Brain responses to drug cues predict craving changes in abstinent heroin users: A preliminary study.

BACKGROUND: Loss of control over drug intake occurring in drug addiction is believed to result from disruption of reward circuits, including reduced responsiveness to natural rewards (e.g., monetary, sex) and heightened responsiveness to drug reward. Yet few studies have assessed reward deficiency and related brain responses in abstinent heroin users with opioid use disorder, and less is known whether the brain responses can predict cue-induced craving changes following by prolonged abstinence. METHOD: 31 heroin users (age: 44.13±7.68 years, male: 18 (58%), duration of abstinence: 85.2 ± 52.5 days) were enrolled at a mandatory detoxification center. By employing a cue-reactivity paradigm including three types of cues (drug, sexual, neutral), brain regional activations and circuit-level functional coupling were extracted. Among the 31 heroin users, 15 were followed up longitudinally to assess cue induced craving changes in the ensuing 6 months. RESULTS: One way analysis of variance results showed that heroin users have differential brain activations to the three cues (neutral, drug and sexual) in the left dorsolateral prefrontal cortex (DLPFC), insula, orbiotofrontal cortex (OFC) and the bilateral thalamus. Drug cue induced greater activations in left DLPFC, insula and OFC compared to sexual cue. The psychophysiological interactions (PPI) analysis revealed negative couplings of the left DLPFC and the left OFC, bilateral thalamus, putamen in heroin users during drug cue exposure. In the 6-month follow-up study, both drug cue induced activation of the left DLPFC and the functional coupling of the left DLPFC-bilateral thalamus at baseline was correlated with craving reductions, which were not found for sexual cues. CONCLUSION: Our preliminary study provided novel evidence for the reward deficiency theory of opioid use disorder. Our findings also have clinical implications, as drug cue induced activation of the left DLPFC and functional coupling of left DLPFC-bilateral thalamus may be potential neuroimaging markers for craving changes during prolonged abstinence. Evidently, the findings in the current preliminary study should be confirmed by large sample size in the future.

Reduced thalamic resting-state functional connectivity and impaired cognition in acute abstinent heroin users.

As a critical component of cortico-striato-thalamo-cortical loop in addiction, our understanding of the thalamus in impaired cognition of heroin users (HU) has been limited. Due to the complex thalamic connection with cortical and subcortical regions, thalamus was divided into prefrontal (PFC), occipital (OC), premotor, primary motor, sensory, temporal, and posterior parietal association subregions according to white matter tractography. We adopted seven subregions of bilateral thalamus as regions of interest to systematically study the implications of distinct thalamic nuclei in acute abstinent HU. The volume and resting-state functional connectivity (RSFC) differences of the thalamus were investigated between age-, gender-, and alcohol-matched 37 HU and 33 healthy controls (HCs). Trail making test-A (TMT-A) was adopted to assess cognitive function deficits, which were then correlated with neuroimaging findings. Although no significant different volumes were found, HU group showed decreased RSFC between left PFC_thalamus and middle temporal gyrus as well as between left OC_thalamus and inferior frontal gyrus and supplementary motor area relative to HCs. Meanwhile, the higher TMT-A scores in HU were negatively correlated with PFC_thalamic RSFC with inferior temporal gyrus, fusiform, and precuneus. Craving scores were negatively correlated with OC_thalamic RSFC with accumbens, hippocampus, and insula. Opiate Withdrawal Scale scores were negatively correlated with left PFC/OC_thalamic RSFC with orbitofrontal cortex and medial PFC. We indicated two thalamus subregions separately involvement in cognitive control and craving to reveal the implications of thalamic subnucleus in pathology of acute abstinent HU.

2Hz-electroacupuncture attenuates heroin-seeking behaviors via adjusts CB1-Rs and CB2-Rs expression in relapse-relevant brain regions of heroin self-administration rats.

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

Heroin addiction engages negative emotional learning brain circuits in rats.

Opioid use disorder (OUD) is associated with the emergence of persistent negative emotional states during drug abstinence that drive compulsive drug taking and seeking. Functional magnetic resonance imaging (fMRI) in rats identified neurocircuits that were activated by stimuli that were previously paired with heroin withdrawal. The activation of amygdala and hypothalamic circuits was related to the degree of heroin dependence, supporting the significance of conditioned negative affect in sustaining compulsive-like heroin seeking and taking and providing neurobiological insights into the drivers of the current opioid crisis.

Investigation of brain electrophysiological properties among heroin addicts: Quantitative EEG and event-related potentials.

