Acupuncture-mediated inhibition of ethanol-induced dopamine release in the rat nucleus accumbens through the GABAB receptor

Neural circuit mechanisms of acupuncture effect: where are we now?

Recently, there has been increasing attention on the impact of acupuncture on the dysregulated neural circuits in different disease. This has led to new understandings of how acupuncture works. This review presents a comprehensive analysis of research that have examined the impact of acupuncture on abnormal neural circuits associated with pain, anxiety, Parkinson's disease, addiction disorders, cognitive problems, and gastrointestinal disorders. These studies have shown that acupuncture's therapeutic effects are mediated by specific brain areas and neurons involved in neural circuit mechanisms, emphasising its wide-ranging influence. The positive impacts of acupuncture can be ascribed to its ability to modify the functioning of neurocircuits in various physiological conditions. Nevertheless, contemporary studies on acupuncture neural circuits frequently overlook the comprehensive circuit mechanism including the periphery, central nervous system, and target organ. Additionally, the scope of diseases studied is restricted. Future study should focus on broadening the range of diseases studied and exploring the neural circuit mechanisms of these diseases in depth in order to enhance our understanding of acupuncture's neurobiological impacts.

Acupuncture in the treatment of cocaine addiction: how does it work?

Cocaine is a frequently abused and highly addictive drug that damages brain health and imposes substantial social and economic costs. Acupuncture has been used in the treatment of cocaine addiction and has been shown to improve abnormal mental and motor states. This article mainly focuses on the neurobiological mechanisms involving the central nervous system (CNS) and peripheral nervous system (PNS) that underlie the effects of acupuncture in the treatment of cocaine addiction. The central dopamine system is a key player in acupuncture treatment of cocaine addiction; the ventral tegmental area (VTA)-nucleus accumbens (NAc) signaling pathway, which has a modulatory influence on behavior and psychology after chronic use of cocaine, is a significant target of acupuncture action. Moreover, acupuncture alleviates cocaine-induced seizures or acute psychomotor responses through the paraventricular thalamus and the lateral habenula (LHb)-rostromedial tegmental (RMTg) nucleus circuits. The data suggest that acupuncture can impact various cocaine-induced issues via stimulation of diverse brain areas; nevertheless, the interconnection of these brain regions and the PNS mechanisms involved remain unknown. In this review, we also discuss the effects of specific acupuncture protocols on cocaine addiction and note that variations in needling modalities, current intensities and traditional acupuncture point locations have led to different experimental results. Therefore, standardized acupuncture protocols (with respect to stimulation methods, point locations and number of sessions) may become particularly important in future studies.

Mediation of mPFC-LHb pathway in acupuncture inhibition of cocaine psychomotor activity

The medial prefrontal cortex (mPFC) and the lateral habenula (LHb) play roles in drug addiction and cognitive functions. Our previous studies have suggested that acupuncture at Shenmen (HT7) points modulates mesolimbic reward system in order to suppress drug-induced addiction behaviours. To explore whether an mPFC-LHb circuit mediates the inhibitory effects of acupuncture on addictive behaviours, we examined the projection from mPFC to LHb, excitation of mPFC neurons during acupuncture stimulation, the effects of optogenetic modulation of mPFC-LHb on HT7 inhibition of cocaine-induced locomotion and the effect of mPFC lesion on HT7 inhibition of nucleus accumbens (NAc) dopamine release. Acupuncture was applied at bilateral HT7 points for 20 s, and locomotor activity was measured in male Sprague-Dawley rats. Although cocaine injection significantly increased locomotor activity, HT7 acupuncture suppressed the cocaine-induced locomotion. The inhibitory effect of HT7 on cocaine-enhanced locomotion was blocked by optogenetic silencing of the mPFC-LHb circuit. In vivo extracellular recordings showed that HT7 acupuncture evoked an increase in the action potentials of mPFC neurons. Optopatch experiment proved glutamatergic projections from mPFC to LHb. HT7 acupuncture suppressed NAc dopamine release following cocaine injection, which was blocked by electrolytic lesion of mPFC. These results suggest the mediation of mPFC-LHb circuit in the inhibitory effects of acupuncture on cocaine psychomotor activity in rats.

The Effects of Electroacupuncture via Chronically Implanted Electrodes on Alcohol Drinking and Withdrawal Signs in Rats

BACKGROUND

In the United States, more than 14 million adults suffer from alcohol use disorder (AUD). We proposed a stress-free method of electroacupuncture (EA) using chronically implanted electrodes. We aimed to develop an effective method of EA for treating AUD by testing various stimulation locations and parameters, and then investigate the effects of the daily EA on alcohol consumption and withdrawal signs in rats.

MATERIALS AND METHODS

Sprague-Dawley rats were trained to voluntarily drink ethanol under the intermittent access two-bottle choice procedure. By the end of four weeks, rats with ethanol consumption ≥1.5 g/kg/24 h were considered alcohol-dependent and included in an acute and prolonged experiments. The acute study was designed to investigate the effects of EA with different parameters and at different locations. EA treatment was applied at bilateral ST36 alone or bilateral ST36 and HT7 acupoints for 30 minutes. We investigated the effects of EA on 24-hour alcohol consumption, preference ratio (alcohol drink vs total drink), alcohol withdrawal signs (AWS), and prolonged alcohol consumption. Each animal served as its own control.

RESULTS

1) By the end of week 4, 70% of rats became alcohol-dependent. 2) Following ethanol withdrawal, there was a gradual increase in AWS over time that peaked at two hours and dropped at six hours. Among the tested stimulation parameters and locations: 3) The best stimulation location was ST36 alone, and the best stimulation parameters were a combination of 100 and 2 Hz. EA at best stimulation location and parameters reduced ethanol intake by 27% (p < 0.05 vs baseline) and marginally reduced preference ratio by 23% (p = 0.05 vs baseline). 4) EA reduced AWS at two- and four-hours following ethanol withdrawal (p ≤ 0.03 each vs no EA). 5) Daily EA (for five consecutive days) resulted in a substantial reduction in ethanol intake and preference ratio by 44% and 47%, respectively (p = 0.002 each).

CONCLUSIONS

This work shows the potential of this novel method of EA for the treatment of AUD. Further studies are warranted to investigate the mechanisms through which EA exerts its effects.

