Chapter 1 Highlights

Question 1

Different types of Glial Cells

Answer 1

1-Astrocytes
2-Oligodendrocyte; Schwann cells
3-Microglial 
4-Glial stem cell
5-Oligodendrocyte precursors

Question 2

What are Scaffolding proteins?

Answer 2

• Link receptors to cytoskeletal elements
• Proteins in the extracellular space between the axon and its target muscle (green)
• Example: K scaffolding protein here is dsytrophin; mutations in muscular dystrophy

Question 3

Function of Astrocytes

Answer 3

• Only in CNS
• Main function is Phagocytosis
• Propagate Ca++ waves
• Release gliotransmitters
• Provide physical support
• Provide neurons with nutrients

Question 4

Function of Oligodendrocytes

Answer 4

• CNS only
• Myelin formation; insulation
• One oligodendrocytes can integrate multiple neurons (contrast to Schwann cell)

Question 5

Function of Schwann cell

Answer 5

• Found in the peripheral axons
• make myelin
• wrap around one cell per Schwann

Question 6

Function of Microglia

Answer 6

• Participate in Phagocytosis via releasing a variety of cytotoxic substances
• Immune defense system of the CNS
• Attack and excavate invading microorganism

Question 7

Function of Glial Stem Cell (Radial glial cells)

Answer 7

• Found in adult and developing brain
• Proliferate and generate additional precursors or differentiated glia (sometimes neurons)
• Found in sub ventricular r zone or adjacent to SVZ blood vessels

Question 8

Function of Oligodendrocyte precursor (progenitor; NG2-glia)

Answer 8

• Can also differentiate into neurons and astrocytes

- Dysregulation results in myelination impairments

Question 9

What are the different staining methods?

Answer 9

• Golgi Staining
• Fluorescent Dye
• Enzymatic labeling
• Nissl stain (shows stains in the CNS, shows cortex, cell bodies)
• Cresyl Violet Stain: Stains RNA, organelles (RER and nuceluolus)

Question 10

Arrangement of neural circuits

Answer 10

• Neuropil: Synaptic connectivity
• Afferent neurons
• Efferent neurons
• Interneurons

Question 11

Function of Sensory neuron

Answer 11

-Detects changes in the external or internal environment and sends this info to the CNS

Question 12

Function of Motor neuron

Answer 12

-Located within the CNS that controls the contraction of a muscle or the secretion of a gland.

Question 13

Difference between Efferent and Afferent

Answer 13

• Afferent nerve carries information from sensory receptors in skin to the brain
• Efferent nerve carries information from the brain to neurons controlling leg muscles producing a response

Question 14

Define interneuron

Answer 14

-A cell that is located entirely within the CNS

Question 15

Define Optogenetic Methods

Answer 15

• Stimulate or inhibit particular types of neurons in particular brain regions
• capitalizes on photosensitive proteins in algae and bacteria
• When blue light strikes one of these proteins, ChR2 channel opens and rush of positively charged sodium and calcium ions depolarizes the membrane causing excitation.

Question 16

Define a Nerve

Answer 16

-several axons running together. Also referred to as “a track”

Question 17

Define Ganglia

Answer 17

-Local accumulation of nerve cell bodies

Question 18

Some studies used to analyze neural studies (4)

Answer 18

• Lesion studies
• Neural tracing
• Molecular + Histological techniques
• Genetic engineering used to show pathways in the nervous system

Question 19

Radio frequency lesion

Answer 19

• Alternating current with high frequency
• through tips of electrodes, heat kills cells.
• Clinically, used for head and neck pain (kills targeted and isolated nerves)

Question 20

Excitotoxic lesions

Answer 20

• Mostly Kainic acid-acid derivative in some seaweed
• Glutamate agonist at kainite receptor
• kills cell bodies but spares axons that are passing through
• Uncontrolled increase of Ca++ causes the cell to degenerate
• So we look at this and be like ok what does this part do?

Question 21

Anterograde neural tracing

Answer 21

• PHA-L is injected
• Animal is perfused brain fixed and sliced
• Use immunocytochemical techniques to make visible
• Taken up by dendrites and cell bodies and carried to the ends of axons
• Traces efferent axons

Question 22

Retrograde neural tracing

Answer 22

• Traces afferent axons
• circuits before a structure
• “Upstream” components of a circuit
• Taken up by terminal buttons and carried back to the cell bodies
• Fluorogold is the chemical,

Question 23

Pneumoencephalography

Answer 23

• abbreviated as PEG

- referred to as air study, infect air to see the inside of brain

Question 24

Cerebral angiogram

Answer 24

-useful to examine blockages or other abnormalities in blood vessels of head and neck.

Question 25

Event related potential recording in an awake state

Answer 25

- Comparing the response intensity recorded at each site provides a low resolution map of localized activity - nonevasive

Question 26

Electroencephalography (EEG)

Answer 26

- Electrodes are taped to the scalp in several locations; electrical activity reflects the sum of electrical events of populations of neurons - Comparison of signals from different locations can identify the origin of some waves - Response to momentary sensory stimulation-Event related potentials - non evasive

Question 27

Transcranial magnetic stimulation (TMS)

Answer 27

- Magnetic field based on current flow through a magnetic coil - Deliver a pulse of current to the surface of the cerebral cortex - Causing a brief disruption of electrical activity in that area - Clinical treatment for depression and other mood disorders - Non-evasive

Question 28

Functional MRI (fMRI)

Answer 28

-oxygenated hemoglobin has different magnetic resonance signal than oxygen depleted hemoglobin -Active brain cells need more O2 and thus blood flow increases. real time brain activity -Combined with EEG, one can see changing locations of brain activity during a task or cognitive process -

Question 29

Pharmacological MRI (phMRI)

Answer 29

Analyzes changes in brain function following drug administration, location and time course of drug action - brain penetrability parameters, or dose ranging information for novel therapeutic compounds - may be useful in predicating response of a patient by screening brain function

Question 30

Positron emission tomography (PET)

Answer 30

- maps distribution of a radioactively labeled substance that has been injected into an individual - think radioactivity - locate areas of brain (blood flow, glucose or O2 utilization) when person is performing certain tasks or cognitive problem solving - Resolution is less accurate but combined with CT or MRI

Question 31

Diffusion tensor imaging (DTI)

Answer 31

- Uses a modified MRI scanner - Reveals bundles of myelinated axons in the living human brain - H20 movement