Search

Abstract While EZH2 enzymatic activity is well-known, emerging evidence suggests that EZH2 can exert functions in a methyltransferase-independent manner. In this study, we have uncovered a novel mechanism by which EZH2 positively regulates the expression of SKP2, a critical protein involved in cell cycle progression. We demonstrate that depletion of EZH2 significantly reduces SKP2 protein levels in several cell types, while treatment with EPZ-6438, an EZH2 enzymatic inhibitor, has no effect on SKP2 protein levels. Consistently, EZH2 depletion leads to cell cycle arrest, accompanied by elevated expression of CIP/KIP family proteins, including p21, p27, and p57, whereas EPZ-6438 treatment does not modulate their levels. We also provide evidence that EZH2 knockdown, but not enzymatic inhibition, suppresses SKP2 mRNA expression, underscoring the transcriptional regulation of SKP2 by EZH2 in a methyltransferase-independent manner. Supporting this, analysis of the Cancer Genome Atlas database reveals a close association between EZH2 and SKP2 expression in human malignancies. Moreover, EZH2 depletion but not enzymatic inhibition positively regulates the expression of major epithelial-mesenchymal transition (EMT) regulators, such as ZEB1 and SNAIL1, in transformed cells. Our findings shed light on a novel mechanism by which EZH2 exerts regulatory effects on cell proliferation and differentiation through its methyltransferase-independent function, specifically by modulating SKP2 expression.

Ras proteins are integral to the mediation of signaling cascades to downstream effectors, regulating a multitude of cellular processes. Mutations within Ras and its associated signaling pathways are implicated in various human pathologies, including inflammatory disorders and malignancies. The immune checkpoint proteins, programmed cell death protein 1 (PD-1) and its ligands PD-L1, along with Indoleamine 2,3-dioxygenase-1 (IDO1), are pivotal in facilitating tumor immune escape. While the influence of oncogenic Ras on PD-L1 expression is extensively documented, the regulatory role of KRas in IDO1 expression remains inadequately understood. In the current study, we demonstrate that IDO1 and PD-L1 expressions are differentially regulated in KRas-mutant cancers. Treatment with the KRasG12C-specific inhibitor, ARS-1620, significantly increased IDO1 expression, which inversely correlated with PD-L1 expression in the KRasG12C-mutant H358 cell line. Notably, IDO1 expression was slightly diminished in KRas-mutant patients with lung and pancreatic ductal adenocarcinomas. Experimental data revealed that IFN-γ induces IDO1 expression; however, this induction is attenuated in the presence of constitutively active KRas. These findings suggest that KRas signaling negatively regulates IDO1 expression while enhancing PD-L1 expression. Moreover, the induction of IDO1 expression following KRas inhibition appears to operate independently of the MAPK pathway. Our results propose that concurrent targeting of KRas and IDO1 could potentiate therapeutic efficacy in KRas-mutant cancers, overcoming resistance to immune checkpoint blockade.

Alzheimer’s disease and related dementias (ADRD) are an expanding worldwide crisis. In the absence of scientific breakthroughs, the global prevalence of ADRD will continue to increase as more people are living longer. Racial or ethnic minority groups have an increased risk and incidence of ADRD and have often been neglected by the scientific research community. There is mounting evidence that vascular insults in the brain can initiate a series of biological events leading to neurodegeneration, cognitive impairment, and ADRD. We are a group of researchers interested in developing and expanding ADRD research, with an emphasis on vascular contributions to dementia, to serve our local diverse community. Toward this goal, the primary objective of this review was to investigate and better understand health disparities in Alabama and the contributions of the social determinants of health to those disparities, particularly in the context of vascular dysfunction in ADRD. Here, we explain the neurovascular dysfunction associated with Alzheimer’s disease (AD) as well as the intrinsic and extrinsic risk factors contributing to dysfunction of the neurovascular unit (NVU). Next, we ascertain ethnoregional health disparities of individuals living in Alabama, as well as relevant vascular risk factors linked to AD. We also discuss current pharmaceutical and non-pharmaceutical treatment options for neurovascular dysfunction, mild cognitive impairment (MCI) and AD, including relevant studies and ongoing clinical trials. Overall, individuals in Alabama are adversely affected by social and structural determinants of health leading to health disparities, driven by rurality, ethnic minority status, and lower socioeconomic status (SES). In general, these communities have limited access to healthcare and healthy food and other amenities resulting in decreased opportunities for early diagnosis of and pharmaceutical treatments for ADRD. Although this review is focused on the current state of health disparities of ADRD patients in Alabama, future studies must include diversity of race, ethnicity, and region to best be able to treat all individuals affected by ADRD.