Role of Lateral Hypothalamus in Acupuncture Inhibition of Cocaine Psychomotor Activity

Acupuncture modulates the mesolimbic dopamine (DA) system; an area implicated in drug abuse. However, the mechanism by which peripheral sensory afferents, during acupuncture stimulation, modulate this system needs further investigation. The lateral hypothalamus (LH) has been implicated in reward processing and addictive behaviors. To investigate the role of the LH in mediating acupuncture effects, we evaluated the role of LH and spinohypothalamic neurons on cocaine-induced psychomotor activity and NAc DA release. Systemic injection of cocaine increased locomotor activity and 50 kHz ultrasonic vocalizations (USVs), which were attenuated by mechanical stimulation of needles inserted into HT7 but neither ST36 nor LI5. The acupuncture effects were blocked by chemical lesions of the LH or mimicked by activation of LH neurons. Single-unit extracellular recordings showed excitation of LH and spinohypothalamic neurons following acupuncture. Our results suggest that acupuncture recruits the LH to suppress the mesolimbic DA system and psychomotor responses following cocaine injection.

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 the central amygdala in acupuncture inhibition of methamphetamine-induced behaviors in rats

Methamphetamine (METH) enhances dopamine (DA) transmission in the mesolimbic system implicated in its reinforcing effects. Our previous studies have shown that acupuncture attenuates drug-seeking behaviors by modulating GABAergic transmission in the ventral tegmental area and DA release in the nucleus accumbens (NAc) of the striatum. The effects of acupuncture on METH-induced behaviors and its mediation by neural pathways remain a relatively understudied area of research. The central amygdala (CeA) plays a critical role in physiological and behavioral responses to somatosensory and drug stimuli and has been implicated in negative reinforcement. Thus, we evaluated the role of the CeA in acupuncture effects on locomotor activity, positive affective states, and DA release in the NAc following acute administration of METH. Acupuncture at acupoint HT7 reduced locomotor activity, 50-kHz ultrasonic vocalizations (USVs), and NAc DA release following systemic injection of METH, which was prevented by electrolytic lesions or optogenetic inhibition of the CeA. Acupuncture alone excited CeA neurons and reversed the suppression of CeA neurons induced by METH. These results suggest that acupuncture can relieve psychomotor responses and positive affective states following METH by inhibiting NAc DA release and this effect is mediated by activation of CeA neurons.

Interventions to prevent periodontal disease in tobacco-, alcohol-, and drug-dependent individuals

Substance abuse affects more than one sixth of the world's population. More importantly, the nature of the abuse and the type of addictive substances available to individuals is increasing exponentially. All substances with abusive potential impact both the human immuno-inflammatory system and oral microbial communities, and therefore play a critical role in the etiopathogenesis of periodontal diseases. Evidence strongly supports the efficacy of professionally delivered cessation counseling. Dentists, dental therapists, and hygienists are ideally placed to deliver this therapy, and to spearhead efforts to provide behavioral and pharmacologic support for cessation. The purpose of this review is to examine the biologic mechanisms underlying their role in disease causation, to understand the pharmacologic and behavioral basis for their habituation, and to investigate the efficacy of population-based and personalized interventions in prevention of periodontal disease.

Involvement of the Cuneate Nucleus in the Acupuncture Inhibition of Drug-Seeking Behaviors

Our previous studies have shown that acupuncture suppresses addictive behaviors induced by drugs of abuse, including cocaine, morphine and ethanol, by modulating GABA neurons in the ventral tegmental area (VTA) and dopamine (DA) release in the nucleus accumbens (NAc). The mechanisms by which the peripheral signals generated by acupoint stimulation are transmitted to brain reward systems are largely unexplored. The present study aims to investigate the role of spinal dorsal column (DC) somatosensory pathways in the acupuncture inhibition of drug addictive behaviors. Thus, we tested whether acupuncture at Shenmen (HT7) points reduces drug-seeking behaviors in rats self-administering morphine or ethanol and whether such effects are inhibited by the disruption of the cuneate nucleus (CN). The stimulation of HT7 suppressed morphine and ethanol self-administration, which were completely abolished by surgical lesioning of the CN. In in vivo extracellular recordings, single-unit activity of the CN was evoked during acupuncture stimulation. The results suggest that acupuncture suppresses morphine- and ethanol-seeking behaviors through the modulation of the CN, second-order neurons of the DC somatosensory pathway.

Acupuncture inhibition of methamphetamine-induced behaviors, dopamine release and hyperthermia in the nucleus accumbens: mediation of group II mGluR

Methamphetamine (METH) increases metabolic neuronal activity in the mesolimbic dopamine (DA) system and mediates the reinforcing effect. To explore the underlying mechanism of acupuncture intervention in reducing METH-induced behaviors, we investigated the effect of acupuncture on locomotor activity, ultrasonic vocalizations, extracellular DA release in the nucleus accumbens (NAcs) using fast-scan cyclic voltammetry and alterations of brain temperature (an indicator of local brain metabolic activity) produced by METH administration. When acupuncture was applied to HT7, but not TE4, both locomotor activity and 50-kHz ultrasonic vocalizations were suppressed in METH-treated rats. Acupuncture at HT7 attenuated the enhancement of electrically stimulated DA release in the NAc of METH-treated rats. Systemic injection of METH produced a sustained increase in NAc temperature, which was reversed by the DA D1 receptor antagonist SCH 23390 or acupuncture at HT7. Acupuncture inhibition of METH-induced NAc temperature was prevented by pre-treatment with a group II metabotropic glutamate receptors (mGluR2/3) antagonist EGLU into the NAc or mimicked by injection of an mGluR2/3 agonist DCG-IV into the NAc. These results suggest that acupuncture reduces extracellular DA release and metabolic neuronal activity in the NAc through activation of mGluR2/3 and suppresses METH-induced affective states and locomotor behavior.

Peripheral Sensory Nerve Tissue but Not Connective Tissue Is Involved in the Action of Acupuncture

Acupuncture has been used to treat a variety of diseases and symptoms for more than 2,500 years. While a number of studies have shown that nerves are responsible for initiating the effects of acupuncture, several lines of study have emphasized the role of connective tissue in the initiation of acupuncture signals. To determine whether nerves or connective tissue mediate the action of acupuncture, we constructed a robotic acupuncture needle twister that mimicked the twisting of the needle by an acupuncturist, and we examined the role of nerves and connective tissues in the generation of acupuncture effects in rat cocaine-induced locomotion, stress-induced hypertension, and mustard oil-induced visceral pain models. Robotic or manual twisting of acupuncture needles effectively suppressed cocaine-induced hyperactivity, elevated systemic blood pressure or mustard oil-induced visceral pain in rats. These acupuncture effects were completely abolished by injecting bupivacaine, a local anesthetic, into acupoints. However, disruption of connective tissue by injecting type I collagenase into acupoints did not affect these acupuncture effects. Our findings suggest that nerve tissue, but not connective tissue, is responsible for generating the effects of acupuncture.

