Which chemicals facilitate communication across nerve synapses?

Neurotransmitters play a central role in the communication between neurons across synapses. When an electrical signal reaches the end of a neuron, it triggers the release of neurotransmitters from vesicles into the synaptic cleft. These chemicals then bind to specific receptors on the surface of the neighboring neuron, leading to either the excitation or inhibition of that neuron, effectively facilitating the transmission of signals throughout the nervous system. This process is essential for a wide range of functions, including muscle contraction, mood regulation, and cognitive processes.

Hormones, while also important for communication, primarily work through the endocrine system and affect distant organs rather than facilitating transmission between neurons at synapses. Ions are crucial for establishing the electrical gradients and action potentials in neurons, but they do not serve as the chemicals that transmit signals between neurons. Proteins may have various functions within the body, including structural and signaling roles, but they do not specifically mediate the synaptic communication like neurotransmitters do. Thus, neurotransmitters are the key chemicals responsible for the direct communication at nerve synapses.