Neuro 54 Limbic System

Front 1

what structures are included in the limbic system

Back 1

both cortical "limbic lobe" and
Subcortical structures

Front 2

what composes the hippocampal formation

Back 2

subiculum: transition btwn entorhinal ctx (5layers) nad hippocampus prpper with 3 layers

hippocampus proper: 3 layers, polymorphic, pyramidal, molecular

dentate gyrus: polymorphic, granular, molecular

Fornix: alveu

Front 3

what is the transition btwn the 5 layer entorhinal ctx and the hippocampus proper with 3 layers

Back 3

subiculum (part of hte hippocampal formation)

Front 4

what are the 3 parts that make up the hippocampal formation, white or grey

Back 4

1. Subiculum (cortical area)
2. Hippocampus proper
3. Dentate Gyrus

Front 5

the fornix is input to where?
where does it originate

Back 5

hypothalamus

originates from hippocampus, main output of hippicampus

Front 6

the major output of the hippocampus is what

Back 6

the fornix

**the fornix originates in hippocampus and then enters te hypothalamus

Front 7

as we move into the hippocampal formation from the parahippocampal G. what is happening tot he layers of cortex

Back 7

6 layers of cortex as seen in the parahippocampal g is being turned into 3 layers in the hippocampal formation

Front 8

what is the organization of the hippocampal formation

Back 8

as we go from the parahippocampal g into the hippocampal formation teh most proximal structure is the subiculum, it then moves into teh 3 layers of hippocampus proper, and then into the 3 layers of the dentate g

Front 9

what are the 3 layers of the hippocampus proper? what happens to these layers as we move into the dentate gyrus

Back 9

1. polymorphic (surface, eexternal)
2. pyramidal
3. molecular layer (deepest)

Dentate:
1. polymorphic (internal layer)
2. granular
3. Molecular

**the polymorphic layer switched form the external to internal leyer in development

Front 10

where is the polymorphic layer in the hippocapus proper and dentate g?

Back 10

in teh hippocampus its the most externa, then the dentate its the most internal

**hippocampal has pryamidal, the dentate has pyramidal

Front 11

what is the origin of the fornix (where specifically)

Back 11

hippicampus

*large pyramidal cells from hippocampus have axons that become the alveus, and then the finbrea and then the fornix

Front 12

whats the alveus

Back 12

its the axon bundle of the fornix as the axons just come together.

**the axons come from pyramidal layers and are conducted adjacent to the polymorphic layer (surface, external) in a structure called the alvelus

**the alvelus then connects to the finbrea which is the real start of the fornic

Front 13

the majority of axons htat form the fornix are from where int eh hippocampus

Back 13

pyramidal cells of the hippocampus proper

Front 14

what is the finbrea?

Back 14

the true beginning of the fornix in the hippocampus

**the pyramidal cells of the hippocampus proper give rise to axons that travel int eh alvelus on the external surface of the hippocampal g, the alvelous then joins with the finbrea which is the start of the fornix

Front 15

the axons that leave the hippocampus do so in wht structue

Back 15

fornix

Front 16

what is the afferent/efferent path of the hippocapus

Back 16

1. Afferent: perfornat Path
2.Efferent: Fornix (from pyramidal cells of HC proper)

Front 17

the perforant path is what

Back 17

afferntes into teh HC

Front 18

what is the flow of info in the huppocampus, input, where does it go, how does it leave

Back 18

1, Enters: perforant pathway, then some go to pyramidical cells direclty (in the HC proper) others go to the granule cells in the dentate

2. All info goes to pyramidal cells, the pyramidal then go to the fornix as output

**the granule cells synapse on pyramidal cells and then pyramidal sends the info out

Front 19

what are the inputs to the pyramidal cells of the HC prpoer

Back 19

1. direct from perforant path
2. indirect from granule cells of dentate

**all pyramidal then leave via fornix

Front 20

the HC is input to where?

Back 20

hypothalamus

**mammillary nuclei of the hypothalamus

Front 21

what is korsikoffs? what structure

Back 21

cant convers short to long term memory

**affects the hippocampus, can be a thriamin deficit

Front 22

what is it called when the hippocampus cant convert short to long term memory

Back 22

korsikoff

Front 23

what is wernikie korsikoff?

Back 23

just like korsikoff (cant convert short to long term memory) but...

cerebellum is also affected: gaze palsie, ataxia, nystagmous

Front 24

how can you tell korsikoff from wenikie korsikoff?

