Amygdaloid Corticotropin-releasing Factor is Involved in the Anxiolytic Effect of Acupuncture during Ethanol Withdrawal in Rats

A protocol for the integration of multi-omics bioinformatics: Mechanism of acupuncture as an adjunctive therapy for alcohol use disorder

Background

Alcohol use disorder (AUD) has become a significant global factor in various diseases. As a non-pharmacological therapy, certain therapeutic potential has been found in acupuncture; however, in-depth mechanistic studies related to acupuncture for patients with AUD are still insufficient.

Methods

Based on a randomized control design and a multi-omics analysis plan, this protocol details the recruitment (42 AUD patients), group allocation (21 in acupuncture group vs. 21 in sham acupuncture group), intervention and follow-up (replacement drugs as a normal treatment, 2 weeks acupuncture duration, and 3 month follow-up), and data collection and analytical processes. For the clinical outcomes, in addition to the time required for alcohol withdrawal symptoms to subside as the primary outcome, changes in the alcohol withdrawal symptoms, alcohol craving, mood dysfunction, sleep disorder, fatigue, self-efficacy, gastrointestinal symptoms, the quality of life, and the relapse outcomes will be compared between the groups to confirm the acupuncture clinical effectiveness on alcohol withdraw. The gut microbiome and the fecal metabolomics will also be assessed to explore the association of the structure and the function of gut microflora and the mediation of acupuncture effect on AUD fully utilizing gut microflora multi-modal data and clinical information, via the combination of multi-omics methods, feature screening algorithms and appropriate models.

Discussion

The results of this study may help to strengthen clinical evidence of the mechanism of acupuncture intervention in patients with AUD, through understanding of the regulatory mechanism of acupuncture in the gut microbiome and its metabolism as well as AUD-related clinical manifestations.

Trial registration

Chinese Clinical Trial Registry ChiCTR2200058120. Registered on 24 Mar 2022.

Long-term consequences of alcohol use in early adolescent mice: Focus on neuroadaptations in GR, CRF and BDNF

Our aim was to assess the cognitive and emotional state, as well as related-changes in the glucocorticoid receptor (GR), the corticotropin-releasing factor (CRF) and the brain-derived neurotrophic factor (BDNF) expression of adolescent C57BL/6J male mice after a 5-week two-bottle choice protocol (postnatal day [pd]21 to pd52). Additionally, we wanted to analyse whether the behavioural and neurobiological effects observed in late adolescence (pd62) lasted until adulthood (pd84). Behavioural testing revealed that alcohol during early adolescence increased anxiety-like and compulsive-related behaviours, which was maintained in adulthood. Concerning cognition, working memory was only altered in late adolescent mice, whereas object location test performance was impaired in both ages. In contrast, novel object recognition remained unaltered. Immunohistochemical analysis showed that alcohol during adolescence diminished BDNF+ cells in the cingulate cortex, the hippocampal CA1 layer and the central amygdala. Regarding hypothalamic-pituitary-adrenal axis (HPA) functioning, alcohol abuse increased the GR and CRF expression in the hypothalamic paraventricular nucleus and the central amygdala. Besides this, GR density was also higher in the prelimbic cortex and the basolateral amygdala, regardless of the animals' age. Our findings suggest that adolescent alcohol exposure led to long-term behavioural alterations, along with changes in BDNF, GR and CRF expression in limbic brain areas involved in stress response, emotional regulation and cognition.

Acupuncture Alleviates Anxiety and 22-kHz Ultrasonic Vocalizations in Rats Subjected to Repeated Alcohol Administration by Modulating the Brain-Derived Neurotrophic Factor/Corticotropin-Releasing Hormone Signaling Pathway