Cyanobacterial blooms and the associated release of cyanotoxins pose problems for many conventional water treatment plants due to their limited removal by typical unit operations. In this study, a conventional water treatment process consisting of coagulation, flocculation, sedimentation, filtration, and sludge dewatering was assessed in lab-scale experiments to measure the removal of microcystin-LR and Microcystis aeruginosa cells using liquid chromatography with mass spectrometer (LC-MS) and a hemacytometer, respectively. The overall goal was to determine the effect of recycling cyanotoxin-laden dewatered sludge supernatant on treated water quality. The lab-scale experimental system was able to maintain the effluent water quality below relevant the United States Environmental Protection Agency (US EPA) and World Health Organisation (WHO) standards for every parameter analyzed at influent concentrations of M. aeruginosa above 106 cells/mL. However, substantial increases of 0.171 NTU (Nephelometric Turbidity Unit), 7 × 104 cells/L, and 0.26 µg/L in turbidity, cyanobacteria cell counts, and microcystin-LR concentration were observed at the time of dewatered supernatant injection. Microcystin-LR concentrations of 1.55 µg/L and 0.25 µg/L were still observed in the dewatering process over 24 and 48 h, respectively, after the initial addition of M.aeruginosa cells, suggesting the possibility that a single cyanobacterial bloom may affect the filtered water quality long after the bloom has dissipated when sludge supernatant recycling is practiced.

No artigo se realiza um exame crítico das relações entre a União Européia, América Latina e Caribe. O objetivo é explicitar a "associação estratégica" entre aqueles parceiros, proposta no Rio de Janeiro em 1999 e reiterada pela Cúpula de Viena em 2006. O texto pretende mostrar ainda por que estas reuniões não conseguiram uma aproximação efetiva.A critical analysis of the relations between the European Union, Latin America and Caribbean. This article aims to explicit the "strategic association" between those partners, proposed in Rio de Janeiro, in 1999, and reiterated by the Vienna Summit in 2006. The text also intends to demonstrate why these meetings failed to foster an effective approximation.

Abstract Reorganizing curricula to meet competency-based requirements is a challenge for residency and fellowship programs. Building a new curriculum is not easy, and confusion about what exactly is required and then how to meet those requirements has frustrated many program leaders. The ACGME Outcome Project was launched before real solutions to the problem of evaluating competencies of residents had been solved. The Faculty Development Tutorial system was created to help residency educators meet these challenges, particularly educators using the Educational Guidelines for Pediatric Residency website, which provides the platform for these tutorials. This website is a curriculum-building resource for pediatric residency programs, but the tutorials contain information valuable to educators from any discipline. The tutorials are brief, practical, and focused on the key challenges of competency-based curriculum development. They can be used independently of the Educational Guidelines and are not specific to pediatrics. Users must create a username and password to log on. Otherwise access is cost-free and not restricted in any way. Once inside the website, users go to the Menu of Options, and there click on Tutorials to access the system. The Faculty Development Tutorial System webpage includes a separate instruction set called “How to Use This Faculty Development Tutorial System,” six tutorial modules, and a dictionary of terms and concepts. The modules are presented in two formats: MS Word for screen-reading or downloading and MS PowerPoint for downloading to use in faculty development presentations. Customization of all the tutorial files after downloading from the website is encouraged. The six modules are organized around the elements of a planned curriculum: using goals and objectives to plan whole programs and rotations (Modules 2 and 3), planning learning experiences (Module 4), evaluating residents (Module 5), and evaluating programs (Module 6). The supplementary resource called “Medical Education Terms and Concepts” is electronically linked to the tutorials through clickable terms that occur throughout the modules. Data collected online show that during the 30 months after completion of the Guidelines, 1,129 tutorial files were downloaded from the website, with about equal numbers of Word and PowerPoint files. Tutorial users come from 50% of pediatric residency programs nationwide. Comments from tutorial users suggest varied and creative use of the modules.