This study aims to introduce a new approach of a comprehensive paradigm to evaluate brain electrophysiological properties among addicts. Electroencephalographic spectral power as well as amplitudes and latencies of mismatch negativity (MMN), P300, and P600 components were evaluated among 19 male heroin addicts and 19 healthy nonsmoker subjects using a paradigm consisting of three subparadigms, namely (1) digit span Wechsler test, (2) auditory oddball, and (3) visual cue-reactivity oddball paradigms. Task 1 provided auditory P300 and P600 in association with working memory. Task 2 provided auditory P300 as well as small and large deviant MMN event-related potential (ERPs). Finally, task 3 provided visual cue-reactivity P300. Results show that beta power was higher among heroin addicts while delta, theta, and alpha powers were decreased compared with healthy subjects. ERP analysis confirmed the decline of brain-evoked potential amplitudes when compared with healthy subjects, thus indicating a broad neurobiological vulnerability of preattentive and attentional processing including attentional deficits and compromise of discrimination abilities. The prolonged latency of ERPs reflects poor cognitive capacity in the engagement of attention and memory resources. On the other hand, an increase of attention towards the heroin-related stimuli could be concluded from the increase of P300 in the cue-reactivity condition among heroin addicts. Findings suggest that applying this paradigm in addiction studies benefits comprehensive evaluation of neuroelectrophysiological activity among addicts, which can promote a better understanding of drugs' effects on the brain as well as define new neuroelectrophysiological characteristics of addiction properties. © 2016 Wiley Periodicals, Inc.

Acupuncture regulates the unfolded protein response and inhibits apoptosis in a rat model of heroin relapse.

OBJECT: To explore the unfolded protein response (UPR) in the hippocampus of rats undergoing heroin relapse and the mechanisms underlying the acupuncture-mediated inhibition of brain damage caused by heroin relapse. METHODS: 60 Sprague-Dawley rats (30 females and 30 males) were randomly divided into four groups: Control group, Heroin group, Heroin+acupuncture group, and Heroin+methadone group (n=15 each). In the latter three groups, a model of heroin addiction was established by successive increments of intramuscular heroin injections for 8 days, according to the exposure (addiction)→detoxification method. A UPR RT2 Profiler PCR array was used to screen for differentially expressed genes in the hippocampus. Apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining. The protein expression levels of the following three differentially expressed genes were detected by Western blot to validate the results of the PCR array: heat shock protein (HSP)70, HSP105, and valosin-containing protein (Vcp). RESULTS: The UPR RT2 Profiler PCR Array detection results indicated that acupuncture increased the expression levels of the molecular chaperones HSP70, HSP105, and Vcp. The degree of neuronal apoptosis in the hippocampus of rats in the Heroin+acupuncture and Heroin+methadone groups was significantly reduced compared with the untreated Heroin group (p<0.01). Protein expression of HSP70, HSP105, and Vcp in the Heroin+acupuncture and Heroin+methadone groups was significantly higher than the Heroin group (p<0.01). CONCLUSIONS: The positive effects of acupuncture on brain damage caused by heroin may be closely related to up-regulation of HSP70, HSP105, and Vcp, and reduced apoptosis.

Predicting subsequent relapse by drug-related cue-induced brain activation in heroin addiction: an event-related functional magnetic resonance imaging study.

Abnormal salience attribution is implicated in heroin addiction. Previously, combining functional magnetic resonance imaging (fMRI) and a drug cue-reactivity task, we demonstrated abnormal patterns of subjective response and brain reactivity in heroin-dependent individuals. However, whether the changes in cue-induced brain response were related to relapse was unknown. In a prospective study, we recruited 49 heroin-dependent patients under methadone maintenance treatment, a gold standard treatment (average daily dose 41.8 ± 16.0 mg), and 20 healthy subjects to perform the heroin cue-reactivity task during fMRI. The patients' subjective craving was evaluated. They participated in a follow-up assessment for 3 months, during which heroin use was assessed and relapse was confirmed by self-reported relapse or urine toxicology. Differences between relapsers and non-relapsers were analyzed with respect to the results from heroin-cue responses. Compared with healthy subjects, relapsers and non-relapsers commonly demonstrated significantly increased brain responses during the processing of heroin cues in the mesolimbic system, prefrontal regions and visuospatial-attention regions. However, compared with non-relapsers, relapsers demonstrated significantly greater cue-induced craving and the brain response mainly in the bilateral nucleus accumbens/subcallosal cortex and cerebellum. Although the cue-induced heroin craving was low in absolute measures, the change in craving positively correlated with the activation of the nucleus accumbens/subcallosal cortex among the patients. These findings suggest that in treatment-seeking heroin-dependent individuals, greater cue-induced craving and greater specific regional activations might be related to reward/craving and memory retrieval processes. These responses may predict relapse and represent important targets for the development of new treatment for heroin addiction.