The Shenmen point (acupuncture point heart 7: HT7), located in the heart meridian, is frequently used to treat mental disorders, including drug addiction, anxiety, and depression. This study aimed to determine how HT7 regulates anxiety and negative emotions caused by repeated alcohol administration, focusing on the amygdala and paraventricular nucleus (PVN). Repeated administration of alcohol (ETOH; 2 g/kg, i.p. injection, 16% v/v) for 14 days increased the corticosterone (CORT) levels, and HT7 stimulation reduced the plasma CORT levels. HT7 stimulation mitigated anxiety-like behaviors and reduced 22-kHz ultrasonic vocalizations in rats receiving repeated ETOH injections. HT7 stimulation increased the amygdala expression of mature brain-derived neurotropic factor (mBDNF) and phosphorylated tropomyosin receptor kinase B (pTrkB) and decreased the PVN corticotropin-releasing hormone (CRH) expression. Amygdala microinjections of the TrkB antagonist ANA-12 (0.1 pmol/1 μL) reversed the increase in PVN CRH levels. The reduced PVN CRH levels were regulated by CRH-expressing neurons in the amygdala, and the increased amygdala CRH levels were affected by the HT7-stimulation induced increases in mBDNF. HT7 stimulation alleviates increased stress hormone levels and mitigates anxiety and negative emotions caused by repeated ETOH administration. These results provide scientific support for the clinical use of acupuncture to treat various alcoholism-induced diseases.

Bidirectional role of acupuncture in the treatment of drug addiction

Drug addiction is a chronically relapsing disorder, affecting people from all walks of life. Studies of acupuncture effects on drug addiction are intriguing in light of the fact that acupuncture can be used as a convenient therapeutic intervention for treating drug addiction by direct activation of brain pathway. The current review aims to discuss the neurobiological mechanisms underlying acupuncture's effectiveness in the treatment of drug addiction, on the basis of two different theories (the incentive sensitization theory and the opponent process theory) that have seemingly opposite view on the role of the mesolimbic reward pathways in mediating compulsive drug-seeking behavior. This review provides evidence that acupuncture may reduce relapse to drug-seeking behavior by regulating neurotransmitters involved in drug craving modulation via somatosensory afferent mechanisms. Also, acupuncture normalizes hyper-reactivity or hypoactivity of the mesolimbic dopamine system in these opposed processes in drug addiction, suggesting bidirectional role of acupuncture in regulation of drug addiction. This proposes that acupuncture may reduce drug craving by correcting both dysfunctions of the mesolimbic dopamine pathway.

Role of corticotropin-releasing factor in alcohol and nicotine addiction

The two most prevalent substance use disorders involve alcohol and nicotine, which are often co-abused. Robust preclinical and translational evidence indicates that individuals initiate drug use for the acute rewarding effects of the substance. The development of negative emotional states is key for the transition from recreational use to substance use disorders as subjects seek the substance to obtain relief from the negative emotional states of acute withdrawal and protracted abstinence. The neuropeptide corticotropin-releasing factor (CRF) is a major regulator of the brain stress system and key in the development of negative affective states. The present review examines the role of CRF in preclinical models of alcohol and nicotine abuse and explores links between CRF and anxiety-like, dysphoria-like, and other negative affective states. Finally, the present review discusses preclinical models of nicotine and alcohol use with regard to the CRF system, advances in molecular and genetic manipulations of CRF, and the importance of examining both males and females in this field of research.

Driving the Downward Spiral: Alcohol-Induced Dysregulation of Extended Amygdala Circuits and Negative Affect

Alcohol use disorder (AUD) afflicts a large number of individuals, families, and communities globally. Affective disturbances, including stress, depression, and anxiety, are highly comorbid with AUD, contributing in some cases to initial alcohol use and continued use. Negative affect has a particularly strong influence on the withdrawal/abstinence stage of addiction as individuals with AUD frequently report stressful events, depression, and anxiety as key factors for relapse. Treatment options for negative affect associated with AUD are limited and often ineffective, highlighting the pressing need for preclinical studies examining the underlying neural circuitry driving AUD-associated negative affect. The extended amygdala (EA) is a set of brain areas collectively involved in generating and regulating affect, and extensive research has defined a critical role for the EA in all facets of substance use disorder. Here, we review the expansive historical literature examining the effects of ethanol exposure on the EA, with an emphasis on the complex EA neural circuitry driving negative affect in all phases of the alcohol addiction cycle. Specifically, this review focuses on the effects of alcohol exposure on the neural circuitry in 2 key components of the EA, the central nucleus of the amygdala and the bed nucleus of the stria terminalis. Additionally, future directions are proposed to advance our understanding of the relationship between AUD-associated negative affect and neural circuitry in the EA, with the long-term goal of developing better diagnostic tools and new pharmacological targets aimed at treating negative affect in AUD. The concepts detailed here will serve as the foundation for a companion review focusing on the potential for the endogenous cannabinoid system in the EA as a novel target for treating the stress, anxiety, and negative emotional state driving AUD.