Background: The female sex hormones estradiol (E) and progesterone (P) galvanize the ventral striatal reward pathway. E elevates ventral striatal dopamine and accelerates drug-cued reinstatement, while P has opposing 'protective' effects on drug-related behavior. We hypothesize that women may exhibit greater ventral striatal responses to smoking cues (SCs) during the late follicular phase of the menstrual cycle (MC) when E is high and unimpeded by P, and reduced responses during the late luteal phase when P is high., Methods: To test our hypothesis, 24 naturally cycling cigarette-dependent women completed functional magnetic resonance (fMRI) sessions over the course of 3 MCs at select time points to reflect the early follicular (low E and P; LEP, control condition), late follicular (high E, low P; HE) and mid-luteal (high E, high P; HEP) MC phases. During fMRI sessions (counterbalanced by phase), women were exposed to a SC versus nonSC audio-visual clip. Ovulation was verified for each MC, and hormone levels were acquired prior to sessions., Results: Contrasts within conditions showed that ventral striatal brain responses to SCs versus nonSCs were negligible during LEP and greater during HE (p=0.009) and HP (p=0.016). Contrasts across conditions showed that HE and HEP had greater responses than LEP (p=0.005), and HE had greater responses than HEP (p=0.049)., Conclusions: Results support and extend our retrospective cross-sectional study of the influence of the hormonal milieu on SC reactivity. Results are clinically relevant as they may guide novel, hormonally-informed and immediately translatable treatment strategies that can potentially reduce relapse in naturally cycling women., Competing Interests: Given her role as Editor-in-Chief, Teresa Franklin, PhD had no in-volvement in the peer-review of this article and has no access to infor-mation regarding its peer-review. Given her role as an Editorial Board Member, Reagan Wetherill, PhD had no involvement in the peer-review of this article and has no access to information regarding its peer-review. Full responsibility for the editorial process for this article was delegated to Associate Editor, Sherry McKee, PhD., (© 2022 The Authors. Published by Elsevier B.V.)

The relationship of cannabis-use disorder and trauma exposure at the level of the brain is not well-understood. Cue-reactivity paradigms have largely focused on characterizing aberrant subcortical function by averaging across the entire task. However, changes across the task, including a non-habituating amygdala response (NHAR), may be a useful biomarker for relapse vulnerability and other pathology. This secondary analysis utilized existing fMRI data from a CUD population with (TR-Y, n  = 18) or without trauma (TR-N, n  = 15). Amygdala reactivity to novel and repeated aversive cues was examined between TR-Y vs. TR-N groups, using a repeated measures ANOVA. Analysis revealed a significant interaction between TR-Y vs. TR-N and amygdala response to novel vs. repeated cues in the amygdala (right: F (1,31) = 5.31, p  = 0.028; left: F (1,31) = 7.42, p  = 0.011). In the TR-Y group, a NHAR was evident, while the TR-N group exhibited amygdala habituation, resulting in a significant difference between groups of amygdala reactivity to repeated cues (right: p  = 0.002; left: p < 0.001). The NHAR in the TR-Y (but not TR-N) group was significantly correlated with higher cannabis craving scores, yielding a significant group difference ( z  = 2.1, p  = 0.018). Results suggest trauma interacts with the brain's sensitivity to aversive cues, offering a neural explanation for the relationship between trauma and CUD vulnerability. These findings suggest the importance of considering the temporal dynamics of cue reactivity and trauma history in future studies and treatment planning, as this distinction may help decrease relapse vulnerability., Competing Interests: Given her role as Editor-in-Chief, Teresa Franklin, PhD had no involvement in the peer-review of this article and has no access to information regarding its peer-review. Given her role as an Editorial Board Member, Reagan Wetherill, PhD had no involvement in the peer-review of this article and has no access to information regarding its peer-review. Full responsibility for the editorial process for this article was delegated to Associate Editor, Sherry McKee, PhD., (© 2022 The Authors. Published by Elsevier B.V.)

