UCSD PSYC 106 - Behavioral Neuroscience

prof dobkins

Non-glands

 parts of the body that does not secrete stuff into bloodstream or local area (heart or liver)

Glands

body parts that secrete stuff

Endocrine gland

1. secrete hormones into the blood

   • Where they influence cell activity, gene expression

   • Long-lasting effect

Exocrine gland

Secrete stuff locally through ducts(sweat, saliva; sublingual, breastmilk)

• Some hormones are also neurotransmitters:

[Adrenaline (epinephrine) and noradrenaline (norepinephrine)]

Hypothalamus (hypo=below)

releases hormones into the pituitary gland and into the blood

steroid hormones:

1. Diffuse across cell membrane

2. Attach to receptors in the cytoplasm 

3. Receptor-hormone complex enters nucleus

4. Triggers gene expression

   1. Long-lasting effects (days)

5. cortisol

6. sex hormones

Non-steroid hormone

1. Attach receptor on cell membrane

2. Activate 2nd messenger system inside cell

3. Alters metabolism of cell (breakdown of glycogen to glucose)

   1. Effects last for mins or hrs

cortisol is _______

produced and secreted by the adrenal cortex

the 2 sex hormones are:

androgens: testorsterone(TTT)

estrogens: estradiol, aromatase is much higher in concentration in females than male gonads (its why we have more estrogen)

androgen is ______

testosterone (TTT) which is higher levels in males

estrogen

• estradiol

• aromatase

release of hormones depends on

• how much substrate

• how much enzyme

• the varying effects on the biological sexes in diff organs

what are gonads

•  endocrine glands which are part of the reproductive organs

  • Secrete sex hormones

  • produce/release gametes

Male gonads are

•  testes 

  • Secrete hormone TTT

  • Produce and release sperm

Female gonads are

•  ovaries

  • Secrete hormone estradiol

  • Produce and release ovum (egg) (female gamete)

  • All eggs present at birth

Genitalia

non-endocrine parts of the reproductive organs

Genetic gender (XX and XY) - genotype

• Determines the outcome of the gonads (male vs female)

  • The y chromosome contains the gene to form the testes 

  • At 7 wks, prenatal, in humans, if you have Y chromosome → testes

  • If no Y chromosome → ovaries

• Gonads are based on genetics–xx and xy–its fixed

Gender phenotype

how organ/organism appears

• Sex hormones determine the outcome of the genitalia 

  • Early in fetal development, genitalia appear female-like for both males and females

• TTT in utero (released by the testes in male fetus) “masculinizes’ the genitalia

• Without TTT, the genitalia continue to be female genitalia

Female masculinization

• Exposed to TTT in utero

• Adrenal cortex in mother or fetus can produce excess of TTT (adrenal androgens)

• Anti-miscarriage drugs → agonist drug that mimics TTT

• Genitalia are intermediate 

  • These people are infertile

Testicular feminization

androgen insensitivity syndrome

• Genetic male (XY)

• Insensitive to TTT in utero bc lacking TTT receptor and cant activate genes inside cells

• Genitalia and appearance are female but have testes that are small and do not descend and their estradiol later leads to formation of breasts

what are the effects of TTT and estradiol in puberty?

sex hormones start being produced again by the testes and ovaries; hypothalamus starts releasing gonadotropic releasing hormone then thalamus starts talking to pituitary gland and releases LH and FSH

what are the effects of sex hormones on gender phenotype?

• Estradiol: broader hips, breast development

• TTT: 

  • Physical features

    • Bones and muscles: growth/strength

    • Voice deepening

    • Body hair 

  • Behaviours 

    • Sex drive

    • Rough aggressive behavior

what are the effects of sex hormones on gonads?

• Testes (secrete TTT) → continual sperm production

• Ovaries (secrete estradiol) → menstrual (reproductive cycle) = releasing of eggs

what are the effects of TTT on gender phenotype

• Physical features

  • Bones and muscles (males have bigger everything)

  • Voice deepening-larynx gets low

  • Body hair (facial, pubic, underarm)

• Behaviors

  • Sex drive (libido)

  • Rough and tumble, aggressive behavior

Levay study 1993

• Got brains of homosexual males and females

  • Replicated result that sexually dimorphic nuclei are twice as large in men than women

  • Found that the size of homosexual male brains had about the same size as females

Encoding

processing new information into a form that can be ‘stored’

Storage

retaining memory

Retrieval

• getting information out of storage into conscious awareness

  • Recall: to bring back to mind

  • Recognition: to perceive something as previously known

recall

to bring back to mind

recognition

to perceive something as previously known

Define Short term memory (STM)

short-lived memory for things that just happened–or currently occupy your attention

Long term memory (LTM)

•  memory for things that do not occupy your attention that must be retrieved which has a large storage capacity

• Permanent memories

what is the limit capacity of stm?

