2B - Neurohistology (2)

Question 1

cortex has 2 surfaces

Answer 1

1) . outer –> pial surface

2) . inter –> pia mater

Question 2

apical dendrites of pyramidal cells extend toward?

Answer 2

pial surface of brain

Question 3

T/F: Basilar dendrites come off at level of cell body

Answer 3

True

Question 4

predominant cell in cortex?

Answer 4

pyramidal

Question 5

Dendrites of pyramidal cells

Answer 5

• not smooth

- covered with thick layer of spines

Question 6

Purkinje Cells

Answer 6

• By Jan Purkyne

- Large cell found in cerebellum

Question 7

2 types of cortex

Answer 7

1) cerebral –> pyramidal cells

2) cerebellar –> Purkinjee cells

Question 8

How many layers within cerebellar cortex?

Answer 8

3

Question 9

T/F: There are more cerebellar granule cells than neurons

Answer 9

True

Question 10

Purkinjee cells have a massive dendritic tree, thinly compressed to sagittal plane. Means what?

Answer 10

There is a speicalized form of processing called parallel fibers.

Question 11

Cerebellar granule cells

Answer 11

• small
• round cel lbody
• 1 single axon that goes up to molecular layer
• dendrites smooth/spiny
• granule cell claw shape is where dendrites end

Question 12

Parallel fibers

Answer 12

• Parallel fibers represent 1 of 2 major inputs to purkinjee cells
• run back/forth through molecular layer (top) at right angles

Question 13

T/F: pigeon purkinjee cells are similar in mammals

Answer 13

true

Question 14

What is the predominant cell found in striatum?

Answer 14

medium spiny cells and multi-polar cells (many dendrites)

Question 15

Main source of input to striatum

Answer 15

Cerebral cortex projects heavily on striatum

Question 16

true/false: synapses located on heads of spines

Answer 16

true

Question 17

Inputs can terminate where

Answer 17

either spines or shafts

Question 18

Processing of info is diff on spines vs shafts

Answer 18

• due to passive spread of current through dendrite

- individual spine = single, little unit which integrates many inputs

Question 19

spines

Answer 19

• not static
• plastic
• individual spines will grow out of dendrite, at the same time, other spines that were there before
• continuosly produced and withdrawn
• greatly affected by inputs to cell

Question 20

where are synapses located?

Answer 20

head of spines

Question 21

MORE spine info

Answer 21

• spines at synapses are active

- spines that are active are stable through depolarization

Question 22

More spine info

Answer 22

• spines that dont receive external input are reabsorbed
• may change through learning, behavioral pathological conditions
• 1960, examine rats
• isolation or enriched environment
• more spines on dendrites of cortical pyramdial cells in enriched environment
• experience can affect structure of brain

Question 23

Another cell type is striatum

Answer 23

• large, aspiny cells

- in addition to medium size spiny cells

Question 24

Not all neurons are the same

Answer 24

• curly-cued dendrites –> inferior olivary nucleus
• 2 apical dendrites –> cerebellum
• starburst amacrine cell –> retina –> has no axon

Question 25

Classification of neurons through axon type

Answer 25

1) Anaxonal (amacrine) 2) Golgi Type 1 3) Golgi Type 1

Question 26

Golgi Type 1

Answer 26

- projection neurons - from 1 part of the brain to another part of nervous system - cortical pydramical cells to cell body in cortex, axons terminate far away to spinal cord - long axons

Question 27

Golgi Type 1

Answer 27

- projection neurons - from 1 part of the brain to another part of nervous system - cortical pydramical cells to cell body in cortex, axons terminate far away to spinal cord - long axons - transfer of information

Question 28

Golgi Type 2

Answer 28

- local circuit neurons - interneurons - short axons - local processinng