Brain And Behavior Final (Just Last Chapters)

Front 1

difference between learning and memory

Back 1

learning: acquiring new info
memory: store and retrieve info

Front 2

Karl Lashley

Back 2

rat lesion studies to find cortical area critical for memory (using mazes)

concluded that large areas are required for memories and lot of compensation (no clear localization of memory in the brain)

Front 3

Law of Mass Action

Back 3

(Karl Lashley)

The severity of the memory impairment for maze performance correlated with the SIZE of the cortical area removed and not with its specific location

Front 4

Patient HM

Back 4

(Scolville and Milner)

Young HM had seizures
removed left and right hippocampi, but discovered he had a profound memory deficit

Major Findings:
Memory could be impaired selectively without loss of other cognitive functions
Memory function is localized to the medial temporal lobes
The hippocampus thought to be a key structure for memory, but the impairment may be due to combined damage of the hippocampus and the amygdala – localization of memory not completely clear.

Front 5

Anterograde amnesia

Back 5

inability to form new memories after onset of a disorder (completely impaired)

Front 6

Retrograde amnesia

Back 6

the loss of memories formed before onset of amnesia (partially impaired)

MTL is critical for the initial formation/encoding of new memory but not the place where well-established long-term memories are stored

Front 7

What could HM learn and remember?

Back 7

Motor Procedural memory: part of what is called non-declarative memory (completely spared)

Front 8

LONG TERM MEMORY

Back 8

- declarative: things you know that you can tell others
- non-declarative (procedural): things you know that you can show by doing

Front 9

DECLARATIVE memory

Back 9

Conscious

Semantic memory – Memory for facts (knowing the capital of France)
Episodic memory – autobiographical (remembering your first day in school)

MEDIAL TEMPORAL LOBE

Front 10

NON-DECLARATIVE memory

Back 10

Unconscious

Skill learning – learning to perform a task requiring motor coordination (Mirror drawing or mirror reading)

Priming- being more likely to use a word you heard recently

Conditioning – the association of two stimuli, or of a stimulus and a response (Pavlov’s dog experiment)

Front 11

Mishkin study

Back 11

Delayed non-matching-to-sample task: must choose the object that was not seen previously

Bilateral and hippocampal lesions/ Medial temporal lobe damage causes impairment on this task.

Front 12

Theory of Consolidation

Back 12

1) You need your MTL to make new declarative memories

2) The MTL remains important for a variable amount of time as memories “consolidate” or strengthen with practice.

3) Ultimately, the memories appear to reside in the same cortical areas that initially processed them and are no longer dependent on the MTL.

Front 13

Synaptic reorganization

PLASTICITY

Back 13

Structural changes at the synapse may provide long-term storage and new synapses may be formed!

similar to digit amputation of D3, thalamic input from D2 start to invade D3s space. also extensive stimulation of D2 and D3 --> inputs D1 retract, inputs of D2 invade D1s location

after training/learning: more NT release, bigger EPSP, bigger and more sensitive post synaptic membrane, entire synapse enlarges

Front 14

Hebb's Law

Back 14

Synapses grow stronger when the presynaptic neuron repeatedly causes the postsynaptic cell to fire

Cells that fire together, wire together

Front 15

Why use aplysia?

Back 15

used to study plastic synaptic changes in neural circuits because it has fewer nerve cells + create detailed circuit maps in invertebrate ganglia – little variation between individuals

has a siphon, if stimulated with touch, gill withdrawal reflex

Front 16

Habituation in aplysia

Back 16

After repeated squirts, the animal retracts the gills less – it has learned that the water poses no danger.

Caused by synaptic changes between the sensory cell in the siphon and the motoneuron that retracts the gill

Less transmitter released in the synapse results in less retraction.

Over several days the animal habituates faster, representing long-term habituation.

The number of synapses between the sensory cell and the motoneuron is reduced.

Front 17

Long term potentiation (LTP)
What is tetanus?

