BioG 101
Name ____________________________
Worksheet —Events at the Chemical Synapse
Instructions: Print out this document and complete it as you study the interactive module on the
chemical synapse.
TUTORIAL (numbers below refer to pages of the tutorial)
Pages 4–8: Summarize the observations you made doing the activities in these pages by entering "+" or
"–" signs to complete the following table. Note AP= Action Potential; EPSP = Excitatory Postsynaptic
Potential
Observed in…
Condition:
Neuron A
Neuron B
AP
EPSP
AP
EPSP
Stimulate Neuron A at
Intensity Level "L"
Stimulate Neuron A at
Intensity Level "H"
Stimulate Neuron B at
Intensity Level "H"
Pages 9, 10, 14: Summarize the observations you made doing the activities in these pages by entering
"+" or "–" signs to complete the following table.
Observed in…
Structures:
Presynaptic Cell
Postsynaptic Cell
Synaptic Vesicles
Neurotransmitter Receptors
Omega Figures
Page 11: Describe your observations in the vesicle injection study and a logical conclusion supported by
these results:
Observations:
Conclusion:
Page 15: Describe your observations in the study where Mg++ replaced Ca++ in the extracellular
environment and a logical conclusion supported by these results:
Observations:
Conclusion:
Page 16: Describe your observations in the vesicle injection study when Mg++ replaced Ca++ in the
extracellular environment and a logical conclusion supported by these results:
Observations:
Conclusion:
Page 17: Describe your observations in the study where Ca++ was injected into the axon terminal and a
logical conclusion supported by these results:
Observations:
Conclusion:
Page 18: Describe the two main observations of the BABTA injection study and a logical conclusion
supported by these results:
Observation 1:
Observation 2:
Conclusion:
Page 19: Describe your observations in the aqueorin injection study and a logical conclusion supported
by these results:
Observations:
Conclusion:
Page 21: Describe your observations in the study where the axon terminal was exposed to increased [K+]
in the presence of the Na+-channel blocker TTX and a logical conclusion supported by these results:
Observations:
Conclusion:
Page 22: Describe your observations in the study where the axon terminal was stimulated after exposure
to Cd++ and a logical conclusion supported by these results:
Observations:
Conclusion:
Now use the information you have entered in this section to complete the matching exercise on page 23.
Page 28: relative to the resting potential of the neuron in the activity on this page, would –55 mV be an
EPSP
depolarizing
or
IPSP (circle)
or hyperpolarizing (circle)
ACTIVITES—Neural Integration
1. What is the threshold required to propagate an action potential at the axon hillock? _________ mV
2. Complete the following table with data you collected in activity 4:
Synapse Position
Near to Hillock
1
2
3
4
Away from Hillock
5
EPSP (mV)
3. Describe below a situation in which the arrangement of synapses you simulated in activity 10 might
be advantageous.