Why does the brain mostly use chemical synapses when electrical ones are faster? · Grey Matter

An electrical synapse passes current straight through gap junctions with almost no delay, in both directions, but the receiving cell gets only a fraction of the signal and its sign cannot change.

Why does the brain mostly use chemical synapses when electrical ones are faster?

An electrical synapse passes current straight through gap junctions with almost no delay, in both directions, but the receiving cell gets only a fraction of the signal and its sign cannot change. A chemical synapse costs a delay (about 0.15 ms at the fastest mammalian synapses at body temperature, 0.5 to 1 ms in textbook figures) and in exchange it can amplify, since one vesicle opens hundreds of receptors. It can also turn excitation into inhibition by releasing GABA, be tuned by neuromodulators, and change its strength with experience. Electrical synapses are kept for jobs where speed and synchrony matter more than control, such as coupling interneurons into a common rhythm.