Methanol extract of semen Ziziphi Spinosae attenuates ethanol withdrawal anxiety by improving neuropeptide signaling in the central amygdala

Background

Ethanol withdrawal (EtOHW) anxiety is a crucial risk factor for alcoholic relapse. The neuropeptide nociceptin/orphanin FQ (N/OFQ) acts upon its receptor (NOP) to antagonize corticotropin-releasing factor (CRF) and elicit anxiolytic actions. Semen Ziziphi Spinosae (SZS), a prototypical hypnotic-sedative herb in Oriental medicine, exhibits anxiolytic effects during nicotine withdrawal by improving amygdaloid CRF/CRF1 receptor (CRFR1) signaling. Therefore, we evaluated the effects of SZS on EtOHW anxiety and the involvement of amygdaloid CRF/CRFR1 and N/OFQ/NOP pathways.

Methods

Male Sprague Dawley rats received intraperitoneal injections of 2 g/kg EtOH (20% v/v) once daily for 28 d followed by a 3-d withdrawal. During EtOHW, the rats were given once-daily intragastric treatments of a methanol extract of SZS (MESZS, 60 or 180 mg/kg/d). Anxiety-like behaviors were measured with the open field (OF) and elevated plus maze (EPM) tests, and plasma corticosterone (CORT) levels were examined by an enzyme-linked immunosorbent assay. mRNA and protein expression levels of the neuropeptides and their receptors were determined by quantitative polymerase chain reaction and Western blot assays.

Results

MESZS increased the distance traveled in the center zone of the OF and dose-dependently elongated the duration of staying in the center zone in EtOHW rats. MESZS increased both the number of entries into and the time spent in the open arms of the EPM by EtOHW rats. And, MESZS inhibited the over secretion of plasma CORT during EtOHW. EtOHW enhanced CRF and CRFR1 gene and protein expression in the central nucleus of the amygdala (CeA), which were inhibited by 180 mg/kg/d MESZS. EtOHW increased amygdaloid NOP mRNA and protein expression but spared N/OFQ mRNA expression, and 180 mg/kg/d MESZS further promoted these increases. Additionally, a post-MESZS intra-CeA infusion of either CRF or the selective NOP antagonist UFP-101 abolished the expected anxiolytic effect of 180 mg/kg/d MESZS.

Conclusions

These results suggest that MESZS ameliorates EtOHW anxiety by improving both CRF/CRFR1 and N/OFQ/NOP transmissions in the CeA.

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2546-0) contains supplementary material, which is available to authorized users.

Acupuncture on the Stress-Related Drug Relapse to Seeking

Drug addiction is a chronic relapsing disease, which causes serious social and economic problems. The most important trial for the successful treatment of drug addiction is to prevent the high rate of relapse to drug-seeking behaviors. Opponent process as a motivational theory with excessive drug seeking in the negative reinforcement of drug dependence reflects both loss of brain reward system and recruitment of brain stress system. The negative emotional state produced by brain stress system during drug withdrawal might contribute to the intense drug craving and drive drug-seeking behaviors via negative reinforcement mechanisms. Decrease in dopamine neurotransmission in the nucleus accumbens and recruitment of corticotropin-releasing factor in the extended amygdala are hypothesized to be implicated in mediating this motivated behavior. Also, a brain stress response system is hypothesized to increase drug craving and contribute to relapse to drug-seeking behavior during the preoccupation and anticipation stage of dependence caused by the exposure to stress characterized as the nonspecific responses to any demands on the body. Acupuncture has proven to be effective for reducing drug addiction and stress-related psychiatric disorders, such as anxiety and depression. Furthermore, acupuncture has been shown to correct reversible brain malfunctions by regulating drug addiction and stress-related neurotransmitters. Accordingly, it seems reasonable to propose that acupuncture attenuates relapse to drug-seeking behavior through inhibition of stress response. In this review, a brief description of stress in relapse to drug-seeking behavior and the effects of acupuncture were presented.

