In the hypoglossal nucleus, BBs and TDP-43 inclusions were found in 31.1% and 41.8% of total neurons, respectively, and 29.2% contained both BBs and TDP-43 inclusions (Table 2). In the facial nucleus, BBs and TDP-43 inclusions were found in 21.5% and 24.4% of total neurons, respectively, and 17.3% contained both BBs and TDP-43 inclusions (Table 2). In the present study, the virtual slide system using sequential staining of the same sections with HE and anti-TDP-43 antibody effectively revealed co-localization of BBs and TDP-43 Gefitinib ic50 inclusions in the same neurons. TDP-43-immunoreactive wisp-like and skein-like inclusions were closely associated

with BBs (Fig. 1a–d). BBs were also located in the peripheral portion of TDP-43-immunoreactive YAP-TEAD Inhibitor 1 clinical trial round inclusions (Fig. 1e,f). In the spinal cord, 30.5% of anterior horn cells with TDP-43 inclusions contained BBs and 89.8% of anterior horn cells with BBs contained TDP-43 inclusions. In the hypoglossal nucleus, 61.0% of neurons with TDP-43 inclusions contained BBs and 97.2% of neurons with BBs contained TDP-43 inclusions. In the facial nucleus, 76.1% of neurons with TDP-43 inclusions contained BBs and 76.7% of neurons

with BBs contained TDP-43 inclusions. Murayama et al.[7] reported that ubiquitin-positive, ill-defined structures were closely associated with BBs in lower motor neurons in 15 out of 23 cases of sporadic ALS. van Welsem et al.[11] immunohistochemically examined the lower motor neurons (spinal anterior horn and hypoglossal nucleus) in patients with ALS, using antibodies against cystatin C and ubiquitin, and reported that the incidence

of BBs and skein-like inclusions in the lower motor neurons was 15.3% and 5.3%, respectively. The latter authors have also described that BB-containing neurons were devoid of skein-like inclusions, whereas skein-containing neurons always exhibited BBs.[11] We demonstrated that the incidence of co-localization of BBs and TDP-43 inclusions was 15.2% of total neurons in the anterior horn, 29.2% in the hypoglossal nucleus and 17.3% in the facial nucleus. Thus, the incidence of co-localization of these two inclusions is much higher than was previously thought. The frequency of TDP-43 inclusions next was significantly higher in neurons with BBs than in those without BBs in the anterior horn (Fig. 2a), hypoglossal nucleus (Fig. 2b) and facial nucleus (Fig. 2c) in patients with ALS by statistical analysis (Chi-square for independence test and Fisher’s exact probability test). Mantel-Haenszel chi-square analysis showed that the frequency of TDP-43 inclusions in the spinal cord and brainstem motor neurons with BBs was significantly higher (P < 0.01) than in those without. Immunoelectron microscopy demonstrated co-existence of TDP-43-immunoreactive structures and BBs in the cytoplasm of anterior horn cells (Fig. 3a). TDP-43-immunoreactive granulofilametous structures were found within and around moderately electron-dense amorphous BBs, surrounded by vesicular structures (Fig.