When a neuron is stimulated, channels in the membrane open to allow [[1]] ions to flow into the neuron, causing a depolarization of the membrane.

When a neuron is stimulated, channels in the membrane open to allow sodium ions (Na+) to flow into the neuron. This influx of positively charged ions causes a change in the electrical potential of the neuron's membrane, which is known as depolarization. This depolarization is the first step in the process of generating an action potential, which is the electrical signal that allows neurons to communicate with each other and transmit information throughout the nervous system.

The opening of sodium channels is typically triggered by the binding of neurotransmitters to receptors on the surface of the neuron, or by other stimuli such as changes in the voltage of the membrane itself. Once the sodium channels open, sodium ions flow into the neuron, causing the membrane potential to become less negative (i.e., more positive). This change in potential can then trigger the opening of additional channels, including voltage-gated calcium channels, which play a key role in the release of neurotransmitters from the neuron.