In your Ph.D. research, you use thin slices of brain tissue to study neuronal signaling. You attach an electrode to a single neuron, but cannot detect any activity. What is the most likely explanation?

Question

A.  When you sliced the brain, you disconnected the cell from its dendrites.
B.  Neurons are not electrically active -- you should be recording neuroglia instead.
C.  When you sliced the brain, you disconnected the cell from its neuroglia.
D.  Excessive myelination is blocking inputs to the cell.

Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?

Gather Content
What do you already know about neuronal signaling? What other information is related to the question?

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

A.  When you sliced the brain, you disconnected the cell from its dendrites.

Clarify Question
What is the key concept addressed by the question?
        · This question is asking about the nature of the detectable signaling of the brain.
What type of thinking is required?
        · Apply level:
            o You are being asked to take what you already know and use, or apply, it to the passage of signals within the brain.

Gather Content
What do you already know about neuronal signaling? What other information is related to the question?
        · Neurons are the basic units of nervous tissue.
        · A neuron receives messages through its dendrites, passes the message along the cell body, and passes the message along through its axon.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · Neuroglia are support cells for neurons; they do not pass messages along.
        · Myelination insulates the axon, it does not block the passage of a signal.
        · Since dendrites are the input for a signal, the only correct answer from these choices is that the dendrites were cut, thereby stopping the neuronal signal by severing the inputs to the nerve cell.

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        · Apply level:
            o Answering this question correctly depended on your ability to use neuronal signaling in a new situation. If you got an incorrect answer, did you remember that dendrites receive neuronal signals, or that axons pass signals along? Did you have trouble extending neuronal signaling to determine the correct answer?