A few years ago I caught a frog (have no idea what species it is but must have been a common one) and gave its organs to a friend for sectioning. These are stained with the regular H&E.
The first image shows a group of nerve cells situated among the connective tissue of the heart. Notice the single densely stained nucleolus and the homogeneous cytoplasm and nucleoplasm.
The second shot shows a neuron with a fragmented nucleolus and fairly heterogenous cyto- and nucleoplasm. These are both indicative of cell senescence and death in neurons.
Obj. 40x, eyepiece 10x.