lecture 8 Flashcards
(32 cards)
what are 2 examples in the brain that show learning occurs
strength of response to a stimulus
more synaptic connections
what does hebbs rule state
connection between 2 neurons will strengthen if they are activated in the same space and same time
what does hebb mean by “space” in his rule?
neurons have to be connected with one another in some way
what does hebb mean by “time” in his rule?
activation of one neuron highly correlated with activation of another
fire together wire together hypothesis
there should be changes as a function of this temporal and spatial correlation that will result in fundamental change in way that the connection between the 2 neurons works
what do we measure to measure the physiological change in neurons
changes in strength of EPSP
what does reliable pairing between 2 neurons that elicit depolarization result in
increase strength or magnitude of EPSP
if stimulus does not reliable produce response and depolarizing current is small, over time …?
strength / magnitude of EPSP decreases
aka long term depression
what does presynaptic learning look like
increase in neurotransmitter release
what does postsynaptic learning look like
more receptors in synapse
why does phantom limb pain occur
we have a body map in our head
for example, head and hand are next to eachother in the brain so it misinterprets signals from body
there is a massive reorganization in brain after surgery to remove limb
what was discovered about the memory of sea slugs? (3)
they can learn and do nonassociative learning
they have sensitization
they show habituation
explain sensitization of sea slug through gill siphon withdrawal reflex
gill stays retracted for long period when theyve previously been shocked so they learned to protect themselves
how do sea slugs show habituation
decrease response to stimulus following repeated representation of that stimulus (decrease in withdrawal response)
why was it useful to study sea slugs (3)
they have massive neurons that are easy to see
very low number of neurons
only one synapse between neurons
enrichment conditions for animals do what
affect their ability to learn
what is an example of an enrichment condition
rats in cage w food and water vs rats in cage w food, water, pla spaces, engaging features, more space
what do enrichment conditions show in terms of brain (2)
alterations in amount of dendrites formed
significantly more third fourth and fifth order branches (neurons making more connections)
do musicians have different brains? how?
yes, they have greater thickness in some brain areas such as posterior part of frontal lobe for motor function
whats the role of NMDA receptors in synaptic learning
NMDA is a post synaptic receptor that binds to glutamate
do NMDA receptors contribute to depolarization or EPSPs themselves?
no
do AMPA receptors contribute to potential?
yes
how are mg ions released from nmda channel
if non nmda receptors depolarize the neuron first
what does calcium trigger
activation of intracellular enzymes, specifically 1) can interact with AMPA channels to enhance conductance 2) can cause release of internal stores of gas
