Table 1.
Immunohistochemical scoring of Aβ42 and AT8.
Table 2.
Primary antibodies used in the present study.
Figure 1.
Distributions of hyperphosphorylated tau (A) and Aβ42 (B) in the leopard cat brains.
(A) Hyperphosphorylated tau-positive cells were observed throughout the hippocampus and extended into the parahippocampal gyrus and the ectosylvian gyrus. (B) Aβ42 was deposited throughout the cerebral cortex as well as in the hippocampus. Speckled deposits of Aβ42 (arrowheads) were observed in a severely affected brain. Note that these deposits were not argyrophilic plaques. Bar = 2 mm. PHP: parahippocampal gyrus, DG: dentate gyrus, LRS: lateral rhinal sulcus, ESG: ectosylvian gyrus, EMG: ectomarginal gyrus, MG: marginal gyrus, FG: fornicatus gyrus.
Figure 2.
Sequential sections subjected to immunohistochemical examinations of Aβ and tau protein expression in the cerebral cortex.
Figure 3.
Argyrophilic NFT and neuropil threads were abundantly observed in the areas containing hyperphosphorylated tau-positive cells. Bar = 100 µm. Inset: higher magnification of the affected neurons. Bar = 20 µm.
Figure 4.
(A) Some neuronal somata and neurites were filled with filamentous bundles (black arrows). Bar = 1 µm. (B, C) The filaments formed paired structures with diameters of 10–20 nm. Straight laminar filaments (white arrowheads) and constrictions (white arrows) suggesting helical structure. Bar = 50 nm.
Figure 5.
Double immunofluorescence staining of hyperphosphorylated tau (AT8)/MAP2 (A), AT8/GFAP (B), and AT8/Olig2 (C).
Hyperphosphorylated tau was mainly localized in neuronal cells (MAP2+) and a few oligodendrocytes (Olig2+) (A, C), but not in astrocytes (GFAP+) (B). Bars = 100 µm.
Figure 6.
Double immunofluorescence staining of hyperphosphorylated tau (AT8)/GSK-3β (A), AT8/Phospho-GSK-3β (Ser9) (B), AT8/ubiquitin (C), and hyperphosphorylated tau (AT100)/tau (D).
(A, B) AT8 colocalized with GSK-3β but not with phospho-GSK-3β (Ser9). Bars = 100µm. (C) Granular staining of ubiquitin was observed in the hyperphosphorylated tau-positive neurons. Bar = 50 µm. (D) AT100 colocalized with aggregated tau. Bar = 50 µm.
Figure 7.
Sequential sections subjected to immunohistochemical staining of hyperphosphorylated tau (AT8), 3R-tau, and 4R-tau in the CA1 region of a neonate brain (A), an adult brain without AT8-positive aggregates (B), and an adult brain with AT8-positive aggregates (C). (A) Only the 3R-tau isoform was expressed in the brain of the neonatal leopard cat.
(B, C) In the adult brains, both the 3R-tau and 4R-tau isoforms were expressed regardless of the presence or absence of AT8-positive aggregates. Bar = 100 µm.
Figure 8.
Nucleic acid and amino acid sequences of leopard cat and human Aβ region.
In humans, the 7th amino acid residue of the Aβ peptide is aspartic acid (D), while in leopard cats it is glutamic acid (E).
Table 3.
Senile plaque and neurofibrillary tangle formation in humans, leopard cats, and rodents.