Topic 4 Action pt 2

Question 1

A person has problems with pattern movements as well as range of movements (eg touching their head then touching their nose). This person likely has damage to their ________

Answer 1

cerebellum

Question 2

White matter of cerebellum

Answer 2

arbor vitae

Question 3

gray matter of cerebellum

Answer 3

folia

Question 4

which ventricle is seen adjacent to the cerebellum?

Answer 4

4th ventricle

Question 5

How many granule cells are there in the cerebellum ?

Answer 5

50 billion (3/4 of all the neurons in the brain)

Question 6

cerebellum

Answer 6

• uses forward model to predict results of motor command
• uses difference between actual results and predicted results for online error correction and motor learning
• feedback control

Question 7

less feedback leads to ______ error

Answer 7

less feedback leads to greater error

Question 8

What does Fitt’s Law describe?

Answer 8

Fitt’s Law describes the speed/accuracy tradeoff in pointing motions

Question 9

In Fitt’s Law, what does a and b represent?

Answer 9

a = initiation time for limb 
b = relative pace of limb

Question 10

If you want to reach a distance D in less time, what must happen to W?

Answer 10

If you want to reach a distance (D) in less time, target must get wider (W)

Question 11

If you want to reach a greater distance (D) in the same amount of time, what must happen to W?

Answer 11

If you want to reach a greater distance (D) in the same amount of time, target must get wider (W)

Question 12

Axons from M1 synapse directly onto

Answer 12

Axons from M1 synapse directly onto lower motor neurons

Question 13

Local circuit neuron

Answer 13

interneuron

Question 14

Is inhibition of a reflex possible?

Answer 14

yes, as long as we plan to inhibit reflex before the reflex happens

Question 15

What can local circuits in spinal cord do? (3 points)

Answer 15

• can control complex movement
• can respond to environmental changes
• do not require higher level inputs

Question 16

Where do lower motor neurons synapse?

Answer 16

directly on the mm fibers

Question 17

what causes mm fibers to contract?

Answer 17

release of neurotransmitters cause mm fibers to contract. Once contracted, the mm spindles send signals back to the spinal cord via dorsal root ganglia

Question 18

What happens with finer motor control?

Answer 18

for limbs with finer motor control, each motor neuron innervates fewer mm fibers

Question 19

intracellular electrical recording ( 3 points)

Answer 19

• used mostly in vitro
• voltage clamp / current clamp
• patch clamp

Question 20

extracellular electrical recording (3 points)

Answer 20

• single unit recording
• multi- electrode recording
• field potentials

Question 21

in vitro

Answer 21

used to describe work that’s performed outside of a living organism

Question 22

in vivo

Answer 22

used to describe work that’s performed within an entire living organism

Question 23

what do we use to research awake animals?

Answer 23

in vivo multi-electrode recording (extracellular electrical recording) on awake animals

Question 24

when do we use intracellular electrical recordings?

Answer 24

used in in vitro (performed outside of a living organism)

Question 25

What is the resulting data of using in vivo multi-electrode recordings on awake animals? What challenges do we face ?

Answer 25

• individual actions in individual neurons (great spatial and temporal resolution)
• challenges include finding the “right neurons” and finding out how these neurons relate to the billions of other neurons

Question 26

What are the areas of potential concerns in animal experimentation? (4 points)

Answer 26

• care and housing
• surgical implantation of electrodes
• training and performance (food/water deprivation and physical coercion and restraint)
• killing and sacrifice after experiment

Question 27

what are larger things to consider in animal experimentation?

Answer 27

• pain and suffering
• lack of consent
• killing living creatures
• interspecies differences
• benefit to humanity
• necessity for knowledge

Question 28

from most superficial to deepest, what are the cell layers of the cerebellum?

Answer 28

Molecular layer
Purkinje Layer
Granular Layer

Question 29

the primary motor cortex is to the _____ model and the cerebellum is to the _____ model

Answer 29

the primary motor cortex is to the inverse model and the cerebellum is to the forward model

Question 30

the smaller the target, the _____ the accuracy, the _____ the time

Answer 30

the smaller the target, the greater the accuracy, the greater the time

Question 31

what does “a” represent in the Fitt’s Law equation?

Answer 31

“a” represents initiation time

Question 32

what does “b” represent in the Fitt’s Law equation?

Answer 32

“b” represents relative pace of limb

Question 33

does intracellular recording occur most in vitro or in vivo?

Answer 33

intracellular = mostly in vitro

Question 34

which extracellular recording (single-unit recording or multi-electrode recording) is used in awake animals?

Answer 34

we use extracellular (multi-electrode) recording in awake animals, allowing us to see individual action potentials in individual neurons with better spatial and temporal resolution

Question 35

how does the “in vivo multi-electrode recording in awake animal” get recorded and converted to data on a screen? (4 points)

Answer 35

1. ) commutator
2. ) amplifier / filter
3. ) analog to digital converter and data storage
4. ) spike clustering

Question 36

what “device” interprets the signals of the microelectrodes and then sends it to the robotic arm?

Answer 36

brain machine interface