RESUMO
AIMS: Considering that serotoninergic agents attenuate symptoms of anxiety and are used to treat depression, we investigated whether subchronic treatment with imipramine, a serotonin/noradrenaline reuptake inhibitor, would prevent the anxiogenic-like behaviour induced by acute and/or chronic ethanol withdrawal. We also investigated whether those changes were related to the disfunctioning of hypothalamic-pituitary-adrenal (HPA) axis and serotonergic neurotransmission. MAIN METHODS: 264 Male Wistar rats were treated with ethanol 6% (vol./vol.) for 21 days. Acute ethanol withdrawal was induced by abrupt discontinuation of treatment and sustained for 48â¯h. Protracted abstinence was sustained for an additional period of 21 days. Behavioural tests included the Elevated Plus Maze (EPM) or Light/Dark Box (LDB) after acute abstinence, and the Forced Swim Test (FST) after protracted abstinence. Imipramine (15â¯mg/kg, i.p.) was administered 24, 19 and 1â¯h before EPM or LDB tests. KEY FINDINGS: Acute abstinence decreased exploration of the open arms of the EPM, without changing exploration of LDB. Additionally, chronic abstinent rats displayed more time immobile in the FST, when compared to control animals. These effects were attenuated by imipramine treatment, without changing basal response. Imipramine prevented protracted abstinence -induced decrease in glucocorticoid receptor (GR) and serotonin transporter (SERT) expression in the dorsal hippocampus. SIGNIFICANCE: Our findings indicate that chronic ethanol withdrawal affects the hippocampal serotonergic system by decreasing serotonin transporter expression. It also disturbs the HPA axis functioning through an imbalance on GR and mineralocorticoid (MR) expression.
Assuntos
Abstinência de Álcool , Ansiedade , Comportamento Animal , Depressão , Hipocampo , Proteínas de Ligação a RNA , Receptores de Glucocorticoides , Animais , Ansiedade/tratamento farmacológico , Ansiedade/fisiopatologia , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Depressão/tratamento farmacológico , Depressão/fisiopatologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Imipramina , Masculino , Proteínas de Ligação a RNA/efeitos dos fármacos , Proteínas de Ligação a RNA/metabolismo , Ratos , Ratos Wistar , Receptores de Glucocorticoides/efeitos dos fármacos , Receptores de Glucocorticoides/metabolismoRESUMO
Nitric oxide has been implicated in symptoms of ethanol withdrawal in animal models. Zebrafish have been used as models to study neurobehavioral effects of ethanol (EtOH) withdrawal, but the mechanisms associated with these effects are not yet clear. Adult zebrafish were treated with 1% EtOH for 20â¯min per day for 8 days, injected with the nitric oxide synthase 2 (NOS-2) inhibitor aminoguanidine (50â¯mg/kg), and allowed to experience withdrawal (WD) in their hometanks for 7 days. EtOH WD increased anxiety-like behavior in the novel tank test, an effect that was blocked by aminoguanidine. EtOH WD also increased brain levels of nitrite, an effect that was partially blocked by aminoguanidine. These results underline a novel mechanism by which NOS-2 controls anxiety-like responses to ethanol withdrawal, with implications for the mechanistic study of symptoms associated with chronic ethanol abuse. Preprint: https://dx.doi.org/10.20944/preprints201912.0219.v1 Data and scripts: https://github.com/lanec-unifesspa/etoh-withdrawal/tree/master/NOS2.
Assuntos
Alcoolismo/metabolismo , Etanol/farmacologia , Óxido Nítrico Sintase Tipo II/metabolismo , Síndrome de Abstinência a Substâncias/metabolismo , Animais , Ansiedade/tratamento farmacológico , Comportamento Animal , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/efeitos dos fármacos , Peixe-Zebra/metabolismoRESUMO
Chronic and/or excessive consumption of alcohol followed by reduced consumption or abstention can result in Alcohol Withdrawal Syndrome. A number of behavioral changes and neurological damage result from ethanol (EtOH) withdrawal. Ceftriaxone (Cef) modulates the activity of excitatory amino acid transporters by increasing their gene expression. Zebrafish are commonly used to study alcohol exposure. The aim of this study was to evaluate the influence of Cef (100 µM) on behavior patterns, glutamate transport activity, and oxidative stress in zebrafish brains subjected to EtOH (0.3% v/v) withdrawal. The exploratory tests using Novel tank showed that EtOH withdrawal promoted a decrease in the time spent and number of entries of in the bottom displaying an anxiety-like behavior. In contrast, treatment with Cef resulted in recovery of exploratory behavioral patterns. Ceftriaxone treatment resulted in increased glutamate uptake in zebrafish subjected to EtOH withdrawal. Furthermore, EtOH withdrawal increased reactive species, as determined using thiobarbituric acid and dichlorodihydrofluorescein assays. Treatment with Cef reversed these effects. Ceftriaxone promoted a significant reduction in brain sulfhydryl content in zebrafish subjected to EtOH withdrawal. Therefore, Cef treatment in conjunction with EtOH withdrawal induced anxiolytic-like effects due to possible neuromodulation of glutamatergic transporters, potentially through mitigation of oxidative stress.
