Abnormal neuron morphology Axonal spheroids Axonal spheroids have been found in developmental degeneration and the aging brain, as well as in injury, neuropathy, neuroaxonal dystrophy, and many neurodegenerative diseases. Axonal spheroids can be observed in neurons in a conjunctival biopsy. During neurodegeneration, bubble-like swellings form along the length of the axon, a primary and early effect of dynamic axonal deformation. These varicosities, spheroids, or swellings have been described as beads on a string and branches bearing fruit, and they frequently appear on degenerating axons. axonal spheroids spheroid axon