PSYC 2: Biological Foundations - Fall 2012 - Professor Claffey

Unit: Neurons

10/26/12 - formatting changed
10/5/12 - Added to "Questions" and "Terms"
10/4/12 - Added reading on sea slug
10/3/12 - Added "Clicker Questions" section
10/1/12 - Original


3.2 Cells of the Nervous system
4-- Neural Conduction and Synaptic Transmission
11.8 Synpatic Mechanisms of Learning and Memory section on Habituation and Sensitization (Sea slug topic)

Support resources:

Study Questions

    What structures/resources are necessary for keeping the neuron alive and healthy?
    What are the structures of a neuron that support communication?
    How does the neuron use electrical and chemical signals to communicate?
Resting/Action Potential
    How is the action potential a unit of communication among neurons?
    What biochemical processes does a neuron use to prepare for an action potential?
    What is the resting potential?
    What ions are involved in establishing the resting potential?
    How is an action potential triggered or inhibited?
    How is a postsynaptic potential generated?
    How are postsynaptic potentials integrated?
Synapse & Neurotransmitters
    How is the synapse an interface between electrical and chemical signals?
    What is the role of neurotransmitters in the synapse?
    What is the sequence of steps that a neurotransmitter goes through?
    What is the role of receptors in the synapse?
    What are the different types of neurotransmitters?
    How do drugs affect the synapse?
Synaptic Plasticity
    How can a synapse be changed by experience?
    What is long term potentiation (LTP)?
    What mechanisms are necessary for LTP?
    How do synaptic changes produce changes in the performance of a neuron?
    How can these synaptic changes be considered learning?
    How is protein synthesis involved in synaptic changes?
    What neuronal changes underlie habituation and sensitization in Aplysia?
Glial cells
    What role do glial cells play in the nervous system?
Neural recording
    What characteristics/behaviors of neurons do neuroscientists measure?
    What techniques do neuroscientists use to measure neural activity?
    What are some examples of how neural activity relates to an animal's behavior?


myelin sheath
node of ranvier
axon terminal
synapse / synaptic cleft
Schwann cell
concentration gradient
electrostatic pressure
resting potential
action potential
lipid bilayer membrane
saltatory conduction
sodium potassium pump
voltage-gated channel
ligand-gated channel
excitatory postsynaptic potential
inhibitory postsynaptic potential
subthreshold depolarization
rising phase
absolute/relative refractory period
spatial / temporal integration
ionotropic receptor
metabotropic receptor
enzymatic degradation
dopamine / epinephrine / norepineprhine / serotonin
    (be able to recognize these as NTs, but do not have to know their function for test 1)
gap junction
synaptic plasticity

Clicker Questions

Q: Where are the answers to these clicker questions?

A: The answer to these questions will not be posted. If the answers are posted, the average student has a tendency to only check that the answer makes sense rather than taking the time to really think about the question and arrive at a confident answer. For the answers, you will have to attend class, ask a classmate, check the podcast, or ask the prof/TAs.

For the Oct 1 & 3rd, responses were not recorded for these questions; there are no points associated with them.

Monday, Oct 1

1. How do you and your brain make decisions?
  1.     My past experiences predispose my brain to react in a certain way
  2.     A combination of past experiences and an inner dialogue
  3.     An inner dialogue, which can react independently of my past experiences
2. Which neuron structure is NOT correctly matched to function?
  1.     mitochondria - energy metabolism
  2.     nucleus - regulation of gene (protein) expression
  3.     dendrites - sending out communication to other neurons
  4.     myelin - insulation
3. Which is true about neurons but not other types of cells?
  1.     it has axons and dendrites
  2.     neurons all have a highly similar shape
  3.     its metabolic needs (glucose, oxygen) are handled by other support cells
  4.     it has a lipid membrane to compartmentalize ions and organelles

Wednesday, Oct 3

1. A left and right chamber are separated by a membrane. To start:
100 mM of A (no charge)

100 mM of B (no change)

If the membrane is only permeable to A, what will happen?

