Lecture 14

Question 1

Sleep molecule hypothesis

Answer 1

SCN makes sleep regular, what decides how much we sleep?
Build up of adenosine during wake/massive drop even with a small amount of sleep
Drowsiness and duration of sleep are modulated by adenosine receptor signaling in the brain
Caffeine - promotes carousal - is an adenosine antagonist
Likely adenosine is one of the chemicals that builds up which makes us sleepy

Question 2

Norepinephrine neuron activity

Serotonin activity

Answer 2

rises with concentration and focus
Locus coeruleus - makes it

correlates with cortical arousal (as measured by EEG) and drugs that increase serotonin function tend to suppress REM sleep
Raphe nucleus - makes it

Made in brain stem, distributed all over brain

Question 3

5 hormones that seem to control arousal

Answer 3

All found in neurons that are active when aroused and alert and dropped in slow wave sleep
Histamine
Serotonin
Norepinephrine
Ach
Hypocretin/Orexin

Question 4

Histamine and orexin

Answer 4

neuropeptides
Only made in hypothalamus
Antihistamines are histamine blockers
The first generation antihistamines caused drowsiness

Question 5

Neural control of sleep/wake behaviour

Answer 5

Neurons in the ventral lateral preoptic area (vIPOA) of the hypothalamus promote sleep
INHIBIT arousal centers
Electrical stimulation causes drowsiness and sometimes immediate sleep
Lesions suppress sleep and cause insomnia
They inhibit wake-promoting neurons such as histamine or serotonin neurons

Question 6

The sleep/wake flip-flop circuit

Answer 6

The vIPOA receives inhibitory inputs from the areas it inhibits

So there is reciprocal inhibition
both cannot be active at once
Animal is awake when the wake-promoting system is more active than the vIPOA
Asleep when not

Question 7

Sleep molecule 2

Answer 7

Adenosine receptors are expressed by many neurons in the brain
Excites vIPOA and inhibits ACh
So the idea is that the build ip promotes vIPOA and inhibits Ach
Reduces arousal and promotes sleep
In sleep, adenosine is cleared and the animal wakes up

Question 8

Orexin/hypocretin

Answer 8

Made in hypothalamus
promotes wakefulness
LH orexinergic neurons have inputs from hunger and satiety and also the SCN
Allows them to influence wakefulness

Question 9

Narcolepsy

Answer 9

Sleep disorder
Excessive daytime sleepiness and urge to sleep
Hereditary autoimmune disorder for most
Death of orexin neurons in the hypothalamus

Question 10

REM in the waking state

Answer 10

Cataplexy - complete paralysis that occurs while awake
Often due to a strong emotion or physical effort

Sleep Paralysis - REM associated paralysis just before a person falls asleep
Often with vivid dream-like hallucinations

Question 11

Determining the stages of sleep

Answer 11

Orexin neurons weigh in on sleep/wake cycles but also sleep stages
Without them, sometimes REM comes on while awake
When these people sleep - straight to REM
Narcolepsy people wake up a lot at night cos in REM sleep which is light and easy to wake from

Question 12

A lot of knowledge about sleep comes from

Answer 12

sleep disorders

Question 13

Insomnia

Answer 13

Difficulty falling asleep or awakening in the night

25% of population, 9% regularly

Question 14

Fatal Familial Insomnia/Sporadic Fatal Insomnia

Answer 14

Worsening insomnia
Hallucinations
Delirium
Confused states
Can be inherited (normally) but also spontaneous
No cure
Die after 18 months from onset

Question 15

Michael Jackson

Answer 15

Died to to anesthetics
Had insomnia
Doc put him to sleep nightly
Cos anesthetics do the same thing

Question 16

Non-REM parasomnias

Sleep-X

Sleep terrors

Answer 16

Sleep disorders that occurs in NREM or transitions out of sleep. The brain can get caught between a sleeping and waking state. Many are unaware they do this.

Sleep: Walking, talking, crying, eating, sex, teeth-grinding. More prevalent in kids. Episodes last seconds to minutes or longer. Can be caused by medications or conditions.
1st half of the night.
Usually grown out of/gone by 12 years old.

Sleep terrors - overwhelming terror on waking. Can include panic or screaming and harm caused by rash actions. Sometime shave no recollection of these events. Prevalent in PTSD.

