Withdrawal Memory Research Articles

Crucial role of feedback signals from prelimbic cortex to basolateral amygdala in the retrieval of morphine withdrawal memory.

An important reasons for drug relapse is the retrieval of drug withdrawal memory induced by conditioned context. Previous studies have suggested that the basolateral amygdala (BLA) plays an important role in conditioned context-induced retrieval of morphine withdrawal memory. However, the downstream neuronal circuits of the activation of the BLA in conditioned context-induced retrieval of morphine withdrawal memory remain unknown. Using retrograde labeling, immunohistochemical, and optogenetic approaches, we found that, although BLA neurons projecting to the prelimbic cortex (PrL) played an important role in conditioned context-induced retrieval of morphine withdrawal memory, they do not exhibit increased expression of the neuronal plasticity marker Arc. However, when PrL neurons activated by the BLA send feedback signals to the BLA, a neuronal-related process is induced in other BLA neurons that do not project to the PrL, a finding that is relevant to conditioned context-induced retrieval of morphine withdrawal memory.

Key determinants for morphine withdrawal conditioned context-induced increase in Arc expression in anterior cingulate cortex and withdrawal memory retrieval

Addiction memory is subjected to time-dependent shifts toward neocortex in remote period to promote long-term addiction memory storage, which plays an important role in drug relapse. However, how the activity and neuroplasticity of the anterior cingulate cortex (ACC) change after contextual morphine withdrawal conditioning and what factors determine this change remain to be determined. In this paper, using immunohistochemical and single-cell microinjection techniques, combining behavioral assay, we found that (1) contextual withdrawal conditioning increases the expression of c-Fos, but not Arc, in the ACC in morphine withdrawal mice; (2) at the first day after conditioning, conditioned context has no influence on the expression of c-Fos and Arc in the ACC in morphine withdrawal mice; (3) at the 14th day after conditioning, conditioned context increases the expression of both c-Fos and Arc in the ACC in morphine withdrawal mice; (4) the inhibition of dendritic spines of the ACC or projection neurons from the CA3 of the hippocampus to the ACC attenuates the conditioned context-induced increase of Arc expression in the ACC and abolishes the retrieval of withdrawal memory at the 14th day after conditioning. These results suggest that the ACC may exhibit a change in neuroplasticity at the 14th day after conditioning, and the dendritic spines of the ACC and the projection neurons from the CA3 of the hippocampus to the ACC are key determinants for conditioned context induced-increase in Arc expression in the ACC and the retrieval of withdrawal memory at the 14th day after conditioning.

Clinical observation of Qingrehuatan method in the treatment of insomnia elderly patients with benzodiazepines dependence

Objective To investigate the clinical curative effect of Qingrehuatan method in the treatment of insomnia elderly patients with benzodiazepines dependence. Methods From April 2016 to April 2017, 49 insomnia elderly patients with benzodiazepines dependence in the Second People's Hospital of Zhoushan were divided into the observation group(20 cases) and control group (29 cases) according to the different treatment methods.In the gradual reduction at the same time, the control group was treated with trazodone, the observation group was treated with Qingrehuatan method.Before treatment and after treatment for 1 course, the revised Pittsburgh sleep quality scale (PSQI), index of insomnia symptom score, TCM symptom score, Zung Anxiety Rating Scale score, Wechsler Adult Intelligence Scale(WAIS-RC) and Wechsler Memory Scale(WMS-RC) score were observed in the two groups. Results After treatment, the rate of withdrawal and discontinuation of the observation group was significantly higher than that of the control group(90.0% vs.68.9%), the difference was statistically significant (χ2=6.918, P<0.05). After treatment, the PSQI scores and symptom scores of the two groups were significantly decreased, and the PSQI scores and TCM symptom scores of the observation group improved significantly better than those of the control group[(8.8±1.1)points vs.(10.6±1.3)points, (2.9±0.8)points vs.(4.6±1.2)points], the differences were statistically significant(t=5.063, 5.535, all P<0.05). After treatment, the Zung Anxiety Scale scores of the two groups were significantly lower, and the improvement of the observation group was significantly better than that of the control group[(42.90±5.65)points vs.(48.21±5.27) points], the difference was statistically significant(t=3.366, P<0.05). After treatment, the long-term memory, short-term memory and memory quotient of the two groups were significantly increased, and short-term memory and memory quotient of the observation group improved significantly better than those of the control group[(23.30±5.31)points vs.(20.55 ±6.58)points, (76.67±12.70)points vs.(67.36±19.13)points], the differences were statistically significant (t=2.274, 2.047, all P<0.05). Conclusion Qingrehuatan method in the treatment of insomnia elderly patients with benzodiazepines dependence can improve the possible reduction in the process of stopping drug withdrawal symptoms and memory function, and can improve the symptoms of patients at the same time, and it is worthy of clinical application. Key words: Sleep initiation and maintenance disorders; Benzodiazepines; Medicine, chinese traditional; Aged