Aqueous Extract of Semen Ziziphi Spinosae Exerts Anxiolytic Effects during Nicotine Withdrawal via Improvement of Amygdaloid CRF/CRF1R Signaling

Anxiety during nicotine withdrawal (NicW) is a key risk factor for smoking relapse. Semen Ziziphi Spinosae (SZS), which is a prototypical hypnotic-sedative herb in Oriental medicine, has been clinically used to treat insomnia and general anxiety disorders for thousands of years. Thus, the present study evaluated the effects of the aqueous extract of SZS (AESZS) on NicW-induced anxiety in male rats that received subcutaneous administrations of nicotine (Nic) (0.4 mg/kg, twice a day) for 7 d followed by 4 d of withdrawal. During NicW, the rats received four intragastric treatments of AESZS (60 mg/kg/d or 180 mg/kg/d). AESZS dose-dependently attenuated NicW-induced anxiety-like behaviors in the elevated plus maze (EPM) tests and 180 mg/kg/d AESZS inhibited NicW-induced increases in plasma corticosterone. Additionally, the protein and mRNA expressions of corticotropin-releasing factor (CRF) and CRF type 1 receptor (CRF1R) increased in the central nucleus of the amygdala (CeA) during NicW, but these changes were suppressed by 180 mg/kg/d AESZS. A post-AESZS infusion of CRF into the CeA abolished the attenuation of anxiety by AESZS and 180 mg/kg/d AESZS suppressed NicW-induced increases in norepinephrine and 3-methoxy-4-hydroxy-phenylglycol levels in the CeA. The present results suggest that AESZS ameliorated NicW-induced anxiety via improvements in CRF/CRF1R and noradrenergic signaling in the CeA.

Low doses of methylmercury intoxication solely or associated to ethanol binge drinking induce psychiatric-like disorders in adolescent female rats

Methylmercury (MeHg) is an environmental contaminant that provokes damage to developing brain. Simultaneously, the consumption of ethanol among adolescents has increased. Evidence concerning the effects of MeHg low doses per se or associated with ethanol during adolescence are scarce. Thus, we investigate behavioral disorders resulted from exposure to MeHg low doses and co-intoxicated with ethanol in adolescent rats. Wistar rats received chronic exposure to low doses of MeHg (40 μg/kg/day for 5 weeks) and/or ethanol binge drinking (3 g/kg/day at 3 days per week for 5 weeks). Animals were submitted to behavioral assays to assess emotionality and cognitive function. Total mercury content was evaluated in the brain and hair. Oxidative parameters were analyzed in blood samples. MeHg at low doses or associated to ethanol binge drinking produced psychiatric-like disorders and cognitive impairment. Peripherally, MeHg altered oxidative parameters when associated to ethanol. Ethanol administration reduced brain mercury deposit. We proposed that ethanol reduces the necessity of mercury tissue levels to display psychiatric-like disorders/cognitive impairment.

Strong Manual Acupuncture Stimulation of "Huantiao" (GB 30) Reduces Pain-Induced Anxiety and p-ERK in the Anterior Cingulate Cortex in a Rat Model of Neuropathic Pain

