6: Biological Basis of Memory Flashcards
What is habituation?
Decrease in strength of a behaviour due to repeated exposure (We get used to it )
What is dishabituation?
If we’re not exposed to a stimulus for a while, habituation wears off
What is sensitisation?
In increase in the strength of a behaviour due to an arousing stimulus
What animal is memory usually studied on?
Aplysia californica (Sea snail) as it has very large axons
What reflex of the Aplysia californica is studied when looking at memory?
The gil withdrawl reflex as there are only 2 neurons involved
How does habituation occur biologically?
Less calcium over time so less exocytosis and less neurotransmitter being released into the synapse - making action potential less likely
How does sensitisation occur biologically?
Look in notes
Basically protein kinase A blocks potassium and causes prolongued action potentials which causes a stronger response
What is the main difference between sensitisation and classical conditioning?
Conditioning produces a stronger reaction as more potassium channels are blocked.
What is long term potentiation?
Strengthening of the synapses based on patterns of activity. Occurs due to high frequency stimulation of the Schaffer collaterals
What are shaffer collaterals?
Axons connecting the CA3 and CA1 areas of the hippocampus together
How does long term potentiation occur biologically?
NMDA is blocked and glutamate allows calcium into the cell
AMPA receptors increase on the post synaptic membrane
Synapse is more efficient
What is long term depression?
A loss of AMPA receptors causing a reduction in efficiency in the neurone
Occurs with low frequency stimulation of the schaffer collaterals
