Limbic System

Question 1

Limbic Structures

Answer 1

• Hippocampus
• Amygdala
• Mammillary bodies
• Cingulate cortex
• Hypothalamus
• Septal Nuclei

Question 2

Limbic Cortex (cingulate, parahippocampal cortex)

Answer 2

• two-way communication between prefrontal cortex and lower limbic structures to control behavioral responses
• damage: less well regulated behavior (Phineas Gage)

Question 3

Salience Network

Answer 3

• detects behaviorally relevant stimuli and responses

collection of regions of the brain that select which stimuli are deserving of our attention

Question 4

Hippocampus (function)

Answer 4

consolidation of info from short –> long term memory and in spatial memory / navigation

Question 5

Hippocampal formation

Answer 5

• Hippocampus
• Alveus
• Fornix
• Fimbria
• Hippocampal commissure

Question 6

Alveus

Answer 6

axons from hippocampus –> forms fimbria –> joins together to become fornix –> project to mammillary bodies –> anterior nucleus of thalamus

Question 7

Hippocampal commissure

Answer 7

how hippocampi communicate w/ each other

Question 8

damage to fornix

Answer 8

long term memory loss, but not fact-based/ spatial memory

Question 9

Association areas

Answer 9

process sensory input, produce conscious awareness of emotional feelings

Question 10

Pre-frontal and limbic association areas (function)

Answer 10

conscious, learned control of reflexive behavioral patterns

Question 11

Pre-frontal cortex (function)

Answer 11

plans and guides behavior, suppresses amygdala-induced emotional/fear responses that may be inappropriate for the situation

Question 12

Sensory Over-responsibility

Answer 12

• extremely common in those w/ autism

negative reaction to/ avoidance of sensory stimulus (auditory and tactile most common)

Question 13

Dentate Gyrus

Answer 13

location of neural stem cell population in adult hippocampus

Question 14

Cornu Ammonis areas

Answer 14

dentate gyrus –> CA4 –> CA3 –> CA2 –> CA1

Question 15

Entorhinal cortex (function)

Answer 15

declarative / spatial memory consolidation during space

- input of signal to hippocampus

Question 16

Hippocampal Output

Answer 16

Fornix –> amygdala, mammillary bodies, thalamus, hypothalamus, cingulate / frontal cortex

Question 17

Anterograde Amnesia

Answer 17

can’t form new memories

Question 18

Retrograde Amnesia

Answer 18

can’t retrieve stored memories for a specific time

Question 19

Hippocampal Injuries

Answer 19

• memory loss of function, anterograde amnesia

- no recall of declarative memory (especially spatial)

Question 20

Amygdala (functions)

Answer 20

social interactions, anxiety, aggression, fear, rewards

lesions = block memory formation, can’t discriminate emotions in facial expression

Question 21

Medial Nuclei

Answer 21

linked to olfactory system

associated w/ aggression, repetitive behavior

Question 22

Central Nuclei

Answer 22

linked to hypothalamus and periaqueductal gray

controls body’s physiological emotional response

Question 23

Basolateral Nuclei

Answer 23

links sensory experiences, memory and emotional response

continuous w/ parahippocampal gyrus, links to central nuclei

Question 24

Hyperthymesia

Answer 24

enhanced autobiographical memory

greater amygdala-hippocampus connectivity

Question 25

GABAergic neurons (in medial nuclei)

Answer 25

fear and aggression

Question 26

Glutamatergic neurons (in medial nuclei)

Answer 26

repetitive behaviors

Question 27

Mammillary Bodies

Answer 27

memory recall, add smell to memories

lesions = amnesia syndromes

Question 28

Wernicke-Korsakoff syndrome

Answer 28

thiamine deficiency leads to retrograde and anterograde amnesia

Question 29

Hypothalamus

Answer 29

regulate emotions, produces autonomic responses associated with emotions (unconsciously controls endocrine glands)

Question 30

Septum Pellucidum (of Hypothalamus)

Answer 30

part of walls of lateral ventricles

Question 31

Septal Nuclei (of Hypothalamus)

Answer 31

processes rewarding experiences; learning and memory
receives afferent connections from other limbic structures
also sends projections