3α-diol administration decreases hippocampal PKA (II) mRNA expression and impairs Morris water maze performance in adult male rats.

The effect of testosterone and its metabolites on learning and memory has been the subject of many studies. This study used the Morris water maze task to investigate the effect of intra-hippocampal injection of 3α-diol (one of the metabolites of testosterone) on acquisition stage of spatial memory in adult male rats. During the experiment we observed that 3α-diol, significantly impaired Morris water maze performance in treated rat's compared with controls. Because signaling event mediated by protein kinase A (PKA) especially PKA (II) are critical for many neuronal functions such as learning and memory, the hippocampus was analyzed for mRNA expression of PKA (II) using TaqMan real time RT-PCR. The results indicated that the transcription levels of PKA (II) were significantly decreased in animals treated with 3α-diol compared with controls. Thus, the findings suggest that administration of 3α-diol in hippocampus of adult male rats impairs memory function, possibly via down-regulation of PKA.