Acupuncture reduces relapse to cocaine-seeking behavior via activation of GABA neurons in the ventral tegmental area

There is growing public interest in alternative approaches to addiction treatment and scientific interest in elucidating the neurobiological underpinnings of acupuncture. Our previous studies showed that acupuncture at a specific Shenmen (HT7) points reduced dopamine (DA) release in the nucleus accumbens (NAc) induced by drugs of abuse. The present study was carried out to evaluate the effects of HT7 acupuncture on γ-aminobutyric acid (GABA) neuronal activity in the ventral tegmental area (VTA) and the reinstatement of cocaine-seeking behavior. Using microdialysis and in vivo single-unit electrophysiology, we evaluated the effects of HT7 acupuncture on VTA GABA and NAc DA release and VTA GABA neuronal activity in rats. Using a within-session reinstatement paradigm in rats self-administering cocaine, we evaluated the effects of HT7 stimulation on cocaine-primed reinstatement. Acupuncture at HT7 significantly reduced cocaine suppression of GABA release and GABA neuron firing rates in the VTA. HT7 acupuncture attenuated cocaine-primed reinstatement, which was blocked by VTA infusions of the selective GABA_B receptor antagonist 2-hydroxysaclofen. HT7 stimulation significantly decreased acute cocaine-induced DA release in the NAc, which was also blocked by 2-hydroxysaclofen. HT7 acupuncture also attenuated cocaine-induced sensitization of extracellular DA levels in the NAc. Moreover, HT7 acupuncture reduced both locomotor activity and neuronal activation in the NAc induced by acute cocaine in a needle-penetration depth-dependent fashion. These results suggest that acupuncture may suppress cocaine-induced DA release in the NAc and cocaine-seeking behavior through activation of VTA GABA neurons. Acupuncture may be an effective therapy to reduce cocaine relapse by enhancing GABAergic inhibition in the VTA.

Spinal pathways involved in somatosensory inhibition of the psychomotor actions of cocaine

Previous studies have demonstrated that somatosensory stimuli influence dopamine transmission in the mesolimbic reward system and can reduce drug-induced motor behaviors, craving and dependence. Until now, the central links between somatosensory and brain reward systems are not known. Here, we show that the dorsal column (DC) somatosensory pathway contains projections that convey an inhibitory input from the periphery to mesolimbic reward circuits. Stimulation of the ulnar nerve under HT7 acupoint suppressed psychomotor response to cocaine, which was abolished by disruption of the DC pathway, but not the spinothalamic tract (STT). Low-threshold or wide-dynamic range neurons in the cuneate nucleus (CN) were excited by peripheral stimulation. Lesions of dorsal column or lateral habenula (LHb) prevented the inhibitory effects of peripheral stimulation on cocaine-induced neuronal activation in the nucleus accumbens (NAc). LHb neurons projecting to the ventral tegmental area (VTA)/rostromedial tegmental nucleus (RMTg) regions were activated by peripheral stimulation and LHb lesions reversed the inhibitory effects on cocaine locomotion produced by peripheral stimulation. These findings suggest that there exists a pathway in spinal cord that ascends from periphery to mesolimbic reward circuits (spino-mesolimbic pathway) and the activation of somatosensory input transmitted via the DC pathway can inhibit the psychomotor response to cocaine.

Impulsivity and Stillness: NADA, Pharmaceuticals, and Psychotherapy in Substance Use and Other DSM 5 Disorders

Pharmaceuticals and psychotherapy are commonly used in the management of impulsivity. The National Acupuncture Detoxification Association (NADA) protocol is an adjunctive therapy that involves the bilateral insertion of 1 to 5 predetermined ear needle points. One of the main benefits reported by patients, providers, and programs utilizing NADA is the sense of stillness, centering, and well-being. The induction of this attitude is seen as contributing to improved clinical outcomes including engagement and retention. The attitude of stillness is also suggestive of a pathway to mitigating impulsivity. Impulsivity is associated with substance use disorders and other DSM 5 diagnoses. Impulsivity has characteristics that are manifested clinically in behaviors such as disinhibition, poor self-control, lack of deliberation, thrill seeking, risk-taking. NADA holds promise as a useful treatment adjunct in the comprehensive management of disorders for which impulsivity is a prominent component.

Laser Acupuncture for Neonatal Abstinence Syndrome: A Randomized Controlled Trial

BACKGROUND

Neonatal abstinence syndrome (NAS) is usually treated with opiate derivatives and supported with nonpharmacological treatment.

METHODS

This prospective, randomized, controlled, blinded, single-center study was carried out between March 2009 and November 2014. Newborn infants diagnosed with NAS after maternal opioid substitution therapy were eligible for inclusion. Infants were randomly allocated to the acupuncture group (combining laser acupuncture and pharmacological therapy of morphine and phenobarbital) or control group (pharmacological therapy alone). Laser acupuncture was performed with a LABpen MED 10 (675 nm/10 mW) at 5 ear and 4 body acupuncture points, bilaterally, and sessions were repeated every day. The primary outcome measure was duration of oral morphine therapy for NAS. Secondary outcomes included highest single Finnegan score, time to highest single Finnegan score, maximum amount of oral morphine solution (in milliliters per kilogram and milligrams per kilogram), time to maximum amount of oral morphine solution, and length of hospital stay.

RESULTS

Twenty-eight newborns (14 in each group) were eligible for analysis. Duration of oral morphine therapy was significantly reduced in the acupuncture group compared with the control group (28 vs 39 days, respectively, P = .019). In addition, we observed a significantly reduced length of hospital stay in the acupuncture group compared with the control group (35 days [interquartile range 25 to 47] vs 50 days [36 to 66], P = .048).

CONCLUSIONS

Adjunctive laser acupuncture significantly reduced the duration of morphine therapy in newborns with NAS.

Comparison of the efficacy of aroma-acupressure and aromatherapy for the treatment of dementia-associated agitation

Background

One of the most common symptoms observed in patients with dementia is agitation, and several non-pharmacological treatments have been used to control this symptom. However, because of limitations in research design, the benefit of non-pharmacological treatments has only been demonstrated in certain cases. The purpose of this study was to compare aroma-acupressure and aromatherapy with respect to their effects on agitation in patients with dementia.