Assuntos
Ansiedade/metabolismo , Encéfalo/metabolismo , Ceftriaxona/uso terapêutico , Etanol/efeitos adversos , Ácido Glutâmico/metabolismo , Síndrome de Abstinência a Substâncias/metabolismo , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/psicologia , Animais , Ansiedade/tratamento farmacológico , Ansiedade/psicologia , Encéfalo/efeitos dos fármacos , Ceftriaxona/farmacologia , Etanol/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Síndrome de Abstinência a Substâncias/prevenção & controle , Síndrome de Abstinência a Substâncias/psicologia , Peixe-ZebraRESUMO
Fear memory reactivation does not always lead to memory destabilization-reconsolidation. For instance, fear memories formed following withdrawal from chronic ethanol consumption or a stressful event are less likely to become destabilized after reactivation, with the effect of recall of these memories on the affective state still requiring elucidation. Here, we investigated the negative emotional-like responses following fear memory reactivation in ethanol-withdrawn (ETOH) rats by focusing on the possible role played by destabilization. Our findings indicated that ETOH rats displayed an increased freezing in a novel context and an anxiogenic-like response in the elevated plus maze (EPM) following memory reactivation, whereas the behavior of CON animals was not affected. The destabilization blockade by pre-reactivation nimodipine (16â¯mg/kg, s.c) administration promoted in CON animals a similar behavior in the EPM and in a novel environment as that exhibited by ETOH rats after the reminder. Moreover, facilitating destabilization by pre-reactivation d-cycloserine (5â¯mg/kg, i.p) administration prevented the emotional-like disturbances observed in ETOH rats. Finally, using restraint stress, which is also an inductor of a fear memory resistant to destabilization, an increased fear response in an unconditioned environment and an anxiogenic-like state was also found after the presentation of the fear reminder in stressed rats. Our results suggest that, in the context of resistant fear memories, the occurrence of destabilization influences how animals respond to subsequent environmental challenges following reactivation.
Assuntos
Emoções , Medo/psicologia , Memória , Rememoração Mental , Animais , Condicionamento Clássico , Ciclosserina/farmacologia , Emoções/efeitos dos fármacos , Etanol/efeitos adversos , Medo/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Rememoração Mental/efeitos dos fármacos , Nimodipina/farmacologia , Ratos , Ratos Wistar , Estresse Psicológico/psicologia , Síndrome de Abstinência a Substâncias/psicologiaRESUMO
The effects on the vasculature produced by ethanol withdrawal include both vasodilatation and hypocontractility, although a detailed biochemical understanding of these processes is yet to be accomplished. Here, we sought to investigate some of the mechanisms underlying vascular hypocontractility induced by ethanol withdrawal. Male Wistar rats were treated with increasing doses of 3-9% ethanol (v/v) for 21 days and the impact of ethanol withdrawal on the vascular function was assessed 48â¯h after immediate ethanol suspension. Endothelium-denuded rat aortic rings showed a reduced contractile response to phenylephrine, angiotensin II, serotonin and KCl after ethanol withdrawal, but the same phenomenon was not observed in endothelium-intact rings. Indomethacin, but not L-NAME, tiron, PEG-catalase and SC560, restored the contractile response to phenylephrine of endothelium-denuded aortas from abstinent rats. Hyporeactivity to phenylephrine induced by ethanol withdrawal was reversed by SC236, a selective cyclooxygenase (COX)-2 inhibitor. Similarly, Ro1138452, a selective prostacyclin IP receptor antagonist, reversed vascular hypocontractility induced by ethanol withdrawal. Increased concentrations of 6-keto-prostaglandin (PG)F1α, a stable product of PGI2, was detected in endothelium-denuded aortas from abstinent rats, and this response was prevented by indomethacin. However, no changes in aortic PGE2 levels were detected after ethanol withdrawal. In situ quantification of hydrogen peroxide (H2O2) and nitric oxide (NO) using fluorescent dyes revealed that ethanol withdrawal decreased the levels of these two compounds in the tunica media. Our studies show that the vascular hypocontractility induced by ethanol withdrawal is independent of the endothelium and it is mediated by PGI2 derived from COX-2.
