26 - Corticolimbic System

Question 1

Rostral Components, Function

Answer 1

• Construction of emotion
• Components
  
  • Olfactory system
  • Insula = interoceptoin (viscerosensory)
  • Amygdala
  • Anterior cingular cortex

Question 2

Caudal Components, Function

Answer 2

• Memory and visuospatial function
• Components
  
  • Parahippocampal gyrus
  • Hippocampus
  • Posterior cingulate cortex

Question 3

CeA Outputs

Answer 3

• Occurs when stimulus is not neutral, so requires a response
• Hypothalamus: cortisol release
• Brainstem: startle and flight or flight response
• Substantia innominata (NBM + NBST): anticipation of threat

Question 4

Hypothalamic Output

Answer 4

• Output of CeA
• Cortisol = stress response
  
  • Increased glucose production
  • Increased BP
  • Vasoconstriction
  • Immune suppression

CeA > PVN releases CRF into hypohyseal portal system > anterior pituitary releases ACTH > adrenal gland releases cortisol (= stress response) > hipoocampus (=flashbulb m emories)

Question 5

Brainstem Output

Answer 5

• Output of CeA
• Startle response, fight or flight

1. RPC: startle response
2. PAG: defensive behaviors (freezing)
3. RVLM: increases HR via IML
4. NTS+NucAmbig (INHIBITORY): stops parasympathetics that slow down HR
5. Pneumotaxic: increase RR and depth
6. VTA: dopamine
7. Locus coeruleus: norepinephrine
8. Dorsal raphe nuclei: serotonin

Question 6

Substantia Innominata Output

Answer 6

• Output of CeA
• For anticipation of threat

1. NBM: release ACh all over cortex for potentiation/readiness
2. BNST: anticipation of threat

Question 7

BLA Outputs

Answer 7

• ALL of these also receive ACh from CeA NBM
• Anterior insula: awareness of body state in response to stimuli
• Hippocampus:
  
  • Flashbulb memories
  • Feedback inhibition to amygdala via PVN
• vmPFC:​
  
  • ​Valence
  • Feedforward inhibition via dlPFC, which signals to ICM to stop amygdala signaling for valence change

Question 8

Kluver-Bucy Syndrome

Answer 8

• Bilateral amygdala damage
• Symptoms are broadly consistent with models of amygdala function:
  
  • Psychic blindness: inability to detect emotional/social significance of objects or persons
    
    • Not sensitive to emotions in others
  • Hypersexuality: lack of discrimination in sexual partners
  • Lack of fear: and other aversive responses
  • Hyperorality: increased appetite, lack of discrimination of food items
  • Memory and learning deficits

Question 9

Medial Nuclei of Amygdala Pathway

Answer 9

medial nuclei -> stria terminalis -> runs with thalamostriate vein (into the wall of the lateral ventricle)-> bed nucleus of stria terminalis -> anterior hypothalamus (sexual and agonistic behavior)