Fig. 2.

Representative distributions of tau and TDP-43 pathology in cortical layers and juxtacortical white matter in pathologic subgroups of FTLD-tau and FTLD-TDP. FTLD-tau typically displayed a lower layer-predominant profile of AT8-immunoreactive tau pathology, while FTLD-TDP displayed an upper layer-predominant profile of 1D3-immunoreactive TDP-43 pathology. Neuronal and glial inclusions were interspersed among cortical layers and consistent with each pathologic subtype. In FTLD-tau, neuronal inclusions (i.e., pre-tangles, tangles, globose tangles, ballooned neurons) and glial inclusions (i.e., tufted astrocytes, astrocytic plaques, ramified astrocytes, coiled bodies) were found in all cortical layers in most regions examined, with high densities of neuritic threads common to lower layers in many regions. WM tau accumulation was often similar to total GM tau burden, and generally resembled neuritic threads or coiled bodies. In FTLD-TDP, TDP-43 pathology was observed more often in upper layers and was comprised of mostly small neuronal cytoplasmic inclusions and dystrophic neurites (open arrows point to examples of small neurites) depending on the pathologic subtype of TDP. TDP-43 pathology in WM typically resembled curvilinear oligodendrocytic inclusions that were consistently less frequent than TDP-43 pathology in GM. All images acquired from the MFC region. Roman numerals indicate cortical layers. Scale bars = 100 µm