Biofeedback combined with cue-exposure as a treatment for heroin addicts.

The aim of this study was to test if cue-exposure therapy (CET) combined with biofeedback therapy (BT) could decrease craving and physiological reactivity to drug-related cues in heroin dependents. Forty-five participants were randomly assigned to usual rehabilitation with or without CET combined with BT. Craving was assessed by a 100-point visual analog scale (VAS). Skin conductance (SC) and muscle electromyography (MEG) were recorded using a biofeedback device. After 2 months of treatment, both the pre-cue exposure craving and the post-cue exposure craving, SC, and MEG were lower in the experimental group than in the control group. Compared to the control group, the experimental group had a greater decrease in craving, SC, and MEG from baseline after the treatment. The results suggest that CET combined with BT treatment is effective in reducing craving and physiology reactivity in heroin dependents and could be used as a component of heroin-dependence rehabilitation.

Effect of electro-acupuncture intervention on cognition attention bias in heroin addiction abstinence-a dot-probe-based event-related potential study.

OBJECTIVE: To study the changes of cognitive attention-related brain function in the heroin addicts before and after electro-acupuncture (EA) intervention for exploring the concerned neuro-mechanism of addictive relapse and the central action role of EA intervention. METHODS: Adopting event-related potential (ERP) technique, the ERP at 64 electrode spots in 10 heroin addicts (test group) were recorded before and after EA intervention with dot-probe experimental form during implementing cognitive task on positive emotional clue (PEC), negative emotional clues (NEC), and heroin-related clue (HRC). The P200 amplitude components on the selected observation points (Fz, Cz, and Pz) were analyzed and compared with those obtained from 10 healthy subjects as the control. RESULTS: Before EA, the ERP of attention on HRC in the test group was higher than that on PEC and NEC (P<0.05) and significantly higher than that in the control group (P<0.05); after EA, the P200 amplitude of attention on HRC at Cz and Pz was significantly lowered (P<0.05) and that on PEC at Fz was significantly elevated (P<0.05). After EA, the P200 amplitude at Pz was ranked as NEC > PEC > HRC, but in the control group, it showed PEC > HRC at all three observation points and PEC > NEC at Pz. CONCLUSION: Heroin addicts show attention bias to HRC, which could be significantly reduced by EA intervention, illustrating that EA could effectively inhibit the attention bias to heroin and so might have potential for lowering the relapse rate.

Effect of rapamycin on cue-induced drug craving in abstinent heroin addicts.

The mammalian target of rapamycin is an evolutionarily conserved serine-threonine kinase (mTOR), which controls protein synthesis and catabolism in response to environmental cues. This randomized double-blind clinical trial enrolled 60 abstinent heroin addicts and randomly assigned them to three groups: placebo, 2.5 mg and 5 mg rapamycin. The participants were given the cue-reactivity paradigm with 5 min exposures to neutral and drug-related imagery while craving, anxiety, blood pressure and heart rate pre- and post-exposure were assessed. We found that drug-related cues increased both craving and anxiety of abstinent heroin addicts, and had no effect on blood pressure and heart rate. A single high-dose of rapamycin significantly reduced the craving, but not anxiety induced by drug-related cues. Our findings suggested that rapamycin merits outpatient clinical trials as a potential pharmacotherapy for relapse prevention from drug-related cue induced craving.

Chronic cannabis use does not affect the normalization of hypothalamic-pituitary-adrenal (HPA) axis induced by methadone in heroin addicts.

The hypothalamic-pituitary-adrenal (HPA) axis activity is usually altered by heroin use. In the present study we evaluated in one hundred twenty-one heroin addicts the effects of marijuana smoking on the normalization of HPA axis upon methadone treatment. The study showed that in heroin addicts who are chronic cannabis smokers a treatment with methadone lasting 12 months was able to normalize both plasma corticotropin (ACTH) and cortisol levels, as well as to control both heroin withdrawal symptoms and opioid craving. As expected in the same group of patients marijuana smoking and its craving were not reduced by methadone treatment. Our data confirm that methadone treatment outcomes are not modified by cannabis use and they add in the literature the evidence that chronic cannabis use is not able to affect the normalization of HPA axis upon methadone treatment in heroin addicts.

Gender and stimulus difference in cue-induced responses in abstinent heroin users.

