Lecture 4 - Limbic System

Question 1

Critiques of limbic system

Answer 1

• The exact brain regions are not agreed on
• Limbic regions aren’t functionally or anatomically isolated in some special way from the rest of the brain

Question 2

Autonomic nervous system 4 functions

Answer 2

Fighting
Fleeing
Feeding
F*cking

Question 3

What does the ANS control

Answer 3

The viscera (non-skeletal muscle ex: heart, lungs)

Question 4

2 main divisions of the ANS

Answer 4

Parasympathetic system
Sympathetic system

Question 5

Role of parasympathetic system

Answer 5

Preserving energy (rest and digest)

Question 6

Role of sympathetic system

Answer 6

Expending energy (fight or flight)

Question 7

Hypothalamus what it is and role

Answer 7

Collection of nuclei with control over autonomic nervous system and hormone secretion (homeostatic needs)

Question 8

How does the hypothalamus interact with the endocrine system

Answer 8

Through the pituitary gland

Question 9

Parts of the limbic system

Answer 9

Hypothalamus
Hippocampus
Amygdala
Limbic cortex

Question 10

Landmarks to find hippocampus

Answer 10

• Start at temporal lobe and go medial until you hit a bump
• If sagittal section you will see a long rod like structure right next to a ventricle (black hole empty space)

Question 11

Functions of hippocampus

Answer 11

• Consolidation of memory
• Spatial memory

Question 12

Hippocampus get input from where

Answer 12

Entorhinal cortex

Question 13

Hippocampus sends output where

Answer 13

Through fimbria, fornix to mammillary bodies/hypothalamus

Question 14

Hippocampal circuitry

Answer 14

Input from entorhinal cortex to dentate gyrus to CA3 to CA1 and then output from CA3 and CA1 to the fimbria then fornix then to mammillary bodies and hypothalamus

Question 15

CA3

Answer 15

More contextual memory (context in which you learn something)

Question 16

CA1

Answer 16

More specific objects that you are remembering

Question 17

Neurogenesis

Answer 17

New cells are born in the dentate gyrus of the hippocampus throughtout life

Question 18

Where else does neurogenesis happen

Answer 18

Olfactory bulb

Question 19

What factors might promote neurogenesis in the hippocampus

Answer 19

Exercise, sleep, good diet

Question 20

What factors might inhibit neurogenesis in the hippocampus

Answer 20

Age, chemical substances, stress

Question 21

How could you test whether factors affect neurogenesis in animal models?

Answer 21

Label cells that are neurons, and cells that are newly born, and see if they overlap

Question 22

How could you test whether factors affect neurogenesis in humans?

Answer 22

Exercisers vs non-exerciser study and see the difference in hippocampus size, pre-post hippocampus size after exercise

Question 23

Study of hippocampus size

Answer 23

London taxi drivers have larger hippocampus – good spatial memory

Question 24

Amygdala functions

Answer 24

• FEAR
• Rage and aggression
• Sexual behavior
• Learning/memory
• Attention
• Novelty detection

Question 25

Basolateral nucleus

Answer 25

• Slower, cognitive
• Inputs from hippocampus, association cortex, sensory cortex/thalamus (processed & filtered sensory info)

Question 26

Central nucleus

Answer 26

• Faster, automatic
• Lower-level sensory input from (from viscera and body)

Question 27

Both basolateral and central nuclei

Answer 27

Controlled by medial prefrontal cortex (anterior cingulate)

Question 28

Basolateral nucleus outputs

Answer 28

Outputs to medial prefrontal cortex (higher order cognition), association cortex, ventral striatum/nucleus accumbens (reward and decision making)

Question 29

Central nucelus outputs

Answer 29

Outputs to autonomic nervous system and modulatory systems (systems that regulate neurotransmitters)

Question 30

Limbic cortex

Answer 30

Cingulate gyrus

Question 31

Korsakoff syndrome

Answer 31

• Caused by thiamine deficiency, most commonly in alcoholism
• Damage to mammillary bodies and limbic thalamus
• Symptoms: amnesia and confabulation (fake memories)

Question 32

Toxoplasmosis

Answer 32

• Parasite that lives in cat guts
• Infects the amygdalae of rats and makes them unafraid of cats
• May have some effects in adult humans, dangerous to fetuses