Intro & Nervous System

Question 1

What is neuroscience?

Answer 1

• Study of the function and structures of the nervous system

Question 2

What is behaviour?

Answer 2

• Observable actions of humans, animals

Question 3

What is neurogenesis?

Answer 3

• The generation of new neurons

Question 4

Who was the first to propose that the brain controls the body?

Answer 4

• Hippocrates (Ancient Greece)
  
  • Brain = Command Centre of body (not heart → Egyptian, Indian, Chinese)
  • Noted the behavioural effects of brain damage

Question 5

Who formulated the mind-body problem?

Answer 5

• Rene Descartes (France)
  
  • First to discuss interactions between mental and physical
  • Considered humans and animals like machines
    
    • Reflexes → Don’t require participation from the mind = Environmental stimuli
  • Brain contains chambers with fluid (ventricles)
    
    • Thought they were under pressure (disproven later)

Question 6

What is dualism?

Answer 6

• Belief in the dual nature of reality
• Mind and body are separate
  
  • Body is made of ordinary matter
  • Mind is not

Question 7

What is monism?

Answer 7

• Belief that everything in the universe consists of matter and energy
• Mind is a phenomenon produced by the workings of the nervous system

Question 8

Who was the first to suggest nerve signals are electrical (not fluid = Descartes)?

Answer 8

• Luigi Galvani (zapped frog leg = contract)
  
  • Rejected the idea of animal spirits flowing through hollow nerves
  • Suggested that nerves must be coated in fat to prevent electricity leaking

Question 9

Who created phrenology?

Answer 9

• Franz Joseph Gall (Germany)
  
  • Idea of a modular brain = Parts assigned to have specific function
  • Physiognomy → Art of ascribing personality characteristics to facial features

Question 10

Describe phrenology

Answer 10

• Gall proposed that the brain is composed of several distinct ‘organs of thought’ = Faculties
  
  • Reflected by characteristic patterns of bumps on the skull → Read a person’s character
• Compared animal and human skulls
  
  • Includes ‘extremes’ of society → Criminals and famous artists
• Introduce ‘cortical localisation of function’ although flawed

Question 11

Who developed the doctrine of specific nerve energies?

Answer 11

• Johannes Muller (Germany)
  
  • Observed that although all nerves carry the same basic message → We perceive messages of different nerves in different ways
  • Insisted that understanding of humans would be advanced by removing animal organs + Testing chemicals to see how they respond

Question 12

Who first performed experimental ablation?

Answer 12

• Pierre Flourens (French)
  
  • Removed various parts of animals’ brains and observed their behaviour
  • See what they could no longer do → Infer function of missing portion of brain

Question 13

Who discovered first solid evidence of brain modularity?

Answer 13

• Paul Broca
• Discovered in patient Leborgne
  
  • Unable to speak after damage to left frontal lobe → Yet normal chewing and language comprehension
• Broca’s Aphasia = Damage to Broca’s area
  
  • Damages speech production

Question 14

What was discovered after Broca’s area?

Answer 14

• Carl Wernicke (Germany) → Discovers Wernicke’s area
  
  • Patient unable to comprehend speech → Yet normal hearing and language production
• Wernicke’s Aphasia = Damage to Wernicke’s area
  
  • Damages speech comprehension

Question 15

Does the size of one’s brain matter?

Answer 15

• No
  
  • Does not equate to intelligence level
  • Only scales with the size of the organism’s body

Question 16

What is functionalism?

Answer 16

• All characteristics of organisms have functional significance

Question 17

What do human brains have in common with fruit flies?

Answer 17

• Fruit Flies
  
  • Similar patterns of activity in sleep anaesthesia
  • Used to model human disease

Question 18

Explain Darwin’s theory of evolution

Answer 18

• Gradual change in the structure and physiology of organisms as a result of natural selection (cornerstone)
  
  • Not all members of species identical ∴ Must be because of favourable characteristics inherited (for reproduction)
  • Characteristics become more prevalent

Question 19

What does the Allen Brain Institute aim to do?

Answer 19

• Create detailed maps of human brains
  
  • Use mouse data
  • Brain areas
  • Neurons
  • Genes

Question 20

What are mutations?

Answer 20

• Accidental physical changes in chromosomes of gametes that produce the zygote
  
  • Causes different characteristics in offspring
• Most = Offspring fails to survive/ does survive with defect
  
  • Sometimes harbour selective advantage → More likely to live long enough to reproduce = Pass down chromosomes

Question 21

What does the Human Brain Project (HBP) aim to do?

Answer 21

• Reduce need for animal experiments
• Study diseases in unprecedented silico experiments
  
  • Makeshift disease states
• Improve the validation of data and experiments with computational validation

Question 22

What is a way that mutations can be beneficial?

Answer 22

• Physical change… (brain)
  
  • Favourable effects (seen in behaviour)
  • Not immediately favourable but since there is no inherent disadvantage = Trait is passed down

Question 23

Describe the central nervous system (CNS)

Answer 23

• Brain (including retinal cells within the eyeball)
  
  • Encased by skull
• Spinal cord
  
  • Sits within vertebrae → Protection and flexibility in moving body

Question 24

Why does the size of a baby’s brain grow over time?

Answer 24

• From birth, they are guaranteed to be exposed to adults who care for them
  
  • ∴ Not required to have a brain that has specialised circuits
  • Instead produce larger brain with an abundance of neural circuits that can be modified by experience (grow larger later in life)

Question 25

Describe the peripheral nervous system (PNS)

Answer 25

• Network of nerves that extend out from the CNS throughout the body
  
  • Cranial
  • Spinal
• Sends messages from brain
  
  • Control muscle movement
• Receives sensory information about body position, pain, temperation → Transmit to CNS
• Cannot function without brain

Question 26

Describe the somatic nervous system

Answer 26

• Subdivision of PNS
• Receives sensory information from sensory organs
  
  • Controls movement of skeletal muscle
• Efferent → To PNS from CNS
• Afferent → Away from PNS to CNS
• Includes spinal nerves

Question 27

Describe the autonomic nervous system (ANS)

Answer 27

• Subdivision of PNS
• Smooth muscle, cardiac muscle and glands
  
  • Heart, skin, blood vessels, eyes, gut
• Non-voluntary functions of nervous system
• Rest and digest
  
  • Acetylcholine release
• Flight or fight
  
  • Noradrenaline and adrenaline

Question 28

What is neoteny?

Answer 28

• Prolongation of maturation of human brain - “Extended youth”
  
  • Allows more time for growth
  • Prenatal period prolonged
  • After birth → Production of new neurons almost cease = Those already present grow and establish connections with each other

Question 29

Describe the sympathetic division of the ANS

Answer 29

• Motor neuron bodies in gray matter of thoracic and lumbar regions in spinal cord → Exit via ventral roots
  
  • Join spinal nerves → Branch into sympathetic ganglia
• Arousing → Prepare for activity
  
  • Dominates during times of stress or threat
  • ‘Fight or Flight’ mode
• Controls adrenal medulla
  
  • Adrenaline, noradrenaline → Also called epinephrine

Question 30

Describe the enteric division of the ANS

Answer 30

• Gut and gastrointestinal
• ‘2nd Brain’
• Has own reflexes and senses
  
  • Can act independently of the brain
• Nearly every neurotransmitter found in brain is also in gut
• Role in emotions and stress
• 90% of connections between brain and gut go from the gut to the brain