Chronic morphine selectively sensitizes the effect of D1 receptor agonist on presynaptic glutamate release in basolateral amygdala neurons that project to prelimbic cortex

Drug addiction is a brain disorder characterized by chronic, compulsive use of drugs. Previous studies have found a number of chronic morphine-induced changes in the brain at molecular levels. A study from our lab showed that chronic morphine-induced increase in the expression of presynaptic D1 receptors in basolateral amygdala (BLA) neurons played an important role in environmental cue-induced retrieval of morphine withdrawal memory. However, the downstream neurocircuitry of chronic morphine-induced increase presynaptic D1 receptors in the BLA remains to be elucidated. Using retrogradely labelling technique combined with whole-cell patch-clamp methods, our results showed that (1) chronic morphine sensitized the effect of D1 receptor agonist on presynaptic glutamate release in BLA neurons that projected to the prelimbic cortex (PrL), but had no influence on that in BLA neurons that projected to the nucleus accumbens (NAc) or the CA1 of the hippocampus; (2) chronic morphine sensitized the effect of D1 receptor agonist on action potential firing in BLA neurons that projected to the PrL, but without affecting the intrinsic excitability and the sensitivity of postsynaptic glutamate receptors to glutamate in BLA neurons that projected to the PrL. These results suggest that chronic morphine selectively sensitizes the effect of D1 receptor agonist on presynaptic glutamate release in BLA neurons that project to PrL and induces a sensitization of the effect of D1 receptor agonist on action potential firing in BLA neurons that project to the PrL.

The involvement of CRF1 receptor within the basolateral amygdala and dentate gyrus in the naloxone-induced conditioned place aversion in morphine-dependent mice

Drug withdrawal-associated aversive memories trigger relapse to drug-seeking behavior. Corticotrophin-releasing factor (CRF) is an important mediator of the reinforcing properties of drugs of abuse. However, the involvement of CRF1 receptor (CRF1R) in aversive memory induced by opiate withdrawal has yet to be elucidated. We used the conditioned-place aversion (CPA) paradigm to evaluate the role of CRF1R on opiate withdrawal memory acquisition, along with plasticity-related processes that occur after CPA within the basolateral amygdala (BLA) and dentate gyrus (DG). Male mice were rendered dependent on morphine and injected acutely with naloxone before paired to confinement in a naloxone-associated compartment. The CPA scores as well as the number of TH-positive neurons (in the NTS-A2 noradrenergic cell group), and the expression of the transcription factors Arc and pCREB (in the BLA and DG) were measured with and without CRF1R blockade.Mice subjected to conditioned naloxone-induced morphine withdrawal robustly expressed CPA. Pre-treatment with the selective CRF1R antagonist CP-154,526 before naloxone conditioning session impaired morphine withdrawal-induced aversive memory acquisition. CP-154,526 also antagonized the enhanced number of TH-positive neurons in the NTS-A2 that was seen after CPA. Increased Arc expression and Arc-pCREB co-localization were seen in the BLA after CPA, which was not modified by CP-154,526. In the DG, CPA was accompanied by a decrease of Arc expression and no changes in Arc-pCREB co-localization, whereas pre-treatment with CP-154,526 induced an increase in both parameters. These results indicate that CRF-CRF1R pathway could be a critical factor governing opiate withdrawal memory storage and retrieval and might suggest a role for TH-NA pathway in the effects of withdrawal on memory. Our results might indicate that the blockade of CRF1R could represent a promising pharmacological treatment strategy approach for the attenuation of the relapse to drug-seeking/taking behavior triggered by opiate withdrawal-associated aversive memories.

