Association between reduced expression of hippocampal glucocorticoid receptors and cognitive dysfunction in a rat model of traumatic brain injury due to lateral head acceleration

Expression of hippocampal glucocorticoid receptors (GRs) and spatial learning and memory were observed in rat model of diffuse traumatic brain injury (TBI) due to lateral head acceleration with an aim at investigating the relation between GRs expression and cognitive deficits. Immunohistochemical staining, Western blotting, and RT-PCR indicated that down-regulation of GRs expression occurred in the hippocampus among TBI-rats which demonstrated reduced performance of learning and memory in Morris water maze. As the GRs expression bounced up, the cognitive function approached to normal. It is concluded that reduced expression of hippocampal GRs was closely associated with learning and memory deficits in TBI-rats. Hippocampal GRs was involved in the biochemical mechanisms of cognitive deficits after TBI.

► Hippocampual GRs was down-regulated. ► GRs decrease was accompanied by spatial learning and memory deficits. ► As GRs expression bounced up, this cognitive function also recovered. ► There was a close association between reduced expression of hippocampal GRs and learning and memory deficits. ► Hippocampal GRs expression was involved in the biochemical mechanisms in learning and memory disorder after TBI.