Paraphrased from the Wikipedia article "Synapse":
There are two fundamentally different kinds of synapses:
Chemical synapses, which convert electrical activity in the presynaptic neuron into the release of neurotransmitters via the activation of voltage-gated calcium channels. The released neurotransmitters, which vary in type by cell, bind to receptors of the postsynaptic cell, giving rise to complex behaviors.
Electrical synapses, in which presynaptic and postsynaptic are connected by "gap junctions" or synaptic clefts capable of passing electrical current, resulting in rapid signal transduction.
Are there certain structures and locations in the nervous system that are mostly or exclusively chemical synapses, and certain ones that are mostly or exclusively electrical? Or, are they mixed throughout the nervous system?
For example, one might suppose that the neurons which transmit signals from brain to limbs might be electrical, due to the apparent advantage of fast transduction times in this scenario. On the other hand, it might be advantageous for the brain to be capable of more the dynamic, albeit slower, signal transmissions made possible by chemical synapses. Are these intuitions accurate?