Question

during an action potential, the electrical charge within the axon changes briefly from
o neutral to negatively charged.
o neutral to positively charged.
o negatively to positively charged.
o positively to negatively charged.

Explanation:

During an action potential, the resting membrane potential of a neuron is around -70 mV (negative/neutral relative to outside). When an action potential occurs, voltage - gated sodium channels open, allowing sodium ions (positively charged) to rush into the axon. This causes the inside of the axon to become positively charged relative to the outside, so the charge changes from neutral (or negative) to positively charged? Wait, no, let's recall correctly. The resting state: inside is negative relative to outside (so the charge inside is negative or neutral - like, the resting potential is negative inside). During action potential, depolarization occurs: sodium ions enter, making the inside positive. Wait, the options: the first option is "neutral to negatively charged" – no. Wait, the correct process: at rest, the axon's interior is negatively charged (relative to outside, which is considered neutral or positive). During action potential, the interior becomes positively charged. Wait, the options: let's list the options again from the image (as per the user's image):

Options:

1. neutral to negatively charged.

1. neutral to positively charged.

1. negatively to positively charged.

1. positively to negatively charged.

Wait, the user's image text: "During an action potential, the electrical charge within the axon changes briefly from" then the options:

First option: neutral to negatively charged.

Second: neutral to positively charged.

Third: negatively to positively charged.

Fourth: positively to negatively charged.

Now, the resting membrane potential: the inside of the neuron (axon) is negatively charged relative to the outside (the outside is more positive, inside more negative, due to ion distribution: more Na⁺ outside, more K⁺ and negative ions inside). When an action potential is initiated, voltage - gated Na⁺ channels open, Na⁺ (positive) rushes into the axon, causing the inside to become positively charged (depolarization). So the charge within the axon changes from negatively charged (at rest) to positively charged. So the correct option is the third one: "negatively to positively charged."

Answer:

C. negatively to positively charged (assuming the third option is labeled C, but based on the order: the third option in the list is "negatively to positively charged")