Persistent neuropathic pain is associated with anxiety. The phosphorylation of extracellular signal-regulated kinase (p-ERK) in the anterior cingulate cortex (ACC) plays an important role in pain-induced anxiety. Acupuncture is widely used for pain and anxiety. However, little is known about which acupuncture technique is optimal on pain-induced anxiety and the relationship between acupuncture effect and p-ERK. The rat model was induced by L5 spinal nerve ligation (SNL). Male adult SD rats were randomly divided into control, SNL, strong manual acupuncture (sMA), mild manual acupuncture (mMA), and electroacupuncture (EA) group. Bilateral "Huantiao" (GB 30) were stimulated by sMA, mMA, and EA, respectively. The pain withdrawal thresholds (PWTs) and anxiety behavior were measured, and p-ERK protein expression and immunoreactivity cells in ACC were detected. PWTs increased significantly in both sMA and EA groups. Meanwhile, anxiety-like behavior was improved significantly in the sMA and mMA groups. Furthermore, the overexpression of p-ERK induced by SNL was downregulated by strong and mild manual acupuncture. Therefore, strong manual acupuncture on bilateral "Huantiao" (GB 30) could be a proper therapy relieving both pain and pain-induced anxiety. The effect of different acupuncture techniques on pain-induced anxiety may arise from the regulation of p-ERK in ACC.

Preclinical evidence implicating corticotropin-releasing factor signaling in ethanol consumption and neuroadaptation

The results of many studies support the influence of the corticotropin-releasing factor (CRF) system on ethanol (EtOH) consumption and EtOH-induced neuroadaptations that are critical in the addiction process. This review summarizes the preclinical data in this area after first providing an overview of the components of the CRF system. This complex system involves hypothalamic and extra-hypothalamic mechanisms that play a role in the central and peripheral consequences of stressors, including EtOH and other drugs of abuse. In addition, several endogenous ligands and targets make up this system and show differences in their involvement in EtOH drinking and in the effects of chronic or repeated EtOH treatment. In general, genetic and pharmacological approaches paint a consistent picture of the importance of CRF signaling via type 1 CRF receptors (CRF(1)) in EtOH-induced neuroadaptations that result in higher levels of intake, encourage alcohol seeking during abstinence and alter EtOH sensitivity. Furthermore, genetic findings in rodents, non-human primates and humans have provided some evidence of associations of genetic polymorphisms in CRF-related genes with EtOH drinking, although additional data are needed. These results suggest that CRF(1) antagonists have potential as pharmacotherapeutics for alcohol use disorders. However, given the broad and important role of these receptors in adaptation to environmental and other challenges, full antagonist effects may be too profound and consideration should be given to treatments with modulatory effects.

Hypothalamic Norepinephrine Mediates Acupunctural Effects on Hypothalamic-Pituitary-Adrenal Axis During Ethanol Withdrawal

A previous study demonstrated that acupuncture at ST36 (Zu-San-Li) attenuates ethanol withdrawal (EW)-induced hyperactivation of the hypothalamic-pituitary-adrenal axis in rats. The current study investigated the involvement of hypothalamic norepinephrine (NE) in that process. Rats were intraperitoneally treated with 3 g/kg/d of ethanol or saline for 28 days. After 24 hours of EW, acupuncture was applied to rats at bilateral ST36 points or at nonacupoints (tail) for 1 minute. A high-performance liquid chromatography analysis showed that EW significantly increased both the NE and the 3-methoxy-4-hydroxy-phenylglycol (MHPG) levels in the hypothalamic paraventricular nucleus (PVN). Western blot analysis also revealed that EW markedly elevated the phosphorylation rates of tyrosine hydroxylase (TH), but spared TH protein expression in the PVN. However, acupuncture at ST36, but not at nonacupoints, greatly inhibited the increase in the hypothalamic NE, MHPG, and phosphorylation rates of TH. Additionally, postacupuncture infusion of NE into the PVN significantly attenuated the inhibitory effects of acupuncture at ST36 on the oversecretion of plasma corticosterone during EW. These results suggest that acupuncture at ST36 inhibits EW-induced hyperactivation of the hypothalamic NEergic system to produce therapeutic effects on the hypothalamic-pituitary-adrenal axis.

Korean Red Ginseng attenuates anxiety-like behavior during ethanol withdrawal in rats

BACKGROUND

Korean Red Ginseng (KRG) is known to have antianxiety properties. This study was conducted to investigate the anxiolytic effects of KRG extract (KRGE) during ethanol withdrawal (EW) and the involvement of the mesoamygdaloid dopamine (DA) system in it.

