Topic 4 Action pt 2 Flashcards
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 ________
cerebellum
White matter of cerebellum
arbor vitae
gray matter of cerebellum
folia
which ventricle is seen adjacent to the cerebellum?
4th ventricle
How many granule cells are there in the cerebellum ?
50 billion (3/4 of all the neurons in the brain)
cerebellum
- 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
less feedback leads to ______ error
less feedback leads to greater error
What does Fitt’s Law describe?
Fitt’s Law describes the speed/accuracy tradeoff in pointing motions
In Fitt’s Law, what does a and b represent?
a = initiation time for limb b = relative pace of limb
If you want to reach a distance D in less time, what must happen to W?
If you want to reach a distance (D) in less time, target must get wider (W)
If you want to reach a greater distance (D) in the same amount of time, what must happen to W?
If you want to reach a greater distance (D) in the same amount of time, target must get wider (W)
Axons from M1 synapse directly onto
Axons from M1 synapse directly onto lower motor neurons
Local circuit neuron
interneuron
Is inhibition of a reflex possible?
yes, as long as we plan to inhibit reflex before the reflex happens
What can local circuits in spinal cord do? (3 points)
- can control complex movement
- can respond to environmental changes
- do not require higher level inputs
Where do lower motor neurons synapse?
directly on the mm fibers
what causes mm fibers to contract?
release of neurotransmitters cause mm fibers to contract. Once contracted, the mm spindles send signals back to the spinal cord via dorsal root ganglia
What happens with finer motor control?
for limbs with finer motor control, each motor neuron innervates fewer mm fibers
intracellular electrical recording ( 3 points)
- used mostly in vitro
- voltage clamp / current clamp
- patch clamp
extracellular electrical recording (3 points)
- single unit recording
- multi- electrode recording
- field potentials
in vitro
used to describe work that’s performed outside of a living organism
in vivo
used to describe work that’s performed within an entire living organism
what do we use to research awake animals?
in vivo multi-electrode recording (extracellular electrical recording) on awake animals
when do we use intracellular electrical recordings?
used in in vitro (performed outside of a living organism)
What is the resulting data of using in vivo multi-electrode recordings on awake animals? What challenges do we face ?
- 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
What are the areas of potential concerns in animal experimentation? (4 points)
- care and housing
- surgical implantation of electrodes
- training and performance (food/water deprivation and physical coercion and restraint)
- killing and sacrifice after experiment
what are larger things to consider in animal experimentation?
- pain and suffering
- lack of consent
- killing living creatures
- interspecies differences
- benefit to humanity
- necessity for knowledge
from most superficial to deepest, what are the cell layers of the cerebellum?
Molecular layer
Purkinje Layer
Granular Layer
the primary motor cortex is to the _____ model and the cerebellum is to the _____ model
the primary motor cortex is to the inverse model and the cerebellum is to the forward model
the smaller the target, the _____ the accuracy, the _____ the time
the smaller the target, the greater the accuracy, the greater the time
what does “a” represent in the Fitt’s Law equation?
“a” represents initiation time
what does “b” represent in the Fitt’s Law equation?
“b” represents relative pace of limb
does intracellular recording occur most in vitro or in vivo?
intracellular = mostly in vitro
which extracellular recording (single-unit recording or multi-electrode recording) is used in awake animals?
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
how does the “in vivo multi-electrode recording in awake animal” get recorded and converted to data on a screen? (4 points)
- ) commutator
- ) amplifier / filter
- ) analog to digital converter and data storage
- ) spike clustering
what “device” interprets the signals of the microelectrodes and then sends it to the robotic arm?
brain machine interface
