<human>:  Where does the spike come from in a spiking neuron?
<bot>: The spike comes from the synapse. The synapse is the point where the neuron connects to another neuron. The synapse is made up of a neurotransmitter, which is a chemical that is released from the neuron, and a receptor, which is a protein on the other neuron. When the neurotransmitter is released, it binds to the receptor, and this causes the neuron to fire.