Methods

In this experimental study, the participants were randomly assigned to three groups: 56 patients were included in the aroma-acupressure group, 73 patients in the aromatherapy group, and 57 patients in the control group who received daily routine as usual without intervention. The Cohen-Mansfield Agitation Inventory (CMAI) scale and the heart rate variability (HRV) index were used to assess differences in agitation. The CMAI was used in the pre-test, post-test and post-three-week test, and the HRV was used in the pre-test, the post-test and the post-three-week test as well as every week during the four-week interventions.

Results

The CMAI scores were significantly lower in the aroma-acupressure and aromatherapy groups compared with the control group in the post-test and post-three-week assessments. Sympathetic nervous activity was significantly lower in the fourth week in the aroma-acupressure group and in the second week in the aromatherapy group, whereas parasympathetic nervous activity increased from the second week to the fourth week in the aroma-acupressure group and in the fourth week in the aromatherapy group.

Conclusions

Aroma-acupressure had a greater effect than aromatherapy on agitation in patients with dementia. However, agitation was improved in both of the groups, which allowed the patients with dementia to become more relaxed. Future studies should continue to assess the benefits of aroma-acupressure and aromatherapy for the treatment of agitation in dementia patients.

Trial registration

ChiCTR-TRC-14004810; Date of registration: 2014/6/12

Acupuncture reduces memory impairment and oxidative stress and enhances cholinergic function in an animal model of alcoholism

Currently, the therapeutic strategy against memory deficit induced by alcoholism is not satisfactory and is expensive. Therefore, an effective, low-cost strategy is required. On the basis of the memory-enhancing effect of stimulation of the HT7 acupoint, we aimed to determine whether acupuncture at the HT7 acupoint can reduce alcoholism-induced memory impairment. The possible underlying mechanism was also explored. Alcoholism was induced in male Wistar rats weighing 180-220 g. The alcoholic rats received either acupuncture at HT7 or sham acupuncture for 1 minute bilaterally once daily for 14 days. Their spatial memory was assessed after 1 day, 7 days, and 14 days of treatment. At the end of the study, the malondialdehyde level and the activities of catalase, superoxide dismutase, glutathione peroxidase, and acetylcholinesterase enzymes in the hippocampus were determined using colorimetric assays. The results showed that acupuncture at HT7 significantly decreased the acetylcholinesterase activity and the malondialdehyde level, but increased the activities of catalase, superoxide dismutase, and glutathione peroxidase in the hippocampus. These results suggest that acupuncture at HT7 can effectively reduce the alcoholism-induced memory deficit. However, further studies concerning the detailed relationships between the location of the HT7 acupoint and the changes in the observed parameters are required.

Efficacy of acupuncture for psychological symptoms associated with opioid addiction: a systematic review and meta-analysis

This review systematically assessed the clinical evidence for and against acupuncture as a treatment for psychological symptoms associated with opioid addiction. The database was accessed from MEDLINE and China Knowledge Resource Integrated Database. We included all randomized clinical trials published in Chinese and English regardless of their controls. Meta-analysis was performed using the RevMan software, version 5.2. We conducted a literature search of 16 databases from their inception to January 2014. Four studies from Western countries did not report any clinical gains in the treatment of psychological symptoms associated with opioid addiction. 10 of 12 studies from China have reported positive findings regarding the use of acupuncture to treat the psychological symptoms associated with opioid addiction. The methodological quality of the included studies was poor. The meta-analysis indicated that there was a significant difference between the treatment group and the control group for anxiety and depression associated with opioid addiction, although groups did not differ on opioid craving. This review and meta-analysis could not confirm that acupuncture was an effective treatment for psychological symptoms associated with opioid addiction. However, considering the potential of acupuncture demonstrated in the included studies, further rigorous randomized controlled trials with long followup are warranted.

Acupuncture and related interventions for smoking cessation

BACKGROUND

Acupuncture and related techniques are promoted as a treatment for smoking cessation in the belief that they may reduce nicotine withdrawal symptoms.

OBJECTIVES

The objectives of this review are to determine the effectiveness of acupuncture and the related interventions of acupressure, laser therapy and electrostimulation in smoking cessation, in comparison with no intervention, sham treatment, or other interventions.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialized Register (which includes trials of smoking cessation interventions identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and PsycINFO) and AMED in October 2013. We also searched four Chinese databases in September 2013: Sino-Med, China National Knowledge Infrastructure, Wanfang Data and VIP.

SELECTION CRITERIA

Randomized trials comparing a form of acupuncture, acupressure, laser therapy or electrostimulation with either no intervention, sham treatment or another intervention for smoking cessation.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of smokers recruited, the nature of the intervention and control procedures, the outcome measures, method of randomization, and completeness of follow-up.We assessed abstinence from smoking at the earliest time-point (before six weeks) and at the last measurement point between six months and one year. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Those lost to follow-up were counted as continuing smokers. Where appropriate, we performed meta-analysis pooling risk ratios using a fixed-effect model.

MAIN RESULTS

We included 38 studies. Based on three studies, acupuncture was not shown to be more effective than a waiting list control for long-term abstinence, with wide confidence intervals and evidence of heterogeneity (n = 393, risk ratio [RR] 1.79, 95% confidence interval [CI] 0.98 to 3.28, I² = 57%). Compared with sham acupuncture, the RR for the short-term effect of acupuncture was 1.22 (95% CI 1.08 to 1.38), and for the long-term effect was 1.10 (95% CI 0.86 to 1.40). The studies were not judged to be free from bias, and there was evidence of funnel plot asymmetry with larger studies showing smaller effects. The heterogeneity between studies was not explained by the technique used. Acupuncture was less effective than nicotine replacement therapy (NRT). There was no evidence that acupuncture is superior to psychological interventions in the short- or long-term. There is limited evidence that acupressure is superior to sham acupressure for short-term outcomes (3 trials, n = 325, RR 2.54, 95% CI 1.27 to 5.08), but no trials reported long-term effects, The pooled estimate for studies testing an intervention that included continuous auricular stimulation suggested a short-term benefit compared to sham stimulation (14 trials, n = 1155, RR 1.69, 95% CI 1.32 to 2.16); subgroup analysis showed an effect for continuous acupressure (7 studies, n = 496, RR 2.73, 95% CI 1.78 to 4.18) but not acupuncture with indwelling needles (6 studies, n = 659, RR 1.24, 95% CI 0.91 to 1.69). At longer follow-up the CIs did not exclude no effect (5 trials, n = 570, RR 1.47, 95% CI 0.79 to 2.74). The evidence from two trials using laser stimulation was inconsistent and could not be combined. The combined evidence on electrostimulation suggests it is not superior to sham electrostimulation (short-term abstinence: 6 trials, n = 634, RR 1.13, 95% CI 0.87 to 1.46; long-term abstinence: 2 trials, n = 405, RR 0.87, 95% CI 0.61 to 1.23).