Question 17

REM sleep behavior disorder

Answer 17

Does not become paralyzed during REM sleep
Can act out dreams
Maybe neurodegenerative
Associated with better known neurodegenerative conditions like Parkinson’s

Question 18

Sexual dimorphism

Answer 18

Two sexes of same species exhibit different characteristics beyond their sexual organs

Can be subtle or exaggerates and include secondary sex characteristics at puberty

associated with genetic and hormonal differences before and after birth

Question 19

Sexual dimorphic behavior

Answer 19

behaviors with different forms or frequencies across males and females
Mammals have this in mating behavior
Brain gives rise to this as it is a sexually dimorphic organ
Genes and socialization both play roles in this
We do not know which is more important

Question 20

Differences in the sexes

Answer 20

Can be caused by biology, socialization or the two
There are differences in mix of talents, temperament and interests
If you cannot study this you cannot treat mental illness
Even though some say you should not because genderless society is good

Question 21

Sex and gender terminology

Answer 21

Sex is defined at birth by chromosomes, hormones and organs

Gender refers to the range of characteristics that pertain to masculinity and femininity, which are the characteristics associated with men and women, respectively. Reflect biology and culture

Gender expression is the expression of masculinity or fem

Gender role is the behaviors deemed appropriate for people of a given sex

Sexual behavior refers to sexual acts performed by people

Sexual orientation one’s enduring sexual attractions

Sexual identity individuals conception of themselves in terms of whether they identify or not with a sexual orientation

Gender identity is one’s personal sense of their gender.

Question 22

Gender is a social construct

Answer 22

Consensual rules for determining gender and race designations differ across time and cultures
Independent of biology
Understanding and categorization of masculine/feminine are socially constructed from our shared xp
Biology influences these but its contributions are not decisive
Biology’s influence differs with the strength of the cultural inputs
Brains and behaviors are outcomes of conditioning and biology

Question 23

Differences between sexes

Answer 23

There are _____ difference between the brains of men and women
There are _____ differences between the behavior of males and females’

The adjective placed in here is all to do with the opinion of the person making the statement about how much the culture should influence this

In genderless culture biology exerts it biggest effect as not masked

Question 24

Socialization

Answer 24

Kids are taught by parents of something is good or bad

Kids are often racist. It is parents that socialize that kid depending on their opinion

WE ASSIGN the value to innate behavior. It is just THERE

Question 25

Sex determination

Answer 25

X and Y chromosomes are SEX chromosomes

Gonads - ovaries or testes make sperm or ova

Gametes have 23 in total

Sex is determined by 5 factors at birth

Sex chromosomes: XX XY
Sec hormones: Androgen signaling

Gonads: testes/ovaries
Internal reproductive anatomy
External anatomy
(3 categories of sex organs)

Usually all 5 are male or female. If not = intersex

Question 26

Embryonic sex organs

Answer 26

All embryos contain the precursor to male and female sex organs

In the second month of gestation, the undifferentiated gonads develop into testes or ovaries

In the theirs month, the Mullerian (female) or Wolffian (male) system develops and the other withers

Question 27

Male sex organ development

Answer 27

The SRY gene on the Y chromosome overpowers all others

Grow testes

XXY also grow testes

SRY gene
Testes
Anti-Mullerian hormone - stops development of internal female sex organs
Test - triggers development of male sex organs via Wolffian system

DHT comes from test. Triggers development of external sex organs

Question 28

Female sex organ development

Answer 28

XX
Silent until puberty
No anti Mullerian hormone so female sex organs develop
No test so external female sex organs develop
Female development is the default

You must have XX to have ovaries. One X is not enough

Question 29

Genetic abnormalities - female sexual organs internal

Answer 29

XO - turners syndrome
XY but bad SRY gene - Swyer syndrome

Female internal sex organs develop but NO OVARIES so at puberty, no change.

STERILE

Can develop given hormones at puberty but are still sterile

Question 30

Genetic abnormalities - male sexual organs internal

Answer 30

Two or more X chromosomes and an SRY gene eg XXY or XXXY

Develop as males with small testes, often sterile and have trouble growing a beard

Question 31

Genetic abnormalities - Mullerian issues

Answer 31

XY male chromosomes and SRY gene but with either insufficient anti-Mullerian or no receptors

Testes so male characteristics develop. No defeminization

Male and female organs

Often functional male external organs

Question 32

Androgen insensitivity syndrome

Answer 32

no masculinization

No internal sex organs develop

External female genitalia

Identify as hetro woman who is sterile with a short vagina

Grade 1 is mild - external male genitalia
Grade 6-7 is severe - female external genitals
Grade 2-5 are in between with mixed genitalia

Question 33

Sex hormones

Answer 33

Influence development of body and brain. Permeant effects, put you on a track going forward.

Behavioral determinization - organizational effect of androgens on brain that prevents animals from displaying female-typical behaviors in adulthood

Behavioral masculinization - organizational effect of androgens on brain that causes animals to display male-typical behaviors in adulthood

Activational effects - puberty causes sex hormones’ to be released by the gonads which influence body and mind.
Ovulation/horniness
How the mind responds to this in adulthood depends how the body and brain were organized by hormones’ signaling in utero