scholarly journals Dysregulation of Dopamine and Glutamate Release in the Prefrontal Cortex and Nucleus Accumbens Following Methamphetamine Self-Administration and During Reinstatement in Rats

2013 ◽  
Vol 39 (4) ◽  
pp. 811-822 ◽  
Author(s):  
Aram Parsegian ◽  
Ronald E See
2014 ◽  
Vol 998-999 ◽  
pp. 164-168 ◽  
Author(s):  
Lin Chen ◽  
Bao Miao Ma ◽  
Kai Yue ◽  
Qin Ru ◽  
Xiang Tian ◽  
...  

In order to investigate the influence of electroacupuncture on heroin seeking behavior and the expression of CB2-Rs in the relapse-relevant brain regions, heroin self-administration rat model which represents the heroin relapse behaviors was developed with progressive fixed ratio program. The model rats were randomly divided into 3 groups: control group, heroin-addicted group and 2Hz electroacupuncture group (stimulating on acupoints zusanli and sanyinjiao). The expression of CB2-Rs in the relapse-relevant brain regions were assessed with immunohistochemistry technologies. The reinstatement of heroin seeking behavior induced by conditioned cue priming showed that compared with the heroin-addicted group, active pokes in the 2Hz electroacupuncture group decreased significantly (p<0.05). Compared with the control group, the expression of CB2-Rs in prefrontal cortex (PFC) and nucleus accumbens (NAc) was significantly decreased (p<0.05) in heroin-addicted group and increaseed significantly recover (p<0.05) in the 2Hz electroacupuncture group. Our present results showed that 2Hz-electroacupuncture could attenuate the conditioned cue-evoked heroin-seeking behavior and the inhibitory effect was mediated partially by the increase CB2-Rs expression in relapse-relevant brain regions in heroin-addicted rats.


2019 ◽  
pp. 835-844
Author(s):  
L. CHEN ◽  
X.-K. GONG ◽  
C.-L. LENG ◽  
B.-M. MA ◽  
Q. RU ◽  
...  

Opiate addiction has a high rate of relapse. The accumulating evidence shows that electroacupuncture (EA) may be effective for the treatment of opiate relapse. However, the change of expression of CB1-Rs and CB2-Rs involve in 2Hz EA anti-relapse pathway is still unclear. To explore the changes of expression of CB1-Rs and CB2-Rs, heroin self-administration (SA) model rats were adopted and treated using 2Hz EA. The expressions of CB1-Rs and CB2-Rs were observed using immunohistochemistry method. The results showed that, compared with the control group, active pokes in the heroin-addicted group increased, while the active pokes decreased significantly in 2Hz EA group compared with heroin-addicted group. Correspondingly, the expression of CB1-Rs in prefrontal cortex (PFC), hippocampus (Hip), nucleus accumbens (NAc) and ventral tegmental area (VTA) all increased significantly while the expression of CB2-Rs in those relapse-relevant brain regions decreased obviously in heroin-addicted group when compared with the control group. In addition, the expression of CB1-Rs obviously decreased in the 2Hz EA group while the expression of CB2-Rs in those relapse-relevant brain regions increased significantly when compared with the heroin-addicted group. It indicated that 2Hz EA could attenuate the heroin-evoked seeking behaviors effectively. The anti-relapse effects of 2Hz EA might be related to the decrease of CB1-Rs and increase of CB2-Rs expression in relapse-relevant brain regions of heroin SA rats.


2016 ◽  
Vol 36 (31) ◽  
pp. 8149-8159 ◽  
Author(s):  
M. M. M. Verheij ◽  
L. F. Vendruscolo ◽  
L. Caffino ◽  
G. Giannotti ◽  
M. Cazorla ◽  
...  

2020 ◽  
Author(s):  
Anna Kruyer ◽  
Peter W. Kalivas

ABSTRACTBACKGROUNDCues predicting heroin delivery induce heroin seeking by initiating synaptic glutamate release in the nucleus accumbens core. The intensity of heroin seeking is negatively modulated by cue-induced increases in synaptic proximity of astrocytes. Glutamate-driven heroin seeking is also negatively regulated by compounds that promote glutamate uptake through the astrocytic transporter GLT-1. We hypothesized that the cue-induced increase in astrocyte synaptic proximity reduces heroin seeking by increasing GLT-1 synaptic proximity.METHODSRats were trained to self-administer heroin or sucrose before undergoing extinction and cued reinstatement of heroin or sucrose seeking. We used confocal microscopy to assess expression and co-registration of GLT-1 with the synaptic marker Synapsin I in the nucleus accumbens core.RESULTSExtinction from heroin, but not sucrose self-administration, downregulated GLT-1. Heroin cues increased surface expression of GLT-1 in parallel with heroin seeking, but counter to expectations, the increase was not proximal to synapses identified by Synapsin I. In fact, astroglia showing cue-induced increased surface expression of GLT-1 constituted a distinct subpopulation of astroglia from those showing increased synaptic proximity. Supporting discrete mechanisms, preventing cue-evoked increases in astrocyte synaptic proximity by knocking down the astroglial-selective actin binding protein ezrin did not impact cue-induced increases in GLT-1 surface expression.CONCLUSIONSOur data demonstrate that heroin-paired cues elicit two transient adaptations in astrocytes in the nucleus accumbens core, restoration of synaptic proximity and increased surface expression of GLT-1. Each adaptation occurs in largely non-overlapping subpopulations of astrocytes, but both adaptations appear to dampen reinstated heroin seeking.


