Answer:
The charges inside and outside of the neuron before receiving a stimulus are negative and positive, respectively, which corresponds to the transmembrane rest potential.
Explanation:
Neuron is the specialized cell of the nervous system in charge of transmitting electrical impulses. The generation of a nerve impulse in the form of an electric current is due to a change in the transmembrane potential.
Outside the neuron cell, electrical charges are predominantly positive, and the ion with the highest concentration is sodium. In the intracellular space, a great quantity of proteins provide negative charge, and there is a predominance of potassium ions. Under these conditions, the ionic channels are closed.
For this reason, a neuron at rest, before receiving a stimulus, presents positive charges on the outside and negative charges on the inside, and the membrane potential in this condition is estimated at a value of -65 mV.
Once a stimulus is produced, the ionic channels open and Na+ ions enter the cytoplasm, exchanging them for K+, which implies a change in the membrane potential which, on reaching the threshold, produces an action potential and the nerve impulse is produced.
