Vagus nerve stimulation has been used for the treatment of neuropsychiatric disorders, such as
epilepsy. However, little is known whether it is also effective for the treatment of
heroin dependence, in particular for relapse to
heroin seeking. In the present study, we investigated the effects of
vagus nerve stimulation on reinstatement (relapse) of
heroin-seeking behavior induced by
heroin priming or
heroin-associated cues. The rats were trained for
heroin self-administration for 14days and followed by extinction training in which
heroin was replaced by saline and
heroin-associated cues were turned off. In addition, animals were also received daily electric stimulation of vagus nerve (30Hz, pulse width of 0.5ms, 0.5mA (low-intensity) or 1mA (high-intensity); 30s on, 5min off; 10 continuous cycle per day) or false stimulation during extinction training. We found that such
vagus nerve stimulation significantly inhibited
heroin priming (0.25mg/kg, s.c.) - or
heroin-associated conditioned cue-induced reinstatement of drug-seeking behavior, when compared to false stimulation control. Further, such a behavioral inhibition was correlated to a reduction in the expression of FosB and an increase in the expression of phosphorylation of
cAMP response element binding protein (p-CREB) in nucleus accumbens. The data suggest that
vagus nerve stimulation may inhibit
heroin- or
heroin cue-induced relapse, possibly by regulation of the expression of Fos and CREB in nucleus accumbens.