60. Anatomy Of The Limbic System

Front 1

What gets integrated in the LIMBIC SYSTEM?

Back 1

Cortical info and Hypothalamic Impulses

Front 2

What does limbus mean? Who gave that name to the limbic system?

Back 2

Border - between the new (neocortex) and old (brainstem) brain. Broca

Front 3

Who came up with the limbic circuit's being associated with emotion?

Back 3

Papez

Front 4

What type of input does the limbic cortex receive?

Back 4

Multisensory

Front 5

In the hierarchical setup of the limbic system what's at the bottom?

Back 5

Primary sensory and motor areas

Front 6

What are the 4 levels of the limbic system hierarchy in ascending order?

Back 6

1. Primary sensory/motor areas
2. Modality-specific association areas
3. Higher order association areas
4. Limbic areas

Front 7

What happens in general to visual sensation when there is damage to the limbic system?

Back 7

Too much or not enough emotional input is associated with the vision.

Front 8

What were the 5 steps in the Papez circuit? What was missing?

Back 8

1. Cingulate gyrus/perf pathwy
2. Hippocampus
3. Fornix
4. Mammillary bodies
5. Anterior Thalamus
(back to cingulate)
-Missing the amygdala

Front 9

What did McLean add to Papez's circuit?

Back 9

-The amygdala
-Prefrontal cortex
-Nucleus accumbens
-Septal areas

Front 10

What virus has special affinity for limbic regions? What symptoms result?

Back 10

-Herpes
-Severe memory and behavioral disturbances

Front 11

What is the limbic system susceptible to?

Back 11

Kindling and development of seizure foci

Front 12

What receptors and innervation allow the limbic system to be involved in memory and pain/pleasure perception?

Back 12

-Opiate receptors
-Cholinergic innervation

Front 13

Where does Herpes encephalitis cause most significant swelling and hemorrhage?

Back 13

In the right temporal lobe

Front 14

What nuclei provide the cholinergic input for the brain?

Back 14

-Septal nuclei
-Nucleus Basalis

Front 15

What are limbic structures interposed between?

Back 15

The hypothalamus and neocortex

Front 16

What makes up the outer core of the limbic system?

Back 16

Cortical structures

Front 17

What 3 cortical structures make up the outer core?

Back 17

-Cingulate cortex
-Orbital frontal lobe
-Temporal lobe

Front 18

what are the 2 parts of the Cingulate cortex? What is each responsible for?

Back 18

Rostral - emotions/motor
Caudal - Visual spatial / memory

Front 19

What is the Orbital Frontal part of the outer limbic core responsible for?

Back 19

-Personality
-Behavioral control
-Self awareness

Front 20

What are the 3 important structures in the temporal lobe? What are they responsible for?

Back 20

-Hippocampus
-Parahippocampus
-Entorhinal cortex
MEMORY

Front 21

What makes up the inner core of the limbic system?

Back 21

Subcortical structures

Front 22

What 5 important structures make up the inner core:

Back 22

-Hypothalamus
-Septal nuclei
-Mammillary body
-Amygdala
-Anterior Nu: of Thalamus

Front 23

What 3 things are coordinated by the hypothalamus?

Back 23

-Pleasure center
-Autonomic
-Endocrine integration

Front 24

What are 5 things controlled by the amygdala?

Back 24

-Self Preservation
-Social behavior
-Aggression/defense
-Sex
-Affective significance of visual stimuli

Front 25

What will happen if you damage a monkey's amygdala?

Back 25

It won't be afraid of anything

Front 26

What is the septum responsible for?

Back 26

-Preservation of species behaviors
-sexual behaviors
-emotionality

Front 27

What are most anatomical connections in the limbic system?

Back 27

Reciprocal

Front 28

Fornix: connects what to what

Back 28

Hippocampus to septum and mammillary bodies

Front 29

What does the mammillothalamic tract connect?

Back 29

Mammillary bodies to anterior nucleus of the thalamus

Front 30

What does Stria terminalis connect?
What does the perforant path connect?

Back 30

Stria: Amygdala with septum

Perforant path: enterhinal cortex to dentate gyrus

Front 31

Why is the Perforant path important?

