Final answer:
The molecules found in sphere-shaped deposits between neurons in individuals with Alzheimer's disease are amyloid plaques, composed of beta-amyloid peptide fragments.
Step-by-step explanation:
The sphere-shaped deposits found in spaces between neurons in the hippocampus in individuals with Alzheimer's disease are called amyloid plaques. These deposits consist primarily of extracellular aggregations of beta-amyloid (Aβ) peptide fragments. Along with neurofibrillary tangles of hyperphosphorylated tau inside of neurons, amyloid plaques are classic indications of Alzheimer's disease, contributing to the progressive death and degeneration of neurons, which leads to memory loss and dementia.