Assuntos
Ciclo-Oxigenase 2/metabolismo , Epoprostenol/metabolismo , Etanol/efeitos adversos , Síndrome de Abstinência a Substâncias/metabolismo , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Compostos de Benzil/farmacologia , Catalase/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Endotélio Vascular/metabolismo , Peróxido de Hidrogênio/farmacologia , Imidazóis/farmacologia , Indometacina/farmacologia , Masculino , Fenilefrina/farmacologia , Polietilenoglicóis/metabolismo , Pirazóis/farmacologia , Ratos , Ratos Wistar , Sulfonamidas/farmacologia , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacosRESUMO
A 1-day fear memory in ethanol withdrawn (ETOH) rats is resistant to destabilization-reconsolidation process. However, d-cycloserine (DCS) reverts this disturbance. Considering that the formation of pathological fear memories in humans often occurs long time before the requirement of an intervention, the study of older memories is relevant in ETOH rats. In addition, the resistance to destabilization and DCS effect on this memory phase at molecular level in ETOH rats have not been corroborated yet. Firstly, we examined the effect of a pharmacological intervention after reactivation on reconsolidation of a 7-day fear memory in ETOH rats. Then, and considering that enhanced GluN2B expression and ubiquitin-proteasome system (UPS) activity are involved in destabilization, we evaluated them following reactivation in ETOH rats. Furthermore, DCS effect on such destabilization markers was examined. It was found that the pharmacological intervention after reactivation did not affect the 7-day fear memory in ETOH rats with DCS reversing this resistance. Memory reactivation increased GluN2B expression, polyubiquitination levels and proteasome activity in the basolateral amygdala complex (BLA) of control (CON) rats only; without affecting these molecular events in ETOH rats. Finally, ETOH rats treated with DCS and CON animals displayed elevated and similar UPS activities in the BLA after reactivation. In conclusion, the reactivation of an older fear memory formed during ethanol withdrawal does not trigger the molecular events associated with destabilization, and DCS facilitates this memory phase by enhancing the UPS activity.
Assuntos
Transtornos Relacionados ao Uso de Álcool/metabolismo , Medo/fisiologia , Memória/fisiologia , Síndrome de Abstinência a Substâncias/metabolismo , Síndrome de Abstinência a Substâncias/psicologia , Transtornos Relacionados ao Uso de Álcool/psicologia , Animais , Antimetabólitos/farmacologia , Complexo Nuclear Basolateral da Amígdala/efeitos dos fármacos , Complexo Nuclear Basolateral da Amígdala/metabolismo , Depressores do Sistema Nervoso Central/efeitos adversos , Condicionamento Psicológico/efeitos dos fármacos , Condicionamento Psicológico/fisiologia , Ciclosserina/farmacologia , Etanol/efeitos adversos , Medo/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Distribuição Aleatória , Ratos Wistar , Receptores de N-Metil-D-Aspartato/metabolismoRESUMO
Chronic alcohol use induces adaptations and toxicity that can induce symptoms of anxiety, autonomic hyperarousal, and epileptic seizures when alcohol is removed (withdrawal syndrome). Zebrafish has recently gained wide attention as a behavioral model to study the neurobehavioral effects of acute and chronic alcohol use, including withdrawal. The literature, however, is very contradictory on findings regarding withdrawal effects, with some studies reporting increased anxiety, while others report no effect. A meta-analytic approach was taken to find the sources of this heterogeneity, and ethanol concentration during exposure and exposure duration were found to be the main sources of variation. A conceptual replication was also made using continuous exposure for 16â¯days in waterborne ethanol (0.5%) and assessing anxiety-like behavior in the light/dark test after 60â¯min withdrawal. Withdrawal was shown to reduce preference for darkness, consistent with decreased anxiety, but to increase risk assessment, consistent with increased anxiety. Animals were also subjected to the withdrawal protocol and injected with pilocarpine in a sub-convulsive dose to assess susceptibility to epileptic seizure-like behavior. The protocol was sufficient to increase susceptibility to epileptic seizure-like behavior in animals exposed to ethanol. Finally, withdrawal also decreased catalase activity in the brain, but not in the head kidney, suggesting mechanisms associated with the behavioral effects of ethanol withdrawal.
Assuntos
Etanol/efeitos adversos , Síndrome de Abstinência a Substâncias/metabolismo , Síndrome de Abstinência a Substâncias/psicologia , Peixe-Zebra/fisiologia , Animais , Ansiedade/etiologia , Encéfalo/enzimologia , Catalase/metabolismo , Escuridão , Metanálise como Assunto , Modelos Biológicos , Pilocarpina/farmacologia , Medição de Risco , Convulsões/induzido quimicamenteRESUMO
The pharmacological blockade of memory reconsolidation has been suggested as a potential treatment to the attenuation of maladaptive memories associated to psychiatric disorders and drug addiction. To interfere with the process of fear memory reconsolidation using a manipulation safer than pharmacological interventions, here we examined whether a positive reinforcing stimulus (non-alcoholic beer, NB) post-memory retrieval can decrease the fear response in ethanol withdrawn (ETOH) animals. We first evaluated the potential interfering effect of NB on memory reconsolidation in non-ethanol dependent (control, CON) rats. Non-alcoholic beer intake shortly after memory retrieval attenuated the fear response in CON rats. A resistance to destabilization/reconsolidation process was previously observed in ETOH rats, which was reversed by the activation of NMDA receptor induced by pre-retrieval d-cycloserine (DCS) administration. Therefore, the influence of DCS (5mg/kg; i.p.) to facilitate the disruptive effect of NB on fear memory was examined in ETOH animals. As expected, NB was ineffective to attenuate the fear response in ETOH rats, with DCS being necessary to promote the disruptive effect of NB on the reconsolidation in these animals. Hence, DCS/reinforcing stimulus in combination with memory reactivation can be considered as an alternative approach for disrupting resistant fear memories.