AUTHORS' CONCLUSIONS

Although pooled estimates suggest possible short-term effects there is no consistent, bias-free evidence that acupuncture, acupressure, or laser therapy have a sustained benefit on smoking cessation for six months or more. However, lack of evidence and methodological problems mean that no firm conclusions can be drawn. Electrostimulation is not effective for smoking cessation. Well-designed research into acupuncture, acupressure and laser stimulation is justified since these are popular interventions and safe when correctly applied, though these interventions alone are likely to be less effective than evidence-based interventions.

Peripheral afferent mechanisms underlying acupuncture inhibition of cocaine behavioral effects in rats

Administration of cocaine increases locomotor activity by enhancing dopamine transmission. To explore the peripheral mechanisms underlying acupuncture treatment for drug addiction, we developed a novel mechanical acupuncture instrument (MAI) for objective mechanical stimulation. The aim of this study was to evaluate whether acupuncture inhibition of cocaine-induced locomotor activity is mediated through specific peripheral nerves, the afferents from superficial or deep tissues, or specific groups of nerve fibers. Mechanical stimulation of acupuncture point HT7 with MAI suppressed cocaine-induced locomotor activity in a stimulus time-dependent manner, which was blocked by severing the ulnar nerve or by local anesthesia. Suppression of cocaine-induced locomotor activity was elicited after HT7 stimulation at frequencies of either 50 (for Meissner corpuscles) or 200 (for Pacinian corpuscles) Hz and was not affected by block of C/Aδ-fibers in the ulnar nerve with resiniferatoxin, nor generated by direct stimulation of C/Aδ-fiber afferents with capsaicin. These findings suggest that HT7 inhibition of cocaine-induced locomotor activity is mediated by A-fiber activation of ulnar nerve that originates in superficial and deep tissue.

Trials of Acupuncture for Drug Dependence: A Recommendation for Hypotheses Based on the Literature

Objectives

After initial promising research into acupuncture for withdrawal from drugs of dependence, two large negative trials were published in 2002 and the use of acupuncture in US rehabilitation facilities fell. However, subsequently it has been maintained, despite a lack of support from systematic reviews. This suggests a mismatch between research and clinical observation, which could be due to the acupuncture technique used, choice of controls or outcome measures. This study aims to explore the mismatch.

Methods

An exploratory review of all 48 clinical trials on alcohol, cocaine, nicotine or opioid dependence included in current reviews.

Results

Studies with sham controls (that could be active) were less likely to be positive (33%) than those with non-acupuncture controls (75%). Positive results were more likely when measuring craving (56%) or withdrawal symptoms (58%) than when measuring abstinence (31%) or attrition (31%). Three treatment variables appeared to be associated with positive results: (1) body acupuncture, used in 13 studies, was associated with positive outcomes for craving and withdrawal symptoms but not for abstinence or attrition; (2) electroacupuncture, used in seven studies, was associated with positive results with all four outcomes; and (3) bilateral needling in 20 studies was associated with effects on abstinence, craving and withdrawal symptoms.

Conclusions

The current evidence suggests that acupuncture may have some effects on drug dependence that have been missed because of choice of outcome in many previous studies, and future studies should use outcomes suggested by clinical experience. Body points and electroacupuncture, used in the original clinical observation, justify further research.

Neural substrates of acupuncture in the modulation of cravings induced by smoking-related visual cues: an fMRI study

RATIONALE

Cue reactivity is a key factor in modulating motivational and goal-directed behaviors associated with compulsive drug intake and relapse. Smoking-associated cues produce smoking urges and cravings and are accompanied by the activation of brain regions involved in attention, motivation, and reward.

OBJECTIVES

We investigated whether acupuncture ameliorates cravings induced by smoking-related visual cues, and we explored the neural mechanisms underlying the effects of acupuncture on modulating smoking urges.

METHODS

After 36 h of smoking abstinence, 25 right-handed male smokers underwent fMRI, during which smoking-related and neutral visual cues were presented. Twelve subjects were treated with real acupuncture (RA) at HT7 and 13 subjects received sham acupuncture (SA). During the scanning sessions, craving scores to smoking-related visual cues were assessed before and after RA or SA treatment. The differences in brain responses to smoking vs. neutral cues after treatment between the RA and SA groups were detected using three-way ANOVAs (Cue × Session × Group).

RESULTS

After treatment, the craving scores were significantly decreased in the RA group, as compared to the SA group. When we explored the neural substrates of acupuncture on the modulation of cravings induced by smoking cues, significant differences were found in the medial prefrontal cortex, the premotor cortex, the amygdala, the hippocampus, and the thalamus.

CONCLUSIONS

These findings suggest that acupuncture alleviates cue-induced cravings through the regulation of activity in brain regions involved in attention, motivation, and reward relative to craving scores in the initial abstinence phase.

Systematic review and meta-analysis of the effects of acupoint stimulation on smoking cessation

Smoking represents a serious worldwide public health problem because of its close association with the development of chronic disease and cancer. Acupoint stimulation has been used as treatment mode for smoking cessation but its efficacy remains controversial. This systematic review and meta-analysis aimed to determine the effects of acupoint stimulation on smoking cessation rate and daily cigarette consumption. Electronic literature searches in eight electronic databases up to March 2011 were performed to identify acupoint stimulation for smoking cessation. The outcomes assessed were smoking cessation rate and cigarette consumption. We assessed abstinence from smoking at the earliest and last measured time points, and at the 3- and 6-month follow-ups. Meta-analysis was performed using CMA software. A total of 20 RCTs were included in the meta-analysis. A significant effect of acupoint stimulation was found in smoking cessation rates and cigarette consumption at immediate, 3- and 6-month follow-ups, with effect sizes 1.24 (95%CI = 1.07 ~ 1.43, p = 0.003), -2.49 (95%CI = -4.65 ~ -0.34, p = 0.02), 1.70 (95%CI = 1.17 ~ 2.46, p = 0.01), and 1.79 (95%CI = 1.13 ~ 2.82, p = 0.01), respectively. Multi-modality treatments, especially acupuncture combined with smoking cessation education or other interventions, can help smokers to eschew smoking during treatment, and to avoid relapse after treatment.

