While looking at slides of brain tissue in a physiology class, you see groups of damaged neurons that have collected around a core of protein. what are you looking at?

Looking for neuritic plaques.
Another name for neuritic plaques is senile plaques. It is referred to as extracellular deposits of amyloid beta which is found the grey matter of the brain.
The abundance of astrocytes and microglia and degenerative of neural structures are being associated with senile plaque can be a characteristic of Alzheimer disease.