The effects of glial cells inhibition on spatial reference, reversal and working memory deficits in a rat model of traumatic brain injury (TBI).

AIMS: Evidence suggests that glial cells are influenced by Traumatic brain injury (TBI). Both protective and damaging roles have been attributed to reactive glial cells, but their role after TBI has not been well understood. In this study, the role of glial cells in TBI-induced cognitive impairment was investigated. MATERIALS AND METHODS: Male rats were randomly assigned to the following groups: Sham + PBS, sham + FC, TBI + PBS, and TBI + FC. FC (1 nmol/1 µl), a glial cell inhibitor, was injected into the lateral ventricle 10 min after TBI induction and it was repeated every 24 h until the seventh day. On days 8-13 post-injury, reference and reverse memory and on days 8-16 post-injury, working memory was assessed using the Morris water maze test. RESULTS: Brain-injured rats exhibited significant impairments in acquisition and retrieval phases of reference and reverse memory compared to sham rats and FC administration could not attenuate the deteriorative effect of TBI in different learning tasks. TBI rats showed impairment in acquisition (but not retrieval) of working memory. Sham animals which received FC showed a deficit in reversal memory acquisition and retrieval of reference memory compared to sham + PBS rats. CONCLUSION: The present study demonstrates that memory deficit induced by TBI cannot be improved by FC, and glial cells inhibition in uninjured animals causes impairments in reversal memory acquisition and retrieval of reference memory. Our results suggest that in addition to essential role of glial cells for memory formation in normal situation, their responses after TBI may have preventive effect against memory impairments.