Electroacupuncture reverses ethanol-induced locomotor sensitization and subsequent pERK expression in mice

Extracellular signal-regulated kinase (ERK) plays a role in neuronal changes induced by repeated drug exposure. Given that electroacupuncture reverses locomotor sensitization induced by ethanol, we investigated whether this effect is parallel to ERK signalling. Mice received daily ethanol (2 g/kg i.p), for 21 d. Electroacupuncture was performed daily, during four (subsequent) days of ethanol withdrawal. The stimulus of 2 Hz or 100 Hz was provided in combinations of two acupoints: Ea1 (ST-36/Zusanli and PC-6/Neiguan) or Ea2 (Du-14/Dazhui and Du-20/Baihui). The specificity of acupoint effects were assessed by the inclusion of additional groups: Ea3 (ST-25/Tianshu--acupoint used for other non-related disorders), Sham1 or Sham2 (transdermic stimulation near the respective acupoints). The control group was only handled during withdrawal and the saline group was chronically treated with saline and handled similarly to controls. At day 5 of withdrawal, each group was divided in two subgroups, according to the presence or absence of ethanol challenge. The animals were perfused and their brains processed for pERK immunohistochemistry. Only Ea1 at 100 Hz (Ea1_100) and Ea2 at 2 Hz (Ea2_2) reversed locomotor sensitization induced by ethanol. Ethanol withdrawal decreases pERK in the dorsomedial striatum. This decrease is not abolished by electroacupuncture. Conversely, ethanol challenge increases pERK in the dorsomedial striatum, infralimbic cortex and central nucleus of amygdala. The specificity of acupoint stimulation to reverse these increases was seen only for Ea2_2, in the infralimbic cortex and dorsomedial striatum. Therefore, behavioural effects of Ea2_2 (but not Ea1_100) depend, at least in part, on ERK signalling.

Effects of acupuncture on stress-induced relapse to cocaine-seeking in rats

RATIONALE

Cocaine addiction is associated with high rates of relapse, and stress has been identified as a major risk factor. We have previously demonstrated that acupuncture reduces drug self-administration and dopamine release in the nucleus accumbens (NAc), a brain structure implicated in stress-induced reinstatement of drug-seeking behavior.

OBJECTIVE

This study was conducted to investigate the effects of acupuncture on footshock-induced reinstatement of cocaine-seeking and the expression of c-Fos and the transcription factor cAMP response element-binding protein (CREB) in the NAc, used as markers of neuronal activation in conditions of stress-induced reinstatement to cocaine.

METHODS

Male Sprague-Dawley rats were trained to self-administer cocaine (1.0 mg/kg) for 14 days, followed by extinction and then footshock stress. Acupuncture was applied at bilateral Shenmen (HT7) points for 1 min after footshock stress.

RESULTS AND CONCLUSIONS

Acute footshock stress reinstated cocaine-seeking behavior and enhanced c-Fos expression and phosphorylated CREB (pCREB) activation in the NAc shell in cocaine pre-exposed rats. On the other hand, acupuncture at HT7, but not at control point (LI5), markedly reduced reinstatement of cocaine-seeking (86.5 % inhibition vs. control value), c-Fos expression (81.7% inhibition), and pCREB activation (79.3% inhibition) in the NAc shell. These results suggest that acupuncture attenuates stress-induced relapse by regulating neuronal activation in the NAc shell.

Acupuncture Reduces Alcohol Withdrawal Syndrome and c-Fos Expression in Rat Brain

Acupuncture as a therapeutic intervention is widely practiced in the treatment of many functional disorders including alcohol abuse. In the present study, the effects of acupuncture on alcohol withdrawal syndrome (AWS) and Fos-like immunoreactivity (FLI) in the striatum and the nucleus accumbens (NAC) of rats were investigated. During 3 days of cessation following chronic administration of ethanol (3 g/kg, i.p. for 3 weeks), rats showed a significant increase in AWS, such as hypermotility, tail rigidity, grooming and tremor, and an increase in FLI in the dopamine terminal areas of the brain. Treatment with acupuncture at zusanli (ST36) or sanyinjiao (SP6) during the withdrawal period inhibited both AWS and FLI of rats undergoing ethanol injection. These results suggest that acupuncture may be useful in the treatment of alcoholism by modulating post-synaptic neural activation in the striatum and NAC.

Methodological issues in evaluating auricular acupuncture therapy for problems arising from the use of drugs and alcohol

Auricular acupuncture is an accessible, non-confrontational therapy that appears to be effective when used in drug and alcohol treatment facilities, hospitals and prisons in the UK, Europe and the USA. Despite being popular, research evidence on its effectiveness is lacking, and as a result services are underfunded and risk being withdrawn. There are methodological problems in researching auricular acupuncture. In these days of evidence-based medicine, most studies in this area are explanatory randomised controlled trials, which is limited in capturing the complete benefits of the intervention. Furthermore, there is lack of consensus over definitions of the concept of ‘addiction’ and whether or not this should be perceived as a ‘disease’ that can be ‘cured’ by an intervention such as auricular acupuncture. Basic concepts such as these need to inform development of outcome measures, which should include retention of clients in treatment as an indicator of success.It is argued here that the best approach will integrate research on physical effects with research on subjective experience of those with drug and alcohol problems. The challenge is to design large scale, high quality, pragmatic randomised controlled trials to assess the effectiveness of auricular acupuncture over the longer term in settings that mimic the delivery of treatment in practice and are informed by acupuncture's own diagnostic traditions, using a combination of objective, quantitative methods and subjective, qualitative methods.

Low frequency electroacupuncture selectively decreases voluntarily ethanol intake in rats

Although there is increasing clinical acceptance of acupuncture and electroacupuncture (EA) as a treatment of substance abuse-related disorders, our understanding of this treatment remains incomplete. Previous clinical and pre-clinical studies have shown that acupuncture and EA are effective in reducing ethanol consumption. Recent studies have shown that Sprague-Dawley (SD) rats under an intermittent-access two-bottle choice drinking procedure (IE procedure) voluntarily drank high amounts of ethanol. However, an effect of EA on ethanol consumption of the SD rats under this drinking procedure has not been demonstrated. In the present study, we demonstrated that SD rats escalated their ethanol intake and subsequently developed ethanol dependence under the IE procedure. A single low (2 Hz), but not high frequency (100 Hz) EA treatment applied at the bilateral acupoint Zusanli (ST36), but not at the tail reduced voluntary intake of, and preference for ethanol, but not sucrose. Furthermore, repeated EA treatments decreased the intake of and preference for ethanol, without resulting in a rebound increase in ethanol intake when the EA treatments were terminated. These observations indicate that EA may be a useful treatment for alcohol abuse.

Acupuncture and related interventions for smoking cessation

BACKGROUND

Acupuncture and related techniques are promoted as a treatment for smoking cessation in the belief that they may reduce nicotine withdrawal symptoms.