Limit capacity of ~7 items (+/- 2)

LTM - Explicit: episodic

Memory of events that you've experienced, things that you remember

LTM - Explicit: Semantic (facts)

Things that can be stated, things that you “know”

what are the 2 explicit types of memories?

episodic and semantic

what are the 3 types of implicit memories?

procedural, priming, conditioned response

LTM - implicit: procedural

• Procedures, motor skills, habits, things you don't think about

• Shoe tying is learned as an explicit (You think about it, learn it) then, you just know

• Mirror drawing ex.

LTM - implicit: Priming

When exposure to a stimulus influences behavior but you are not consciously aware

Word priming

• Test = “doctor” vs “pwing” 

• Prime = “nurse” vs “car”

• Prime is implicitly retained in memory–implicitly and temporarily put into your memory

• In the study, they were shown prime words milliseconds before showing the word and non-word. Ofc, because nurse associated w doctor in a memory bank, the fact that it preceded it made everyone choose it faster

LTM - implicit: Conditioned response

an automatic response established by training to an ordinarily neutral stimulus

Conditioned response: operant conditioning

reward and punishment; “if you do this, ill do that”

Conditioned response: classical conditioning

uses “natural”, automatic response; “when i do this,YOU will do that”

retrograde amnesia

loss of events prior to the injury

anterograde amnesia

inability to create new memories after the injury

what are the symptoms after hippocampus damage

• severe anterograde amnesia, mild retrograde

• anterograde for LTM, not STM memories

• anterograde for explicit not implicit

what is the role of the hippocampus?

• consolidates STM —> LTM

• consolidates explicit, not implicit LTM

• it is not where memories are stored

positive reinforcement

• if you do X, ill give you candy (i give you something you desire)

  • Refers to GIVING

Negative reinforcement

• if you do X, ill stop nagging you (i remove something you would like yo avoid)

  • Refers to REMOVING

  • or stopping

Limbic system is

More medial, is controlled by prefrontal cortex; involved in executive function

• Reasoning, inhibition, control

Septum, cingulate gyrus, nucleus accumbens (in limbic system)

• Reinforced behaviors/rewards: dopamine

• Addition to gambling, drugs = searching reward

what structures get input to amygdala?

Visual and auditory cortex from brain

amygdala responds to:

facial expressions and vocal emotions

output to amygdala:

• Hypothalamus

  • Sympathetic autonomic response → increased heart rate, blood pressure, breathing

  • Midbrain → pons (hindbrain) → muscles

    • Flinching, freezing–not good for health

Loud noise is

innate, you flinch

What happens if lesion in the amygdala–cats and monkeys?

they become excessively tame and have a lack of aggression

What happens if you stimulate the amygdala in cats?

‘Affective’ attack (shrieks, hiss, hunch back)

Lesion in the amygdala

• Cannot learn new fear associations

• Lose old learned fear associations

  • Amygdala MUST store memories

males have ____ TTT, and are more ______ than female

higher; aggressive

bodybuilders using _____ are _____ than bodybuilders who don’t

anabolic steroids; more aggressive

Castrated male rats

1. Become less aggressive 

2. Become more aggressive when given TTT

Female rats

1. Become more aggressive when given TTT

2. Less aggressive when given estradiol

structures for short-term stress response involving outputs of the amygdala

• Midbrain → pons 

• Hypothalamus

short-term stress response—Direct behavioral

• Freeze, flinch (via pons)

• Subconscious no thinking required

Sympathetic system

• Originates in the hypothalamus

  • Receives from the amygdala

• Neural projections from the hypothalamus to: 

  • Heart: increase heart rate and blood pressure

    • Gets fuel (glucose/oxygen) via blood to brain and muscles to make energy–ATP

  • Lungs: increase breathing rate, dilate air passages

    • Gets fuel (O2) into blood

    • O2 is fuel we need to get to muscles

  • Adrenal medulla (inner of adrenal gland): 

    • Releases adrenaline and norepinephrine (hormones into blood)

sympathetic ns—heart function:

