Practice Passage Test - 2 | Practice Passages for MCAT PDF Download

A scientist is investigating a mouse model of peripheral demyelinating disease, characterized by the gradual loss of myelin in the peripheral nervous system and the development of neurological abnormalities. In this study, the scientist aims to understand the relationship between the loss of myelin and the conduction of action potentials along axons. To achieve this, the scientist utilizes electrical stimulation to induce action potentials in the mice's nerves and records the resulting electrical response closer to the point where the axons enter the central nervous system.

To test the hypothesis, the scientist plans two experiments. In the first experiment, the speed of action potential conduction will be compared between younger and older mice affected by the disease. By comparing the conduction speed in these different age groups, the scientist can assess whether the loss of myelin impacts the transmission of action potentials along the axons.

In the second experiment, the scientist will compare the speed of action potential conduction in the nerves of mice with the disease to those without the disease. However, prior to the comparison, both groups of mice will undergo a period of frequent electrical stimulation of their nerves. This additional experiment aims to determine whether the frequency of electrical stimulation can affect the conduction speed in mice with the disease compared to healthy mice.

Through these experiments, the scientist hopes to gain insights into the relationship between myelin loss and the conduction of action potentials in the peripheral nervous system. The findings may contribute to a better understanding of the mechanisms underlying peripheral demyelinating diseases and potentially lead to the development of novel therapeutic strategies.