Effects of naloxone on the withdrawal symptoms in heroin-dependent conditioned place preference rats and influences the spontaneous discharges in nucleus accumbens
10.13699/j.cnki.1001-6821.2017.05.016
- VernacularTitle:纳洛酮对海洛因依赖位置偏爱系统大鼠戒断症状及伏隔核自发放电的影响
- Author:
Zai-Man ZHU
1
;
Tian-Miao HUA
;
Qun-Wan PAN
;
Jing LI
;
Min LI
Author Information
1. 皖南医学院生理学教研室
- Keywords:
heroin;
naloxone;
conditioned place preference;
nucleus accumbens;
electroencephalogram wireless telemetry
- From:
The Chinese Journal of Clinical Pharmacology
2017;33(5):443-447
- CountryChina
- Language:Chinese
-
Abstract:
Objective To determine the effects of naloxone on the withdrawal symptom in heroin-induced conditioned place preference (CPP) rats and the spontaneous firing properties in nucleus accumbens (NAc).Methods The heroin-dependent rat models were established,and the recording electrodes were implanted to NAc via stereotaxic apparatus.After 4 days of natural withdrawal,rats were injected with naloxone (0.5mg· kg-1),after which the withdrawal symptoms were evaluated.The electrical activities of NAc neurons were recorded by wireless telemetry at the following stages:before modeling,immediately after heroin administration,and heroin withdrawal.The frequency distribution at 0.5 ~ 30.0 Hz of the spontaneous firing was arranged and compared with that after naloxone administration.Results The heroin-dependent rat model was effectively established through the CPP system.Rats showed significant withdrawal symptoms with dynamic characteristics,which appeared the most significant on the first two days of withdrawal (6.6 ± 1.7) point,compared with before modeling with statistical difference (P <0.01).After naloxone irritability,the withdrawal symptoms reached the highest level(7.2 ± 1.3) point,compared with before modeling with statistical difference(P < 0.01).In each state,δ wave occupied the largest ratio in the spontaneous discharge,while β wave held the smallest proportion.However,the distribution gradient of the different electroencephalogram(EEG) in each state demonstrated similar characters.Compared with the state immediately after heroin administration ofδ wave (45.58 ± 7.80)% and θ wave (22.67 ± 3.37)%,the ratio of δ wave (38.58 ±5.76%),θ wave (18.75 ±3.31)% in the state of naloxone irritation with statistical difference(P <0.05).Compared with the state immediately after heroin administration of the ratio of β31 wave (7.50 ±2.28)% and β2 wave (10.17 ± 3.33) %,the ratio of β1 wave (11.00 ± 1.35) % and β2 wave (16.50 ± 2.15) % in the state of naloxone irritation with statistical difference (P < 0.01).In summary,after naloxone irritability,EEG energy state showed the largest difference with the state immediately after heroin administration,and differed less with the state before heroin administration.Conclusion Naloxone can stimulate the withdrawal symptoms in heroin-dependent rats,and significantly affect the electrophysiological properties in NAc,which implies that naloxone exerts an important role in NAc energy state in drug-dependent rats.