Figure 6. L-BMAA injections stimulated the emergence of cytosolic TDP-43 immunoreactive aggregates in spinal cord motor neurons. Scale bar = 100 μm. In the motor neurons of normal control rats, TDP-43 expression was primarily confined to the nucleus (indicated by the arrow in O). However, approximately 6 weeks after L-BMAA injection, a decline in the distinct nuclear expression of TDP-43 was accompanied by the emergence of cytosolic staining in a proportion of degenerating motor neurons. By 8 weeks after L-BMAA injection, a pronounced decline in TDP-43 expression in the nuclei of damaged motor neurons was observed (indicated by the arrow in P), and the nuclei showed a bulging and vacuolated morphology. With C16+Ang-1 or L-serine treatment, the TDP-43 labeling in large motor neurons was mainly localized in the nuclei compared with that in the control group, and this phenomenon was more visible in the combined treated group (shown by the arrow in S).