If a child is watching a favorite sibling getting scolded for misbehavior which type of neuron is likely to be activated in an empathetic response to this observation?

Answer 1

In short - there is no one type of neuron that would be activated; there would be many types across a number of regions such as those involved in appreciation (temporal association areas, occipital cortices, prefrontal areas) as well limbic areas involved in emotion (amygdala, orbifrontal cortex, raphe nuclei, locus coerules and the hippocampus).

It's the Mirror Neuron