2021 ◽  
Author(s):  
◽  
Ross van de Wetering

<p>Rationale. ±3,4-Methylenedioxymethamphetamine (MDMA; ‘ecstasy’) is a popular recreational drug of abuse. Like other drugs of abuse, a proportion of users develop symptoms that are characteristic of a Substance Use Disorder (SUD). The behavioural and neurobiological consequences of repeated misuse of MDMA are not well understood, however.  Objectives. The purpose of the present thesis was to investigate behaviourally relevant neuroadaptations that develop with repeated MDMA exposure in laboratory rats.  Methods. First, the effect of chronic, long-access (6 hour) self-administration of MDMA on the accumulation of the transcription factor, ΔFosB, in the nucleus accumbens (core, shell), dorsal striatum (dorsomedial, dorsolateral, ventromedial, ventrolateral), prefrontal cortex (anterior cingulate, prelimbic, infralimbic, orbitofrontal), amygdala (central, basolateral), ventral tegmental area (anterior, posterior), and raphe (dorsal, median) was measured using immunohistochemistry. Second, the behavioural relevance of these findings was determined by examining the effect of bi-lateral intra-striatal (nucleus accumbens, dorsomedial striatum, dorsolateral striatum) microinjections of MDMA (200 μg/1 μL/side) on the expression of behavioural sensitisation following two days of withdrawal from a regimen of repeated, systemic MDMA exposure (10 mg/kg/day, i.p., for 5 days). Third, a procedure was developed to examine neurochemical correlates of sensitised MDMA-produced behaviour (0, 5, 10 mg/kg, i.p.) following the same regimen of repeated MDMA exposure. Samples were collected from the medial striatum using in vivo microdialysis and the extracellular concentrations of serotonin, dopamine, MDMA, and their metabolites were quantified using liquid chromatography coupled with quadrupole time-of-flight (Q-TOF) mass spectrometry. Lastly, a unique untargeted metabolomics procedure was developed to further analyse these microdialysis samples and to identify novel or unexpected metabolites that were relevant to the sensitised behavioural response produced by MDMA.  Results. MDMA self-administration produced region-dependant increases in ΔFosB. Significant increases in ΔFosB were observed in the nucleus accumbens core, the medial areas of the dorsal striatum, as well as all areas of the prefrontal cortex and amygdala. Small, but significant increases were also observed in the dorsal raphe. Increases were observed in the nucleus accumbens shell and the posterior tail of the ventral tegmental area, but these increases were not significant following statistical correction for multiple comparisons. Acute exposure to MDMA increased locomotor activity only when the drug was infused into the nucleus accumbens. Following repeated systemic exposure, behavioural sensitisation was expressed when MDMA was infused into both the nucleus accumbens or the dorsomedial striatum, but not the dorsolateral striatum. Analysis of microdialysates from the medial striatum indicated that behavioural sensitisation was accompanied by small increases in baseline levels of extracellular serotonin and decreased MDMA-produced increases in serotonin, but these changes were not statistically significant. Behavioural sensitisation was also accompanied by increased extracellular concentrations of dopamine at baseline and following acute MDMA exposure, but these data were not statistically analysed due to small sample sizes. MDMA-produced extracellular concentrations of MDMA did not change with repeated exposure. Untargeted metabolomics revealed potential changes in MDMA and dopamine metabolism that might be relevant to the sensitised behavioural response.  Conclusions. The findings of the current research suggest that repeated MDMA exposure results in many of the same neuroadaptations that result from repeated exposure to other drugs of abuse. These included increased ΔFosB expression in many brain regions that are relevant to addiction, such as the nucleus accumbens, dorsal striatum, and prefrontal cortex. Dopaminergic mechanisms also appeared to be influenced and were associated with sensitised MDMA-produced behaviour. Surprisingly, serotonergic mechanisms were not significantly impacted by repeated MDMA exposure under the current conditions. Some of the procedures developed in this thesis are unique and may be of value for future research investigating the neurochemical underpinnings of addictive behaviour or other disease states.</p>


