Principles Of Neuroscience Lecture 29 Disorders of the Nervous System II Flashcards
What irreversible deficits come about due to abuse induced trauma?
Social behaviour
Neuro cognitive impairment
Fearful, timid, withdrawn
What are some examples of abuse/trauma?
Neglect
Physical
Sexual
Psychological
Give some examples of studies connecting abuse and trauma (3)
a. Time spent in orphanage vs. incidence of neuro cognitive impairment
b. Harlowe’s monkeys: reared in isolation –> fearful, timid withdrawn monkeys
c. MRI tractography of deprived children: reduced connection between PFC and the rest of the brain
What are the requirements for the critical period?
Tactile based attachment
Nurturing
Describe how the analogy of vision can be used for critical periods
There is a critical period for development of the occular dominance columns and stereoscopic vision.
If one eye is covered during this time, normal vision can never be regained
Describe the study in which cats eyes were sutured
Normal cat: most neurons in V1 receive input from both eyes, some receive input from only one eye
Eye sutured shut during critical period: every when reopened, the neurons in the V1 only receive input from neurons from one eye
Eye sutured after critical period: once reopened, the neurons in V1 can regain the normal input patterns
What does the sutured eye experiments in cats tell us about critical periods?
There is a critical time during which all the important things occurin terms of organisation of the system.
This can be used as an analogy for normal social behaviour. If a child does not receive the correct care during this time, it will never acquire normal social behaviour
What is stereopsis?
This is normal 3D and depth vision
What is strabismus?
This is abnormal stereoscopic vision. The depth of objects can no be seen
Monocular deprivation can lead to …
How long must the monocular deprivation last?
Strabismus
3 days is sufficient to generate biasing to one eye
6 days: there will be complete biasing to one eye
How do inputs into neurons in layer IV in the visual cortex establish dominance?
The input neuron that correlates most with the activity of the neuron it is inputting into will have its connection strengthened
Describe the three eyed frog experiment
Normally, the input from each eye in frogs goes to separate parts of the brain.
Attaching a third eye results in occular dominance columns in the brain, because the inputs from the two eyes compete for space in the visual cortex
What were the conclusions of the three eyed frog experiment?
Competition for space results in ocular dominance columns
What is the hyper plastic state, and why is it important?
This is a state when also the connections and organisation of the neural circuits are made
It is important because if the individual does not get the right stimuli during this time, the function may never be properly developed
What are some examples of processes that are set up in the hyper plastic state?
What are some common molecules?
Neuromuscular junctions
Ocular dominance
Language
Stress
NMDA
GABA
CREB