A SOMATODENDRITIC DISTRIBUTION OF RAB11 IN RABBIT BRAIN NEURONS

COMPARISONS of subcellular targeting in neurons and epithelial cells h ave led to suggestions that apical epithelial antigens localize to axo ns and nerve terminals. We have studied the distribution in brain of t he small GTP-binding protein, Rab11, which is localized to apical vesi cular populations in epithelial cells. Sections of rabbit brain were e xamined by immunohistochemistry using a monoclonal antibody against ra bbit Rab11. Rab11 immunoreactivity was present exclusively in neurons. In all regions examined, including forebrain, cerebellum, thalamus an d brainstem, Rab11 immunoreactivity was observed in cell bodies and de ndrites. No staining was observed in hippocampal neurons. These result s indicate that the distribution of Rab11 does not support previous su ggestions that apical epithelial markers should localize to axons and synaptic endings.