Back 24

korsikoff is JUST the inability to convert short to long term memory

**wernikie also has cerebellar involvement so there are gaze problems and ataxia (wenikie is comprehension)

Front 25

what is teh hippocampal circuit. stat with hippocampus

Back 25

Hippocampus
Fornix
Mamilary Nucleus
Mammilothalamic tract
antieor Thalamic nucleus
cingulate G
enterohinal cortex
perforant path
hippocampus

Front 26

from the fornix where does the HC path go?

Back 26

HC to Fornix
Fornix to mammillary nuc
mammillary nuc to the mammilothalamic tract then to the ant thalamic, then cingulate g, to enterohinal, then its the perforant path and then back to the hippocampus and on to the fornix

Front 27

the mammilothalamic tract connects what

Back 27

the mammily nulcues to teh anterior thalamuc nucleus

**from thalmus to cingulate gyrus, then enterohinal cortex, and then perforant path

Front 28

what the key sx for hippocampal damage? amygdaloid

Back 28

Hippocampal: korsikoff

Amydgaloid: placid, hypersexual, hyperoral bc of visual agnosia, hyperphagic, dementia, hypermetamorphosis

Front 29

what are the 2 regions of the amygdaloid complex

Back 29

1. Corticomedial: contains central nucleus

2. Basolateral:

Front 30

is thy hypothalamus part of the limbic system

Back 30

yep

Front 31

waht are the afferents into the amydgalois

Back 31

1. prefrontal, cingulate cortex, parahippocampal g, olfactory cortex

2. Thalamus, hypothalamus

3. Brainstem visceral Nuclei (solitary, dorsal vagal, PAG)

Front 32

what areas of cortex enter amysgaloid, what do they control

Back 32

emotional behacior

prefrontal
parahippocampal
cingulate
olfactory (several regions)

Front 33

does the amygloid have input form the hypothalmus? thalamus?

Back 33

yep to both

Front 34

does the amygdaloid get input from brainstem viasceral uclei?

Back 34

yep

solitary
dorsal vagal
Peri Aquaductal grey (PAG)

Front 35

what are the efferents of the amygdaloid (seperate based on location in amygdaloid)

Back 35

1. Corticomedial: stria terminalis to hypothalamus, septal nucleus, nucleus accumbans

2. Basolateral: VAF and then ascends to hypothalamus, frontal, cingulate, and temporal cortex. descedning to brainstem visceral nuclei

Front 36

how is the stria terminalis associated with the limbic system

Back 36

its an efferent of the corticomedial area of the amydgaloid

Front 37

the efferent of the corticomedial amygdaloid is what

Back 37

stria terminalis to the hypothalamus, septal nucleus, nucleus accumbans

Front 38

the effernets of the basolateral group of the amygdaloid go where?

Back 38

Ventral amygdalofugal fibers (VAF)

ascend to hypothalmus, frontal, cingulate, temporal cortex

Descedig to the brainstem visceral nuclei (

Front 39

fear is associated with what

Back 39

amydgaloid

Front 40

a leision of the amygdaloid does what

Back 40

kluver Bucy syndrome

hypersexual, visual agnosia so recognize things orally, hyperphagia, dementia, amnesia, hypermetamorphisis, placid

Front 41

kluver bucy is associated with what

Back 41

amygdaloid leision

hypersexual, visual agnosia, hyperoral, hyperphagic, dementia, amnesia, placid

Front 42

what is the blood supply of the hippocampus and amydgaloid

Back 42

anteiror choroidal a

Front 43

what does hte ant choroidal a supply

Back 43

amygdaloid
hippocampus

Front 44

what limbic structure is associated with calm placid bahavior? what does a leision do

Back 44

septal nucleu

Front 45

if you have a leision that produces rage what area of the libic system was leisioned

Back 45

septal nuclei

Front 46

what does the septal nuclei do

Back 46

calm placid behavior

**leision results in rage

Front 47

what R are found on the nucleus accumbans? what does it do

Back 47

opiate, DOPAMINE

**fx as a reward center, involved in addiction

Front 48

what is the reward center in the limbic system, what R are here

Back 48

nucleus accumbuns

**dopamien and opiate R

**invilved with addistion

Front 49

what is the ventral tegmental area

Back 49

source od dopaminergic input to:
hypothalmus, septal nuclei, nucleas accumbans

**pars compacta of sub niagra

Front 50

what is the source of most domaniergic inputs, where do these inputs project to

Back 50

VTA- ventral tegmental area

**hypothalamus
**septal nuclei
*nucleus accumbans

**pars compacts of sub niagra

Front 51

where is the location of the reticular formation

Back 51

in teh core of the brainstem from the medulla to midbrain

Front 52

what is the core of the brainstem that spans the midbrain to medulla called

Back 52

reticular formation

Front 53

how are the nuclei of the reticular formation generally categorized

Back 53

lateral
medial

**these are the diffise groups of nuclei that are in the core of the brainstem from midbrain to medulla

Front 54

what are the cells of the lateral reticular formation like? medial?

