(B) Apoptotic neuron: the execution phase is mediated by the activation of the caspases that induce the degradation of a series of nuclear and cytosolic targets. This phenomenon culminates in the chromatin condensation with the shrinkage and collapse of the neuron that generates the apoptotic bodies.
(C) Necrotic neuron: the swelling of the entire neuron with grossly swollen organelles is the peculiar feature of this type of death. One of the important steps in necrosis is an excessive influx of intracellular calcium that by damaging the respiratory cycle causes neuronal death.
(D) Autophagic neuron: cytoplasm is characterized by a number of autophagic vacuoles with a double-membrane vesicle that encapsulates whole organelles and bulk cytoplasm. This autophagosome then fuses with the lysosomes where the contents are degraded and recycled: the neuron digests itself as a suicide strategy.