Lec #1

Question 1

Hippocrates

Answer 1

• Brain is the seat of intelligence
•  Epilepsy disorder of the brain
•  Recognized that paralysis occurs on side
of the body opposite of head injury

Question 2

Galen

Answer 2

•  Proposed that nerves convey fluid
secreted by brain and spinal cord to the
body’s periphery
•  Dominate view until microscope revealed
true structure of cells in nervous tissue

Question 3

Renee Descartes

Answer 3

•  Distinguished body and mind = 
“dualism” (vs. monism debate) 
•  Brain mediates everything that can be 
found in lower animals (motor, sensory 
perception, memory, motivation) 
• Mind mediates conscious experience; 
not by brain but by soul that 
communicates with brain via pineal 
gland

Question 4

Luigi Galvani

Answer 4

•  Discovered that muscle and nerve 
cells produce electricity 
• “animal electricity” (a.k.a. 
Galvanism) 
•  Volta discovered battery

Question 5

Johannes Müller

Answer 5

•  Measured speed of conduction 
along nerve cell 
•  Showed one nerves electricity 
affects another cells activity 
•  Birth of modern electrophysiology

Question 6

Franz Joseph Gall and Johann

Spurzheim

Answer 6

•  Unified view of body and mind (monism) 
•  The brain is not a homogeneous organ 
(localism vs holism debate) 
•  Derived from experimental lesions in 
animals 
•  Phrenology

Question 7

Pierre Flourens

Answer 7

•  Stimulated and ablated cortical regions in 
animals 
•  Disputed phrenology 
•  Aggregate theory = all brain regions 
participate in every mental operation

Question 8

Paul Broca and Carl Wernike

Answer 8

•  Challenged aggregate theory 
•  “Behavior linked to postmortem 
studies of lesions in patients with 
focal epilepsy or stroke led to 
evidence of localization of function 
•  “We speak with the left 
hemisphere!” Broca 1864

Question 9

Gustov Fritsch and Eduard Hitzig

Answer 9

•  Characteristic limb movements 
of dogs can be produced by 
electrical stimulation of a 
specific area of the cerebral 
cortex = motor cortex 
•  Right controlled by left 
hemisphere

Question 10

Korbinian Brodmann

Answer 10

•  Classification of cortical
areas based on
cytoarchitecture
•  Nissl stain method

Question 11

Golgi’s Reticular theory

Answer 11

neurons connected by protoplasmic
links to form a reticulum (Latin “net”) for nerve cell
communication; pioneered staining with impregnation with
silver salts = Golgi technique

Question 12

Ramon y Cajal’s Neuron Doctrine

Answer 12

nerve cells are discrete entities that communicate via specialized contacts

Question 13

Charles Sherrington

Answer 13

• Worked on apparent transfer of electrical signals
via reflex pathways
•  Termed them “synapses”, supported the neuron
doctrine
•  Received the Nobel in 1932

Question 14

Nerve cells = Neurons

Answer 14

 Specialized for electrical signaling over long distances
 Neurons communicate via synapses (predominately) or gap
junctions (rarely)
 100 billion in brain
 Projection neurons (afferent and efferent neurons) and
interneurons
 Phenotypes vary with locale
 Greater diversity in brain than in any other organ

Question 15

Diverse subsets of neurons constitute ensembles of _________ = neural systems to process specific types of info

Answer 15

Diverse subsets of neurons constitute ensembles of neural

circuits = neural systems to process specific types of info

Question 16

  \_\_\_\_\_\_\_ = extension of cell body 
that may travel a few hundred 
μm 
  \_\_\_\_\_\_\_ = targets for 
synaptic input from axons of 
other neurons

Answer 16

  Axon = extension of cell body 
that may travel a few hundred 
μm 
  Dendrites = targets for 
synaptic input from axons of 
other neurons

Question 17

 More _________ = more
innervation by other
neurons

Answer 17

 More arborization of
dendrites = more
innervation by other
neurons

Question 18

Convergence

Answer 18

Convergence = inputs to a
single neuron; a single human
neuron will receive 1-100,000
inputs

Question 19

Divergence

Answer 19

Divergence = outputs to other

neurons by any one neuron

Question 20

Action potential

Answer 20

carries signals over
long distances
  Self-regenerating wave of electrical activity
  All or nothing change in electrical potential
(voltage) across membrane
  Propogates from axon hillock to axon
terminal synapses

Question 21

Synaptic transmission

Answer 21

chemical and
electrical processes by which the info
encoded by action potentials is passed
at synapses

Question 22

glia cells

Answer 22

Supporting cells; ratio glia to neurons is 3:1
  Support system; do not participate in synaptic interactions
or electrical signaling
 New evidence that glia cells retain characteristics of stem
cells = can enter mitosis and generate nervous tissue cells

