23B amygdala, hippocampal and limbic Flashcards Preview

Clinical Neuroscience weeks 1-3 > 23B amygdala, hippocampal and limbic > Flashcards

Flashcards in 23B amygdala, hippocampal and limbic Deck (47):
1

Limbic lobe surrounds....

Limbic System consists of circuits concerned with...

lateral ventricles

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

2

Amygdala is located where

Anterior part of temporal lobe

3

Functions of the amygdala and its nuclei

- olfaction
- emotions
- autonomic
- learning and memory

4

Three main groups of amygdaloid nuclei

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

5

Major inputs to the corticomedial nuclei are from

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

6

Primary output of the corticomedial uceli

hypothalamus

7

Central nucleus receives its major inputs from where

basolateral nuceli of the amygdala and from the hypothalamus

8

Principal output of the central nucleus is

brainstem and hypothalamus

9

Main functions of the central nucleus...KNOW

autonomic control (BP, HR)
arousal
subjective experience

10

Amygdala is crucial for regulating

emotional and social behavior

11

Bilateral amygdala lesions=

in a monkey
- hypersexual
- tame
- Hyperphagia if Basolateral nucleus is lesioned, Hypophagia if the central nucleus is lesioned

Central---starve yourself

12

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

ok

13

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

Kluver Bucy syndrome

14

Kluver Bucy symptoms

Rare in human pts
- hypersexual
- hyper oral
- tame
- hyperphagia
- hyperactive
- psychic blindness (don't recognize the emotional content of facial expressions)

15

Urbech Wiethe?

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

16

Which part of the brain is the executor of fear?

Amygdala (esp basolateral )

17

Learning and memories

basolateral nucleus

18

Principal cell type of the Central Nucleus is

medium spiny GABAergic

19

Principal cell type in Basolateral

pyramidal cells

20

Basolateral nucleus of the amygdala receives most of its input from

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

21

Major output of the basolateral nucelus is

Back to the central nucleus

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.

BASOLATERAL NUCLEUS IS RESP for emotional component of learning and memories

23

Hippocampus is derived from what brain region

Telencephalon

24

Describe hippocampal location

temporal lobe, just behind amygdala

25

What is the alveus

Collected axons of hippocampal pyramidal cells

26

Alveus fibers collect and form

fimbria

27

Fimbria becomes

fornix

28

Two major input pathways to hippocampal formation

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

29

Describe the tri-synaptic circuit of the hippocampus

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

30

Almost all inputs to hippocampus come from

Entorhinal complex

31

Almost all outputs of hippocampal formation are from

subiculum

32

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

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

33

Where does the subiculum project?

widely through the cortex

34

Principal cells of CA fields and subiculum are

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

35

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

epilepsy and ischemia

36

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

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

37

Hippocampal pyramidal cells are especially sensitive to what disease

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

38

Hippocampus very important for learnign and memory

especially spatial learnign and memory

39

place cells

activity related to position of anmal in external environment

40

To types of memory

Declarative- available to the conscious mind and encoded in language

Procedural: like riding a bike or playing guitar.

41

Emotional content of memories governed by

amygdala

42

basal ganglia and cerebellum are crucial for

implicit memory formation

43

immediate memory

lasts only a few seconds

44

short term memory

seconds to minutes

45

working memory

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

46

Long term memories last for days weeks, etc

ok

47

What is essential for formation and retreiveal of long term memories

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