海洛因诱导条件性位置偏爱大鼠行为学特征及边缘前区损毁的影响

Effects of prelimbic lesions on behavioral characteristics in heroin-induced conditioned place preference of rats

目的 研究大鼠内侧前额叶皮质的边缘前区(Pr L区)在海洛因诱导的条件性位置偏爱(CPP)形成过程中的作用。方法 (1)按照体重将大鼠分为2组:海洛因诱导组和对照组(0. 9%Na Cl),每组10只。用小剂量递增法建立大鼠海洛因依赖CPP模型,记录大鼠的行为学表现及相应参数。(2)对大鼠脑双侧Pr L区行假手术或立体定向化学损毁,按照体重将大鼠分为2组:假手术组和损毁组,每组10只。测定大鼠海洛因诱导后的行为学参数。结果 (1)行为学实验:在给药7 d后和建模前在白箱(给药箱)停留时间百分比分别为(54. 35±4. 65)%和(16. 90±5. 20)%;这2者的路程百分比分别为(49. 88±10. 96)%和(28. 97±13. 33)%;这2者的黑、白箱穿梭的次数分别为31. 67±13. 66和19. 11±6. 77。海洛因给药7 d后与建模前比较,差异均有统计学意义(均P <0. 05)。(2)损毁实验:假手术组给药前和给药7 d后在白箱停留时间百分比分别为(28. 39±7. 35)%和(62. 81±13. 14)%;这两者的运动路程百分比为(28. 12±7. 01)%和(45. 19±11. 39)%;给药7 d后与给药前比较、或与损毁组给药前比较,上述指标均明显增多,差异均有统计学意义(均P <0. 05)。结论 用CPP系统可成功建立大鼠海洛因依赖模型,且Pr L区损毁影响海洛因依赖CPP的形成,提示Pr L区在海洛因成瘾相关学习记忆中可能起重要作用。

Objective To explore role of the prelimbic(Pr L)area in medial prefrontal cortex in heroin-induced conditioned place preference(CPP)in rats.Methods(1)Rats were divided into two groups:heroin inducted group and control group(saline),each group had 10 rats.The former rats were treated with escalated dose of heroin and the latter ones received only saline administration,the CPP characteristics were recorded and analyzed subsequently.(2)According to body weight,the rats were divided into two groups:sham-operated group and stereotactic chemical lesion group,with 10 rats in each group.After the corresponding operation on bilateral Pr L cortices,the behavioral parameters of rats induced by heroin were recorded.Results(1)In heroin inducted group,the percentages of time spent in the white box after 7 days of heroin administration and before modeling were(54.35±4.65)%and(16.90±5.20)%,the percentages of moving distance in these twostatus were(49.88±10.96)%and(28.97±13.33)%;while the shuttle times between black and white boxes were(31.67±13.66)%and(19.11±6.77)%,respectively.The above results showed significant differences before and after heroin addiction(all P<0.05).(2)In lesion experiment,the percentages of time spent in the white box before modeling and 7 days after heroin administration in the sham-operated group were(28.39±7.35)%and(62.81±13.14)%;the percentages of moving distance in these two status were(28.12±7.01)%and(45.19±11.39)%,respectively;which showed significant differences before and after heroin administration(all P<0.05).Conclusion The heroin addiction model was successfully established by CPP system,and the lesion of PrL area affected the formation of CPP,suggesting PrL cortex plays an important role in heroin-related memory consolidation.