A. Neurocytology 1

Front 1

2 main features of neuron:

Back 1

1. Dynamic polarization
2. Connectional specificity

Front 2

2 parts to neuron soma:

Back 2

-Nucleus/cytoplasmic organelles
-Axon hillock

Front 3

What is in the cytoplasm/nucleus??

Back 3

-Euchromatin
-Nissl substance
-Neurofilament

Front 4

What type of nucleus do glial cells have?

Back 4

Heterochromatin

Front 5

What is nissl substance?

Back 5

Stacked RER that stains with nissl stain - indicates active protein synthesis.

Front 6

What is not in the axon hillock?

Back 6

Nissl substance

Front 7

What type of neurons have basal dendrites?

Back 7

Pyramidal

Front 8

2 Types of dendrites:

Back 8

-Apical - extends away from axon
-Basal - off the sides of soma

Front 9

Characteristics of the Axon cytoplasm:

Back 9

-No Ribosomes
-No RER

Front 10

What occurs at the initial segment of the Axon

Back 10

Initiation of APs

Front 11

What are varicosities?

Back 11

Presynaptic swellings at the terminals of axons that pass impulse to OTHER NEURONS - not the target.

Front 12

Unipolar or pseudounipolar neurons are usually:

Back 12

Sensory ganglion neurons
-invertebrates

Front 13

Bipolar neurons are usually:

Back 13

Retina or olfactory

Front 14

Multipolar neurons are:
(3 examples)

Back 14

The most common ones...
-Pyramidal neurons in cerebral cortex
-Purkinje cells in cerebellum
-Motor neurons in SC

Front 15

Type of axons in:
-Golgi type I neurons
-Golgi type II neurons

Back 15

I: long/project

II: short/connect

Front 16

How many can a neuron have?
-dendrites
-axons

Back 16

one or many dendrites
only one axon

Front 17

Organelles that dendrites can have:

Back 17

All except golgi

Front 18

Organelles that axons can have

Back 18

No Golgi, RER, or RIBOSOMES
-NO PROTEIN PRODUCTION HAPPENS IN THE AXON

Front 19

Shape of Dendrites

Back 19

taper w/ spines

Front 20

Shape of axons

Back 20

cylinder with branches

Front 21

What is myelinated?

Back 21

Axons not dendrites

Front 22

What type of neurons don't have dendrites?

Back 22

Unipolar

Front 23

What uses the most energy; axons or dendrites?

Back 23

Dendrites

Front 24

Energy use in axons:

Back 24

LOW energy consumption

Front 25

3 Main features of Neuron cell membranes:

Back 25

-Maintains resting Em
-Electrically excitable
-Has ion pumps/channels

Front 26

What color is nissl substance and where is it found?

Back 26

Basophilic - anywhere EXCEPT axon hillock or axon.

Front 27

Is nissl substance seen in dendrites?

Back 27

yes

Front 28

3 constituents of the Neuron cytoskeleton:

Back 28

1. Actin microfilaments
2. Neurofilaments (intermediate)
3. Microtubules

Front 29

Microfilament features
-size
made of what
-Where in neurons

Back 29

5-8 nm diameter - made of 2 Actin strands braided together (G->F)
-associated w/ membrane

Front 30

Neurofilament features
-what are they
-size
-where in neuron

Back 30

Neuron-specific intermediate filaments
10 nm in diameter
-in soma, dendrites, & axons.

Front 31

What important disease is associated with intermediate neurofilaments?

Back 31

Alzheimer's disease - neurofibrillary tangles

Front 32

What are Neurofibrils?

Back 32

Aggregates of neurofilaments seen at light microscope level

Front 33

Microtubules
-diameter
-components
-function

Back 33

25 nm diameter
-Tubulin chains
-Function in axonal/dendritic transport of stuff

Front 34

Function of microtubules

Back 34

GTPase for transport

Front 35

What are MAPs

Back 35

Microtubule associated proteins

Front 36

3 High MW MAPs:

Back 36

-Kinesin
-Dynein
-MAP2

Front 37

Low MW MAP:

Back 37

Tau

Front 38

What is Kinesin?

Back 38

Motor/ATPase that propels organelles along microtubules.

Front 39

What stabilizes microtubules?

Back 39

Taxol

Front 40

What depolymerizes Microtubules?

Back 40

Colchicine

Front 41

What is the function of lysosomes in neurons?

Back 41

Membrane turnover

Front 42

What is lipofuscin?

Back 42

Indigestible lysosome material - pigented inclusions associated with aging and dementia

Front 43

Why do neurons need special transport mechanisms?

Back 43

B/c no protein transport in axons, and junk needs to be returned from axons too.

Front 44

3 types of neuron transport:

Back 44

1. Slow axonal - only antero
2/3. Fast axonal - antero/retro

Front 45

Stuff transported by SLOW axonal transport:

Back 45

-Microtubules, neurofilaments, soluble proteins (slower)
-Proteins, metabolic enzymes, Calmodulin (faster)

Front 46

Major difference between slow and fast anterograde transport:

Back 46

Fast needs ENERGY

Front 47

Main protein needed for fast anterotransport:

Back 47

KINESIN -> a MAP that is an ATPase to motor junk along

Front 48

What inhibits kinesin?

Back 48

Colchicine

Front 49

What gets transported by fast anterotransport?

Back 49

-Subcellular organelles
-Mitochondria
-Synaptic vesicle precursors
-Smooth ER vesicles/contents

Front 50

Major protein for fast RETROgrade transport:

Back 50

Dynein

Front 51

Stuff that gets transported by Dynein/retrotransport:

Back 51

-Stuff that's dying
-Stuff for being reused
-Stuff endocytosed at nerve terminal

Front 52

What's a bad thing about retrograde transport?

Back 52

Viruses and toxins take advantage of it

Front 53

What is HRP

Back 53

Horseradish peroxidase - a retrograde tracer to see where the cell body is of a long axon

Front 54

Towards which end of the MT and neuron does dynein go?

Back 54

Towards the neg end of MT at the neuron's cell body.

Front 55

Towards which end of the MT and neuron does kinesin go?

Back 55

Towards the pos end of MT at the neuron's axon terminal.