Background: Here we investigated the effects of electroacupuncture over locomotor sensitization induced by ethanol in mice.
Methods: Adult male Swiss mice were daily injected with ethanol (2 g/kg, i.p.) or saline for 21 days (acquisition phase). After 4 days of withdrawal, all animals were challenged with ethanol (1.4 g/kg, i.p.). The locomotor activity during 30 minutes was accessed just after the ethanol challenge. Electroacupuncture at acquisition, expression, or maintenance phases of locomotor sensitization was provided over ST-36 (Zusanli) or PC-6 (Neiguan) as well as concomitantly over these 2 acupoints. One hour after the challenge with ethanol, the animals were decapitated, the hippocampus, striatum, and prefrontal cortex were dissected, and the expression of homer1A mRNA assessed by PCR.
Results: Electroacupuncture provided simultaneously over ST-36 and PC-6 (but not to ST-36 or PC-6 alone) inhibited the acquisition, expression, and maintenance of ethanol-induced locomotor sensitization. In addition, electroacupuncture blocked the diminution of homer1A mRNA expression triggered by ethanol in the acquisition (striatum and prefrontal cortex), expression (hippocampus), and in the maintenance (hippocampus and prefrontal cortex) phases.
Conclusion: Electroacupuncture provided concomitantly over ST-36 and PC-6 prevents the sensitization of the mesocorticolimbic pathway induced by ethanol in mice. In addition, these effects were accompanied by changes in the expression of homer1A. We suggest that electroacupuncture effects over ethanol-induced locomotor sensitization are associated to its ability to modulate homer1A expression and glutamatergic plasticity.