Problem 2 Flashcards
What does Hebb’s postulate state?
Synaptic terminals are strengthened by correlated activity during development, whereas those that receive uncorrelated activity will weaken
What happens if a young child is not exposed to appropriate stimuli during critical periods?
The skill is not developed correctly and it is nearly impossible to remedy after.
What are oscillations and retinal waves?
Oscillations are waves below the threshold for an action potential that occurs prior to experience driven activity.
Retinal waves are waves of activity in the retina long before birth that leads to modest competitive interaction
Why is the visual system best for studying critical periods?
The orginization of the visual pathways provide ideal opportunities to evaluate how experience influences ongoing function and connections.
What is ocular dominance?
Ocular dominance refers to one eye having a stronger connection to the cells in layer 4 than the other eye
What is the consequence of visual deprivation in kittens? (One and both eyes)
One eye: the ocular dominance shift to the undeprived eyes
Both eyes: the distribution of ocular dominance does not shift
What is strabismus and what effect does it have?
Strabismus is the failure of an ocular muscle causing double vision. Because the visual representations of both eyes no longer fall on the same area of the retina, the cells in all layers are driven exclusively by one eye.
Which excitatory neurotransmitter and which secondmessenger play important roles in critical periods?
Glutamate and calcium
When is the critical period for language?
0-12 years
Hoe do gray matter and white matter volume change over time?
First an increase in gray matter, then a decrease during adolescence and an increase in white matter
Which are the three types of neuronal recovery?
- Peripheral nerve generation
- Restoration of damaged central nerve cells
- Genesis of new neurons
Describe the role of Schwann cells in regeniration of a peripheral nerve?
When a peripheral axon is severed, the dead part is cleared by macrophages. The axon then becomes a growth cone which interacts with adjacent Schwann cells. The Schwann cells secrete neurotrophins which stimulate the regrowth.
What are the major reasons for the differences in recovery between PNS and CNS?
Glial scarring and the inflammatory response in CNS inhibit growth
What are 3 types of damage to the CNS?
Physical trauma, neurodegenerative disease. Hypoxia
What is excitotoxicity?
Elevated neuronal activity releases a large amount of neurotransmitters which can cause cell death
Which cells contribute to glial scarring
Astrocytes and oligodendrocytes
Where does neurogenesis happen most in adult mammal brains?
Hippocampus and olfactory bulb
What is the rostral migratory stream?
A migratory route that facilitates migration of newly generated neurons from the anterior SVZ to the olfactory bulb
What is a transit amplifying cell?
A precursor cell that devides into two cells, the new neuron and a new transit amplifying cell
What is the role of the amygdala in classical conditioning?
The CS and US cause the weak synapses in the lateral amygdala to be strengthened causing a learned response
What is the role of the basal ganglia in operant conditioning?
The basal ganglia pathway starts to learn behavior after frequent repitition, and then the behavior becomes automatic.
Which areas play an important role in motor learning?
Cortex and basal ganglia
What cortical regions play an important role in perceptual recognition and remembering?
The objects are recognized in the Extrastriate cortex and sends this to the Ventral stream and Dorsal stream. In remembering the Extrastriate cortex and PFC are involved. The left basal ganglia filters out the irrelevant and the right PFC keeps the relevant info.
What role does the hippocampus play in relational learning?
The hippocampus receives information and starts processing it to link it to memories that are being consolidated there. This allows us to remember episodes and contexts
