Histological features of the Purkinje neurons of the Albino rat (Rattus norvegicus ) following letrozole administration

Aromatase inhibitors are increasingly being used as adjuvant therapy for hormone-responsive cancers. Thesedrugs may reduce the endogenous estrogen production in the cerebellum. Prolonged use has been associated with symptomssuch as ataxia, poorer balance performance and diminished verbal memory, suggesting impaired cerebellar function. Thus,this study sought to outline the structural basis for the cerebellar deficits observed. Twenty-seven male rats (3 baseline, 15experimental, 9 control) aged three months were recruited with the intervention group receiving 0.5 mg/kg of letrozole dailyfor 50 days by oral gavage while the control group received normal saline. Their cerebella were harvested for histologicalprocessing on days 20, 35, and 50. Photomicrographs were taken and analysed using Fiji ImageJ software. The dendritic spinedensities and Purkinje linear densities were coded and analyzed using IBM SPSS Statistics version 25.0. A P-value of ≤0.05was considered significant. A temporal decline in the Purkinje linear density as well as pyknosis and cytoplasmic eosinophiliawas noted in the intervention group (P=0.165). Further, the dendritic spine density of the Purkinje neurons in the interventiongroup was markedly reduced (P=0.01). The reduction in the linear cell density and the dendritic spine density of the Purkinjecells following letrozole administration may provide an anatomical basis for the functional cerebellar deficits seen in chronicaromatase inhibitor use.