What is the primary role of neurotransmitters in the nervous system?

Neurotransmitters play a crucial role in the nervous system by transmitting signals across synapses, which are the junctions between neurons. When a neuron is activated, it releases neurotransmitters into the synaptic cleft. These chemical messengers then bind to specific receptors on the postsynaptic neuron, leading to various responses such as muscle contraction, initiation or inhibition of action potentials, and modulation of mood and cognition.

This process is fundamental for communication within the nervous system, allowing for rapid and precise control of numerous functions, including reflexes, sensory processing, and complex behaviors. Without neurotransmitters, the ability of neurons to communicate and transmit information effectively would be severely impaired, which could disrupt the entire nervous system's functioning.

The other options, while related to brain functions, do not directly describe the primary role of neurotransmitters. Creating new neurons refers to neurogenesis, storing memories involves complex processes in the brain, and regulating hormonal levels pertains to the endocrine system rather than the specific function of neurotransmitters in neuronal communication.