  1.     A will not change sides
  2.     A will move to the right until there is 50 mM on both the left and the right
  3.     A will move to the right, but only a little

2. A left and right chamber are separated by a membrane. To start:
100 mM of K+
100 mM of Cl-
10 mM of Na+
10 mM of Cl-

The membrane is not permeable. What is the membrane potential?
  1.     0
  2.     inside is more positive than outside
  3.     inside is more negative than outside

3. A left and right chamber are separated by a membrane. To start:
100 mM of K+
100 mM of Cl-
100 mM of Na+
100 mM of Cl-

If the membrane is only permeable to K+, what will happen?
  1.     K+ will not change sides
  2.     K+ will move to the right until there is 50 mM on both the left and the right
  3.     K+ will move to the right, but only a tiny amount, making the left side negative
  4.     K+ will move to the right, but only a tiny amount, making the left side positive

Friday, Oct 5

1. Why is the resting potential negative? (inside the neuron compared to outside)
  1.     The potassium channels are open and some potassium has flowed out
  2.     There are approximately 10 times more positive ions outside the neuron
  3.     There are unequal concentrations of sodium and potassium

2. Continuing with the example above. The membrane was permeable to K+ producing:
100 mM of K+ (minus a tiny amount)

100 mM of Cl-
plus a tiny amount of K+
100 mM of Na+
100 mM of Cl-

If the membrane stopped being permeable to K+ and became permeable to Na+, what would happen?

  1.     The tiny amount of K+ would flow back to the left
  2.     Na+ would flow to the left until there was 50 mM on both the left and right
  3.     Na+ will move to the left, but only a tiny amount, making the left side negative
  4.     Na+ will move to the left, but only a tiny amount, making the left side positive

3. How does the action potential work?
  1.     The NaK pump creates differences in concentration, each action potential undoes these differences in concentration
  2.     The action potential consists of small movements of ions, which switch the potential between positive and negative
  3.     The action potential is a large number of ions diffusing down the axon, not across the membrane

4. SSRIs (selective serotonin reuptake inhibitors) are a class of pharmaceutical drugs that inhibit the reuptake of serotonin (NT). What does this cause?
  1.    More serotonin at the synapse, more activation of receptors
  2.    More serotonin at the synapse, less activation of receptors
  3.    Less serotonin at the synapse, less activation of receptors
  4.    Less serotonin at the synapse, more activation of receptors


Monday, Oct 8

1. (Not for points) The speed of lecture is
  1. too slow
  2. good
  3. too fast

2. (Not for points) In terms of the amount of cell biology (organelles, membranes, ions, proteins)

  1. I understand most of what's mentioned
  2. I have to read the book or review lecture to catch up
  3. There's a lot of new content I don't understand

3. Which will NOT increase the strength of the post-synaptic signal?
  1. Synthesizing more neurotransmitters
  2. Releasing more neurotransmitters
  3. Creating more receptors
  4. Increasing reuptake

4. Which is an example of integration?

  1. Two depolarizations that individually do not reach threshold cause an action potential if they happen closer in time
  2. A neuron is influenced by the number of action potentials it has over minutes or hours
  3. A neuron begins to respond the same as neighboring neurons

5. Which is NOT true of neurotransmitters?

  1. There are 100s of neuroactive substances
  2. They can cause depolarizations or hyperpolarizations
  3. The include ligand-gated channels
  4. They can be made up of small or large molecules

6. Which is correctly paired?
(the original question did not have a correct answer, everyone attending got credit)

  1. Agonist - preventing synthesis
  2. Agonist - blocking receptors
  3. Antagonist - preventing increasing reuptake
  4. Antagonist - increasing exocytosis

Wednesday, Oct 10

Which of the following would NOT block LTP?

  1. Blocking NMDA receptors
  2. Causing the pre-synaptic neuron to have more action potentials than occurs naturally
  3. Preventing the post-synaptic neuron from making new proteins
  4. Inhibiting the post-synaptic neuron so that it can not depolarize
Which of the following is NOT more likely to make a post-synaptic neuron fire?
  1. LTP
  2. Habituation
  3. Sensitization
  4. Re-uptake blocking
How many of the following are functions of the synapse?
  1. 1
  2. 2
  3. 3
  4. 4

Copyright 2012 - Michael Claffey