Q.What is the difference between electrical transmission and chemical transmission?

• At an electrical synapse the membranes of the two neurons lie extremely close together, so electrical current flows directly from one neuron into the next, much like impulse conduction along a single axon.
• At a chemical synapse the two neurons are separated by a fluid-filled synaptic cleft, so the impulse cannot cross directly; instead it is carried across by neurotransmitters released from the presynaptic neuron.
• Electrical transmission is therefore much faster, since there is no intermediate chemical step, while chemical transmission takes slightly longer because vesicle release, diffusion and receptor binding all have to occur. …

Synapses, the junctions where one neuron hands its signal to the next, come in two forms that differ fundamentally in how the signal actually crosses the junction.

At an electrical synapse, the membranes of the presynaptic and postsynaptic neurons lie extremely close together, almost touching. Because of this proximity, an electrical current generated in one neuron can flow directly into the next, in much the same way an impulse continues along a single, uninterrupted axon. This makes electrical transmission very fast, and such synapses are relatively rare in the human body.

At a chemical synapse, by contrast, the two neurons' membranes are not in contact; they are separated by a narrow, fluid-filled synaptic cleft. Since an electrical current cannot leap this gap on its own, the signal must be carried across chemically. The arrival of an impulse triggers the release of neurotransmitters from synaptic vesicles into the cleft; these diffuse across, bind receptors on the postsynaptic membrane, and open ion channels there to regenerate a new potential. …