2021 ◽  
Author(s):  
◽  
Ross van de Wetering

<p>Rationale. ±3,4-Methylenedioxymethamphetamine (MDMA; ‘ecstasy’) is a popular recreational drug of abuse. Like other drugs of abuse, a proportion of users develop symptoms that are characteristic of a Substance Use Disorder (SUD). The behavioural and neurobiological consequences of repeated misuse of MDMA are not well understood, however.  Objectives. The purpose of the present thesis was to investigate behaviourally relevant neuroadaptations that develop with repeated MDMA exposure in laboratory rats.  Methods. First, the effect of chronic, long-access (6 hour) self-administration of MDMA on the accumulation of the transcription factor, ΔFosB, in the nucleus accumbens (core, shell), dorsal striatum (dorsomedial, dorsolateral, ventromedial, ventrolateral), prefrontal cortex (anterior cingulate, prelimbic, infralimbic, orbitofrontal), amygdala (central, basolateral), ventral tegmental area (anterior, posterior), and raphe (dorsal, median) was measured using immunohistochemistry. Second, the behavioural relevance of these findings was determined by examining the effect of bi-lateral intra-striatal (nucleus accumbens, dorsomedial striatum, dorsolateral striatum) microinjections of MDMA (200 μg/1 μL/side) on the expression of behavioural sensitisation following two days of withdrawal from a regimen of repeated, systemic MDMA exposure (10 mg/kg/day, i.p., for 5 days). Third, a procedure was developed to examine neurochemical correlates of sensitised MDMA-produced behaviour (0, 5, 10 mg/kg, i.p.) following the same regimen of repeated MDMA exposure. Samples were collected from the medial striatum using in vivo microdialysis and the extracellular concentrations of serotonin, dopamine, MDMA, and their metabolites were quantified using liquid chromatography coupled with quadrupole time-of-flight (Q-TOF) mass spectrometry. Lastly, a unique untargeted metabolomics procedure was developed to further analyse these microdialysis samples and to identify novel or unexpected metabolites that were relevant to the sensitised behavioural response produced by MDMA.  Results. MDMA self-administration produced region-dependant increases in ΔFosB. Significant increases in ΔFosB were observed in the nucleus accumbens core, the medial areas of the dorsal striatum, as well as all areas of the prefrontal cortex and amygdala. Small, but significant increases were also observed in the dorsal raphe. Increases were observed in the nucleus accumbens shell and the posterior tail of the ventral tegmental area, but these increases were not significant following statistical correction for multiple comparisons. Acute exposure to MDMA increased locomotor activity only when the drug was infused into the nucleus accumbens. Following repeated systemic exposure, behavioural sensitisation was expressed when MDMA was infused into both the nucleus accumbens or the dorsomedial striatum, but not the dorsolateral striatum. Analysis of microdialysates from the medial striatum indicated that behavioural sensitisation was accompanied by small increases in baseline levels of extracellular serotonin and decreased MDMA-produced increases in serotonin, but these changes were not statistically significant. Behavioural sensitisation was also accompanied by increased extracellular concentrations of dopamine at baseline and following acute MDMA exposure, but these data were not statistically analysed due to small sample sizes. MDMA-produced extracellular concentrations of MDMA did not change with repeated exposure. Untargeted metabolomics revealed potential changes in MDMA and dopamine metabolism that might be relevant to the sensitised behavioural response.  Conclusions. The findings of the current research suggest that repeated MDMA exposure results in many of the same neuroadaptations that result from repeated exposure to other drugs of abuse. These included increased ΔFosB expression in many brain regions that are relevant to addiction, such as the nucleus accumbens, dorsal striatum, and prefrontal cortex. Dopaminergic mechanisms also appeared to be influenced and were associated with sensitised MDMA-produced behaviour. Surprisingly, serotonergic mechanisms were not significantly impacted by repeated MDMA exposure under the current conditions. Some of the procedures developed in this thesis are unique and may be of value for future research investigating the neurochemical underpinnings of addictive behaviour or other disease states.</p>


2021 ◽  
Author(s):  
Benjamin M. Siemsen ◽  
Sarah M. Barry ◽  
Kelsey Vollmer ◽  
Lisa M. Green ◽  
Ashley G. Brock ◽  
...  

AbstractBackgroundPrelimbic cortical projections to the nucleus accumbens core are critical for cue-induced cocaine seeking, but the identity of the accumbens neuron(s) targeted by this projection, and the transient neuroadaptations contributing to relapse within these cells, remain unknown.MethodsMale Sprague-Dawley rats underwent cocaine or sucrose self-administration, extinction, and cue-induced reinstatement. Pathway-specific chemogenetics, patch-clamp electrophysiology, in vivo electrochemistry, and high-resolution confocal microscopy were used to identify and characterize a small population of nucleus accumbens core neurons that receive dense prelimbic cortical input to determine their role in regulating cue-induced cocaine and natural reward seeking.ResultsChemogenetic inhibition of prelimbic cortical projections to the nucleus accumbens core suppressed cue-induced cocaine relapse and normalized real-time cue-evoked increases in accumbens glutamate release to that of sucrose seeking animals. Furthermore, chemogenetic inhibition of the population of nucleus accumbens core neurons receiving the densest prelimbic cortical input suppressed cocaine, but not sucrose seeking. These neurons also underwent morphological plasticity during the peak of cocaine seeking in the form of dendritic spine expansion and increased ensheathment by astroglial processes at large spines.ConclusionsWe identified and characterized a unique subpopulation of nucleus accumbens neurons that receive dense prelimbic cortical input. The functional specificity of this subpopulation is underscored by their ability to mediate cue-induced cocaine relapse, but not sucrose seeking. This subset of cells represents a novel target for addiction therapeutics revealed by anterograde targeting to interrogate functional circuits imbedded within a known network.


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