Neurosensory Systems

Question 1

Nuerological disorders are characterized by

Answer 1

physical manifestations

Question 2

Psychiatric disorders are more:

Answer 2

Internal disorders so disruption of mental processes

Question 3

Neuron can repair if damage is slight by:

Answer 3

regrow damaged dendrites or axons by “sprouting” and regrowth

Question 4

Neurons are:

Answer 4

Post-mitotic, so if it dies, it cannot be replaced

CNS disorders

Question 5

Neurons that can regenerate are:

Answer 5

olfactory neurons and hippocampal dentate gyrus neurons

Question 6

Astrocytes

Answer 6

Can be regenerated
During neuronal degenration they become reactive
Help clear cellular debris and seal off damaged regions through glial scar
Participate in neuroinflammation by releasing cytokines and related agents

Question 7

Microglia

Answer 7

Respond to neurodegeneration
Secrete cytokines and chemokines to clear debris
Can be regenrated

Question 8

Oligodendrocytes

Answer 8

When killed or damage = demyelination of axons impairing neuronal signaling

Question 9

Test abnormal function through

Answer 9

PET/SPECT

Question 10

See abnormal CNS structure through

Answer 10

CAT scans or MRI

Question 11

Define elctrophysiology

Answer 11

Elecrodes are inserted into the brain to monitor the electrical activity of the regions
Can record activity or stimulate

Question 12

Define electroencephalography (EEG)

Answer 12

Electrodes placed on the surface of the scalp to record electrical activity occurring in the brain

Question 13

Brain relaxes =

Answer 13

Frequency decreases and amplitude increases

Question 14

Define CT Scanning

Answer 14

Xrays
Attenuated varying degrees in a manner dependent on the tissue density
Data is converted to tissue density
STRUCTURAL ANALYSIS

Question 15

Define Positron Emission Tomography (PET)

Answer 15

Detectors -> exact location of the positron annihilation and the location of the molecule of interest
BLOOD FLOW
Label an agent with PE isotopes and inject so you can measure the concentration of receptors at various regions in the brain

Question 16

Increased neuronal activity –>

Answer 16

Local increase in blood flow supply the metabolic demands of those neurons

Question 17

PET is used for

Answer 17

dementia and PK disease (dopamine transporters in the striatum)

Question 18

Define Magnetic Resonance Imaging (MRI)

Answer 18

WATER CONTENT

Question 19

Define Functional MRI (fMRI)

Answer 19

Monitors time-dependent blood flow to various region sin the brain and thus allows one to ID neuronally active regions

Question 20

Define functional hyperemia

Answer 20

Local flow around an active neuron is altered to meet local metabolic demands

Question 21

Signal is greater=

Answer 21

Parallel bc water molecules line up in the direction of the axons

Question 22

How much O2 does the brain consume?

Answer 22

20%

Question 23

Brain + disruption of blood flow

Answer 23

Sensitive and it only stakes a short disruption to impair neuronal function of ultimately lead to celld eath

Question 24

Astrocytes + Backup

Answer 24

Make small amounts of glycogen as bacjup energy

Question 25

Define selective vulnerability

Answer 25

The pattern of neurologic deficits that arise causing a specific disease

Question 26

Define gliosis

Answer 26

Hypertrophy or multiplication of glial cells

Question 27

Define Reactive gliosis

Answer 27

Normal response to CNS injury

Question 28

What cells are particularly sensitive to glutamate?

Answer 28

Pyramidal neurons in cerebral cortex

Question 29

Glutamate + toxicity

Answer 29

Glutamate binding to NMDA receptor on neurons which allows influx of calcium which can trigger apoptotic pathways

Question 30

Can some cells prevent toxicity?

Answer 30

Yes some have proteins like calbindin which bind and buffer the calcium

Question 31

Glutamate + Cell death

Answer 31

Glutamate opens AMPA channels –> too much sodium which increase pressure, influx of water, swelling and bursting
This induces neuroinflammation and activation of reactive astrocytes and microglia

Question 32

ROS production

Answer 32

Astrocytes and microglia can produce ROS to breakdown tissues and repair