Antigen retrieval was performed by heating/autoclaving (10 min at 121°C in 10 mmol/L sodium citrate buffer, pH 6.0) sections prior to immunohistochemical staining. Sections were then incubated with a given primary antibody (listed in Table 1) overnight at 4°C. Bound antibodies were detected with the appropriate Vectastain Elite ABC kit (Vector Laboratories, Burlingame, CA, USA), with 3,3′-diaminobenzidine tetrahydrochloride

used as the chromogen. We assessed the staining specificity by replacing the primary antibodies with an appropriate amount of non-immune rabbit serum or phosphate-buffered saline solution containing 3% bovine serum albumin. No deposits of reaction products were RG7420 mouse seen in the sections thus treated. In multiple brain and spinal cord regions, TDP-43 pathology severity was graded using a 4-point ordinal scale (0:0/high power field (HPF ×400), 1:1–2/HPF, 2:3–5/HPF, 3: more than 5/HPF) independently by two individuals (MK and HI). General pathological examination demonstrated no significant findings except for lung edema. Although slight optic nerve cupping was noted, optic atrophy was not obvious. No remarkable changes in ciliary body or trabecular

BI 2536 clinical trial meshwork were observed (Fig. 1D,E). Brain weight was 840 g after fixation. Macroscopic examination indicated conspicuous motor cortex atrophy (Fig. 1F). Examination of serial coronal sections revealed greyish-brown discoloration and atrophy of the bilateral putamen (Fig. 1G). Microscopically, bilateral corticospinal tracts exhibited degeneration (Fig. 2A). Loss of spinal anterior horn cells (AHCs) and gliosis were observed (Fig. 2B), whereas posterior columns, Clarke’s columns, intermediate lateral columns and the Onuf’s nucleus were spared. In the brainstem, moderate neuronal loss and gliosis were noted in the hypoglossal and facial

motor nuclei. No Bunina bodies were found in the surviving spinal and brainstem motor neurons. In the motor cortex, Megestrol Acetate most neurons, including Betz cells, exhibited degeneration, and extensive gliosis accompanied by numerous ionized calcium binding adaptor molecule 1 (IBa-1)-positive microglia was observed (Fig. 2C,D). Outside the motor system, neuronal loss was severe in the putamen, moderate in the globus pallidus and mild in the substantia nigra (Fig. 2E,F). TDP-43-positive round and skein-like neuronal intracytoplasmic inclusions (NCIs) were conspicuous throughout the CNS (Fig. 2G,H,I,J), and were observed most frequently in spinal AHCs. Immunohistochemistry for TDP-43 revealed glial cytoplasmic inclusions (GCIs) (Fig. 2H,K), which were more numerous than NCIs. Figure 3 shows semiquantitative analysis of the distribution of these TDP-43-positive NCIs and GCIs. Immunohistochemistry for the Golgi marker, anti-trans-Golgi-network 46 (TGN-46), revealed fragmented Golgi apparatus (GA) in virtually all spinal AHCs and brainstem motor neurons, whereas the GA of other non-motor neuron cells appeared normal (Fig. 2L).