OBJECTIVES

The objectives of this review are to determine the effectiveness of acupuncture and the related interventions of acupressure, laser therapy and electrostimulation in smoking cessation, in comparison with no intervention, sham treatment, or other interventions.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group specialized register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, BIOSIS Previews, PsycINFO, Science Citation Index, AMED, Acubriefs in November 2010; and four Chinese databases: Chinese Biomedical Database, China National Knowledge Infrastructure, Wanfang Data and VIP in November 2010.

SELECTION CRITERIA

Randomized trials comparing a form of acupuncture, acupressure, laser therapy or electrostimulation with either no intervention, sham treatment or another intervention for smoking cessation.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of smokers recruited, the nature of the intervention and control procedures, the outcome measures, method of randomization, and completeness of follow up.We assessed abstinence from smoking at the earliest time-point (before six weeks), and at the last measurement point between six months and one year. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Those lost to follow up were counted as continuing smokers. Where appropriate, we performed meta-analysis using a fixed-effect model.

MAIN RESULTS

We included 33 reports of studies. Compared with sham acupuncture, the fixed-effect risk ratio (RR) for the short-term effect of acupuncture was 1.18 (95% confidence interval 1.03 to 1.34), and for the long-term effect was 1.05 (CI 0.82 to 1.35). The studies were not judged to be free from bias. Acupuncture was less effective than nicotine replacement therapy (NRT). There was no evidence that acupuncture is superior to waiting list, nor to psychological interventions in short- or long-term. The evidence on acupressure and laser stimulation was insufficient and could not be combined. The evidence suggested that electrostimulation is not superior to sham electrostimulation.

AUTHORS' CONCLUSIONS

There is no consistent, bias-free evidence that acupuncture, acupressure, laser therapy or electrostimulation are effective for smoking cessation, but lack of evidence and methodological problems mean that no firm conclusions can be drawn. Further, well designed research into acupuncture, acupressure and laser stimulation is justified since these are popular interventions and safe when correctly applied, though these interventions alone are likely to be less effective than evidence-based interventions.

Photoelectric stimulation of defined ear points (Smokex-Pro method) as an aid for smoking cessation: a prospective observational 2-year study with 156 smokers in a primary care setting

BACKGROUND

Smokex-Pro is a smoking cessation method using a protocol of a standardized consultation and computer-assisted photoelectric stimulation of defined regions in the ear and face.

METHODS

We prospectively enrolled 156 consecutive adult smokers (81 males, 75 females; mean age 43.8 years; body mass index 25.5; daily cigarettes 24.7; Fagerström Test for Nicotine Dependence 5; 30 smoking years). The primary end point was the self-reported continuous abstinence rate.

RESULTS

Participants completed on average only 32% of recommended visits. A total of 76.7% stopped smoking for more than 7 days. Moreover, 53.4% remained free of smoking for more than 90 days. Long-term abstinence rates were 49.3% (1 year) and 47.95% (2 years). Treatment-related side effects were observed in 24.5% of participants. Side effects were mild and resolved within hours.

CONCLUSION

The Smokex-Pro method appears to be an effective aid for smoking cessation. The treatment was well tolerated and showed only mild and temporary side effects. The average cost of treatment is typically less than EUR 90; the total treatment time is typically 60-90 min. These factors make it an attractive alternative compared to traditional smoking cessation methods. Controlled clinical trials will be needed to confirm the results of this study and refine the treatment for maximum efficacy.

Acupuncture inhibits GABA neuron activity in the ventral tegmental area and reduces ethanol self-administration

BACKGROUND

Withdrawal from chronic ethanol enhances ventral tegmental area (VTA) GABA neuron excitability and reduces mesolimbic dopamine (DA) neurotransmission, which is suppressed by acupuncture at Shenmen (HT7) points (Zhao et al., 2006). The aim of this study was to evaluate the effects of HT7 acupuncture on VTA GABA neuron excitability, ethanol inhibition of VTA GABA neuron firing rate, and ethanol self-administration. A role for opioid receptors (ORs) in ethanol and acupuncture effects is also explored.

METHODS

Using electrophysiological methods in mature rats, we evaluated the effects of HT7 stimulation and opioid antagonists on VTA GABA neuron firing rate. Using behavioral paradigms in rats, we evaluated the effects of HT7 stimulation and opioid antagonists on ethanol self-administration using a modification of the sucrose-fading procedure.

RESULTS

HT7 stimulation produced a biphasic modulation of VTA GABA neuron firing rate characterized by transient enhancement followed by inhibition and subsequent recovery in 5 minutes. HT7 inhibition of VTA GABA neuron firing rate was blocked by systemic administration of the nonselective μ-opioid receptor antagonist naloxone. HT7 stimulation significantly reduced ethanol suppression of VTA GABA neuron firing rate, which was also blocked by naloxone. HT7 acupuncture reduced ethanol self-administration without affecting sucrose consumption. Systemic administration of the δ-opioid receptor (DOR) antagonist naltrindole blocked ethanol suppression of VTA GABA neuron firing rate and significantly reduced ethanol self-administration without affecting sucrose consumption.

CONCLUSIONS

These findings suggest that DOR-mediated opioid modulation of VTA GABA neurons may mediate acupuncture's role in modulating mesolimbic DA release and suppressing the reinforcing effects of ethanol.

Acupuncture, the limbic system, and the anticorrelated networks of the brain

The study of the mechanism of acupuncture action was revolutionized by the use of functional magnetic resonance imaging (fMRI). Over the past decade, our fMRI studies of healthy subjects have contributed substantially to elucidating the central effect of acupuncture on the human brain. These studies have shown that acupuncture stimulation, when associated with sensations comprising deqi, evokes deactivation of a limbic-paralimbic-neocortical network, which encompasses the limbic system, as well as activation of somatosensory brain regions. These networks closely match the default mode network and the anti-correlated task-positive network described in the literature. We have also shown that the effect of acupuncture on the brain is integrated at multiple levels, down to the brainstem and cerebellum. Our studies support the hypothesis that the effect of acupuncture on the brain goes beyond the effect of attention on the default mode network or the somatosensory stimulation of acupuncture needling. The amygdala and hypothalamus, in particular, show decreased activation during acupuncture stimulation that is not commonly associated with default mode network activity. At the same time, our research shows that acupuncture stimulation needs to be done carefully, limiting stimulation when the resulting sensations are very strong or when sharp pain is elicited. When acupuncture induced sharp pain, our studies show that the deactivation was attenuated or reversed in direction. Our results suggest that acupuncture mobilizes the functionally anti-correlated networks of the brain to mediate its actions, and that the effect is dependent on the psychophysical response. In this work we also discuss multiple avenues of future research, including the role of neurotransmitters, the effect of different acupuncture techniques, and the potential clinical application of our research findings to disease states including chronic pain, major depression, schizophrenia, autism, and Alzheimer's disease.