Back 31

It is the major afferent to the Hippocampal formation.

Front 32

4 things connected by the cingulum:

Back 32

-Cingulate gyrus
-Entorhinal cortex (then perfp)
-Hippocampus
-Subiculum (output)

Front 33

What does the Medial forebrain bundle connect?

Back 33

-Hypothalamus, septal areas, amygdala, and hippocampus
to
-Midbrain ventral tegmentum VTA

Front 34

What causes kluver bucy syndrome?

Back 34

Bilateral damage to the medial temporal lobes - esp the amygdala.

Front 35

5 main symptoms of Kluver Bucy:

Back 35

-Psychic blindness
-Hypermetamorphosis
-Hypersexuality
-Oral tendencies
-Tameness
P.H. you're HOT

Front 36

What is hypermetamorphosis?

Back 36

Attention/reaction to every visual stimulus w/in the visual field and subsequent compulsive handling of the object

Front 37

What is placidity?

Back 37

Flat affect; lack of aggression, no fear.

Front 38

What is visual agnosia?

Back 38

Loss of recognition of simple familiar objects (faces, utensils)

Front 39

What syndrome is the opposite of Kluver bucy?

Back 39

Geschwind syndrome - Interictal Personality

Front 40

What type of syndrome is
-kluver bucy
-geschwind

Back 40

KB = disconnection
Geschwind = hyperconnection

Front 41

Where Kluver Bucy has lack of emotion, Geschwind has

Back 41

too much

Front 42

What types of symptoms will be seen in Geschwind syndrome?

Back 42

-Increased philosophical cosmic or religious concern
-Altered sexual behavior (want less sex)
-Hypergraphia
-Viscosity

Front 43

When scientists implanted electrodes in these regions of a rat, it would forgo food/water and everything else in preference of stimulation:

Back 43

-Lateral Hypothalamus
-Medial forebrain bundle connecting the hypothalamus and septal areas

Front 44

What is important in effective self-stimulation of pleasure?

Back 44

Catecholamines and Dopaminergic systems

Front 45

What are the 3 most important brain pleasure regions?

Back 45

1. Lateral hypothalamus
2. Medial forebrain bundle
3. Nucleus accumbens

Front 46

Stimulation OR lesion of what area results in pain/rage or strong aversive reactions and hyperemotionality?

Back 46

Ventromedial nucleus of hypothalamus

Front 47

Lesions of what area cause tameness and reduced emotionality?

Back 47

Amygdala

Front 48

Why is the Amygdala important in producing emotion?

Back 48

-It attributes affective significance to visual stimuli
-Integrates emotions & memory

Front 49

What results from lesions to the amygdala?

Back 49

Kluver bucy syndrome
Social isolation

Front 50

What will abolish hypersexuality induced by amygdalar lesions??

Back 50

Lesions to the Septal region - it achieves positive control of sexuality.

Front 51

Where amygdalar lesions produce a reduction in social contacts, Septal lesions result in:

Back 51

Enhancement of social contacts

Front 52

What behaviors do tumors in the septal region result in?

Back 52

RAGE-like attacks
Increased irritibility

Front 53

What is declarative memory?

Back 53

Memory of facts and events

Front 54

What 3 areas are required for declarative memory?

Back 54

-Hippocampus
-Dorsal medial nu of thalamus
-Mammillary bodies

Front 55

What do lesions of the Hippocampus, Dorsal medial nu: of thalamus, or mammillaries lead to?

Back 55

Amnestic states

Front 56

What are the 2 main types of declarative memory?

Back 56

-Episodic
-Semantic

Front 57

What is episodic memory?

Back 57

Memory of personal events in one's life

Front 58

What is semantic memory?

Back 58

Memory of impersonal facts

Front 59

What are the 3 things that make up the hippocampal formation?

Back 59

-Hippocampus
-Dentate gyrus
-Subiculum

Front 60

What has extensive interconnections with the hippocampus and amygdala?

Back 60

Neocortex

Front 61

What is the major efferent from the hippocampal formation?

Back 61

Fornix

Front 62

What is the major afferent going into the hippocampus?

