieved during the night • Increased brain activity occurs in the area of the brain activated by a newly learned task while one is asleep • Patterns of activity in the hippocampus during learning were similar to those shown during sleep • Suggests that the brain replays its daily experiences during sleep • The brain strengthens some synapses and weakens others during sleep • Sleep spindles increase in number after new learning: correlated with nonverbal IQ

Other sleep disorders.....

• Sleep apnea is a sleep disorder characterized by the inability to breathe while sleeping for a prolonged period of time. • Consequences include sleepiness during the day, impaired attention, depression, and sometimes heart problems. • Cognitive impairment may result from loss of neurons due to insufficient oxygen levels. • Causes include, genetics, hormones, old age, and deterioration of the brain mechanisms that control breathing and obesity.

Sleep as a Local Phenomenon

• Sleep can be localized within the brain • Sleepwalkers: awake in one part of the brain and asleep in others • Lucid dreaming: dreaming but aware of being asleep and dreaming • The pons remaining in REM while other brain areas wake up: causes the inability to move

Shift Work???

• Sleep duration depends on when one goes to sleep • Working at night does not reliably change the circadian rhythm • Even after long periods of working at night, people can still feel groggy, sleep poorly during the day, and body temperature peaks while sleeping instead of while working • People adjust best to night work if they sleep in a very dark room during the day and work under very bright lights at night

Stage 2 sleep (NREM-2)

• Stage 2 (NREM-2) sleep is characterized by the presence of: • Sleep spindles - 12- to 14-Hz waves during a burst that lasts at least half a second. • K-complex - a sharp high-amplitude negative wave followed by a smaller, slower positive wave. • Definitely asleep but may respond to events (loud noises)

Stage 3 and 4 sleep (NREM-3)

• Stage 3 and stage 4 (NREM-3) together constitute slow wave sleep (SWS) and is characterized by: • EEG recording of slow, large amplitude wave. (DELTA WAVES) • Slowing of heart rate, breathing rate, and brain activity. • Highly synchronized neuronal activity. • Deep sleep, minimal awareness, partial paralysis

NREM and REM Cycles

• Stages 3 and 4 sleep predominate early in the night • Length of stage decreases as the night progresses • REM sleep is predominant later at night - Length increases as the night progresses

What is "Good" sleep

• Stages other than REM are referred to as non-REM sleep (NREM). • When one falls asleep, they progress through stages NREM-1, 2, 3, and 4 in sequential order. • After about an hour, the person begins to cycle back through the stages from stage 4 to 3 & 2 and then REM. • The sequence repeats with each cycle lasting approximately 90 minutes.

The Activation-Synthesis Hypothesis

• Suggests that dreams begin with spontaneous activity in the pons, which activates many parts of the cortex • The cortex synthesizes a story from the pattern of activation • Normal sensory information is sometimes integrated, but usually is not

Temperature Regulation

• Temperature regulation is vital to the normal functioning of many behavioral processes • Maintaining temperature requires twice as much energy as all other activities combined • Basal metabolism • Energy used to maintain a constant body temperature while at rest

Hormones in Males and Females

• Testes produce more androgens than estrogens • Estrogens: hormones more abundant in females • Androgens and estrogens are steroid hormones

Males—Sexual Arousal

• Testosterone increases touch sensitivity in the penis • Sex hormones bind to receptors in the hypothalamus, including the ventromedial nucleus, the medial preoptic area (MPOA), and anterior hypothalamus • Testosterone triggers the release of dopamine by the MPOA and other areas (hence can trigger sexual activity)

Males—Testosterone Levels

• Testosterone levels correlate positively with sexual arousal and the drive to seek sexual partners • Married men or those in a committed relationship generally have lower testosterone levels - High testosterone levels result in greater than average desire to seek additional sexual partners, even if in a committed relationship