A possible mechanism underlying the effectiveness of acupuncture in the treatment of drug addiction

Clinical trials are currently underway to determine the effectiveness of acupuncture in the treatment of drug addiction. While there are still many unanswered questions about the basic mechanisms of acupuncture, some evidence exists to suggest that acupuncture can play an important role in reducing reinforcing effects of abused drugs. The purpose of this article is to critically review these data. The neurochemical and behavioral evidence showed that acupuncture's role in suppressing the reinforcing effects of abused drugs takes place by modulating mesolimbic dopamine neurons. Also, several brain neurotransmitter systems such as serotonin, opioid and amino acids including GABA have been implicated in the modulation of dopamine release by acupuncture. These results provided clear evidence for the biological effects of acupuncture that ultimately may help us to understand how acupuncture can be used to treat abused drugs. Additional research using animal models is of primary importance to understanding the basic mechanism underlying acupuncture's effectiveness in the treatment of drug addiction.

Acupressure for smoking cessation--a pilot study

Background

Tobacco smoking is a serious risk to health: several therapies are available to assist those who wish to stop. Smokers who approach publicly funded stop-smoking clinics in the UK are currently offered nicotine replacement therapy (NRT) or bupropion, and group behaviour therapy, for which there is evidence of effectiveness. Acupuncture and acupressure are also used to help smokers, though a systematic review of the evidence of their effectiveness was inconclusive. The aim of this pilot project was to determine the feasibility of a study to test acupressure as an adjunct to one anti-smoking treatment currently offered, and to inform the design of the study.

Methods

An open randomised controlled pilot study was conducted within the six week group programme offered by the Smoking Advice Service in Plymouth, UK. All participants received the usual treatment with NRT and group behavioural therapy, and were randomised into three groups: group A with two auricular acupressure beads, group B with one bead, and group C with no additional therapy. Participants were taught to press the beads when they experienced cravings. Beads were worn in one ear for four weeks, being replaced as necessary. The main outcome measures assessed in the pilot were success at quitting (expired CO ≤ 9 ppm), the dose of NRT used, and the rating of withdrawal symptoms using the Mood and Symptoms Scale.

Results

From 49 smokers attending four clinics, 24 volunteered to participate, 19 attended at least once after quitting, and seven remained to the final week. Participants who dropped out reported significantly fewer previous quit attempts, but no other significant differences. Participants reported stimulating the beads as expected during the initial days after quitting, but most soon reduced the frequency of stimulation. The discomfort caused by the beads was minor, and there were no significant side effects. There were technical problems with adhesiveness of the dressing. Reporting of NRT consumption was poor, with much missing data, but reporting of ratings of withdrawal symptom scores was nearly complete. However, these showed no significant changes or differences between groups for any week.

Conclusion

Any effects of acupressure on smoking withdrawal, as an adjunct to the use of NRT and behavioural intervention, are unlikely to be detectable by the methods used here and further preliminary studies are required before the hypothesis can be tested.

Accumbens neurochemical adaptations produced by binge-like alcohol consumption

RATIONALE

The Scheduled High Alcohol Consumption (SHAC) binge drinking model is a simple, partial murine model with which to investigate some of the neurobiological underpinnings of alcoholism.

OBJECTIVES

The SHAC model was used to characterize monoamine and amino acid adaptations produced in the nucleus accumbens (NAC) by repeated bouts of high alcohol consumption.

METHODS

In vivo microdialysis was conducted in the NAC of C57BL/6J (B6) mice during consumption of water, a 5% alcohol (v/v) solution for the first time (SHAC1) or a 5% alcohol solution for the sixth time (SHAC6). A second set of microdialysis experiments assessed the neurotransmitter response to an alcohol challenge injection (1.5 or 2 g/kg, IP).

RESULTS

In both drinking experiments, SHAC1 and SHAC6 mice consumed comparable amounts of alcohol during the 40-min period of alcohol availability (approximately 1.5 g/kg) and total fluid intake was similar between water and SHAC1/6 mice. Despite the similarity in alcohol consumption, alcohol-mediated increases in the extracellular concentration of GABA and serotonin were reduced, but glutamate was increased in the NAC of SHAC6 mice, relative to SHAC1 animals. No differences were observed in extracellular dopamine between SHAC1 and SHAC6 mice during alcohol consumption. After alcohol injection, SHAC6 mice also exhibited sensitized glutamate release, but did not differ from water or SHAC1 animals for any of the other neurotransmitters examined. Brain alcohol concentrations did not differ between groups after injection.

CONCLUSIONS

Repeated bouts of high alcohol consumption induce an imbalance between inhibitory and excitatory neurotransmission within the NAC that may drive excessive drinking behavior.

Behavioral and neurochemical interactions between Group 1 mGluR antagonists and ethanol: potential insight into their anti-addictive properties

Blockade of the mGluR5 subtype of Group 1 metabotropic glutamate receptor (mGluRs) reduces the rewarding effects of ethanol (EtOH), while the effects of mGluR1a blockade remain under-investigated. The present study compared the effects of pretreatment with the mGluR5 antagonist MPEP and the mGluR1a antagonist CPCCPOEt upon behavioral and neurochemical variables associated with EtOH reward in alcohol-preferring C57BL/6J mice. Pretreatment with either antagonist (0-10 mg/kg, IP) dose-dependently reduced measures of EtOH reward in an operant self-administration paradigm and the maximally effective antagonist dose (10 mg/kg) also blocked the expression of EtOH-induced place conditioning, as well as EtOH consumption under 24-h free-access conditions. MPEP pretreatment did not significantly alter the EtOH dose-locomotor response function; however, it prevented EtOH-induced changes in extracellular dopamine, glutamate and GABA in the nucleus accumbens (NAC). In contrast, CPCCOEt shifted the EtOH dose-response function downwards, enhanced the capacity of higher EtOH doses to elevate NAC levels of GABA and lowered extracellular dopamine and glutamate below baseline following EtOH injection. It is suggested that the "anti-alcohol" effects of MPEP may involve an attenuation of the neurochemical signals mediating EtOH reward, whereas those of CPCCOEt may involve an increased sensitivity to the inhibitory effects of EtOH upon brain and behavior.