ABSTRACT
In addition to the essential pharmacologi-cal effects of opioids,situational cues associated with drug addiction memory are key triggers for drug seeking.CircRNAs,an emerging hotspot regulator in crown genet-ics-play an important role in central nervous system-relat-ed diseases.However,the internal mediating mechanism of circRNA in the field of drug reward and addiction mem-ory remains unknown.Here,we trained mice on a condi-tional place preference(CPP)model and collected nucle-us accumbens(NAc)tissues from day 1(T0)and day 8(T1)for high-throughput RNA sequencing.qRT-PCR revealed that circTmeff-1 was highly expressed in the NAc core but not in the NAc shell,suggesting that it plays a role in addiction memory formation.Meanwhile,the reverse regulation of circTmeff-1 by adeno-associated viruses could both inhibit the formation of addiction mem-ory in the NAc core or shell.Subsequently,the GO and KEGG analyses indicated 21 that circTmeff-1 might regu-late the addiction memory via the MAPK and AMPK path-ways.These findings suggest that circTmeff-1 in NAc plays a crucial role in morphine-dependent memory for-mation.
ABSTRACT
Psychoactive substance abuse has been a public health and social problem in the world.The essence of psychoactive substance addiction is a pathological memory (addiction memory) based on alterations in gene expression and synapticplasticity.Here we summarize recent findings in the neurobiological mechanisms of psychoactive substance addiction.
ABSTRACT
Objective To observe the effect of mPFC neuron synaptic plasticity changes in the formation of morphine related reward memory.Methods 40 SD rats were administered morphine (10 mg/kg,ip) or saline (2 ml/kg,ip)and sacrificed 0,2,4 and 8 h after the treatment.The temporal profile of activity-regulated cytoskeleton-associated protein (Arc/Arg 3.1) expression in medial prefrontal cortex (mPFC) was analyzed.Another 40 rats receiving a single injection of morphine at different doses (0,5,10 or 20 mg/kg),and rats were sacrificed by decapitation 2 h later.In mPFC,changes of Arc/Arg 3.1 protein was analyzed by Western Blot,Arc/Arg 3.1 positive cells was detected by immunohistochemistry (IHC),and number of spines were analyzed by Golgi-cox method.In the second experiment,CPP model was established by 5 mg/kg morphine for 8 days.Arc/Arg 3.1 antisense oligodeoxynucleotide (AS) or the control (CS) was microinjected into mPFC 15 minutes before each morphine injection,then CPP score was evaluated.Results Compared with saline groups,Arc/Arg 3.1 protein,Arc/Arg 3.1 positive cells,number of spines ((1.01±0.04) vs (1.58±0.18),P＜0.01 ; (42.80±7.63) vs (74.47±8.02),P＜0.01 ;(17.27±5.64) vs (39.47±7.56),P＜0.01) were significantly increased 2 hours after morphine administration.All three doses of morphine (5,10 and 20 mg/kg) increased Arc/Arg 3.1 protein expression in the mPFC,and there were no dose-dependent effects.In CPP experiments,compared with microinjection of Arc/Arg 3.1 CS (0.74±0.02),Arc/Arg 3.1 AS microinjection significantly decreased the CPP score (0.51±0.01) in morphine group (P＜0.01).Conclusion It is enough to increase Arc/Arg 3.1 protein content and synaptic plasticity in mPFC by 10 mg/kg,and the changes implied in formation of morphine relative reward memory.
ABSTRACT
Long-term potentiation is an important form of synaptic plasticity and a cellular model for study of learning and memory. Long-lasting long-term potentiation is also a cellular model used in the research of long-term memory. The transformation from silent synapses to the functional ones is probably the important mechanism for the LTP maintenance. After induction, the LTP could be reversed by the physiological or artificial stimulations. Owing to the reversibility of LTP and its input-specific characteristics, it is reasonable to interfere specifically the addiction memory with particular deep brain electrical stimulation without damaging the brain functions.