How does the signal at the synapse turn off?

The signal at the synapse is turned off primarily through the reuptake of neurotransmitters by the presynaptic neuron, where they are repackaged into vesicles or broken down by enzymes. Additionally, neurotransmitters can diffuse away from the synaptic cleft, reducing their concentration and effect. Some neurotransmitters are also inactivated by specific enzymes in the synapse, further ensuring that the signal ceases. This coordinated process allows for precise control over synaptic transmission and neural signaling.