Immunomorphological Changes in the Olfactory Bulbs of Rats after Intranasal Administration of Rotenone

Changes in the structure of the olfactory bulbs after long-term intranasal administration of pesticide rotenone, a classical inductor of parkinsonism, to rats were studied by the methods of immunomorphology. In rats intranasally receiving rotenone in a dose of 2.5 mg/kg every other day over 2 weeks, a decrease in the density of dopaminergic neurons and the area of astrocyte processes in the olfactory bulbs, activation of microglia in the glomerular layer, and enhanced α-synuclein phosphorylation and its accumulation in the bodies of mitral layer neurons were observed. The observed changes agree with the hypothesis on pathological α-synuclein transport via the olfactory route in Parkinson's disease and confirm relevance of the rotenone model of Parkinson's disease for studies of the pathological accumulation of α-synuclein.