Week 8 - limbic system

Question 1

Limbic system

Answer 1

amygdala, hippocampus, thalamus, hypothalamus, basal ganglia, and cingulate gyrus, forinx, amygdala-hypothalamic fibres

Question 2

What does the forinx provide?

Answer 2

fibre connection between hippocampus and hypothalamus

Question 3

What does the amygdala-hypothalamic fibres provide?

Answer 3

pass from amygdala complex to the hypothalamus through the stria terminalis

Question 4

How can you recognise the amygdala in a cross section?

Answer 4

thickening of the cortical tissue

Question 5

What’s the function of the amygdala?

Answer 5

emotion, memory

Question 6

Explain the papez circuit

Answer 6

neocortex (emotional colouring) contacts/ contacted <-> cingulate cortex (emotional experience) -> hippocampus -> hypothalamus via forinx (exmopitonal expression) -> anterior nucleus of thalamus -> back to cingulate cortex

Question 7

What were the original components of the limbic system?

Answer 7

hypothalamus with mammilary bodies, anterior nucleus of thalamus, cingulate cortex, hippocampus

Question 8

What did papez incorrectly believe?

Answer 8

that there is a circuit of working memory, keeping memory in constantly reverberating networks - now it is considered for emotional processing and emotional regulation of behaviours

Question 9

What is the official composition of the limbic system?

Answer 9

1. cingulate gyrus
2. parahippocampal gyrus
3. amygdaloid body
4. hippocampus

Question 10

name the four subdivisions of the amygdala

Answer 10

1. basolateral amygdala
2. olfactory amygdala
3. centromedial amygdala
4. extended amygdala

Question 11

What is the basolateral group of the amygdala?

Answer 11

basal nuclei, lateral nucleus

Question 12

What s the corticomedial group of the amygdala?

Answer 12

central and cortical nucleus

Question 13

BSTL

Answer 13

bed nucleus of stria terminalis

Question 14

BSTM

Answer 14

basal nucleus of meynert

Question 15

What does the basolateral amygdala do?

Answer 15

receives highly processed information form modality specific cortical association areas and through reciprocal connections affects processing of sensory information
can also affect cortical procession via reciprocal thalamoamygdaloid and stratal connections

Question 16

what is the function of the olfactory amygdala?

Answer 16

• receives input form both olfactory bulb and olfactory cortex and is involved in processing of olfactory information
• projects to ventromedial amygdala and hypothalamus

Question 17

What is the function of the centromedial and extended amygdala?

Answer 17

• receive primary inputs form hippocampus formation, insulation and orbitofrontal cortex (also cerebral cortex) and other parts of amygdala
• project to regions in hypothalamus and brainstem
• support and affect autonomic, endocrine and somatomotor aspects of emotional and eating, drinking, sexual behaviour

Question 18

Give an example of psychological testing relating to the amygdala

Answer 18

• pavolovs dog experiment with classical conditioning

Question 19

What animal looks like the forinx ?

Answer 19

seahorse

Question 20

Explain HM

Answer 20

temporal lobe epilepsy
removal of parts of hippocampus and amygdala
post surgery HM was unable to make new episodic memories
declarative memories were affected -> parts of hippocampus were missing and important fibre tracts were destroyed

Question 21

What kind of memory does the hippocampus relate to?

Answer 21

declerative memory

Question 22

What kind of memory does the amygdala + cerebellum relate to

Answer 22

non-declarative - simple classical conditioning

Question 23

What does the transverse hippocampus slice looks like?

Answer 23

Horn of Ammon

Question 24

Explain the hippocampus try-synaptic circuit

Answer 24

1. entorhinal cortex activates granular cells in dentate gyrus via performant pathway
2. granular cells of dentate gyrus give rise to Mossy fire axons that innervate CA3 pyramidal cells via giant mossy fibre boutons
3. CA3 pyramidal cells send axons via Schaffer collateral pathway to CA1 area where they activate CA1 pyramidal cells via en passant boutons

Question 25

What is the function of the three synapses int he tri-synaptic circuit?

Answer 25

exhibit synaptic plasticity, such as long-term potentiation, albeit some of the mechanisms involved are quite dissimilar

Question 26

is the hippocampus involved in spatial memory?

Answer 26

yes - +ve correlation between size and time spent as a taxi driver

Question 27

Explain Jennifer Aniston neurons

Answer 27

• same hippocampus cells reacted when they saw an image, her name, heard her voice
• cells in hippocampus respond to different people, objects, places
  -> not just involved in LTM but also working memory