Back 17

a stable and enduring increase in the effectiveness of synapses

Synapses in LTP behave like Hebbian synapses:

Tetanus drives repeated firing
Postsynaptic targets fire repeatedly due to the stimulation
Synapses are stronger than before

Front 18

Tetanus

Back 18

a brief increase of electrical stimulation that triggers thousands of axon potentials

After tetanus, EPSPs remain high.

Front 19

LTP Process

Back 19

The CA1 region has both NMDA and AMPA receptors.
Glutamate first activates AMPA receptors.
NMDA receptors do not respond until enough AMPA receptors are stimulated and the neuron is partially depolarized.
NMDA receptors at rest have a magnesium ion (Mg2+) block on their calcium (Ca2+) channels.
After partial depolarization the block is removed and the NMDA receptor allows Ca2+ to enter in response to glutamate.

Front 20

William James theory of emotion

Back 20

emotional stimulus goes to cerebral cortex and turns into bodily response
then you recognize that and feel the emotion

we are afraid because we run.

Front 21

Walter Cannon theory of emotion

Back 21

disagreed with James - Many emotional situations produced the same kind of bodily emotional response
You already feel the emotion before the stress response
Emotion does not depend on the cerebral cortex because you can elicit “sham rage”

Cannon and Bard proposed circuit:
emotional stimulus
thalamus and hypothalamus
cortex
feelings
bodily response

cut out cortex and hypothalamus found that animals couldnt elicit sham rage

Front 22

Papez theory of emotion

Back 22

limbic lobe of the cortex

hypothalamus to
anterior thalamus
cingulate
hippocampus

Front 23

Kluver Bucy theory of emotion

Back 23

hyper oral, hypersexual tendencies, and psychic blindness (which is not being able to tell which objects should go in mouth) seen in animals

These Studies added the hippocampus and amygdala
to the list of “emotional” structures.

Front 24

MacLean theory of emotion

Back 24

added amygdala to limbic lobe in the proposed circuit

he was known as the great synthesizer

Front 25

WHAT’S WRONG WITH LIMBIC SYSTEM THEORY

Back 25

1) Limbic System has never been satisfactorily defined

1) System was proposed to be an emotion and not a cognition system, but later research showed that a major limbic area (hippocampus) is crucially involved in cognitive memory

3) Most limbic areas have not been implicated in emotion

4) In attempting to explain all emotions at once, it explained no emotions very well.

Front 26

Downer experiment

Back 26

identified amygdala as key structure in emotion

using monkey brains, amygdala lesion only on left side.
transected optic chiasm and corpus callosum.

show a picture of scary snake on left side, monkey shows no fear. show it on the right side, monkey screams

Front 27

Fear conditioning

Back 27

rats hear a tone, tone paired with electric shock, tone elicits fear responses

US – Unconditioned Stimulus (Shock)
UR Unconditioned Response (Freezing)
CS Conditioned Stimulus (Tone)

Front 28

Classical Pavlovian conditioning

Back 28

US – Unconditioned Stimulus (mint) (food)
UR- Unconditioned Response (mouth feeling dry) (salivating)
CS- Conditioned Stimulus (computer tone) (bell)

Front 29

Low road to fear

Back 29

sensory thalamus --> amygdala

Front 30

High road to fear

Back 30

sensory thalamus --> sensory cortex --> amygdala

Front 31

Amygdala circuit (Joe LeDoux)

CS pathway

Back 31

CS
auditory thalamus
auditory cortex
lateral amygdala

Front 32

Amygdala circuit (Joe LeDoux)

US pathway

Back 32

US
somatosensory thalamus
somatosensory cortex
lateral amygdala

Front 33

Amygdala circuit (Joe LeDoux)

CR pathway

Back 33

lateral amygdala
central nucleus
hypothalamus that mediates fear responses like freezing, higher blood pressure, stress hormone release

Front 34

Bilateral Amygdala lesion

Back 34

impair the use of information from the eye region

unable to differentiate emotions on the face (i.e looking randomly at the nose which doesn't give emotional info unlike eyes and mouth)

Front 35

LTP in the amygdala

Back 35

LeDoux and Staubli

hypothesis of having more AMPA receptors enter the brain during (fear) conditioning (which strengthens the synapse)

also played the tone not paired with the shock

conclusion: Natural learning can induce LTP in the brain!

