Plasticity Flashcards
What is dendritic branching?
When the brain rearranges the connections between neurons
What is neural plasticity?
Refers to the ability of neurons to change in structure and function
What is long term potentiation?
When learning can increase / decrease neurotransmission between specific neurons
What is neurogenesis?
When the brain can generate new neurons throughout life
How can the nervous system be assumed to be adaptable?
Because as your behaviour changes, so does the underlying neural circuitry
What is Hebbian Theory?
An increase in synaptic efficacy arises from presynaptic cell’s repeated and persistent stimulation of the postsynaptic cell
Describe Kandel’s work with the marine mollusc Aplysia
- can be classically condition
- touched lightly on it siphon (CS)
- shocked on the its tail (US) so it retracts it
- eventually the animal responds to the CS alone where it retracts its tail once it has been touched
- neurons carrying the tail shock message cause the light touch neurons to increase the amount of NT they release
- eventually the light touch neurons release enough transmitter to activate the motor neurons on their own
When is the brain most plastic?
Early in development
What 3 factors influence plasticity in development?
1) neural growth in infancy & early childhood
2) the effect of the environment on brain growth
3) recovery from brain damage in infancy and early childhood
Describe the development of the cells in the visual cortex between birth to 6 months
Become rapidly more complex and branched
What is synaptic pruning?
When unused connections get severed
Describe Perry’s work (2002)
Investigated the effects of childhood neglect on nature and nurture
CT scans of 3 year old children - one who was ‘normal’ and one who had suffered extreme neglect
Normal child - much larger brain size
Neglect child - abnormal development of the cortex
What can surviving neurons do when nerve tissue is destroyed or neurons die as a part of the ageing process?
Can restore functioning by modifying themselves either structurally or biochemically
Can alter their structure by sprouting enlarged networks of dendrites or by extending axons from surviving neurons to form new synapses
Describe one neurogenesis technique
Transplantation into the brain of stem cells
Injected directly into the brain and travel to regions, especially those which are degenerating or developing areas
Have been successfully transplanted into the spinal cords of injured animals where they have taken hold and organised themselves into neural networks
How can the plasticity of the brain be useful?
Stroke damage - affects the left side which is connected to the right hemisphere of the brain which deals with language
Practice of language skills can help re-wire neurons to form new connections and get back language skills
Help with brain damaged patients
