Effects of morphine on Gi_2 protein in primary cultured hippocampal neurons / 解放军医学杂志

ABSTRACT

Objective The molecular basis for opiate tolerance and dependence remains poorly understood despite extensive investigation in several preparations, including the hippocampus. Recent studies have implicated that the hippocampus played a central role in opiate tolerance, dependence and withdrawal. The current study is to explore the change in guanine nucleotide binding protein-inhabitant (Gi_2) protein in primary cultured hippocampal neurons with morphine treament. Methods The hippocampus was harvested from newborn Sprague-Dawley rats. Primary hippocampal neuronal cultures of 7 days in vitro were used and divided randomly into six groups (n=6), i.e. morphine treatment 4h group (M4), 8h group (M8), 16h group (M16), 24h group (M24), 48h group (M48) and control group (C). All morphine treatment groups were treated with morphine (10?mol/L). C group was treated with saline. The G protein levels were determined with immunofluorscence and laser scanning confocal microscope (LSCM) imaging techniques. Results Gi_2 protein levels in M16, M24 and M48 groups decreased significantly compared with that in C group (P0.05). Among M16, M24 and M48 groups, Gi_2 protein level was lowest in the M48 group. Conclusion The results indicated that Gi_2 protein levels decreased significantly in primary cultured hippocampal neurons with morphine treatment, which might be a potential molecular mechanism of opioid tolerance and dependence.