The acquisition of alcohol-conditioned place preference in post-traumatic stress disorder-like rats and its relationship with the dopamine D1 receptor / 中华行为医学与脑科学杂志

ABSTRACT

ObjectiveTo evaluate whether post-traumatic stress disorder(PTSD)-like rats more easily to acquire the alcohol induced conditioned place preference(CPP),and its relationship with dopamine D1 receptor.Methods40 SD rats were randomly divided into four groupsPTSD + ethanol group ( PE.),control + ethanol group (CE),PTSD + saline group(PS),and control + saline group(CS).All rats of each group were trained for CPP with alternate injections of alcohol ( 2 mg/kg,i.p.) and saline ( 10 ml/kg,i.p.).PE and PS group were subjected to single prolonged stress (SPS) for PTSD model.Four groups were evaluated the performances of freezing behavior and plus maze test after SPS 24 hours and 7 days.And on SPS 7 days four groups were respectively detected D1 dopamine receptor-positive cells number in amygdale by immunohistochemistry.ResultsCompared with control group,freezing time of PTSD group was remarkable longer on 7 days after SPS not 24 hours( (89.13 ±8.60) s vs(22.25± 5.85) s,q =8.77,P ＜ 0.01 ),and number of entry into the open arms and time spent in the open arms of PTSD group were both less than control group on 7 days after SPS not 24 hours( (4.25 ± 1.26) vs ( 14.38 ± 2.18),( 12.38 ± 3.30) s vs (40.38 ± 7.29 ) s,q =4.74 and 4.08,P ＜ 0.01 ).In CPP,the CPP value of post-conditioning only in PE group was obviously higher than that of pre-conditioning ( q=31.81,P＜ 0.01 ).The CPP value of postconditioning in PE group was higher than that of CS group,CE group and PS group( q=-38.32,-22.21,-33.38,P＜0.05).There were no significant differences in the number of D1 dopamine receptor-positive cells in the amygdale region among four groups (F =0.07,P ＞0.05 ).ConclusionThe PTSD-like rats are easier to acquire the alcohol CPP,which maybe not relate to the changes of the number of D1 dopamine receptor-positive cells in amygdala.