Memory retrieval in addiction: a role for miR-105-mediated regulation of D1 receptors in mPFC neurons projecting to the basolateral amygdala

BackgroundDrug addiction is a chronic brain disorder characterized by the compulsive use of drugs. The study of chronic morphine-induced adaptation in the brain and its functional significance is of importance to understand the mechanism of morphine addiction. Previous studies have found a number of chronic morphine-induced adaptive changes at molecular levels in the brain. A study from our lab showed that chronic morphine-induced increases in the expression of D1 receptors at presynaptic terminals coming from other structures to the basolateral amygdala (BLA) played an important role in environmental cue-induced retrieval of morphine withdrawal memory. However, the neurocircuitry where the increased D1 receptors are located and how chronic morphine increases D1 receptor expression in specific neurocircuits remain to be elucidated.ResultsOur results show that chronic morphine induces a persistent increase in D1 receptor expression in glutamatergic terminals of projection neurons from the medial prefrontal cortex (mPFC) to the BLA, but has no influence on D1 receptor expression in projection neurons from the hippocampus or the thalamus to the BLA. This adaptation to chronic morphine is mediated by reduced expression of miR-105 in the mPFC, which results in enhanced D1 receptor expression in glutamatergic terminals of projection neurons from the mPFC to the BLA. Ex vivo optogenetic experiments show that a chronic morphine-induced increase in D1 receptor expression in glutamatergic terminals of projection neurons from the mPFC to the BLA results in sensitization of the effect of D1 receptor agonist on presynaptic glutamate release. mPFC to BLA projection neurons are activated by withdrawal-associated environmental cues in morphine-withdrawal rats, and overexpression of miR-105 in the mPFC leads to reduced D1 receptor induction in response to chronic morphine in glutamatergic terminals of the projection neurons from the mPFC to the BLA, and a reduction in place aversion conditioned by morphine withdrawal.ConclusionsThese results suggest that chronic morphine use induces a persistent increase in D1 receptors in glutamatergic terminals of projection neurons from the mPFC to the BLA via downregulation of miR-105 in the mPFC, and that these adaptive changes contribute to environmental cue-induced retrieval of morphine withdrawal memory.

Memories of Opiate Withdrawal Emotional States Correlate with Specific Gamma Oscillations in the Nucleus Accumbens

Affective memories associated with the negative emotional state experienced during opiate withdrawal are central in maintaining drug taking, seeking, and relapse. Nucleus accumbens (NAC) is a key structure for both acute withdrawal and withdrawal memories reactivation, but the NAC neuron coding properties underpinning the expression of these memories remain largely unknown. Here we aimed at deciphering the role of NAC neurons in the encoding and retrieval of opiate withdrawal memory. Chronic single neuron and local field potentials recordings were performed in morphine-dependent rats and placebo controls. Animals were subjected to an unbiased conditioned placed aversion protocol with one compartment (CS+) paired with naloxone-precipitated withdrawal, a second compartment with saline injection (CS−), and a third being neutral (no pairing). After conditioning, animals displayed a typical place aversion for CS+ and developed a preference for CS− characteristic of safety learning. We found that distinct NAC neurons code for CS+ or CS−. Both populations also displayed highly specific oscillatory dynamics, CS+ and CS− neurons, respectively, following 80 Hz (G80) and 60 Hz (G60) local field potential gamma rhythms. Finally, we found that the balance between G60 and G80 rhythms strongly correlated both with the ongoing behavior of the animal and the strength of the conditioning. We demonstrate here that the aversive and preferred environments are underpinned by distinct groups of NAC neurons as well as specific oscillatory dynamics. This suggest that G60/G80 interplay—established through the conditioning process—serves as a robust and versatile mechanism for a fine coding of the environment emotional weight.

Distinctive Roles of 5-aza-2'-deoxycytidine in Anterior Agranular Insular and Basolateral Amygdala in Reconsolidation of Aversive Memory Associated with Morphine in Rats.

