23B amygdala, hippocampal and limbic

Question 1

Limbic lobe surrounds….

Limbic System consists of circuits concerned with…

Answer 1

lateral ventricles

Limbic system refers to circuits concerned with emotion (Amygdala- frontal part of temporal lobe) and cognitive function (hippocampus)

Question 2

Amygdala is located where

Answer 2

Anterior part of temporal lobe

Question 3

Functions of the amygdala and its nuclei

Answer 3

• olfaction
• emotions
• autonomic
• learning and memory

Question 4

Three main groups of amygdaloid nuclei

Answer 4

• Corticomedial- The olfactory part
• Central: principal output nucleus; striatum like in structure, important for autonomic control
• Basolateral- principal input nucleus

Question 5

Major inputs to the corticomedial nuclei are from

Answer 5

olfactory bulb, parabrachial nucleus (taste), Medial dorsal, ventromedial thalamus

Question 6

Primary output of the corticomedial uceli

Answer 6

hypothalamus

Question 7

Central nucleus receives its major inputs from where

Answer 7

basolateral nuceli of the amygdala and from the hypothalamus

Question 8

Principal output of the central nucleus is

Answer 8

brainstem and hypothalamus

Question 9

Main functions of the central nucleus…KNOW

Answer 9

autonomic control (BP, HR)
arousal
subjective experience

Question 10

Amygdala is crucial for regulating

Answer 10

emotional and social behavior

Question 11

Bilateral amygdala lesions=

Answer 11

in a monkey

• hypersexual
• tame
• Hyperphagia if Basolateral nucleus is lesioned, Hypophagia if the central nucleus is lesioned

Central—starve yourself

Question 12

Animals with bilateral amygdaloid lesions are extremely oral- they put everything in their mouth

Answer 12

ok

Question 13

Bilateral loss of the anterior temporal lobe (amygdala) is called

Answer 13

Kluver Bucy syndrome

Question 14

Kluver Bucy symptoms

Answer 14

Rare in human pts

• hypersexual
• hyper oral
• tame
• hyperphagia
• hyperactive
• psychic blindness (don’t recognize the emotional content of facial expressions)

Question 15

Urbech Wiethe?

Answer 15

Calcifications in neural tissue in the anterior temporal lobes… LIterally cannot recognize fear. Can’t recognize a scared face, can’t draw fear, hav eno idea what it really is. Prevents them from acting appropriately around others

Question 16

Which part of the brain is the executor of fear?

Answer 16

Amygdala (esp basolateral )

Question 17

Learning and memories

Answer 17

basolateral nucleus

Question 18

Principal cell type of the Central Nucleus is

Answer 18

medium spiny GABAergic

Question 19

Principal cell type in Basolateral

Answer 19

pyramidal cells

Question 20

Basolateral nucleus of the amygdala receives most of its input from

Answer 20

• Neocortex (association cortex primarily), thalamus, hippocampal formation…..most of it is highly processed sensory info

Question 21

Major output of the basolateral nucelus is

Answer 21

Back to the central nucleus

Question 22

Important to realize that the basolateral nucleus is ideally placed between cortical and sensory inputs and outputs to the Central Nucleus and hypothalamus in order to integrate sensory experience and emotional behavior.

Answer 22

BASOLATERAL NUCLEUS IS RESP for emotional component of learning and memories

Question 23

Hippocampus is derived from what brain region

Answer 23

Telencephalon

Question 24

Describe hippocampal location

Answer 24

temporal lobe, just behind amygdala

Question 25

What is the alveus

Answer 25

Collected axons of hippocampal pyramidal cells

Question 26

Alveus fibers collect and form

Answer 26

fimbria

Question 27

Fimbria becomes

Answer 27

fornix

Question 28

Two major input pathways to hippocampal formation

Answer 28

1) Perforant pathway from lateral entorhinal cortex | 2) Alvear pathway from medial entorhinal

Question 29

Describe the tri-synaptic circuit of the hippocampus

Answer 29

Main input to hippocampal formation is excitatory projection from the entorhinal cortex to granule cells in the Dentate Gyrus via the perforant path. The Dentate gyrus then projects excitatory cells to CA3 pyramidal cells via mossy fibers (very secure) CA3 then projects to CA1 via schaeffer collaterals. * Alvear path is ERC to CA1 directly

Question 30

Almost all inputs to hippocampus come from

Answer 30

Entorhinal complex

Question 31

Almost all outputs of hippocampal formation are from

Answer 31

subiculum

Question 32

The Entorhinal complex is fucking important. It receives inputs from where

Answer 32

Cortex, thalamus, brainstem.....thus....the ERC is the gateway to the hippocampus and receives highly processed info about most of our experience

Question 33

Where does the subiculum project?

Answer 33

widely through the cortex

Question 34

Principal cells of CA fields and subiculum are

Answer 34

pyramidal neurons....have tons of spines for excitatory inputs

Question 35

Hippocampal pyramidal neurons (esp CA1) are highly susceptible to what

Answer 35

epilepsy and ischemia

Question 36

Because of the prevalence of excitatory neurons and their interconnections, the hippocampal formation is highly susceptible to

Answer 36

seizures....thus, GABAergic inhibitory interneurons play an important role in regulating activity

Question 37

Hippocampal pyramidal cells are especially sensitive to what disease

Answer 37

alzheimers....this loss of hippocampal neurons may be the basis for loss of memory

Question 38

Hippocampus very important for learnign and memory

Answer 38

especially spatial learnign and memory

Question 39

place cells

Answer 39

activity related to position of anmal in external environment

Question 40

To types of memory

Answer 40

Declarative- available to the conscious mind and encoded in language Procedural: like riding a bike or playing guitar.

Question 41

Emotional content of memories governed by

Answer 41

amygdala

Question 42

basal ganglia and cerebellum are crucial for

Answer 42

implicit memory formation

Question 43

immediate memory

Answer 43

lasts only a few seconds

Question 44

short term memory

Answer 44

seconds to minutes

Question 45

working memory

Answer 45

allows us to keep things in mind to allow completion of a task

Question 46

Long term memories last for days weeks, etc

Answer 46

ok

Question 47

What is essential for formation and retreiveal of long term memories

Answer 47

hippocampus.....Long term memories stored in neocortex but hippocampus allows us to retrieve them