BACKGROUND: Environmental stimuli associated with drug taking have been known to elicit drug craving and increase the likelihood of relapse, and sex differences have been observed in the development of drug addiction and relapse to drug taking. Differential cue paradigms (drug-related imagery scripts and drug-related paraphernalia) have been used to investigate cue-induced drug craving. However, there is little research on the possible gender differences in responses to drug cues in heroin-dependent individuals. This study examined whether two different stimuli, drug-related imagery scripts and drug-related paraphernalia, produce similar or different patterns of cue reactivity in heroin-dependent men and women. METHODS: In the laboratory sessions, 26 male and 23 female heroin-dependent subjects were exposed to script-guided imagery of heroin-related cue situations and to heroin-related paraphernalia (e.g., needles, syringes, spoons, cigarette filters, and aluminum foil). Heroin craving, subjective anxiety, emotion state ratings, and cardiovascular changes were assessed. RESULTS: Significant increases in heroin craving were seen with drug-imagery scripts or drug paraphernalia but not with neutral-relaxing imagery or neutral-item handling. In addition, drug imagery and paraphernalia produced significant increases in subjective anxiety, negative emotions, systolic and diastolic blood pressure, and heart rate, as well as decreases in positive emotion. Paraphernalia exposure was somewhat more effective than imagery scripts in inducing heroin craving, primarily reflecting a lower response to imagery scripts among men. Most other dependent measures also differed by gender, and each gender difference occurred with imagery scripts only or with paraphernalia only. CONCLUSIONS: The present results indicate that heroin-imagery scripts and heroin paraphernalia each induce heroin craving and emotional and cardiovascular changes, but that the changes show a complex pattern of gender differences that may need to be taken into account in future laboratory studies.

[Wavelet-based pulse-abnormality analysis for heroin addicts].

Using wavelet transforms method, time-frequency characteristics of pulse signals from 15 heroin addicts and 15 healthy persons were analyzed. According to 3-D and contour plots used to display discrete dyadic wavelet transforms, the significant difference of time-frequency characteristics between the signals of heroin addicts and healthy persons were revealed. A primary criterion was also obtained,with the criterion, 15 heroin addicts were entirely identified, while two healthy subjects were misidentified. The research result shows that the wavelet-based multiresolution analysis is a very effective method to extract characteristics of pulse signals. It is valuable to the diagnosis and therapy for heroin addicts.

Heroin sensitization induces circumventricular organ activation in the rat brain.

Using c-Fos protein immunohistochemistry we previously demonstrated various sites of activation in the rat forebrain according to the animal's drug history. This study originates from a more detailed evaluation ex-post of the same specimens. A discrete number of c-Fos protein immunoreactive nuclei could be observed in some circumventricular organs, including the vascular organ of terminal lamina (OVLT) and subfornical organ (SFO) and in the nucleus of solitary tract near the area postrema, but only in specimens from sensitized rats. We therefore suggest that repeated drug injections activate the normally low drug metabolizing enzyme activity in the circumventricular organs thus implicating these organs in the complex mechanisms underlying behavioral sensitization.

Cerebral phosphorus metabolite and transverse relaxation time abnormalities in heroin-dependent subjects at onset of methadone maintenance treatment.

Cerebral bioenergetic and phospholipid abnormalities have been reported in heroin-dependent subjects. The goal of the present study was to characterize the neurochemical profile of subjects voluntarily enrolled in a methadone maintenance (MM) treatment program to overcome their heroin addiction. Participants included 43 heroin-dependent subjects during their first month of MM and 15 age-matched healthy individuals. Phosphorus magnetic resonance spectroscopy ((31)P MRS) and transverse relaxation times (T2-RT), which can reflect steady state cerebral perfusion and metabolism, were acquired at 1.5 T from an axial slice prescribed through the orbitofrontal and occipital cortices, including basal ganglia and frontal cortex. MM subjects exhibited reduced phosphocreatine (PCr) levels (-15.3%), elevated phosphodiesters (+ 12.9%, PDE) and significantly longer T2-RT ((+) 2.1%) compared with healthy comparison subjects. When MM subjects were stratified into subgroups based on treatment duration, we found a treatment duration effect on metabolite values but not T2-RT; reduced PCr was observed only after 8+ days of MM, and phosphomonoesters (PME) were elevated in the 15-28 day MM group. Taken together, these cross-sectional data suggest that the first month of MM treatment may be associated with altered cerebral bioenergetics and phospholipid metabolite levels.

[Pulse signal processing based on continuous wavelet transform].