5-aza-2′-deoxycytidine (5-aza), an inhibitor of DNA methyltransferases (DNMTs), has been implicated in aversive memory and the function of brain region involved in processing emotion. However, little is known about the role of 5-aza in the reconsolidation of opiate withdrawal memory. In the present study, using the morphine-naloxone induced conditioned place aversion (CPA) model in rats, we injected 5-aza into agranular insular (AI), granular insular (GI), basolateral amygdala (BLA) and central amygdala (CeA) immediately after the memory retrieval and tested the behavioral consequences at 24 h, 7 and 14 days after retrieval test. We found that 5-aza injection into AI disrupted the reconsolidation of morphine-associated withdrawal memory, but 5-aza injection into GI had no impact on the reconsolidation. Meanwhile, 5-aza injection into BLA but not CeA attenuated the withdrawal memory trace 14 days later. However, 5-aza administration to rats, in the absence of memory reactivation, had no effect on morphine-associated withdrawal memory. These findings suggest that 5-aza interferes with the reconsolidation of opiate withdrawal memory, and the roles of insular and amygdala in reconsolidation are distinctive.

Remodeling of the neuronal circuits underlying opiate-withdrawal memories following remote retrieval

Several types of memory display time-dependent reorganization of their underlying neural substrates, but it remains unclear whether affective memories associated with drug effects also follow similar reorganization. Here, we analyzed the neural circuits reactivated by the re-exposure of former dependent rats to the withdrawal-paired environment 1month after conditioning (remote memory) as compared with recent memory (Frenois, F., Stinus, L., Di Blasi, F., Cador, M., & Le Moine, C. (2005) A specific limbic circuit underlies opiate withdrawal memories The Journal of Neuroscience, 25, 1366–1374). C-fos expression showed that the circuits involved in the retrieval of withdrawal memories are partly different when comparing recent and remote reactivation, showing that, like other type of memories, affective memories linked to opiate withdrawal undergo anatomical reorganization, with a shift from extended amygdala regions toward cortical areas.

Reactivity and plasticity in the amygdala nuclei during opiate withdrawal conditioning: Differential expression of c-fos and arc immediate early genes

Opiate withdrawal leads to the emergence of an aversive state that can be conditioned to a specific environment. Reactivation of these withdrawal memories has been suggested to be involved in relapse to drug-seeking of abstinent opiate addicts. Among the limbic areas that are likely to mediate these features of opiate dependence, amygdala nuclei represent critical neural substrates. Using a conditioned place aversion paradigm (CPA), we have previously shown specific opposite patterns of reactivity in the basolateral (BLA) and the central (CeA) amygdala, when comparing the experience of acute opiate withdrawal with the re-exposure to a withdrawal-paired environment. These data gave clues about the potential mechanisms by which amygdala nuclei may be involved in withdrawal memories. To extend these results, the present study aimed to assess the cellular reactivity and plasticity of amygdala nuclei during the opiate withdrawal conditioning process. For this, we have quantified c-fos and arc expression using in situ hybridization in rats, following each of the three conditioning sessions during CPA, and after re-exposure to the withdrawal-paired environment. BLA output neurons showed an increase in the expression of the plasticity-related arc gene during conditioning that was also increased by re-exposure to the withdrawal-paired environment. Interestingly, the CeA showed an opposite pattern of responding, and the intercalated cell masses (ITC), a possible inhibitory interface between the BLA and CeA, showed a persistent activation of c-fos and arc mRNA. We report here specific c-fos and arc patterns of reactivity in amygdala nuclei during withdrawal conditioning. These findings improve our understanding of the involvement of the amygdala network in the formation and retrieval of withdrawal memories. Plasticity processes within BLA output neurons during conditioning, may participate in increasing the BLA reactivity to conditioned stimuli, which could in turn (by the control of downstream nuclei) reinforce and drive the motivational properties of withdrawal over drug consumption.