•  increase heart rate and blood pressure

  • Gets fuel (glucose/oxygen) via blood to brain and muscles to make energy–ATP

sympathetic ns: lungs

• increase breathing rate, dilate air passages

  • Gets fuel (O2) into blood

  • O2 is fuel we need to get to muscles

sympathetic ns: adrenal medulla (inner adrenal gland) releases:

adrenaline and norepinephrine (hormones into blood)

Parasympathetic ns

• ‘rest and digest’ system, energy conserving

  • Does not innervate the adrenal glands

• does the opposite of parasymp

Effects of epinephrine/norepinephrine (adrenaline/noadrenaline)

• Increase heart rate, blood pressure, breathing rate

• Stimulated liver to breakdown glycogen → glucose

Hypothalamus-pituitary-adrenal cortex axis (HPA)

1. Releases corticotropin releasing factor (CRF) into the pituitary gland

2. Pituitary release adrenocorticotropic hormone (ACTH) into blood

3. ACTH activates adrenal cortex

4. Adrenal cortex releases cortisol (stress, steroid hormone) into blood

Effects of cortisol

• Stimulates liver to breakdown glycogen → glucose

  • (As does epinephrine and norepinephrine)

• Increases heart rate, blood pressure

  • (As does epinephrine and norepinephrine)

  • As does direct neural input from hypothalamus to heart and lungs

• Increases metabolic rate: glucose + oxygen → ATP

short-term stress response (fear/anger) is _______

adaptive

Long-term stress (anxiety) response is _______

not adaptive

short-term stress response are:

• Needed for high levels of activity associated with fight or flight

• Turned on everyday

Long-term stress response can

• lead to long-term physical health problems

• Impair well-being

• blame chronic stressors

Behavioral medicine “holistic” medicine

Eating and drinking habits, stress, exercise, and attitudes

what is a psychosomatic illness?

real illness brought on by a negative psychological state

long-term psychosomatic illnesses caused by stress

high blood pressure, memory loss, and ulcers

short-term psychosomatic illnesses caused by stress

indigestion, stress migraine

what is a stomach ulcer

 an open/bleeding sores in the stomach/intestines from gastric enzyme

How could stress dampen the immune system

• there is less energy left over for homeostatic functions, like protein synthesis to create immune cells

• Studies show that immune cell counts are decreased during stressful times

both the sympathetic and hormonal system increase:

• Amount of ATP in blood (through glycogen breakdown)

• Heart rate and blood pressure (speeds up how quickly fuel gets to brain and muscles)

• Metabolic rate–makes atp more quickly

Antigen

• foreign particle (in particular, the protein portion that elicits an immune response

  • Some women attack sperm as it is considered a foreign particle

Leukocytes (white blood cells)

b-cells (make specific antibodies that attach to & attack specific antigens; t-cells directly attack specific antigens—made in the bone but mature in the thymus; Natural killer cells: non-specific killing of antigens; macrocharges: remove waste, cause inflammation

what are the 2 parts to a full language?

semantics and syntax

Semantics

• symbols, meaning

• ‘open’ class—nouns and verbs

• ran vs run

Syntax

• structure

• ‘closed’ class—prepositions and conjunctions

wernicke’s area (temporal lobe) aphasia

• Trouble w comprehension

• Can produce fluent/fluid speech, but often non-sensible and/or the grammar is incorrect

• stumbling of words

• incoherent, what they say makes no sense (nonsensical)

brocas area (left frontal lobe) aphasia

• broken sentences

• understands but struggles to speak

• cannot form closed-class sentences

• involved in syntax^^

individuals w wernicke’s and broca”s aphasia use ________

American Sign Language (ASL)

In hearing ppl, ________ detection is better in ______(right hemis) (bosworth and dobkins, 1999)

visual motion; left visual field (LVF)

In deaf signers, _______ detection is better in _____(left hemis) (bosworth and dobkins, 1999)

visual motion; right visual field (RVF)

If langauge is mostly in LHm, how can we talk ab out things that are presented in the LVF and received by the RH?

connections between hemispheres allow sensory info received by RH to be sent to the LH —> corpus callosum

How is sensory info received between hemispheres?

1. corpus callosum

2. anterior commisure (connects parts of the frontal cortex)

3. hippocampal commisure (connects hippocampi)

adrenal cortex functions:

• increase blood glucose levels

• helps body respond to stress (fight or flight)

• ^^releases cortisol into blood

cortisol is a _____ hormone

steroid

1. secretes CRF into pituitary

HPA axis

2. pituitary releases ACTH to blood

HPA axis

3. ACTH in blood activates adrenal cortex and releases cortisol

HPA axis