NROS 412 Exam #1 Questions And All
Correct Answers.
What is the difference between habituation and adaptation? How could you tell if a decrease in the
behavioral response of an animal is due to habituation or adaptation? - Answer Habituation: The
occurrence of homosynaptic depression of synaptic transmission. (downstream circuitry)
- With habituation, there is no change in the number of action potentials being fired from the sensory
neuron (physiological), but the mind begins to filter out the stimulus via selective attention.
Adaptation: A change in sensory cell response over time.
- relates to the neural processes that constitute this decrease in a behavioral response.
You can tell if an animals behavioral response changed by recording from the sensory neuron.
***Basically, sensory adaptation involves physiological adaptation, while habituation involves
psychological adaptation.
What types of molecular events are likely to underlie short-term memory? long term memory?
Forgetting? - Answer Short-term: Addition or removal of ion channels (AMPA receptors) and
phosphorylation. Increasing or decreasing concentrations.
Long-term: Protein synthesis, phosphorylation, TF, epigenetics
Forgetting: Returning to a baseline by decreasing NT release, changes in structure, decrease receptor
density (weakening of synapes/connections thru LTD)
If molecules in a cell have a relatively short half-life - how can they mediate long term memory? - Answer
Changing the level protein homeostasis for long-term memory.
Activity-induced changes in neuronal and synaptic function can be long-lasting and stable over the
course of days and weeks because everything is in flux and the activity shifts it one way to another
, this constancy and durability of CNS-based phenomena obscures the underlying rapid turnover of most
proteins and protein modifications that turn over at breakneck speed
Describe the difference between hetero-synaptic and homo-synaptic depression. - Answer
Heterosynaptic depression: Adding in a facilitating interneuron (presynaptic inhibition).
- occurs by activating a modulatory cell that inhibits a primary cell of an activated signaling pathway
Homosynaptic depression: Changes of the sensory neuron result in LTD
- does not require modulatory cells, reduction occurs in activated pathway itself
Behaviorally how do you elicit long term habituation? - Answer Through short daily repetitions over a
given period of time.
Multiple spaced trial of non-noxious stimuli. The more you touch the siphon the less the gill will
withdrawl
Propose a hypothesis for the molecular mechanisms underlying long-term habituation in Aplysia. Design
an experiment to test that hypothesis - Answer draw picture.
siphon>sensory neuron>interneuron> motor neuron
The sensory neuron fires as normal but the is less neurotransmitter release in the interneuron and motor
neuron synapses because the threshold changes.
For long-term habituation, multiple spaced trials off touching siphon and observing gill withdrawal.
Measure action potentials of sensory and motor neuron and record neurotransmitter release
Describe the training protocol and outline the neuronal circuitry and signal transduction pathways that
lead to short-term sensitization in Aplysia California. Include the molecular targets of the signal
Correct Answers.
What is the difference between habituation and adaptation? How could you tell if a decrease in the
behavioral response of an animal is due to habituation or adaptation? - Answer Habituation: The
occurrence of homosynaptic depression of synaptic transmission. (downstream circuitry)
- With habituation, there is no change in the number of action potentials being fired from the sensory
neuron (physiological), but the mind begins to filter out the stimulus via selective attention.
Adaptation: A change in sensory cell response over time.
- relates to the neural processes that constitute this decrease in a behavioral response.
You can tell if an animals behavioral response changed by recording from the sensory neuron.
***Basically, sensory adaptation involves physiological adaptation, while habituation involves
psychological adaptation.
What types of molecular events are likely to underlie short-term memory? long term memory?
Forgetting? - Answer Short-term: Addition or removal of ion channels (AMPA receptors) and
phosphorylation. Increasing or decreasing concentrations.
Long-term: Protein synthesis, phosphorylation, TF, epigenetics
Forgetting: Returning to a baseline by decreasing NT release, changes in structure, decrease receptor
density (weakening of synapes/connections thru LTD)
If molecules in a cell have a relatively short half-life - how can they mediate long term memory? - Answer
Changing the level protein homeostasis for long-term memory.
Activity-induced changes in neuronal and synaptic function can be long-lasting and stable over the
course of days and weeks because everything is in flux and the activity shifts it one way to another
, this constancy and durability of CNS-based phenomena obscures the underlying rapid turnover of most
proteins and protein modifications that turn over at breakneck speed
Describe the difference between hetero-synaptic and homo-synaptic depression. - Answer
Heterosynaptic depression: Adding in a facilitating interneuron (presynaptic inhibition).
- occurs by activating a modulatory cell that inhibits a primary cell of an activated signaling pathway
Homosynaptic depression: Changes of the sensory neuron result in LTD
- does not require modulatory cells, reduction occurs in activated pathway itself
Behaviorally how do you elicit long term habituation? - Answer Through short daily repetitions over a
given period of time.
Multiple spaced trial of non-noxious stimuli. The more you touch the siphon the less the gill will
withdrawl
Propose a hypothesis for the molecular mechanisms underlying long-term habituation in Aplysia. Design
an experiment to test that hypothesis - Answer draw picture.
siphon>sensory neuron>interneuron> motor neuron
The sensory neuron fires as normal but the is less neurotransmitter release in the interneuron and motor
neuron synapses because the threshold changes.
For long-term habituation, multiple spaced trials off touching siphon and observing gill withdrawal.
Measure action potentials of sensory and motor neuron and record neurotransmitter release
Describe the training protocol and outline the neuronal circuitry and signal transduction pathways that
lead to short-term sensitization in Aplysia California. Include the molecular targets of the signal