Melatonin

• The SCN regulates waking and sleeping by controlling activity levels in other areas of the brain • The SCN regulates the pineal gland, an endocrine gland located posterior to the thalamus • The pineal gland secretes melatonin, a hormone that increases sleepiness • Melatonin secretion usually begins two to three hours before bedtime • Melatonin feeds back to reset the biological clock through its effects on receptors in the SCN • Melatonin taken in the afternoon can phase-advance the internal clock and can be used as a sleep aid

Gene

• The Y chromosome includes the SRY gene • Causes the primitive gonads to develop into testes, the sperm-producing organs • Developing testes then produce androgens • Increase testes growth • Also produce Müllerian inhibiting hormone (MIH) that causes the Müllerian ducts to degenerate • Females lack the SRY gene and their gonads develop into ovaries, the egg-producing organs

LEPTIN "leptos" (slender)

• The body's fat cells produce the peptide leptin , which signals the brain to increase or decrease eating. • Possibly by indicating nutrition levels (body's fat reserves) • Low levels of leptin (low nutrition) increase hunger/eating behavior • High levels ??? High nutrition? Stop eating?

Stages of Sleep—EEG

• The electroencephalograph (EEG) allowed researchers to discover that there are various stages of sleep - Allows researchers to compare brain activity at different times during sleep • A polysomnograph is a combination of EEG and eye-movement records

Brain Mechanisms of Wakefulness and Arousal— The Hypothalamus

• The hypothalamus contains neurons that release "histamine" to produce widespread excitatory effects throughout the brain • Note: Anti-histamines produce sleepiness

Brain Mechanisms of Wakefulness and Arousal—Orexin

• The lateral and posterior nuclei of the hypothalamus releases orexin • Orexin is a peptide neurotransmitter and is sometimes also called hypocretin • Needed to stay awake rather than wake up • Orexin is released by cells into the basal forebrain to stimulate neurons responsible for wakefulness and arousal • The basal forebrain is an area just anterior and dorsal to the hypothalamus

Brain Mechanisms of Wakefulness and Arousal— The Locus Coeruleus

• The locus coeruleus is a small structure in the pons whose axons release norepinephrine to arouse various areas of the cortex and increase wakefulness - Usually dormant while asleep

The Suprachiasmatic Nucleus (SCN)

• The main control center of the circadian rhythms of sleep and temperature • Located above the optic chiasm and part of the hypothalamus • Damage to the SCN results in less consistent body rhythms that are no longer synchronized to environmental patterns of light and dark

The Stomach and Intestines— Nerves

• The main signal to stop eating is the distention of the stomach • The vagus nerve - Cranial nerve X • Conveys information about the stretching of the stomach walls to the brain

Sleep and Energy Conservation

• The original function of sleep was probably to conserve energy • Conservation of energy is accomplished via: • Decrease in body temperature of about 1-2 Celsius degrees in mammals • Decrease in muscle activity

Brain Mechanisms of Wakefulness and Arousal— The Pontomesencephalon

• The ponto-mesencephalon, a part of the reticular formation in the midbrain, contributes to cortical arousal • Axons extend to the hypothalamus, thalamus, and basal forebrain, which release acetylcholine, glutamate, or dopamine • Produce excitatory effects to widespread areas of the cortex • Stimulation of the pontomesencephalon awakens sleeping individuals and increases alertness in those already awake

Rhythms of Waking and Sleep

• The purpose of the circadian rhythm is to keep our internal workings in phase with the outside world. • Free-running rhythm is a rhythm that occurs when no stimuli resets it. • A zeitgeber is a german term used to describe any stimulus that resets the circadian rhythms. • Light is the primary one. • Exercise, noise, meals, and temperature are other zeitgebers. • Depression, irritability, and impaired job performance are effects of using something other than sunlight as a zeitgeber

Genetics and Body Weight

• Thin parents tend to have thin children and heavy parents tend to have heavy children • People with a mutated gene for the receptors for melanocortin overeat: melanocortin responsible for satiety • Prader-Willi syndrome: genetic condition marked by intellectual disability, short stature, and obesity: high blood levels of ghrelin

Hypovolemic Thirst and Sodium-Specific Hunger

• Thirst associated with low volume of body fluids • Low blood volume —kidneys release enzyme renin which helps forms angiotensin I. Other enzymes convert that into angiotensin II. • Angiotensin II triggers hypovolemic thirst • Animals with hypovolemic thirst have a preference for slightly salty water (to replenish water and lost solutes e.g. sodium) • Sodium-specific hunger: strong craving for salty foods - Develops automatically to restore solute levels in the blood - E.g during Menstruation , pregnancy

Weight loss and dieting...............