Question 23

Astrocytes

Answer 23

 CNS
 Blood-Brain Barrier
 Maintain environment

Question 24

Oligodendrocytes

Answer 24

 CNS

 myelin

Question 25

Schwann cells

Answer 25

 PNS |  myelin

Question 26

Microglia

Answer 26

 Scavengers  Release cytokines  Similar to macrophages

Question 27

Central Nervous System (CNS) consists of : •  __________ •  __________ •  __________

Answer 27

Central Nervous System (CNS) • Sensory systems • Motor systems • Associational systems

Question 28

•  Nerve cells are arranged in 2 | different ways: __________ and __________

Answer 28

• Nuclei = local accumulations of neurons with similar functions; ie brainstem and hypothalamus •  Cortex = sheet-like arrangement of nerve cells; ie cerebral cortex and cerebellum

Question 29

Axons are gathered into tracts, called _________ when they cross the midline (white matter)

Answer 29

Axons are gathered into tracts, called commissures when they cross the midline (white matter)

Question 30

  Peripheral Nervous System (PNS) consistis of :

Answer 30

```   Peripheral Nervous System (PNS) • Sensory neurons with cell bodies localized in ganglia • Axons bundled into nerves • Somatic motor division innervates skeletal muscle • Autonomic motor division innervates smooth muscle ```

Question 31

Autonomic Nervous System (ANS)

Answer 31

Autonomic Nervous System (ANS) • Sympathetic system • Parasympathetic system • Also organized in ganglia and nerves

Question 32

• Representations of the information is processed at various levels : ____________ and ____________

Answer 32

• Representations of the information is processed at various levels • Topographic maps = point-to-point correspondence between the sensory periphery and CNS neurons (vision and somatosensation • Computational maps = compare, assess and integrate stimulus attributes to extract info (olfaction, gustation)

Question 33

• Parallel pathways = ______________

Answer 33

• Parallel pathways = information from each submodality is | processed separately

Question 34

what are the Hallmarks of nervous system and define each.

Answer 34

Unity of function: nterconnected ensemble of neurons with similar dedications Representation of specific information: Representations of the information is processed at various levels: Topographic maps and Computational maps Subdivision into subsystems :  Division of the function of the system into submodalities (ie audition vs vision)

Question 35

what is Tract-tracing and what are its types.

Answer 35

Tract-tracing provides “mapping” of neural connectivity •  Anterograde tract tracing = from cell body to axon terminal; ie biotinylated dextranamine (BDA) and Phaseolus vulgaris leucoagglutinin (PHA-L)   Retrograde tract tracing = from axon terminal to cell body; ie fluorogold (FG), horseradish peroxidase (HRP)

Question 36

what is Extracellular recordings and Intracellular recordings ?

Answer 36

 Extracellular recordings = electrode placed near nerve cell(s) of interest; detect temporal patterns of action potential activity relating to other neural inputs, a stimulus or a behavior  Intracellular recordings = electrode placed inside nerve cell of interest; useful for detailed analysis of communication between neurons; detect smaller graded changes in electrical potentials that trigger action potentials

Question 37

Functional brain imaging records _______

Answer 37

Functional brain imaging records local metabolic activity | within small volumes of brain tissue

Question 38

Neurons transmit and store info by _______

Answer 38

Neurons transmit and store info by generating electrical signals

Question 39

Resting membrane potential is ______ and Action potential makes transmembrane potential ________

Answer 39

Resting membrane potential is negative and Action potential makes transmembrane potential positive

Question 40

All-or-nothing principle

Answer 40

All-or-nothing principle = needs to reach threshold; intensity of stimulus encoded as frequency

Question 41

Receptor potential

Answer 41

* Electrical signals elicited in response to activation of sensory neurons by external stimuli * Info about touch, light, sound, heat, etc. is encoded by receptor potentials * Changes the resting potential proportional to stimulus intensity

Question 42

Synaptic potential

Answer 42

•  Activation of the synapse during communication between neurons at the synapse allows transmission of info to postsynaptic neuron •  Stimulation of presynaptic neuron changes postsynaptic resting membrane potential •  Amplitude varies according to number of synapses activated

Question 43

Ion movements produce electrical signals

Answer 43

•  Electrical signals are generated based on the flow of ions (K+, Cl-, Na+) across the neuron plasma membrane •  Membrane is selectively permeable to particular ions •  Ion concentration gradients depend on active transporters and ion channels in the cell membrane

Question 44

Describe the ionic basis for resting potential

Answer 44

•  Diffusion from high to low concentration •  More K+ inside vs outside neuron (active transporters) •  Gradient causes K+ to diffuse out of cell taking its + charge with it leaving the cell more negative relative to the outside •  Continual resting efflux of K+ holds neuron at negative resting potential

Question 45

Describe the ionic basis for action potential

Answer 45

``` •  More K+ inside neuron, more Na + outside neuron at rest •  Changes in ion channel permeability alter membrane potential •  Membrane becomes temporarily more permeable to Na+ • Na+ channels open • Na+ flows into cell • Membrane depolarizes becoming more positive • Na+ channels close and K+ channels open •  Repolarizes back to resting levels ```