Constant neurofibrillary changes in the neocortex in progressive supranuclear palsy. Basic differences with...

Area of Science:

• Neuropathology
• Neurodegenerative Diseases
• Tauopathies

Background:

• Progressive supranuclear palsy (PSP) is a neurodegenerative disorder.
• Neurofibrillary tangles (NFTs) are a hallmark of several neurodegenerative diseases, including Alzheimer's disease (AD).
• The distribution and characteristics of NFTs in PSP are not fully understood and may differ from AD.

Purpose of the Study:

• To characterize the neocortical neurofibrillary tangles (NFTs) in progressive supranuclear palsy (PSP).
• To compare the pathological features of NFTs in PSP with those observed in Alzheimer's disease (AD) and age-related changes.
• To investigate the presence and distribution of beta-amyloid deposits in PSP.

Main Methods:

• Bodian technique for visualizing NFTs.
• Anti-tau immunolabelling for tau pathology detection.
• Histopathological examination of brain tissue from PSP patients.

Main Results:

• NFTs were present in all 5 PSP cases (ages 58-76).
• PSP NFTs were predominantly in the precentral gyrus (Brodmann's area 4), affecting large pyramidal neurons and small cells, distinct from AD.
• NFTs were concentrated in layers V and VI of area 4, and beta-amyloid deposits were rare or absent in PSP, unlike in AD.
• Neuropil threads and abnormal fibers were observed, including in the hippocampus.

Conclusions:

• Neocortical NFTs in PSP exhibit distinct topographical and cellular distribution compared to AD.
• PSP represents a tauopathy characterized by neocortical tau accumulation in the absence of significant beta-amyloid pathology.
• PSP may serve as a valuable model for studying the mechanisms of tau deposition and spread in the brain.