METHODS

Rats were treated with 3 g/kg/d of ethanol for 28 d, and subjected to 3 d of withdrawal. During EW, KRGE (20 mg/kg/d or 60 mg/kg/d, p.o.) was given to rats once/d for 3 d. Thirty min after the final dose of KRGE, anxiety-like behavior was evaluated in an elevated plus maze (EPM), and plasma corticosterone (CORT) levels were determined by a radioimmunoassay (RIA). In addition, concentrations of DA and 3,4-dihydroxyphenylacetic acid (DOPAC) in the central nucleus of the amygdala (CeA) were also measured by high performance liquid chromatography (HPLC).

RESULTS

The EPM test and RIA revealed KRGE inhibited anxiety-like behavior and the over secretion of plasma CORT during EW. Furthermore, the behavioral effect was blocked by a selective DA D2 receptor (D2R) antagonist (eticlopride) but not by a selective DA D1 receptor (D1R) antagonist (SCH23390). HPLC analyses showed KRGE reversed EW-induced decreases of DA and DOPAC in a dose-dependent way. Additionally, Western blotting and real-time polymerase chain reaction (PCR) assays showed that KRGE prevented the EW-induced reductions in tyrosine hydroxylase (TH) protein expression in the CeA and TH mRNA expression in the ventral tegmental area (VTA).

CONCLUSION

These results suggest that KRGE has anxiolytic effects during EW by improving the mesoamygdaloid DA system.

Involvement of amygdaloid neuropeptide Y in the anxiolytic effects of acupuncture during ethanol withdrawal in rats

The role of neuropeptide Y (NPY) in the central nucleus of amygdala (CeA) in the preventive effects of acupuncture against ethanol withdrawal-induced anxiety was investigated. Rats were treated with 3g/kg/day of ethanol for 28 days, followed by 3 days of withdrawal. Bilateral acupuncture treatment at HT7 (Shen-Men), PC6 (Nei-Guan) or a non-acupoint was respectively added to the rats during the withdrawal once a day for three days. Enzyme-linked immunosorbent assays and real-time polymerase chain reaction analyses showed there was a significant decrease in NPY protein and mRNA expression in the CeA during ethanol withdrawal, which was reversed by acupuncture at HT7 but neither at PC6 nor at a non-acupoint. Acupuncture at HT7 also greatly inhibited the decrease in cAMP response element-binding protein (CREB) phosphorylation in the CeA. In elevated plus maze tests, a selective NPY Y1 receptor antagonist BIBP 3226 into the CeA before the acupuncture abolished almost completely the anxiolytic effect of acupuncture at HT7. These results suggest that acupuncture at HT7 rescues the depletion of amygdaloid NPY and reverses the decrease in CREB phosphorylation to produce anxiolytic effects during ethanol withdrawal.

Effects of acupuncture at Zu-San-Li (ST36) on the activity of the hypothalamic--pituitary--adrenal axis during ethanol withdrawal in rats

The current study investigated the effects of acupuncture at Zu-San-Li (ST36) on the hypothalamic-pituitary-adrenal axis during ethanol withdrawal in rats. Rats were intraperitoneally treated with 3 g/kg/day of ethanol or saline for 28 days. Following 24 hours of ethanol withdrawal, acupuncture was applied at bilateral ST36 points or non-acupoints (tail) for 1 minute. Plasma levels of corticosterone (CORT) and adrenocorticotropic hormone (ACTH) were measured by radioimmunoassay (RIA), and the corticotropin-releasing factor (CRF) protein levels in the paraventricular nucleus of the hypothalamus were also examined by RIA 20 minutes after the acupuncture treatment. RIA showed significantly increased plasma levels of CORT and ACTH in the ethanol-withdrawn rats compared with the saline-treated rats, which were inhibited significantly by the acupuncture at the acupoint ST36 but not at the non-acupoint. Additionally, ethanol withdrawal promoted CRF protein expressions in the paraventricular nucleus of the hypothalamus, which were also blocked by the acupuncture at ST36. These findings suggest that acupuncture at the specific acupoint ST36 can inhibit ethanol withdrawal-induced hyperactivation of hypothalamic-pituitary-adrenal axis, and it may be mediated via the modulation of hypothalamic CRF.