What is the role of neurotransmitters in the nervous system?

Neurotransmitters play a crucial role in the nervous system by serving as chemical messengers that carry signals between neurons. When an electrical impulse, or action potential, reaches the end of a neuron, neurotransmitters are released into the synapse, the gap between two adjacent neurons. These chemicals bind to receptors on the receiving neuron's surface, allowing the transmission of the signal to continue to the next neuron.

This process of carrying messages is essential for various functions, including mood regulation, motor control, and various cognitive processes. By facilitating communication between neurons, neurotransmitters enable the nervous system to coordinate and process information efficiently.

The other options focus on processes that do not accurately describe the primary function of neurotransmitters. For instance, while neurotransmitters are integral to neuron communication, they do not transmit signals along a single neuron, produce energy for neuronal function, or directly protect the brain from injuries. Their main action is, rather, in facilitating the transfer of information between neurons.