Influence of estrogen on the cerebellar cortex of male rats

Effects of estrogen in the brain regions which are not directly related to neuroendocrine functions are not fully known. Therefore we investigated the long term effects on the cerebellar cortex of a neonatally (3rd day) administered single dose (1 mg) of estrogen. Golgi impregnated and paraffin sections (Bielschowsky, Klûver-Barerra and basic fuchsin-alcian-blue) of cerebella of 10 treated adult (365 days old) male rats and of 10 matched controls were studied. Simultaneous to the morphological analysis of the cerebellar cortex, stereological methods were applied. In treated rats the Purkinje neurons had a more developed dendritic arborisation with numerous spines, but had significantly decreased (p<0.001) cellular body volumes (14 x 10-3 mm3) in comparison to controls (27 x 10-3 mm3). In treated animals the molecular layer thickness (148.94 μm) of the cerebellar cortex was significantly decreased (p<0.001) compared to controls (514.52 μm), and the thickness of the granular layer (372.35 μm) was significantly (p<0.001) increased compared to controls (270.80 μm). In treated rats the number of neurons in the granular layer was 338.87 mm2 (controls 118.81 mm2) and in the molecular layer was 22.86 mm2 (controls 55.23 mm2). Our results indicate significant and long term effects of a single dose of estrogen (administered in the neonatal period) on the cerebellar cortex of male rats