Cellular learning and memory

Question 1

What is learning?

Answer 1

the process by which experiences change our nervous system and hence our behavior

Question 2

What are memories?

Answer 2

the changes in the nervous system that derive from the learning

Question 3

What is memory retrieval?

Answer 3

the process of accessing to memories

Question 4

What is the cellular basis of long-term memory?

Answer 4

neuronal plasticity

Question 5

What does the term neuronal plasticity refer to?

Answer 5

the ability of the nervous system to change and adapt

Question 6

What are the two elements used to measure neuronal plasticity?

Answer 6

• intrinsic excitability
• synaptic strength

Question 7

What is the intrinsic excitability of a neuron?

Answer 7

• number of action potentials a neuron exhibits in response to an influx of positive current

Question 8

What determines the intrinsic excitability of a neuron?

Answer 8

the number and type of action channels it expresses

Question 9

What makes a neuron more excitable?

Answer 9

• neuron starts making and expressing less potassium leak channels, which makes its base membrane potential more depolarized, thus facilitates action potentials

Question 10

What is synaptic plasticity?

Answer 10

Changes in the strength of the synaptic connection between two neurons

Question 11

What does the strength of a synaptic connection refer to?

Answer 11

the size of the reaciton in a post-synaptic neuron after a pre-synaptic neuron releases neuro transmitters

Question 12

What influences synaptic strength on a presynaptic neuron?

Answer 12

amount of voltage gated calcium channels (influences intensity of neurotransmitter release)

Question 13

What influences synaptic strength on a post synaptic neuron?

Answer 13

amount of neurotransmitter receptors

Question 14

What is habituation?

Answer 14

Reduced intensity of an innate physiological or behavioural responding to a repeated stimulus

Question 15

What is sensitization?

Answer 15

increased sensitivity to a stimulus

Question 16

What are the two factors that make a a cell less excitable?

Answer 16

• more depolarized state at rest
• fewer ion gated voltage channels, so releases the glutamate when excited

Question 17

What are the two effects that can be had on synapti strength/the two iterations of synaptic plasticity?

Answer 17

• long term potentiation
• long term depression

Question 18

What type of stimulation causes long term depression?

Answer 18

• persistent low frequency stimulation

Question 19

What structural changes are generally associated with long term depression?

Answer 19

• changes on the post synaptic side
• mostly: decrease in neurotransmitter receptors

Question 20

What is the condition for the apparition of long term potentiation?

Answer 20

the release of a neurotransmitter must coincide with a substantial depolarization of the postsynaptic cell

Question 21

What type of stimulation causes long term potentiation?

Answer 21

• persistent high frequency stimulation

Question 22

What structural changes are generally associated with long term potentiation?

Answer 22

• changes on the post synaptic side
• mostly: increase in neurotransmitter receptors

Question 23

How can there be a pre-synaptic long term potentiation?

Answer 23

• retrograde signaling of nitric oxide can cause the release and formation of more vesicles of neurotransmitters

Question 24

Why are action potentials and cell activity both necessary for potentiation to occur IN THE ABSOLUTE (logical reason, not biological facts)

Answer 24

• if the post synaptic neuron is not active at the same time as there is information sent from the pre-synaptic neuron, then this synapse is useless and there is no advantage for the animal in strengthening it.

Question 25

When do NMDA receptors let in ions?

Answer 25

When the cell is deplarized AND they are bound to glutamate

Question 26

What type of receptors are NMDA receptors?

Answer 26

ionotropic glutamate receptors

Question 27

What is the coincidence mechanism of the NMDA receptor?

Answer 27

- If there is glutamate, but the cell is hyperpolarized: Mg2+ blocks the pore - If there is a depolarization, but no glutamate: the channel does not open - need a combination of both to open the channel wide enough so that Ca2+ enters

Question 28

What neurotransmitter are NMDA receptors sensitive to?

Answer 28

glutamate

Question 29

What are AMPA receptors?

Answer 29

- classic glutamate receptors - mediate most excitatory fast synaptic currents in the brain (lets in sodium ions) - ionotropic -

Question 30

What is the enzyme that allows for the strengthening of the synapse?

Answer 30

CaMKII

Question 31

What activates the signaling sent by the CaMKII enzyme?

Answer 31

the entry of calcium in the neuron

Question 32

What is the role of the CaMKII neuron?

Answer 32

Stimulate the formation of new AMPA receptors

Question 33

What does the strength of glutamate synapses correlate with?

Answer 33

- size of the postsynaptic dendritic spine - number of AMPA glutamate receptors

Question 34

What is the definition of perceptual learning?

Answer 34

Learning to recognize stimuli as disctinct entities

Question 35

What is the definition of motor learning?

Answer 35

learning to make skilled and choreographes movements

Question 36

What is the definition of relational learning?

Answer 36

Learning relationships amon individual stimuli

Question 37

What is the definition of stimulus-response learning?

Answer 37

learning to perform a particular behavior when a particular stimulus is present (classical AND instrumental conditioning)

Question 38

What is Hebb's rule?

Answer 38

- the cellular basis of learning involves the strengthening of synaptic connections that are active when the postsynapitc neuron fires an action potential - the synaptic connection has to exist

Question 39

What is associative long-term potentiation?

Answer 39

- increase in synaptic strength - occurs in weak synapses

Question 40

When does associative long-term potentiation occur?

Answer 40

- stronger inputs caused the post-synaptic neuron to spike