Front 36

What is the literal meaning of the word schizophrenia?

Back 36

Schizein = “to split”
Phren = “mind”

Front 37

Schizophrenia: abnormal genes

Back 37

Neuregulin 1 (participates in NMDA, GABA and Ach receptor regulation)
Dysbindin – implicated in synaptic plasticity
COMP- involved in metabolizing dopamine
Disrupted Schizophrina 1 gene (DISC1) – abnormal in a Scottish family with a high incidence of schizophrenia

identical twins- they don't both have schizophrenia

Front 38

Schizophrenia: brain structure abnormalities

Back 38

enlarged ventricles
cellular disarray of the hippocampus-- hippocampus smaller
accelerated loss of gray matter in adolescents-- especially affecting temporal lobe (high level vision), primary motor and somatosensory cortices

Front 39

hypofrontality hypothesis

Back 39

damage to the prefrontal cortex

patients perform very similarly on a card sorting task as people with frontal lobe damage

Front 40

dopamine hypothesis

Back 40

Schizophrenia results from either excessive levels of synaptic DA or excessive postsynaptic sensitivity to DA

DA antagonists relive amphetamine psychosis (disorder with similar symptoms to schizophrenia)

use neuroleptic drugs!

Front 41

problems with dopamine hypothesis

Back 41

but for some people, neurotransmitters other than DA can be inhibited

Many schizophrenic patients have normal levels of DA metabolites
Many schizophrenics have normal densities of DA receptors
Neuroleptics work very slowly at the behavioral level but fast at the receptor level
Many patients are insensitive to neuroleptics but sensitive to atypical neuroleptics
Atypical neuroleptics increases DA in the frontal lobe?!

Front 42

glutamate hypothesis

Back 42

Schizophrenia may result from under-activation of Glutamate receptors

Front 43

depression: genetic

Back 43

There is a clear genetic component
-60% concordance with identical twins
-20% concordance with dizygotic twins
-Adoption studies consistent with genetic component

Front 44

depression: brain changes

Back 44

Increased blood flow in PFC and Amgydala.
Decreased blood flow in parietal and posterior temporal cortex and anterior cingulate

Front 45

What does environmental enrichment do for your brain?

Back 45

Increases cortical thickness
Increases number of synapses
Increases in dendritic branching
Increases number of blood vessels (more oxygen, nutrients)
increases BDNF
Increases NEUROGENESIS (The birth of new neurons) in the hippocampus (dentate gyrus) and olfactory bulb

Front 46

BDNF

Back 46

Brain Derived Neurotrophic Factor

In development: Helps young neurons grow.

In Adults: Is neuroprotective from ischemic damage and potentiates synaptic transmission.

Front 47

Morris Water Maze

Back 47

used to study hippocampal function in rodents

enhanced neurogenesis is associated with improved spatial memory performance in animals, but also, learning itself may also stimulate neurogenesis…. What comes first?

Front 48

Studies in humans: correlation study

Back 48

In older adults:

OUTCOME: MORE PHYSICAL ACTIVITY IS CORRELATED WITH LOWER RATES OF DEMENTIA

Front 49

Studies in humans: intervention study

Back 49

(Colombe)
Subjects 60-79 years old subjects, half participated in a 6 month aerobic exercise program, half did toning & stretching.
Results: Aerobic exercise participation resulted in significant increases in brain volume in the frontal lobes compared to toning & stretching group

Front 50

Effects of exercise in healthy young adults

Back 50

Students in the “Exercise” course got significantly faster at answering a recognition memory test compared to the control task!

Front 51

effects of exercise on depression

Back 51

-only long walks improve mood
-exercise is as good as antidepressant Zoloft at 4 months, and even better than it after 6 months
-medications increase BDNF, exercise increases BDNF

Front 52

You shake a guy's hand and you receive a shock. You come back next week.

Hippocampal lesion?
Amygdala lesion?
Hippocampal and amygdala?

