The figure above shows a synapse through which electrical signals are transmitted from one neuron to another via messenger molecules called . When an action potential reaches the of a presynaptic neuron, these messenger molecules inside the are released out of the presynaptic neuron to the . Then they bind to the present on dendrites of the postsynaptic neuron, causing them to open up. Once they are opened, specific ions depending on the type of the channel flow in or out of the postsynaptic neuron via diffusion. The membrane potential of the postsynaptic neuron changes, either increases or decreases. ligand-gated ion channels neurotransmitters leak channels voltage-gated ion channels electrical synaptic cells synaptic cleft nucleus axon terminals synaptic vesicles chemical cell body