• Thoughts: what if there was a drug that could control hunger and obesity? Would you take it? What potential benefits and problems would result from such a drug?

Genetics of the Circadian Rhythm

• Two types of genes are responsible for generating the circadian rhythm • Period: produce proteins called PER • Timeless: produce proteins called TIM • PER and TIM proteins increase the activity of certain kinds of neurons in the SCN that regulate sleep and waking • Mutations in the PER gene result in odd circadian rhythms or decreased alertness if deprived of a good night's sleep

Sex Differences in Childhood Behavior

• Typically, many boys play with cars, trains, balls and guns, and play roughly • Many girls play with dolls and tea sets, and play cooperatively • Preferences tend to be consistent over time • Partially due to socialization, but also due to general preferences of each sex • Baby monkeys also show the same preferences, but to a lesser extent

Homeostasis

• Various biological processes that keep body variables within a fixed range. • Examples: temperature, levels of water, oxygen, glucose, calcium, protein, fat, and acidity in the body • Set point: a single value that the body works to maintain • Negative feedback: processes that reduce discrepancies from the set point - Much of motivated behavior can be described as negative feedback

Brain Mechanisms of Wakefulness and Arousal— The Reticular Formation

• Various brain mechanisms are associated with wakefulness and arousal • The reticular formation is a part of the midbrain that extends from the medulla to the forebrain and is responsible for arousal

Thirst

• Water constitutes 70 percent of the mammalian body • Water in the body must be regulated within narrow limits - Sufficient fluid needed in circulatory system • The concentrations of chemicals in water determines the rate of all chemical reactions in the body

Wolffian and Müllerian Ducts

• Wolffian ducts are the precursors to other male reproductive organs -Develop into the vas deferens and seminal vesicles • Müllerian ducts are precursors to the female's oviducts, uterus, and upper vagina

Differences in Jealousy

• Women- 'jealous' about emotional ties, flirting • Men-'jealous' about physical ties; other men staring at their 'woman' • Men are more jealous at indications of a wife's infidelity - Evolutionary explanation: • Man needs to be sure that the children he supports are his own • Unfaithful wives threaten this certainty • Cultural attitudes towards infidelity vary - No known culture exists where infidelity is more acceptable for women

Type II diabetes

• body does not use insulin properly. This is called insulin resistance. • At first, your pancreas makes extra insulin to make up for it. • But, over time it isn't able to keep up and can't make enough insulin to keep your blood glucose at normal levels. • Leads to high glucose levels (hyperglycemia) • Treatment: managed through diet and exercise but may need insulin injections later • Note: hence all types of diabetes cause blood glucose levels to be higher than normal

Osmotic thirst

• occurs when certain neurons detect their own loss of water. • Animals with osmotic thirst have a preference for pure water • Happens when solute concentrations in the extracellular fluid are higher than the concentration of solutes in the intracellular fluid • This causes water to be drawn from the intracellular compartment to dilute the solutes in the extra-cellular fluid • Kidneys will also excrete more concentrated urine to rid the body of excess sodium and retain water

Culture and Sexuality

• social and cultural factors in sexuality? • Sex culture-set of requirements, beliefs, symbols and norms regarding sexuality and its expression • Influenced by culture, religion, ideals, politics and environment

A note.......... (5 signs..)

• this ?? Additional info : Anorexic symptoms • Can appear before you see dramatic weight loss.... • Not bound to weight/body type..... • signs to look for: • 1. excessive dieting • 2. excessive exercise • 3. withdrawal from friends and family • 4. fasting • 5. hiding food (e.g. eat in secrecy)