Assuntos
Antimetabólitos/administração & dosagem , Ciclosserina/administração & dosagem , Etanol/efeitos adversos , Medo , Transtornos da Memória/etiologia , Transtornos da Memória/prevenção & controle , Memória/efeitos dos fármacos , Reforço Psicológico , Síndrome de Abstinência a Substâncias/complicações , Animais , Esquema de Medicação , Ratos , Ratos WistarRESUMO
We analyzed the effects of ethanol withdrawal on the vascular and systemic renin-angiotensin system (RAS) and vascular oxidative stress. Male Wistar rats were treated with ethanol 3-9% (v/v) for a period of 21 days. Ethanol withdrawal was induced by abrupt discontinuation of the treatment. Experiments were performed 48 h after ethanol discontinuation. Rats from the ethanol withdrawal group showed decreased exploration of the open arms of the elevated-plus maze (EPM) and increased plasma corticosterone levels. Ethanol withdrawal significantly increased systolic blood pressure and plasma angiotensin II (ANG II) levels without an effect on plasma renin activity (PRA), angiotensin converting enzyme (ACE) activity, or plasma angiotensin I (ANG I) levels. No differences in vascular ANG I, ANG II levels, and ACE activity/expression and AT1 and AT2 receptor expression were detected among the experimental groups. Plasma osmolality, as well as plasma sodium, potassium, and glucose levels were not affected by ethanol withdrawal. Ethanol withdrawal induced systemic and vascular oxidative stress, as evidenced by increased plasma thiobarbituric acid-reacting substances (TBARS) levels and the vascular generation of superoxide anion. Ethanol withdrawal significantly decreased plasma and vascular nitrate/nitrite levels. Major new findings of the present study are that ethanol withdrawal induces vascular oxidative stress and reduces nitric oxide (NO) levels in the vasculature. Additionally, our study provides novel evidence that ethanol withdrawal does not affect the vascular ANG II generating system while stimulating systemic RAS. These responses could predispose individuals to the development of cardiovascular diseases.
Assuntos
Endotélio Vascular/metabolismo , Etanol/administração & dosagem , Óxido Nítrico/sangue , Estresse Oxidativo/fisiologia , Síndrome de Abstinência a Substâncias/sangue , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Disponibilidade Biológica , Endotélio Vascular/efeitos dos fármacos , Etanol/toxicidade , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Síndrome de Abstinência a Substâncias/etiologia , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
BACKGROUND: There is a close relationship between the endocannabinoid system and alcoholism. This study investigated possible differential expression of cannabinoid receptors CB1 (CB1R) and CB2 (CB2R) in an outbred mice strain displaying behavioral variability to ethanol (EtOH)-induced locomotor sensitization. METHODS: Male adult Swiss mice treated chronically with EtOH (2 g/kg, i.p., daily for 21 days) were classified as "EtOH_High" or "EtOH_Low" according to their locomotor activity after the 21st EtOH injection. A control group was similarly injected with saline. Temporal analysis of CB1R and CB2R immunoreactivity was performed in 3 different occasions: (i) at the end of chronic EtOH treatment, (ii) on the fifth day of EtOH withdrawal, and (iii) after EtOH challenge. RESULTS: Overall, no differences were seen between experimental groups regarding the CB1R at the end of acquisition. However, there were decreases in CB2R in the prefrontal cortex and the hippocampus in EtOH_Low mice. On the fifth day of withdrawal, only EtOH_High mice presented increase in CB1R. Nonetheless, CB2R up-regulation was observed in both EtOH_High and EtOH_Low mice. EtOH challenge counteracted CB1R and CBR2 up-regulation, mainly in the EtOH_High, in structures related to emotionality, such as prefrontal cortex, ventral tegmental area, amygdala, striatum, and hippocampus. CONCLUSIONS: There are different patterns of cannabinoid receptor expression during locomotor sensitization paradigm, at both temporal and behavioral perspectives. We hypothesize that CB2R down-regulation might be related to resilience to develop locomotor sensitization, while CB1R up-regulation relates to withdrawal aspects in sensitized mice.