Chapter 25: Molecular Mechanisms of learning and memory

Question 1

What is nonassociative learning? Name two types of nonassociative learning.

Answer 1

It is the change in the behavioral response that occurs over time in response to a single type of stimulus.
Habituation and Sensitization.

Question 2

Which kind of nonassociatve learning does the following graph show?

Answer 2

Habituation: Repeated presentation of the same stimulus produces progessively smaller response.

Question 3

Which kind of nonassociative learning does the following graph show?

Answer 3

Sensitiaztion: A strong stimulus (the arrow) results in an exaggerated response to all subsequent stimuli.

Question 4

What is associative learning? Name two types that are usually distinguished.

Answer 4

During al we form associations between two events.
Classical conditioning and instrumental conditioning.

Question 5

What is the Unconditional Stimulus?

Answer 5

The stimulus that normally evokes the response. (no training/conditioning needed)

Question 6

What is the Conditional Stimulus?

Answer 6

The stimulus that normally does not evoke the same response as the US. (here training conditioning is needed)

Question 7

The learned response to the conditioned stimulus is called the….?

Answer 7

Conditioned response

Question 8

In classical conditioning the subject learsn tha one stimulus CS predicts another stimulus US… In instrumental conditioning the subject learns that a particular……?

Answer 8

behavior is associated with a particular consequence.

Question 9

The amount of what decreases due to habituation (regarding gill withdrawl reflex)

Answer 9

After habituation there are fewer quanta (packets of transmitter molecules) released per action potential, so habituation of the gill-withdrawal reflex is associated with presynaptic modification

Question 10

Habituation of the gill-withdrawal reflex is associatet with ……. modification.

Answer 10

presynaptic

Question 11

Name and explain the mechanism shown in the following picture.

Answer 11

It is a mechanism for sensitization of hte gill-withdrawal reflex.

Serotonin released by L29 in response to the head shock leads to G-protein-coupled activation of adenylyl cyclase in the sensory axon terminal which leads to production of cyclic AMP which in turn activates protein kinase A which then attaches phosphate groups to a potassium channel, causing it to close.

This all results in more quanta of neurotransmitter being released.

Question 12

What are the characteristics of Purkinje Cells?

Answer 12

Their dendrites extend only into the molecular layer

The Purkinje cell axons synapse on neurons in the deep cerebellar nuclei, which are the major output cells of th cerebellum

Purkinje Cells use GABA as a neurotransmitter, so their influence on cerebellar output is inhibitory

Question 13

What is the inferior olive?

Answer 13

Nucleus of the medulla which integrates information from muscle proprioceptors

Question 14

Axons from the inferior olive are called….?

Answer 14

climbing fibers

Question 15

What is the Marr-Albus theory of motor learning?

Answer 15

It predicts plasticity of the parallel fiber synapse if it is active at the same time as the climbing fiber input to the postsynaptic Purkinje cell

Question 16

What are parallel fibers?

Answer 16

Axons of cerebellar granule cells that ascend into the molecular layer where they branch like a T.

Question 17

What does input specifity mean?

Answer 17

The property that only the active inputs show the synaptic plasticity

Question 18

Where can input specifity be detected?

Answer 18

In Long-term depression