lecture 1 macroglia

Question 1

Structural Diversity Can be classified _____ emanating from the cell body

Answer 1

by shape or the number of extensions

Question 2

Bipolar (interneuron)

Answer 2

Have one axon and one dendrite. Found in the retina, ear, olfactory lobes

Question 3

Unipolar neuron:( sensory neuron)

Answer 3

Have one process serving both the axon and dendrite. Found in ganglia

Question 4

Multipolar neuron(motor neuron)

Answer 4

Have three or more processes (one axon and at least two dendrites). Mostly found in the CNS

Question 5

Interneurons maintain physiological activity levels in the brain, by

Answer 5

preventing runaway excitation in recurrent cortical networks Usually inhibitory!

Question 6

Principal Cells are

Answer 6

axonal projections outside of the brain area where the cell bodies and dendrites are located. Local information processing and storage. Mostly Excitatory

Question 7

Diversity within the Neuronal Population

structural

Answer 7

Shape

Organization

Question 8

Diversity within the Neuronal Population (Functional)

Answer 8

Neurotransmitter
Peptides
Electrical Activity
Organization

Question 9

how cells signals: Cellular computational capacity can be dictated by

Answer 9

dendritic geometry.

Question 10

Macroglia: generic term

Answer 10

cells in the NS that are neither neurons or microglia

Question 11

examples of macrogila

Answer 11

Schwann Cells and Oligodendrocytes Myelinating cells of the Nervous System

Question 12

mylin acts like an insulator along the axon, allowing transmembrane currents at specific locations called

Answer 12

the nodes of Ranvier

Question 13

Myelin is actually a specialized membrane that

Answer 13

surrounds axons, and facilitates RAPID nerve impulse conduction

Question 14

Myelin is White matter of and contains

Answer 14

the brain and spinal cord, lipids and proteins

Question 15

what 4 main ways is Myelin important for

Answer 15

insulate, accelerate,preserve energy, axonal maintenance

Question 16

The process of _______ is one of the last events in the formation of the nervous system

Answer 16

myelination

Question 17

In humans, myelination begins in the

Answer 17

third trimester, and continues to early adulthood

Question 18

_____ fibers and _____ fiberes are the first to be myelinated

Answer 18

motor and large

Question 19

Myelin is produced by ______ in the peripheral nervous system

Answer 19

Schwann cells

Question 20

Myelin is produced by ______ in the central nervous system

Answer 20

oligodendrocytes

Question 21

what dictates the amount wraps of mylins around a fibere

Answer 21

size of fibres and activity (to a pt)

Question 22

g ratio

Answer 22

is the diameter of axon to total diameter of when its mylinated 0.6

Question 23

proteins in myelin are different in

Answer 23

PNS and CNS and between species

Question 24

saltatory conduction: In myelinated axons, channels are found only a the nodes of Ranvier. The signal

Answer 24

‘skips’ down the axons

Question 25

continuous or contiguous conduction: In unmyelinated axons,______ event is necessary. There is___depolarization

Answer 25

no further triggering, passive

Question 26

The presence of myelin _______ that is needed to restore the proper ionic gradients.

Answer 26

reduces energy consumption

Question 27

Schwann cells secrete molecules that

Answer 27

foster axonal health and regeneration after injury

Question 28

non-Myelinating Schwann Cells are called

Answer 28

Remaks

Question 29

Multiple Schwann cells myelinate _____ but one schwann cell is _ wrap

Answer 29

same axon, 1

Question 30

After injury, the Schwann cells____ and ____ producing agents that stimulate nerve repair.

Answer 30

de-differentiate and proliferate,

Question 31

How do Schwann cells differentiate and produce myelin?

Answer 31

it requires axonal contact, and likely derives signals from the axon itself (neuron-schwann cell interactions

Question 32

Neuregulin-1 are expressed on

Answer 32

axonal surface

Question 33

________ regulate thickness of myelination produced by Schwann cells

Answer 33

Neuregulin (NRG) levels

Question 34

NRG1 on the axon promotes Schwann cell ___&____

Answer 34

differentiation and proliferation.

Question 35

Oligodendrocytes Myelinate segments of ___ axons

Answer 35

MANY up to 50

Question 36

After injury, the Oligodendrocytes dedifferentiate and proliferate, producing agents that

Answer 36

inhibit nerve repair eg., NOGO)

Question 37

Oligodendrocytes are ______ They can also differentiate in culture without neurons, in contrast to Schwann cells.

Answer 37

complex cells.

Question 38

Oligodendrocyte development and differentiation

Answer 38

Early progenitors are simple and bipolar.

Differentiation in vitro is predictable and controllable

Question 39

3 main take aways about Schwann Cells

Answer 39

1) Myelinate 1 axon segment because whole cells is in contact with axon
2) Protein composition of PNS myelin is different
3) Can promote neuronal repair after injury

Question 40

3 main take aways about Oligodendrocytes

Answer 40

1) Myelinate many axons segments, because of the many processes it extends to contact axons
2) CNS myelin contains some unique proteins
3) Inhibits neuronal regeneration after injury

Question 41

Myelination: Programmed or Plastic?

Answer 41

both

Question 42

Multiple Sclerosis (CNS) and Guillain Barre (PNS)

Answer 42

Demyelinating disorders of auto-immune origin

Question 43

Guillain Barre (PNS)

Answer 43

Weakness/tingling/numbness , can affect diaphram and breathing, people usually recover