Oligodendrocytes are cells in the brain that produce myelin in the central nervous system. Myelin regulatory factor (MyRF) is a transcription factor that is required by oligodendrocytes in order to produce myelin. Researchers investigated the importance of MyRF by having mice learn how to run on complex wheels (there were many gaps in the wheel thus making it difficult to run on-see graph below).

-Researchers created a genetic strain of mice that were lacking both genes for MyRF. What is the most likely effect that this would have on the mice?
A) decreased rate of signal propagation via axons
B) increased flow of ions through voltage-gated sodium channels
C) decreased flow of ions through voltage-gated potassium channels
D) increased number of dendrites on neuron cell bodies

Question

Oligodendrocytes are cells in the brain that produce myelin in the central nervous system. Myelin regulatory factor (MyRF) is a transcription factor that is required by oligodendrocytes in order to produce myelin. Researchers investigated the importance of MyRF by having mice learn how to run on complex wheels (there were many gaps in the wheel thus making it difficult to run on-see graph below).
 
-Researchers created a genetic strain of mice that were lacking both genes for MyRF. What is the most likely effect that this would have on the mice?
A) decreased rate of signal propagation via axons 
B) increased flow of ions through voltage-gated sodium channels 
C) decreased flow of ions through voltage-gated potassium channels 
D) increased number of dendrites on neuron cell bodies

Quizplus · Accepted Answer

Oligodendrocytes produce myelin, which insulates axons and increases the speed of signal propagation. If the mice are lacking MyRF and cannot produce myelin, then the rate of signal propagation via axons would likely decrease. Choice B is incorrect because sodium channels are not directly affected by myelin. Choice C is incorrect because potassium channels are typically found in axons, not oligodendrocytes. Choice D is incorrect because the number of dendrites on neuron cell bodies is not directly related to myelination.

Oligodendrocytes Are Cells in the Brain That Produce Myelin in the Central