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Flashcards in Limbic System- OJ Deck (32):
1

Limbic System

Girdle/ Border
hippocampus, amygdala, anterior thalamic nuclei, fornix, cingulate gyrus, parahippocampal gyrus, limbic cortex, and limbic midbrain areas.

2

how does brain create valence?

nociceptor connected via basic reflexes to withdraw from stimuli

Our circultry wants us to avoid noxious stuff

3

Appetitive reflexes

reflexive ingestion and enteric reflexes move some stimuli through enteric system, reject others

4

Enteric Nervous system

subdivision of the autonomic nervous system (ANS) that directly controls the gastrointestinal system.

5

____________ predict appetitive v. aversive events and engage more
complex behaviors accordingly

feedforward mechanisms

6

Emotion

• the complex psychophysiological experience of
an individual's state of mind, interacting with
environmental influences.

7

emotion fundamentally involves
appetitive or aversive events, via links between:

–physiological arousal
–expressive behaviors (facial), actions, action
tendencies
–conscious experience (feelings), sensations,
perceptions

8

Autonomic Tendency
Anger

Flushing, “Heat” “Pressure”

9

Fear- Autonomic Tendency

Cold”, pallor, diaphoresis, t

10

Desire

Action Tendency
Approach

11

Insula

primary interoceptive cortex

12

Modern Ideas about the
Neurophysiology of Emotion

• The Amygdala
• Ventromedial Prefrontal (Orbitofrontal) Cortex
• Insula
• Ventral Striatum/Nucleus Accumbens
• Ventral Tegmental Area-Dopamine

13

MYTHS about the Neurophysiology
of Emotion

-The Amygdala is all about fear
-Ventral Tegmental Area-Dopamine is all about reward
*Neither is "true"

14

Inferior temporal cells

Integrates sensory input

15

Ganglionic eminences becomes

Amygdala
Striatum

16

Basolateral Amygdala complex does?

Input

17

Centromedial Amygdala complex does?

Output

18

Intercalated cells?

GABAnergic
?

19

Optogenetics

technique using light to control cells in living tissue, typically neurons, that have been genetically modified to express light-sensitive ion channels (rhodopsins= original study channels)

allowed for fundamental wiring discoveries

20

Optogenetics Discoveries

Fear Conditioning,
Fear Extinction,
Appetitive Conditioning

21

Mouse- Sound/ shock experiment

sound: Auditory thalamus, auditory cortex-- amygdala

shock- somatosensory thalamus --> somatosensory cortex--> amygdala

Fire together, wire together: sound will lead to fear response

22

Mouse- Sound/ shock experiment timing

Shock does not need to be immediate

Ach give a "memory window" to relate an event

Half hour

23

Mouse- Sound/ shock --> sound/ neutral experiment
~EXTINCTION

EXTINCTION

Rodent can suppress fear response if sound is paired with something better (vs shock)

Temporary suppression, will revert to fear if neutral pairing stops

Needs intercalated cells for extinction

24

Nucleus Accumbens/
Ventral Striatum Potentiating

Basolateral group in amygdala can project to Nucleus Accumbens/ Ventral Striatum

Potentiate between neutral stimulus (sound) and appetite pairing

25

Ventromedial Prefrontal Cortex
(Orbitofrontal Cortex) and gambling

-High risk vs low risk card piles

-Control subject: did not "understand" the difference, but had ↑ Symp response when picking from high risk pile

-Brain damaged patient
Never responded to more risky pile

26

Iowa Gambling Task & Orbitofrontal
Cortex (VmOFC) Lesions

• Impairment in ability to estimate the risk/reward
associated with certain behaviors

• Impairment in ability to select behaviors based on risk/
reward calculations

27

Iowa Gambling Task & Orbitofrontal
Cortex (VmOFC) Lesions Implications

Implies “subconscious” “gut feeling” about the
implications of a given behavior

• Implies suppression of behaviors felt to be excessively
risky, esp. in context of social function

28

Phineas Gage

Problems estimating strategy esp. in social situations

Orbitofrontal damage

29

Dopaminergic Projections:

• Nigrostriatal
• Mesolimbic
• Mesocortical
• Tuberoinfindibular:
DA inhibits PRL release

30

VTA releases Dopamine in response to errors in predictions different subregions of VTA concerned with _____________________- subregions have different projections

REWARD, PUNISHMENT, or even SALIENCE, SURPRISE

31

Mesolimbic path

?

32

mesocortical pathway

?