limbic system

Question 1

what is the limbic lobe

Answer 1

• Telencephalic structures that circle the interventricular foramen of Monro and border the
  diencephalon

Question 2

what matter is the limbic lobe comprised of

Answer 2

• Comprised of grey matter with a histological
  structure simpler than that of neocortex

Question 3

what does the limbic lobe include

Answer 3

Includes: parahippocampal gyrus and
hippocampus, retrosplenial area, cingulate gyrus,
subcallosal gyri.

Question 4

what is the limbic system
Location an function

Answer 4

• Structures that interface between the cortex
  and the hypothalamus and modulate the motivational and emotional functions
  initiated by the hypothalamus

Question 5

what does the limbic system include

Answer 5

• Limbic system includes all structures that
  are linked to the limbic lobe and that
  project, ultimately, to the hypothalamus or
  its targets

Question 6

what does the limbic recieve input from
What does it modulate

Answer 6

• Limbic system structures receive cortical
  input and modulate hypothalamic functions.

Question 7

the lumbic system functions in controll of ____ , ____, and ______

Answer 7

emotion, motivated behavior, and memory

Question 8

what do lesions of limbic structures not result in

Answer 8

• Lesions of limbic structures do not result in
  paralysis or sensory deficits.

Question 9

how do seizures activity or eliectrical stimulation in limbic strucuters produce

Answer 9

Seizure activity or electrical stimulation in
limbic structures do not produce clonic
movements or sensory perceptions.

Question 10

what does excititation of limbic structures evoke

Answer 10

• Excitation of limbic structures evokes
  emotional states or memory fragments

Question 11

papez circuit

Answer 11

• Start in the hippocampus
• Output pathway of the HPC is the fornix
• Fornix ends in mammillary bodies, which project to the anterior nucleus of the thalamus (AT) via the mammillothalamic tract (MThT)
• From the AT, there are fibers that project through the internal capsule to the cingulate
  gyrus
• Cingulate gyrus project to the entorhinal cortex, which feeds cortical information to the
  hippocampus.

Question 12

Answer 12

fornix ( top)
hippocampus ( bottom)

Question 13

Answer 13

Fx
HPC
EC = entorhinal cortex: cortical input to the hippocampus

Question 14

Answer 14

Question 15

where does the fornix terminate

Answer 15

mammilary bodies

Question 16

Answer 16

MThT: mammillothalamic tract
AT = anterior nucleus of the thalamus
Output of AT → cingulate gyrus of the cortex via the internal capsule

Question 17

Answer 17

Question 18

Answer 18

Question 19

Answer 19

Question 20

declerative memory

Answer 20

short term memory > consolidation» long term memory

Question 21

memory theory
- what is it
- what is involoved in memory consolidation

Answer 21

Theory: when we learn something, it enters our short term memory. If we study it over and over
(pyramidal fibers pierce the pons!), information will get consolidated and put into long term
memory. This process of going from short to long term memory is called memory consolidation.
The hippocampus is involved in memory consolidation.

Question 22

who is henry gustav molasion

Answer 22

he had a degeneratied hippocampis on one side and this was producing seizures.
his hippocampus was taken out on the opposite side in an attempt to stop the seizure.
- he then had bilateral hippocampaeltomy bc both of his hippmcampuses were non funcitonal

Question 23

what did HM have

Answer 23

Severe memory deficit.
- Loss of memory consolidation
-

Question 24

place cells of hippocampus function

Answer 24

d – spatial navigation

Question 25

what would happen if you put HM in a new city vs back at home

Answer 25

HM: you couldn’t put him in a new city; he’d get lost. But if you put him back in montreal, he could get along just fine since that was in his long term memory before his hippocampus degenerated and his surgery

Question 26

role of hippocampus

Answer 26

* Memory consolidation * Spatial navigation

Question 27

what is the uncus next to - what is inside the uncus

Answer 27

uncus is next to the parahippocampal gyrus. Inside the uncus is the amygdala

Question 28

Answer 28

Question 29

amygdala pathways

Answer 29

* Stria terminalis * Ventral amygdalofugal pathway

Question 30

Answer 30

ST = stria terminalis. Like the fornix. Has a c-shape, and goes from the amygdala to the hypothalamus. VAF = ventral amydalofugal pathway. more direct route from amygdala to the hypothalamus

Question 31

what emotion is the amygdala associated with

Answer 31

fear

Question 32

what is a major target of the amygdala

Answer 32

hypothalmus

Question 33

what are the major inputs and outputs of the amygdala

Answer 33

Hypothalamus – Brainstem – Hippocampus and entorhinal cortex – Mediodorsal nucleus of thalamus – Anterior cingulate cortex – Prefrontal cortex – Olfactory tract

Question 34

role of amygdala

Answer 34

Amygdala is the integrative center for emotions, emotional behavior and motivation.

Question 35

kluver-bucy syndrome symptoms - removed amygdala bilaterally in monkeys what were the symptoms

Answer 35

* Tameness * Lack of fear and other emotional reactions * Hypersexuality * Bulemia * Oral tendencies * Hypermetamorphosis

Question 36

temporal lobe epilepsy

Answer 36

* aggression * panic attacks

Question 37

lesions of amygdala

Answer 37

* placidity * flatness of affect * failure to discriminate emotional expressions * loss of emotional memory processing

Question 38

path when you see something scary

Answer 38

- If someone sees something scary like a snake, the visual pathway goes to the thalamus directly (via the dotted blue arrow) to the amygdala → fear/panic reaction. - Later, the person analyzes it (pathway to the visual cortex, then to the amygdala) and recognizes that it’s just a garden snake and nothing to fear