Back 62

Perforant path

Front 63

What makes a sort of interlocking "c" with the hippocampal formation?

Back 63

Entorhinal cortex

Front 64

What perforates the dentate gyrus to get into the hippocampal formation?

Back 64

The entorhinal cortex via the perforant pathway.

Front 65

With what cell type do neurons from the entorhinal cortex synapse in the dentate gyrus?

Back 65

Granule cells

Front 66

What do the granule cells synapse with?

Back 66

Hippocampal pyramidal cells

Front 67

Where do the hippocampal pyramidal cells extend towards and what do they become?

Back 67

Toward the lateral ventricle; become the alveus, fimbria, then fornix.

Front 68

Why does the anterior horn of the lateral ventricle become enlarged after a bilateral temporal lobectomy?

Back 68

Because the hippocampal formation atrophies!

Front 69

What famous person had a bilateral temporal lobectomy?

Back 69

HM

Front 70

What happened to HM?

Back 70

His procedural memory got better but he could not lay down any new memories.

Front 71

What are the 2 things that cause Wernicke Korsakoff's Syndrome?

Back 71

-Chronic alcoholism
-Vit B deficiency

Front 72

Which vit B is deficient in Wernicke Korsakoff's?

Back 72

Thiamine

Front 73

What is the acute state of Wernicke Korsakoff's?

Back 73

Wernicke's encephalopathy

Front 74

What are the 4 symptoms of Wernicke's encephalopathy?

Back 74

CODA:
-Confusion
-Oculomotor dysfunction
-Disorientation
-Ataxia

Front 75

Where are the lesions that develop in Wernicke Korsakoff's?

Back 75

In the mammillary bodies and thalamus

Front 76

What is the cingulate divide into?

Back 76

-Anterior/rostral
-Posterior/caudal

Front 77

What 2 things are associated with the Anterior cingulate?

Back 77

-Emotion
-Motor functions

Front 78

What is the Posterior cingulate associated with?

Back 78

-Visuospatial function
-Memory function

Front 79

What results in general from cingulate damage?

Back 79

Contralateral motor neglect

Front 80

What does motor neglect mean?

Back 80

You can see the space but you're not motivated to move there.

Front 81

What does cingulotomy treat?

Back 81

OCD

Front 82

What can cingulotomy help with?

Back 82

Chronic pain

Front 83

What abnormalities are associated with the cingulate gyrus?

Back 83

-Sociopathy
-Akinetic mutism

Front 84

What is akinetic mutism?

Back 84

Lack of motivation to speak or move

Front 85

Why is Tourette's syndrome postulated to be associated with the anterior cingulate?

Back 85

Because it plays a role in Affective Vocalizations

Front 86

What happens to the anterior cingulate in tourette's patients?

Back 86

It has decreased cerebral glucose utilization - in both the AC and insula

Front 87

What relieves tourette's syndrome symptoms?

Back 87

Disconnection of the AC from the thalamus.

Front 88

So what in general is the anterior cingulate's function?

Back 88

Integration of thought, motivation, and emotion with MOVEMENT

Front 89

What happens when emotional signals in the ant cingulate are excessively amplified?

Back 89

-Anxiety
-OCD

Front 90

What happens when MOTOR behaviors are excessively amplified in the ant cingulate?

Back 90

-Tics
-Impulsive behaviors

Front 91

What happens when there is excessive FILTERING of both motor behaviors and emotions?

Back 91

-Apathy
-Akinesis
-Mutism

Front 92

What are the 3 frontal lobe syndromes associated with the limbic system?

Back 92

-Orbital frontal syndrome
-Frontal convexity/dorsolateral
-Medial frontal

Front 93

Which frontal lobe lesion causes gluttony, careless dressing, tactlessness, etc?

Back 93

Orbital frontal

Front 94

Which frontal lobe lesion causes apathy, slowness, little initiative, lack of expression?

Back 94

Dorsolateral/frontal convexity

Front 95

What results from medial frontal syndrome?

Back 95

Akinetic mutism

Front 96

What happened when the railroad tie when through phineas gage's frontal lobe?

Back 96

Profound changes in his personality and behaviors.