Which intercellular signal is produced by neurons and travels short distances to influence postsynaptic cells?

Neurotransmitters are chemical messengers produced by neurons and are crucial for communication within the nervous system. These substances are released from the axon terminals of a presynaptic neuron into the synaptic cleft, the small gap between the neuron's axon and the postsynaptic cell, which can either be another neuron, a muscle cell, or a gland cell.

Once released, neurotransmitters traverse this short distance and bind to specific receptors on the postsynaptic cell, resulting in various physiological effects depending on the type of neurotransmitter and the receptor involved. This process is essential for the transmission of nerve impulses and plays a critical role in functions such as muscle contraction, mood regulation, and reflexes.

In contrast, the other types of intercellular signals serve different purposes. Pheromones typically influence individuals of the same species and are not primarily involved in the quick signaling required for neuron communication. Neurohormones are released into the bloodstream and travel longer distances to exert their effects on target organs, while autocrine signals act on the same cell that secretes them, which is not the case with neurotransmitters that facilitate communication between different cells.