Back 52

Hippocampal lesion? hesitant about shaking your hand...I don't like you, but I don't know why.
Amygdala lesion? would shake your hand again...it doesn't scare me.
Hippocampal and amygdala? as if the complete episode did not happen.

Front 53

Major functions of the Frontal lobes

Back 53

Social Emotion
Cognition:
-Working Memory
-Task Shifting
-Attention

Front 54

working memory
delayed response task

Back 54

keeping things in mind (comparing prices, remembering phone number)

delayed response task for monkeys: dorsal lateral prefrontal cortex tiny lesion, but couldn't remember where food was

occulomotor delayed response task: fixate on a point, shown a cue in space, delay, eye movements respond to cue

Front 55

task shifting
wisconsin card sort task

Back 55

don't know which to match (by color? by shape?), the rule can change at any point

Front 56

attention

Back 56

overt attention: when eye movements allow the focus of our attention to coincide with point of fixation
covert: focus of our attention is directed not on the point of fixation

posterior parietal cortex (showing spatial neglect: cannot attend to one side of the visual cortex), superior colliculus, frontal eye field (which is just in front of the motor cortex)

dysfunctions of attention -- neglect

Front 57

brain areas important for improv

Back 57

medial prefrontal cortex activated

dorsal lateral prefrontal cortex and lateral orbital frontal cortex are deactivated during improv, releasing from your inhibitions

Front 58

Three Types of Affiliative Behaviors

Back 58

Parent-Child
Filial
Male-Female/Partner

Front 59

What is the hypothalamus good for?

Back 59

2 Key Nuclei in the hypothalamus:
Supraoptic Nucleus
Paraventricular Nucleus

2 Key neuropepties:
Vassopressin
Oxytocin

neurosecretory cells with axons that go to posterior pituitary gland (secretes hormones)

Front 60

Prairie voles vs. montane voles

Back 60

prairie: monogamous, live in multigenerational family groups, both parents take care of young, territorial/reject intruders

montane: promiscuous, social isolation, little parental care

Front 61

How do pair bonds form in prairie voles?

Back 61

female juvenile voles come across the urine smell of an unrelated male
mate for 30-40 hrs
!!

Front 62

female choice test

Back 62

female goes to male partner's cage over neutral or stranger cage

Front 63

Females:
if we inject oxytocin, vassopressin, oxy RA, vasso RA

Back 63

Unmated females: if we inject oxytocin, time spent with stranger male increases/ if we inject vassopressin, time spent with stranger male slightly increases.

In mated females: if we inject oxytocin receptor antagonist, prevents change in behavior/ vassopressin receptor antagonist does not change her at all

Front 64

oxytocin and vassopressin surge....

Back 64

oxytocen surges in females after mating
vassopressin surges in males after cohabitation

Front 65

Males:
if we inject oxytocin, vassopressin, oxy RA, vasso RA

Back 65

Unmated males: if we inject oxytocin, time spent with stranger female slightly increases/ if we inject vassopressin, time spent with stranger female extremely increases

In mated males: if we inject oxytocin receptor antagonist, no change/ vassopressin receptor antagonist extreme decrease

Front 66

Mice can be genetically engineered to be
More affiliative by inclusion of the Prairie
Vole vasopressin Gene

Back 66

extreme increase in affiliative behavior

Front 67

neurobiology of love in humans

Back 67

Lots of overlapping activated areas between maternal and romantic love.
Activate areas involved in both reward and affiliative behavior (with high oxytocin and vasopressin receptors)
Both forms of attachment suppress activity in regions associated with negative emotions (amygdala & prefrontal regions).
Conclusion: Attachment processes may employ a push-pull mechanism that activities specific pathways of reward and affiliation and at the same time suppresses brain areas involved in negative emotions.

Front 68

LTP of the hippocampus (story)
(trisynaptic circuit)

Back 68

inputs from the entorhinal cortex project to dentrate gyrus (via the perforant path and mossy fibers) and then projects to CA3 (has schaffer collaterals) and then goes to CA1

can show artificial learning/ LTP in the hippocampus

Front 69

what does exercise do alone?!

Back 69

improves spacial memory functions