1.*electrical synapses* exist where gap junctions connect two neurons; allow for rapid communication between adjacent neurons via ions flowing through gap junctions in order to transport electrical signals from one neuron to the other
2.*chemical synapses* comprise of one neuron secreting a neurotransmitter into ecf in response to an action potential arriving at its axon terminal; neurotransmitter then binds to receptors on plasma membrane of second cell and triggers an electrical signal in that cell that may or may not initiate an action potential *majority of synapses = chemical synapses!