CHAPTER 37 NEURONS, SYNAPSES, AND SIGNALING
Scientific Skills Exercise
Teaching objective: Students build scientific skills by interpreting data expressed in scientific
notation from an experiment on opiate receptors in the mammalian brain.
Teaching tips: A version of this Scientific Skills Exercise can be assigned in MasteringBiology.
Methadone is a pain reliever used in drug addiction treatment to prevent withdrawal symptoms.
Have students investigate how treatment centers use methadone, gradually reducing its dosage
during recovery.
Answers:
1. Morphine 0.000000006 M, atropine 0.0001 M
Interpret the Data
Summary of Key Concepts, Concept 37.3 The action potential lasts from the beginning of the
rising phase to the point of maximal undershoot, about 4.8-2.5=2.3 msec in the graph shown.
Suggested Answers for End-of-Chapter Essay Questions
See the general information on grading short-answer essays and a suggested rubric at the
beginning of this document.
10. Scientific Inquiry
Despite their wide use, the exact mechanism of action of most anesthetics is not well understood.
Most general anesthetics are a combination of drugs, including opiates, antianxiety medications,
11. Focus on Evolution
Generation of an action potential requires a stimulus of sufficient intensity or duration that the
-or-none) events,
12. Focus on Organization
Sample key points:
All animal cells have a membrane potential.
Neurons differ from most other animal cells in having voltage-gated ion channels.
Sample top-scoring answer:
Like other animal cells, neurons have a negative membrane potential established by the pumping
action of the sodium-potassium ATPase and the selective permeability of the plasma membrane.
13. Synthesize Your Knowledge
Nerve impulses called action potentials are propagated along axons by voltage-gated channels.
The opening of sodium channels initiates the action potential, whereas the inactivation of sodium
channels and opening of potassium channels returns the membrane potential toward (and