neurodegenerative pathway Neurodegenerative Diseases Neurodegenerative diseases group together a number of conditions of various and many times poorly understood origins that are characterized by the progressive loss of particular neurons, the formation of particular structures such as plaques and fibrils, and protein aggregates. Proteosomal degradation, programmed cell death and oxidative stress are among a number of pathways thought to be disrupted. PW:0000014 neurodegenerative disease pathway pathway nervous system disease pathway