Exam 1

Question 1

Stereotaxic Surgery

Answer 1

Brain surgeries are not free-hand. Done overtop the head with machinery, tools, knobs

Question 2

Lesion

Answer 2

Any abnormal damage or change in tissue

Question 3

Cannulation

Answer 3

Insert a specialized probe

Question 4

INfusion

Answer 4

Put chemicals directly IN local brain region (testing one area)

Question 5

Ablation

Answer 5

Removal of tissue

Question 6

Microdialysis

Answer 6

Measure neurotransmitter output from local brain region

Question 7

Electrodes can…

Answer 7

record activity or stimulate activity in small regions

Question 8

Sham surgery

Answer 8

No manipulation of tissue

Question 9

Lesion Methods

Answer 9

Accidental (case studies) or purposeful (experimental)
Electrical (electrodes inserted), Chemical, Mechanical
Can be permanent or temporary

Question 10

Histology

Answer 10

Microanatomy of cells (brain slicing)
Sliced thin

Question 11

Staining Techniques

Answer 11

Golgi Silver Stain = random single cells, can see dendritic spines, shows complete cell
Nissl Stain = cell bodies, dark spots are rough ER in cell nucleus, identifies grey matter
Myelin Stain = stains the fatty MYELIN sheath, axon/fiber tracts (dark coloring), cell bodies/dendrites (light coloring), looks like layers
Brainbow = multicolor labeling of neuronal circuits with fluorescent proteins and chemical tags (tracks cells better than golgi), connectomics (can map the connections between neurons)

Question 12

Action potential

Answer 12

Sudden change of the resting membrane potential in a neuron. Caused by the opening and closing of voltage gated ion channels. Allows transmission of electrical signals along the cell

Question 13

Microelectrode in mice

Answer 13

Fine wire or glass electrodes implanted directly into the brain

Question 14

Electrocorticogram (ECOG)

Answer 14

Electrodes are placed directly on the surface of the cortex (inside skull), records LFP’s and not AP’s

Question 15

Local Field Potentials (LFP)

Answer 15

Slow, more sustained currents. Microelectrodes are implanted into the brain

Question 16

Electroencephalogram (EEG)

Answer 16

Out of the skull, whole brain, measures aggregate graded potentials from lots of neurons (Not AP’s), use it for sleep disorders, epilepsy, consciousness
Desynchronous brain activity = alpha, beta, gamma frequencies. Independent action of neurons, correlated with alertness, faster waves, lower amplitude
Synchronous brain activity = theta, delta frequencies. Neurons firing in unison, correlated with deeper sleep, slower waves, higher amplitude
Records sum total of extracellular post-synaptic potentials

Question 17

Advantages of EEG

Answer 17

Fast, safe, non-invasive, affordable, portable

Question 18

Disadvantages of EEG

Answer 18

Poor signal localization (don’t know where the signals are coming from), signal noise

Question 19

Magnetoencephalography (MEG)

Answer 19

Neurons’ electric activity also magnetic, improved localization over EEG, SQUID sensor that has north and south poles telling us where signals are coming from (detects magnetic field of current)

Question 20

Advantages of MEG

Answer 20

Non-invasive, improved spatial resolution over EEG, fast temporal resolution

Question 21

Disadvantages of MEG

Answer 21

Very large machine, requires helium, very expensive

Question 22

Computed Tomography (CT or CAT scan)

Answer 22

Combines X-ray images taken from different angles and uses computer processing to create cross-sectional images of the bones, blood vessels, and soft tissues
Risk: some exposure to radiation

Question 23

Advantages of CT or CAT scan

Answer 23

Accessible, good for diagnosis, less claustrophobic, quick scan

Question 24

Disadvantages of CT or CAT scan

Answer 24

Not best image quality, not often used in research, some exposure to radiation

Question 25

Advantages of Magnetic Resonance Imaging (MRI)

Answer 25

Very good still image quality (better than CT or CAT scan), no radiation exposure

Question 26

Disadvantages of MRI

Answer 26

Long scan time, more expensive, more claustrophobic

Question 27

Diffusion Tensor Imaging (DTI)

Answer 27

"How are parts of the brain connected to each other?" Uses same machine as MRI Uses diffusion of water along axons to map white matter tracts throughout brain

Question 28

Phrenology

Answer 28

Bumps/depression on the outer surface of the skull were inaccurately linked to traits But led us to discover Localization and how the brain is separated into multiple parts

Question 29

Positron Emission Tomography (PET)

Answer 29

Molecules tagged with radioactive isotope and injected to bloodstream Tracer shows typical and atypical metabolic activity

Question 30

Advantages of PET scan

Answer 30

Useful for identifying cancerous tissue, can create radioactive tags attached to many different molecules, images changing brain metabolism over time

Question 31

Disadvantages of PET scan

Answer 31

Not much structural detail, radioactive isotope exposure

Question 32

Functional Magnetic Resonance Imaging (fMRI)

Answer 32

Changes in blood flow and blood oxygenation closely linked to neural activity Ratio of oxygenated hemoglobin to deoxyhemoglobin determines areas of brain activation BOLD response = Blood Oxygenation Level Dependent MEASURING CHANGES IN BLOOD FLOW

Question 33

fMRI Mechanism

Answer 33

Neurons activate and use more glucose and oxygen When an area of the brain is more active it calls for more blood flow to supply glucose and oxygen Blood vessels dilate to increase blood flow "HEMODYNAMIC" Brain area deactivates Blood vessel returns to normal

Question 34

Factors that can affect fMRI BOLD signals

Answer 34

Neural activity, blood flow, oxygen metabolism, magnetic field strength

Question 35

fMRI uses voxels

Answer 35

voxel = 3D pixels, which limits spatial resolution

Question 36

Advantages of fMRI

Answer 36

Great image quality with function over time, safe

Question 37

Disadvantages of fMRI

Answer 37

Expensive, long scan time, claustrophobic, limited temporal and spatial resolutions

Question 38

CELLS IN THE NERVOUS SYSTEM

Answer 38

NEW CHAPTER

Question 39

Neurons

Answer 39

Primary FUNCTIONING cells of the CNS, basic working unit of the brain, specializes in information processing and communication

Question 40

Glia

Answer 40

Primary SUPPORTING cells of the CNS, macroglia (astrocytes, oligodendrocytes, Schwann cells, Ependymal cells), microglia

Question 41

Dendrites

Answer 41

RECEIVE chemical messages from other cells, conduct post-synaptic potentials toward cell body RECEIVES thousands of inputs (allows cell to receive messages) Group of dendrites on one cell = arborization

Question 42

Dendritic Spines

Answer 42

Small protrusion that RECEIVES input from a single axon Sensitive to type and amount of synaptic activity Shows plasticity (change over time)

Question 43

The Cell Body (Soma)

Answer 43

Contains nucleus and organelles, genetic information Provides metabolic (energy) and synthetic (protein) support Acts to "gate" information flow to and from other neurons RECEIVES and integrates signals from many sources of input

Question 44

Axon

Answer 44

Conducts electrical signals called ACTION POTENTIALS Only 1 axon vs many dendrites Often has myelin sheath Ends in axon terminal which releases neurotransmitter

Question 45

Myelin Sheath (insulates axons)

Answer 45

Fatty insulation made by glial cells (oligodendrocytes or Schwann cells) Gaps between myelination are called Nodes of Ranvier- allows signal to jump from node to node Myelinated neurons are always faster than unmyelinated