---

Impaired motor functions were reported in cholestatic animals. This disorder in the function and death of motor neurons is highly dependent on changes in the environment around astrocytes and the blood-brain barrier, which is moderated by the aquaporin 4 protein. For this reason, the effects of cholestasis on motor cortex histology and morphology and aquaporin 4 protein levels were investigated in this study. Samples were stained by hematoxylin-eosin method. Histological changes in cortical brain were investigated. The amount of AQP4 protein in control, sham, and experimental groups were tested by immunohistochemistry. The thickness of motor cortex in cholestatic samples increased in comparison with the control and sham groups. Also, cholestasis caused wrinkle chromatic nuclei. On the other hand, tissue necrosis was detected in cholestatic group compared with sham and control groups. Reduction of cells densities in some cortical layers has been observed, which is probably indicative of cholestasis-induced cell death. AQP4 expression significantly decreased in BDL (p <0.05), but not in other groups (P<0.05). In this study, the pathology of motor cortex, which has also been associated with the decrease of neurons, could be considered the cause of motion abnormalities and AQP4 level reduction in cholestatic rats.