Refinement of Synapses and Plasticity Over the Lifespan Flashcards
True or False:
The synaptic connections are essential for brain function
True
Does plasticity occur throughout the lifespan
Yes, it weakens as we age
What happens once an axon tip reaches its destination
Rudimentary synapses start to form
Does migration lead to wiring that is perfect
No it is only approximate
How is detailed tuning of neural connections occur (2)
- Eliminating the extra links
2. Strengthening functional synapses based on neural activity
True or False:
During development there is constant rearrangement of synaptic connections
True
What is the purpose of refining/pruning our synaptic connections
It gives us specificity
What is the somatotopy of our brain due to (hamonculus)
Refinement of synapses due to relative sensory and motor experiences
True or False:
Any loss of motor or sensory input will result in changes to the somatotopy over time
True
What are the 2 important steps of brain wiring
- Establishing correct pathways and targets
2. Fine tuning based on experience
What is synaptic plasticity
The variability in strength of a signal transmitted through a synapse
True or False:
Once a neuron is placed is overproduces synapses in an orderly manner
False
When does the majority of the cortex develop
The first 2 years of life
What is older the brainstem or cortex
Brainstem
Where are neurons initially produced
Along the central canal in the neural tube
After the neurons are produced around the central canal where do they migrate to
Their final destination in the brain
Once the neurons reach their destination in the brain what do they do
Collect together to form each of the various brain structures
How many synapses are there per cortical neuron
15000
How many synapses are formed per second in the first 2 years
1.8 million per second
How much does the cerebral cortex thicken in the first year
It triples
True or False:
The quantity of information cannot be genetically micromanaged by chemical environments alone
True, experience plays a huge role
What is experience expectant
Common early experiences that provide essential catalysts for normal brain development
What is an example of experience expectant
Early visual stimulation, hearing, language, and coordinating vision and movement
True or False:
The developing brain does not require these typical experiences, that are unique to each species, and relies on them as a component of its growth
False, It is required
What is experience dependent
Idiosyncratic/individual experience that fosters new brain growth and refines existing brain structuress
What is an example of experience dependent
Reading, golf, singing, music, vocab
Who determined how plasticity occurred
Hebb
What did Hebb say about plasticity
Neurons that fire together wire together, but neurons that fire out of sync lose their link
Example of Hebb’s plasticity
If you show a kid a ball and say the word ball both synapses will be strengthened eventually leading to increased strength of synapse that allows us to make a mental image of the ball. After awhile you can say ball and the kid will get a mental image of a ball
True or False:
Synapses are vacated when they are not strengthened
True
What is a sensitive period
Anatomy and physiology are especially sensitive to modulation of the experience
Does a sensitive period occur rapidly of gradually
Gradually
What is a critical period
Period of maximal sensitivity in which appropriate stimulation is essential for the normal development of a pathway or set of connections
Does a critical period occur rapidly or gradually
Rapidly
Can development beyond the critical period happen
Nope
What is a critical period associated with
A lot of synapse formation or proliferation of cells
Where is the right visual field represented on in the retina
The left hemiretina
Where do the two primary visual cortices share information with each other
The splenium of the posterior corpus callosum
True or False:
Ocular dominance is time dependent
True
What are ocular dominance columns
Stripes of neurons in the primary visual cortex of some mammals
Do the ocular dominance columns respond to both eyes or only one eye
One eye only
True or False:
The ocular dominance columns span multiple cortical layers
True
What is monocular deprivation
Depriving one eye from recieveing sensory input
What does monocular deprivation causes (2)
- Columns to degrade
- Non-deprived eye forms synapses with the cortical cells that would have been occupied by those representing input from the deficient eye
Prenatally what provides the feedback to establish which neural circuits are the right ones to strengthen
Spontaneous activity and input
Prenatally what controls the motor control of the fetus
The midbrain
Why is the midbrain in charge of motor control of the fetus
The cortex is not developed
How are the motor neural circuits strengthened prenatally
The fetus moves their limbs
True or False:
Research indicates that newborns preferentially recognize the sounds of their native language over others
True
How are the auditory neural circuits strengthened
Speech signals reaching the womb
How are visual neural circuits strengthened
Systematic moving patterns of activity of neighboring retinal ganglion cells are spontaneously generated
What do the retinal ganglion cells firing do
Tells the thalamus to send input to the visual cortex producing bursts of color
What are some circumstances that may alter the normal somatotopy (4)
Stroke, hypoxia, toxins, loss of limb
True or False:
Any loss of input or output can affect the plasticity of synapses and representation of the affected area in the brain
True
What are 4 principles that can effect plasticity
- Intensive motor skills repetition
- Enriched physical and social environments
- Aerobic exercise
- Constraint induced movement therapy