Back 54

small

medial are large, long ascending and descending axons with a large collateral plexus near the cell body

Front 55

what is teh ascening pathway of the reticular activating system? what does stimulation lead to

Back 55

EEG changes from sleep to wake

*we start with ascedning sensory input like pain
**it then activates the reticular formation
*the info is then passes to the intralaminar thalamic nuclei
**this leads to diffuse cortex activation

Front 56

what thalamic nuclei gets info from the reticular activating system? where does it project

Back 56

intralaminar thalamic nuclei

*then projects to diffuse areas fo the cortex

**stimulation of reticular activating system an eeg goes from sleep to wake

Front 57

what changes an EEG from sleep to wake?

Back 57

activation of reticular activating system

Front 58

what is the reticulospinal system? medial or lateral reticular formation?

Back 58

its the descending fibers that excite or inhibit extensor mm

**arise from MEDIAL part of reticular formation

**from the pontice it activates,
**medullary inhibits extensors

Front 59

what reticulospinal system ectivates extensors? inhibits?

Back 59

Pontine
Medullary

**BOTH originate from medial portions of the reticular formation

Front 60

what does the pontine reticulospinal tract do?
medullary

Back 60

Pontine; + extensors
Medullary: - extensors

Front 61

what do the visceral centers of the reticular formation control

Back 61

1. respiratory system
2. heart, BP
3. GI

Front 62

what is a somatic fx of the reticular formation

Back 62

saccade gaze control (horizonatal and vertical gaze center)

Front 63

so we said the limbic system is associated with teh hippocampus, amydgala and the limbic cortex. wht is the limbic cortex made of

Back 63

allocortex: less layers (the neocortex is 6 layers)

Front 64

the allocortex is waht? what are the types

Back 64

allocortex has less than 6 layers and is associated with limbic cortex

1. Paleocortex: 3-5 layers, parahippocampal g
2. Archicortex: 3 layers, found in dentate, HC proper

Front 65

what type of cortex is the dentate g, HC proper nad parahippocampal g

Back 65

all are allocortex, which is associated with the limbic cortex

**the 2 types of allocortes are paleocortex adn archiocortex

Paleo is parahippocampal
Archicortex: dentate nad HC proper

Front 66

the limbic cortex invovles what structures

Back 66

cingulate
parahippocampal g
hippocampal
uncus

Front 67

the limbic lobe is associate with what?

Back 67

cingulate g
isthmus
parahippocampal g

Front 68

what are the divisions of the piriform cortex and enterohial cortex

Back 68

divisions of the parahippocampal g (limbic lobe)

**piriform is ant
**enterohinal is post

Front 69

what are the ant and post divisions of the parahippocampal g

Back 69

ant is piriform (uncus, covers amydgala)
post is enterohinal (covers hippocampal formation)

**the parahippocampal g is associated with the limbic lobe

Front 70

so the parahippocampal g is part of the limbic lobe and it covers the hippocampal formation, what structures are deep to teh parahippocampal g

Back 70

1. Piriform Cortex (antieror part of parahippocampal) is aka uncus and covrs the amydgala

2. ENterohinal cortex of the parahippocampal g covers the hippocampal formation

Front 71

what is another work for uncis

Back 71

piriform cortex

*8the anteiror part ofthe parahippocampal g

Front 72

know these limbic cortical structures:
cingulate g
parahippocampal g
piriform cortex
enterohinal cortex
dentate g
uncus
amydgaloid complex

Back 72

Be able to ID thse subcortical Limbic structres:

ventral tegmental area (VTA)
dorsal motor nucleus of vagus
intermediolateral cell column
locus ceruleus
raphe nuclei
amydgaloid
septal nuclei
nucleus accumbans
hypothalamus
sub niagra
ant/dorsomedial thalamic nuclei
PAG

Front 73

know the origin, course nad termination of these limbic system fiber tracfornix
mammillothalamic tract
mammillotegmental tract
posterior longitudinal fasciculus
stria terminalis
VAF
Papez circuitts

Back 73

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