In synaptic signaling, there is a unique structure known as the synapse between the cell originating and the cell receiving the signal. Thus, synaptic signaling exclusively occurs between cells with the synapse. An example is the interaction between a neuron and the muscle that is controlled by neural activity. Paracrine signaling is any type of signaling where signals bind to receptors and stimulate adjacent cells. Synaptic signaling is involved in the communication between neurons. It is triggered by signals from the brain such as touch or eye sensors. Paracrine signaling is used for cell proliferation, differentiation, and growth, and thus has a broader function than synapse signaling, which is more specific.