The expression of growth hormone receptor gene transcript in the prefrontal cortex is affected in male mice with diabetes-induced learning impairments

Previous studies have indicated that both growth hormone (GH) deficiency and diabetes are conditions associated with impairments in learning and memory processes. In this study, we investigated the effect of streptozotocin-induced diabetes on spatial learning in mice using the Barnes maze (BM). The expression of the GH receptor (GHR) gene transcript in areas of the brain associated with learning and memory were examined. The results indicated that the GHR gene transcript is up-regulated in the prefrontal cortex (PFC) of diabetic mice compared to controls. In addition, there was a significant correlation between the expression of GHR mRNA and performance in the BM during the acquisition phase in diabetic but not control mice. These results suggest that diabetes induces an imbalance in the GH/IGF-1 system leading to altered activity in the PFC and associated cognitive deficiencies.

► The Barnes maze is for the first time used to study spatial learning in diabetic mice.
► Diabetic mice differ in latency and primary errors during the acquisition phase.
► Diabetic mice exhibit altered gene expression of the growth hormone receptor (GHR).
► There is a significant correlation between maze performance and GHR gene expression.