Using the common algorithm and the Mellin algorithm of a continuous wavelet transform, we analyzed the pulse signals of 15 heroin addicts and 15 normal persons. With the use of two algorithms, every pulse signal was processed under 4 scales. From the analyzed results, we found that there was significant difference of wavelet transform coefficients in the time interval 0.2 to approximately 0.4 seconds between the heroin addicts and normal persons. In this paper, the critical parameter used to classify heroin addicts and normal persons is given to every algorithm. The research result of this paper shows that the continuous wavelet transform is really an effective method for processing pulse signals.

Brain and body hyperthermia associated with heroin self-administration in rats.

Intravenous heroin self-administration in trained rats was accompanied by robust brain hyperthermia (+2.0-2.5 degrees C); parallel changes were found in the dorsal and ventral striatum, mediodorsal thalamus, and deep temporal muscle. Temperature began to increase at variable latency after a signal of drug availability, increased reliably (approximately 0.4 degrees C) before the first lever press for heroin, increased further (approximately 1.2 degrees C) after the first heroin injection, and rose more slowly after the second and third injections to stabilize at an elevated plateau (39-40 degrees C) for the remainder of the session. Brain and body temperature declined slowly when drug self-administration was terminated; naloxone precipitated a much more rapid decrease to baseline levels. Changes in temperature were similar across repeated daily sessions, except for the increase associated with the first self-administration of each session, which had progressively shorter latency and greater acceleration. Despite consistent biphasic fluctuations in movement activity associated with heroin self-administrations (gradual increase preceding the lever press, followed by an abrupt hypodynamia after drug infusion), mean brain temperature was very stable at an elevated plateau. Only mean muscle temperature showed evidence of biphasic fluctuations (+/-0.2 degrees C) that were time locked to and correlated with lever pressing and associated movements. Drug- and behavior-related changes in brain temperature thus appear to reflect some form of neuronal activation, and, because temperature is a factor capable of affecting numerous neural functions, it may be an important variable in the control of behavior by drugs of abuse.

Onset and pattern of substance use in intravenous drug users of an opiate maintenance program.

OBJECTIVES: To assess the initiation of substance use of participants in an opiate maintenance program by a cross-sectional survey. METHOD: Participants (n=184) filled out a questionnaire assessing age at initial substance use and age at onset of regular drug use. RESULTS: Of 15 substances investigated, alcohol, nicotine, analgesics and marijuana were initiated and consumed regularly before the age of 18 years. Barbiturates, benzodiazepines, cocaine, and opiates were begun later. The time gap between initial and regular use varied depending on the substance. Regular use exceeded 50% for alcohol, benzodiazepines, cocaine, heroin, marijuana and nicotine. CONCLUSIONS: Specific knowledge about the age of onset and sequence of substances used by drug addicts may help to prevent substance use more age specifically.

Effects of acupuncture and an agonist of opiate receptors on heroin dependent patients.

This study examined the influence of acupuncture and an agonist of opiate receptors (Procedol) by means of temperature in both the left and right auricular "Lung" points, and on the coefficient of interhemisphere asymmetry. Twenty heroin dependent patients participated in this research. They were evenly divided into two groups. Both groups consisted of 10 male drug addicts (18-19 years old) who had been using heroin for 8-10 months. Group 1 received 1.0 ml procedol (i.m.). Group 2 were treated with acupuncture. Temperature was measured on the acupuncture points before and after treatment. Results of this study showed that temperature increased on the left and decreased on the right acupuncture points in both the procedol and acupuncture treated groups. The net changes before and after treatment were 92.87% and 92.53% in groups 1 and 2 respectively. The therapeutic effect of acupuncture on treatment of heroin dependence is through the same pathway as the agonist on opiate receptors, 20% of patients are resisted to acupuncture.

Heroin dependence effects on some major and trace elements.

In this study, 56 (14 control and 42 addicts) adult human subjects of both sexes of different periods of heroin dependence were subjected to the measurement of whole blood, serum, and red blood cell levels of some trace elements (zinc, manganese, iron copper, and bromine), as well as some major elements (phosphorus, sulfur, calcium, potassium, and chlorine). This was done by the energy-dispersive X-ray fluorescence (EDXRF) technique, in which copper and bromine showed a significant rise in whole blood (male) (22 and 32%, respectively), while zinc, iron, manganese, calcium, sulfur phosphorus, potassium, and chlorine showed a significant drop (49, 8, 25, 34, 21, 51, 61, and 72%, respectively) in proportion to the period of heroin intake (6 yr) and in comparison with the control group. No significant sexual variation has been reported.