ALTERATIONS IN MIR33 EXPRESSION FOLLOWING MORPHINE ADMINISTRATION

Background and Aim : The importance of non-coding RNA involved in biological processes, such as learning and memory, has become prominent in recent years. Micro RNAs (miRs) represent a class of small regulatory non-coding RNAs that mediate gene silencing by identifying specific sequences in the target messenger RNAs (mRNAs). In addition, morphine administration at different times relative to training or testing has different effects on animals learning and memory. The aim of the current study was to investigate the expression of miR33 following pre-/post-training administration of morphine in the rat.Methods : To determine the expression of miR33 we used PCR on hippocampal samples, we used pre-/post-training administration of different doses of morphine (2.5, 5, or 7.5 mg/kg/ip) in an inhibitory avoidance model of memory. The relative expression of miR33 in different morphine-treated groups were determined by real-time qRT-PCR Results : The comparison of relative expression of miR33 between sham and control groups showed no difference (p> 0.05). However, the comparison of relative expression of miR33 between the morphine-treated groups and the control showed a significant difference (p<0.05).Conclusion : The pre-/post-training administration of different doses of morphine in the rat alters the relative expression of hippocampal miR33.

Keywords:

miR33 , Learning , Memory , Rat , qRT-PCR