Do all types of synapses in the brain change based on spike-timing-dependent plasticity? Synapses likely change their strengths based on a form of spike-timing-dependent plasticity. Is this true for all types of synapses in all parts of the human brain? I wonder if there are also synapses with hard-wired connectivity, i.e. that do not depend on the activations of nearby neurons or do not change at all.
Probably not. STDP has mostly been demonstrated in excitatory glutamatergic neurons in the hippocampus. Considering all the other types of cells in the brain (dopaminergic, serotonergic, inhibitory, those located in cortical areas with closed plasticity windows those in the brain stem), it's erroneous to assume they all implement STDP like rules. That said, I can't think of any examples off the top of my head...