Cells of the nervous system

Question 1

newly discovered layer in the meninges

Answer 1

The SLYM

Question 2

The SLYM

Answer 2

Subarachnoid Lympatic-like membrane, very thin layer, helps control follow of CSF and contains immune cells to fight infections

Question 3

The blood barrier

Answer 3

Allows only certain substance to reach the brain, formed of tightly packed endothelial cells that line blood vessels and capillaries as well as the “feet” of astrocytes that surround capillaries, keep out pathogens, toxins, it allows oxygen , glucose, and a selection of other necessary compounds and proteins to pass through, psychoactive drugs must be able to cross the BBB

Question 4

What is the nervous system made o

Answer 4

Glial cells and neurons

Question 5

Multiple sclerosis

Answer 5

Characterized by numbness or weakness in limbs, difficulty walking, lack of coordination, and other symptoms, it is caused by the immune system attacking the myelin sheath around axons in the brain and spinal cord, it slows or stops transmission of signals by those neurons

Question 6

Glia

Answer 6

Vital, in the brain, just as numerous as
neurons
* More than just “glue”: support,
maintain, repair, insulate neurons,
and regulate neural activity.
- Problems with glia involved in many
neurological disorders

Question 7

Astrocytes

Answer 7

Regulate chemical content of extracellular fluid, regulate synaptic transmission: they suck up neurotransmitter from the synaptic cleft, they also respond electrochemically to neurotransmitters, they support the blood-brain barrier, regular the blood flow

Question 8

Why are axons wrapped in myelin

Answer 8

It provides insulation for better electrical conductance, NOT all neurons are myelinated tho

Question 9

Oligodendrocytes

Answer 9

in the brain and spinal cord

Question 10

Schwann cells

Answer 10

in the peripheral nerves

Question 11

Microglia

Answer 11

Borne in bone marrow, enter the brain along with blood and immune cells, respond to damage, clean up dead cells, trigger inflammation, remodel synapses

Question 12

Ependymal cells

Answer 12

line the central canal of the spinal cord and the ventricle of the brain, help create cerebra-spinal fluid an keep it moving with cilia

Question 13

Radial glia

Answer 13

From a “scaffold” in the developing cerebal cortex, baby neurons migrate to their correct positions in the cortical layers by crawling of “migrating” along the radial glia fiber

Question 14

WHAT IS A NEURON (REVIEW FROM PREVIOUS DECK)

Answer 14

A specific type of cell that in the nervous tissue of almost all animals.
* Its key function is to receive and process information and send signals to other
cells.
‣Neurons do computations
* When a neuron “fires,” or produces an “action potential,” an electrical signal
travels down its length.
* It then releases neurotransmitters onto other cells.
* Special features: shape, membrane channels & receptors, electrical charge,
action potentials & neurotransmitter release.

Question 15

The neuron doctrine

Answer 15

Cell theory of biology: animal tissues are made of discrete cells, which are the fundamental building block of life

Question 16

Gologis reticular theory

Answer 16

the nervous system is a continuous network, the the blood vessels

Question 17

Cajal’s neuron doctrine

Answer 17

neurons are discrete cells and there is a cleft at the synapse each neuron is a ‘computational unit’

Question 18

Outer membrane of a neuron

Answer 18

5 nm thick, studded with receptors and channels that differ in axon vs dendrites and differ across neuron types

Question 19

Nucleus of a neuron

Answer 19

It is in the soma, transcribing genes and exporting mRNA

Question 20

Rough endoplasmic reticulum

Answer 20

makes proteins for outer membrane, processed and shipped by the Golgi body

Question 21

Mitochondria

Answer 21

Makes energy for all activity in the neuron

Question 22

Cytoskeleton

Answer 22

microtubules, microfilaments, neurofilaments, continually shape the cell and transport molecules

Question 23

The axon

Answer 23

When the cell receives enough positive input, it “fires” and send an electrical signal down it axon to other cells, <1mm to 1m long, variable thickness (thicker=faster), no rough ER or ribosomes, special proteins embedded in the membrane (channels, receptors and ion pumps), often wrapped in myelin, branches=axon collaterals

Question 24

Axon terminal

Answer 24

aka “bouton”, is a swelling with no microtubules, many synaptic vesicles containing neurotransmitters, many mitochondria to meet a high energy demand, many protein molecules in the membrane, sometimes multiple boutons on the little branches (the terminal arbor); sometimes the axon continue past this point

Question 25

Synapse

Answer 25

the point of contact between a presynaptic terminal of one cell and a postsynaptic dendrite of another cell, Cleft between them

Question 26

Synaptic transmission

Answer 26

Presynaptic electrical signal which release of neurotransmitters then leading to postsynaptic electrical signal

Question 27

Dendrites

Answer 27

Many little branches that form a tree, or arbor, membrane at synapses contains receptors for specific neurotransmitters, some spines which develop fluidly and isolate chemical reactions from the rest of the cell, lots of mitochondria and cytoskeletal structures, sometimes contain ribosomes for protein synthesis in reaction to synaptic transmission

Question 28

Cytoskeleton

Answer 28

Microtubules, neurofilaments, microfilaments

Question 29

Microtubulues

Answer 29

run lengthwise down axon and dendrites, microtuble-associate Proteins (MAPS) hold the structure together; One MAP, tau, is abnormal in Alzheimers disease, associate with distorted and dying neurons in the cerebral cortex, and severe dementia

Question 30

Neurofilaments

Answer 30

provide strong structure

Question 31

Microfilaments

Answer 31

made of actin, change cell shape, also in muscle cells

Question 32

Axoplasmic transport

Answer 32

Stuff made in the soma must be transported down the axon, microtubules are the railroad tracks

Question 33

Anterograde transport

Answer 33

Kinesin molecules use ATP to walk down the track, from soma to axon terminal, carrying vesicles full of proteins

Question 34

Retrograde transport

Answer 34

Dynein molecules go the other day (1 meter a day)

Question 35

Primary sensory neurons

Answer 35

activated directly by external energy of contact (light in the eye, touch of the skin)

Question 36

Motor neurons

Answer 36

synapse onto muscle cells to make them contract

Question 37

Interneurons (the most common)

Answer 37

form connections only with other neurons

Question 38

Projection neurons

Answer 38

very long axons, like pyramidal cells

Question 39

Local circuit neurons

Answer 39

short axons, like stellate cells

Question 40

Dendrites are ____ or not

Answer 40

spiny

Question 41

The axon is _____ or not

Answer 41

mylenated

Question 42

Electron microscopy

Answer 42

electron bean rather than light to form images, much higher resolution to see tiny details

Question 43

Fluorescence

Answer 43

When a substance absorbs light and then releases that energy as light of another wavelength

Question 44

Laser microscopy

Answer 44

Scan a tissue sample with laster beams of a particular wavelength, often elicit fluorescence in tagged molecules

Question 45

Retrograde tracing

Answer 45

• Some materials enter axon terminals and hitch a ride with Dynein
  back up to the soma
• Examples: horseradish peroxidase (HRP), herpes & rabies viruses
• Scientists attach a fluorescent molecule to that material
• This retrograde tracing reveals the bodies of cells that synapse into
  a target region

Question 46

Genetic engineering

Answer 46

The genomes of many organisms, including humans, have been fully sequenced.
* Scientists can create organisms with specific genes modified, deleted, or prevented from expression.
* They can copy a gene from one organism (“transgene”) and insert it into a particular place in the DNA of another
organism, such that it will only be expressed in certain cell types, in certain conditions.

Question 47

GFP

Answer 47

green florescent protein