ABSTRACT
Objective To investigate the influence of deep brain stimulation (DBS) at high frequency to the bilateral nucleus accumbens on morphine-induced conditioned place preference (CPP) and relapse behaviors during extinction phase in rats. Methods Twenty adult SD rats were employed in the experiment. Through stereotactic operation, outer electrode cannula was implanted into rats' bilateral nucleus accumbens. After 5 days of rest, the morphine-dependent rat model with CPP was established through intraperitoneal morphine injection (10 mg/kg). The rats, after being randomly divided into experimental group (morphine+DBS) and control group (morphine+sham DBS), were electrically stimulated using DBS circuits. Rats in the experimental group were given high frequency electrical stimulations while the control group was given sham stimulation. The CPP score of the two groups was recorded the day after stimulation until successful extinction and then the extinction time was compared between the two groups. After successful extinction the rats were given small dose of morphine to trigger relapse within 24 hours, and the CPP score was recorded and compared between the two groups.Results Compared with the control group (six days), the experimental group (26 days) had a longer extinction time. After relapse, the retention time within the drug-paired chamber of the experimental group was (357.01±192.72) s, obviously shorter than that of the control group ((704.91±181.35) s;t=2.370, P=0.034 6). Conclusion High frequency DBS to rats' bilateral nucleus accumbens can prolong extinction time but inhibit relapse behavior.
ABSTRACT
Objective To investigate the effect of high frequency stimulation of bilateral nucleus accumbens on relapse behaviors in morphine-dependent rats.Methods Twenty adult SD rats were employed in the experiment.Through stereotactic operation,outer electrode cannula was implanted into rats' bilateral nucleus accumbens.After 5 days of rest,the morphine-dependent rat model with conditioned place preference (CCP) was established through intraperitoneal morphine injection (10 mg/kg).After acquisition of CPP,normal saline was replaced with morphine for CPP extinction training.CPP test was used to exam the effect of extinction.The rats,after being randomly divided into experimental group (morphine+DBS) and control group (morphine+sham DBS),were electrically stimulated using modified DBS circuits.Rats in the experimental group were given high frequency electrical stimulation while the control group was sham stimulation.After consecutive stimulation for 7 days,rats in the two groups were given small dose of morphine (3 mg/kg)to trigger relapse.Results (1) The CPP score increased after the establishment of rat models compared with pre-establishment of the rat models((616.2±74.7) s vs (353.9±84.3) s,P<0.01).(2) The CPP score after extinction training decreased compared with pre-conditioned CPP score ((456.4± 148.8) s vs (353.9±84.3) s),P=0.0847) and had no statistical difference compared with post-conditioned CPP score ((456.4±148.8) s vs (616.2± 74.7) s,P=0.0219).(3) When the relapse was induced by small doses of morphine within 24h after the last stimulation,the CPP score of the experimental group decreased compared with the CPP score of control group ((330.1 ±212.6) s vs (684.2±230.2)s,P=0.0029),and the relapse was restrained.Conclusion High frequency DBS of bilateral nucleus accumbens can attenuate relapse behavior in rats
ABSTRACT
Depression is a common complication after stroke.It is often associated with disability,cognitive impairment,and increased mortality.This article reviews the epidemiology,risk factors,predictive factors,and pathophysiology mechanisms of post-stroke depression.
ABSTRACT
Flavonoids are widely used today in the treatment of ischemic stroke. The therapeutic effects and functions of flavonoids are, therefore, generating more and more interest.