Aim: 

To evaluate the effect of testosterone levels and spatial performance in rats during adulthood and to assess whether testosterone affects spatial performance itself or via its metabolite estradiol.

Methods: 

In 40 male rats divided into 4 groups (control, testosterone, cyproterone acetate, testosterone+cyproterone acetate) spatial memory and learning was tested in Morris water maze during 5 consecutive days. Latency times were assessed by video tracking AnyMaze™ software. Frontal cortex and hypothalamus were stored in trizol for RNA isolation and RT-PCR was performed to assess RNA expression of genes for aromatase and GnRH. Testosterone levels were determined.

Results: 

All groups improved during 5 days (p < 0.02), on the third and the fourth day, there were no significant differences in latency times between the groups. During the first and the second day, however, control and combined groups reached shorter latency times in comparison to testosterone and cyproterone acetate, groups (p < 0.02 and p < 0.04, respectively). In hypothalamus, aromatase expression was the highest in the control group (p < 0.003), and in cortex, testosterone group showed the highest expression rate of aromatase (p < 0.01). There were no significant differences among groups in cortex regarding GnRH, however, in hypothalamus, control group reached the highest expression (p < 0.001).

Conclusion: 

The results suggest that aromatization of testosterone may play a role in spatial memory and learning in adult rat males, however, it seems that for working memory non-genomic effects of androgens should be considered.