Comparative cytoarchitectural and proteomic analysis of the primary motor cortex in pigs and wild boars reveals domestication associated changes

Background Domestication appears to modify the morphology and physiology of the central nervous system. Owing to the limited availability of proteomic and cytoarchitectural data for comparisons between wild and domesticated species, we conducted a comparative analysis of the cytoarchitecture and protein profile of the primary motor cortex (M1), the key region controlling motor activity, in pigs and wild boars to assess the effects of domestication. Methods M1 samples used in this study were obtained from brains previously analyzed in an earlier investigation. From six pig and wild boar brains fixed in paraformaldehyde, the right and left M1 regions were isolated. Paraffin sections, 5 µm thick, were prepared for histological and immunohistochemical analyses, and 10 µm sections were used for proteomic analysis. In M1, cortical thickness, cell density, and the density of parvalbumin-positive neurons were quantified, while proteomic analysis was performed to characterize the M1 protein profile. Results Our results revealed a lower density of parvalbumin-expressing interneurons compared with wild boars. Moreover, proteomic analyses showed an overexpression in wild boars of proteins involved in oxidative stress protection and synaptic plasticity. Conclusions These findings indicate that domestication may have influenced the cytoarchitecture of the pig M1. The reduced number of parvalbumin-expressing interneurons may reflect a modification in neuronal network properties in pigs compared with wild boars. In contrast, the proteomic profile of wild boars revealed an enrichment of proteins associated with oxidative stress protection and synaptic plasticity, supporting structural distinctions in the M1. Collectively, these results suggest that the wild boar may exhibit more finely tuned regulation of motor control, supported by enhanced mechanisms to sustain neuronal activity and viability.