Research Techniques in Neuroscience Text Book

Question 1

What are the 4 Methods of Studying the Nervous System?

Answer 1

1) Examining Case Studies (ie Phineas Gage, 1848)
2) Screens - performing unbiased searches
3) Description - observing without manipulating
4) Manipulation - testing a hypothesis

Question 2

What are the 2 Methods of Whole Brain Imaging?

Answer 2

1) Structural

2) Functional

Question 3

What are examples of structural brain imaging?

Answer 3

1) Cerebral Angiography
2) Computerized Tomography (CT)
3) Magnetic Resonance Imaging (MRI)
4) Diffusion MRI

Question 4

How does imaging take advantage of different biochemical composition of brain regions to form an image?

Answer 4

Gray matter = is made up of cell bodies that contain biomolecules including protein and carbohydrate
White matter = axons and fibers are fatty
Structural imaging shows the difference between proteins and carbohydrates (cell bodies), fat (axon tracts), and salt water (CSF)

Question 5

Which great neuroscientist used the Golgi stain to visualize the morphology and architecture of neurons propelling the field of neuroscience?

Answer 5

Santiago Ramon y Cajal

Question 6

What is a Loss of Function experiment?

Answer 6

when part of the nervous system is diminished or removed in an attempt to determine if it is necessary

Question 7

What is a rescue experiment?

Answer 7

When the aspect of a nervous system that is lost is deliberately returned
Acts as a good follow-up to Loss of Function experiment

Question 8

What is a Gain of Function experiment?

Answer 8

when an aspect of the nervous system is increased relative to normal

Question 9

What is a cerebral angiogram?

Answer 9

an X-ray that uses a radio-opaque dye that absorbs x-ray better than surrounding tissues
Dye is injected into the femoral artery that delivers blood to the brain
can show vascular damage- indicate presence of tumor, aneurysms, abnormal ballooning

Question 10

What is a CT

Answer 10

Computerized Tomography
Beam & detector rotate in a slow arc, taking many individual x-ray scans from different (4) angles (typically 8 - 10 images)
The computer analyzes whole body by dividing it into boxes called voxels
Attenuation is numbered from all angles (more solid = bone, less solid = skin)
Quality depends on- the width of the beam, the sensitivity of the x-ray and computer power
Good for identifying bony/ calcified structures in head or fluid boundaries

Question 11

What is an MRI?

Answer 11

Magnetic Resonance Imaging
Produces highly detailed strutural image of brain and body
Far superior to CT image
Used in Clinical and Research Settings
MRI excites hydrogen protons and measures relaxation
Measured in Tesla - strength of the magnetic field (most machines are 1.5 - 3T which is 30k stronger than earths magnetic field)
Benefits = non-invasive, can see slices of brain from any angle, no x-ray radiation needs to be applied to subject

Question 12

What is radiofrequency pulse (RF)?

Answer 12

= pulse of electromagnetic energy subject is exposed to in an MRI machine

Question 13

What is Diffusion MRI?

Answer 13

Its used to examine the structure of axon fiber tracs in the brain
Can provide info about which areas of the brain are connected

Question 14

What is the most comon isotope used in PET scans?

Answer 14

Fluorodeoxyglucose (FDG)

Question 15

What is the independent vs. dependent variable?

Answer 15

Independent = experimental variable that is intentionally manipulated
Dependent = the quantifiable variable measured by the researcher to determine the effect of the independent variable

Question 16

What are the 3 R’s?

Answer 16

Ethical considerations for animal use

1) Replacement - if there is a way to do the research without animals, it should be done
2) Reduction - use minimum number of animals necessary
3) Refinement - optimize procedures to minimize distress and pain and enhance well-being of animal

Question 17

What are the 3 Main Categories of Electrophysiology?

Answer 17

1) Extracellular recording
2) Intracellular recording
3) Patch clamp

Question 18

What is electrophysiology?

Answer 18

studies the electrical properties of biological cells and tissues. It involves measurements of voltage changes or electric current or manipulations on a wide variety of scales from single ion channel proteins to whole organs like the heart (Wikipedia definition)

Question 19

What is Ohm’s law?

Answer 19

Ohm’s law is the relationship among the membrane potential, current flow, and membrane resistance
V (voltage) = I (current) x R (resistance)

Question 20

At what mV does an action potential usually occur?

Answer 20

-55mV