Expression of Gi_2 proteins in brain regions of acute or chronic morphine dependent rats / 解放军医学杂志

ABSTRACT

Objective To investigate the changes in inhibitory guanine nucleotide binding protein Gi_2 in five brain regions of morphine addicted rats ventral tegmental area, nucleus accumbens, prefrontal cortex, hippocampus and locus caeruleus. Methods 36 adult male SD rats were randomly divided into six groups (n=6) acute morphine dependent group, acute abstinence group, acute control group, chronic morphine dependent group, chronic abstinent group and chronic control group. Morphine dependent models were reproduced. Withdrawal syndrome was induced with naloxone 5mg/kg for 30min in rats of abstinence group. All rats were sacrificed by decapitation. Frozen sections of coronal plane of respective brain regions (ventral tegmental area, nucleus accumbens, prefrontal cortex, locus coeruleus, hippocampus) were prepared. The relative concentrations of Gi_2 protein were determined with immunohistochemical methods. Results Gi_2 proteins in acute morphine dependent group and acute abstinence group were significantly decreased compared with that of acute control group in nucleus accumbens (P