Disrupting Reconsolidation of Conditioned Withdrawal Memories in the Basolateral Amygdala Reduces Suppression of Heroin Seeking in Rats

Recent data from our laboratory have demonstrated that appetitive drug memories undergo protein synthesis-dependent reconsolidation in the basolateral amygdala (BLA), an area important in the formation of emotional memories. We here investigated the importance of the BLA in the reconsolidation of opiate conditioned withdrawal memories. Rats with bilateral cannulas implanted in the BLA were trained to respond for heroin (0.12 mg/kg, i.v.) under a seeking-taking schedule, which required responding on a seeking lever to gain the opportunity to self-administer heroin by a single response on a taking lever. After induction of opiate dependence with subcutaneously implanted, heroin-filled osmotic minipumps (3 mg x kg(-1) x d(-1) heroin), rats received five consecutive pairings of a conditioned stimulus (CS) (tone, light, and odor compound) paired with naloxone (0.10 mg/kg, s.c.)-precipitated withdrawal. We replicated our previous findings that heroin seeking is suppressed in the presence of the withdrawal-associated CS. However, infusion of Zif268 antisense oligodeoxynucleotide into the BLA before reactivation of the CS-withdrawal association abolished this conditioned suppression in a reactivation-dependent manner. We also report that reconsolidation of CS-withdrawal memories upregulates Zif268 protein in the basolateral but not central nucleus of the amygdala and that Zif268 knockdown occurs selectively in the BLA. These results demonstrate that drug withdrawal memories undergo protein synthesis-dependent reconsolidation in the BLA and suggest a common mechanism for the reconsolidation of both appetitive and aversive drug memories.

A specific limbic circuit underlies opiate withdrawal memories.

Compulsive drug-seeking behavior and its renewal in former drug addicts is promoted by several situations, among which reactivation of drug withdrawal memories plays a crucial role. A neural hypothesis is that such memories reactivate the circuits involved in withdrawal itself and promote a motivational state leading to drug seeking or taking. To test this hypothesis, we have analyzed the neural circuits and cell populations recruited when opiate-dependent rats are reexposed to stimuli previously paired with withdrawal (memory retrieval) and compared them with those underlying acute withdrawal during conditioning (memory formation). Using in situ hybridization for c-fos expression, we report here that reexposure to a withdrawal-paired environment induced conditioned c-fos responses in a specific limbic circuit, which can be partially dissociated from the structures involved in acute withdrawal. At the amygdala level, c-fos responses were doubly dissociated between the central and basolateral (BLA) nuclei, when comparing the two situations. Detailed phenotypical analyses in the amygdala and ventral tegmental area (VTA) show that specific subpopulations in the BLA are differentially involved in the formation and retrieval of withdrawal memories, and strikingly that a population of VTA dopamine neurons is activated in both situations. Together, this indicates that withdrawal memories can drive activity changes in specific neuronal populations of interconnected limbic areas known to be involved in aversive motivational processes. This first study on the neural substrates of withdrawal memories strongly supports an incentive-motivational view of withdrawal in opiate addiction that could be crucial in compulsive drug seeking and relapse.

The Motivational Component of Withdrawal in Opiate Addiction: Role of Associative Learning and Aversive Memory in Opiate Addiction from a Behavioral, Anatomical and Functional Perspective

A major challenge in current drug addiction research is not only to understand the immediate effects of drugs of abuse on brain operations, but also to define at the behavioral and neural levels how cognitive, emotional and motivational processes interact with drug use in order to lead to this psychopathological state which defines addiction. It is now clear that factors other than the direct effects of drugs of abuse are able to powerfully affect drug-seeking and drug-taking behaviors. In former opiate addicts, re-exposure to environmental situations previously paired with withdrawal is able to induce strong craving episodes. It has been proposed that these conditioned stimuli could be strongly involved in precipitating relapse in drug-taking behavior by re-activating the neurobiological circuits which are engaged in an unconditioned way by the withdrawal state itself, leading to a powerful aversive state relieved by drug consumption renewal. In the present review, we provide evidence from a neuropsychopharmacological viewpoint that environmental situations previously paired with the opiate withdrawal syndrome might be able to maintain drug-seeking motivation. Using behavioral models which allow assessment of the aversive and motivational properties of opiate withdrawal both in the unconditioned and conditioned situations, we have recently investigated using extensive mapping the neurobiological correlates which underlie acute withdrawal and the trace of its memory in the brain in terms of localization and neuronal population involved, with an anatomical and functional approach. Thus, on the basis of our results, and together with a number of data in the literature, we provide a functional model for the formation and retrieval of opiate withdrawal memories.