Objective: Cigarette smoking and obesity are the leading causes of premature morbidity and mortality and increase the risk of all-cause mortality four-fold when comorbid. Although research suggests that smoking motives may differ based on body mass index (BMI), it is unclear how these differences translate to smoking behavior., Method: Three groups of adults who smoke cigarettes ( N  = 79; obese n  = 25, overweight n  = 30, and lean n  = 24) completed measures of smoking and the Smoking Motivations Questionnaire. Groups did not differ on age, education, cigarettes per day (CPD), pack-years, or nicotine dependence, as measured by the Fagerström Test for Cigarette Dependence (FTCD)., Results: Analyses revealed different associations between reasons for smoking and smoking behavior depending on lean, overweight, or obesity status. Participants ( N   =  37 female, average age 39.8 years) self-reported smoking was positively associated with Addictive, and Automatic subscale scores among lean participants, with only the Addictive subscale score among those with overweight, and only the Automatic subscale score among those with obesity. Post hoc MANCOVA analysis revealed a significant interaction effect of Group x Automatic Smoking on Pack-years (F (2, 79)=3.34, p  = 0.04)., Conclusion: Findings suggest smoking motives are differentially associated with smoking behavior in adults who smoke depending on weight status. The daily smoking rate of participants with obesity may be less related to the addictive quality of smoking, and automaticity may be less associated with smoking history in those with overweight. Additional research on the influence of BMI on cigarette smoking is necessary to fully elucidate how obesity may impact treatment outcomes to optimize smoking cessation treatment among those with excess body weight., Competing Interests: The authors declare no financial interests or conflicts of interest., (© 2021 The Authors. Published by Elsevier B.V.)

Background: Obesity and cigarette smoking are two leading preventable causes of death. Previous research suggests that comorbid smoking and obesity likely share neurobehavioral underpinnings; however, the influence of body mass index (BMI) on resting-state functional connectivity (rsFC) in smokers remains unknown. In this study, we explore how BMI affects rsFC and associations between rsFC and smoking-related behavior., Methods: Treatment-seeking cigarette smokers (N = 87; 54 % men) completed a BOLD resting-state fMRI scan session. We grouped smokers into BMI groups (N = 23 with obesity, N = 33 with overweight, N = 31 lean) and used independent components analysis (ICA) to identify the resting state networks commonly associated with cigarette smoking: salience network (SN), right and left executive control networks (ECN) and default mode network (DMN). Average rsFC values were extracted (p < 0.001, k = 100) to determine group differences in rsFC and relationship to self-reported smoking and dependence., Results: Analyses revealed a significant relationship between BMI and connectivity in the SN and a significant quadratic effect of BMI on DMN connectivity. Heavier smoking was related to greater rsFC in the SN among lean and obese groups but reduced rsFC in the overweight group., Conclusions: Findings build on research suggesting an influence of BMI on the neurobiology of smokers. In particular, dysfunction of SN-DMN-ECN circuitry in smokers with overweight may lead to a failure to modulate attention and behavior and subsequent difficulty quitting smoking. Future research is needed to elucidate the mechanism underlying the interaction of BMI and smoking and its impact on treatment., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

A threefold increase in fatal cocaine overdoses during the past decade highlights the critical lack of medications for cocaine use disorders. The brain response to drug cues can predict future drug use; however, results have been mixed. We present preliminary evidence that a sustained response to repeated cocaine cues within a single task is a significant predictor of drug-use outcomes. Seventy-three cocaine inpatients were administered a passive-viewing fMRI task, featuring 500 ms novel evocative (cocaine, sexual, aversive) and neutral comparator cues in the first half (Half1), which were then repeated in the second half (Half2). After the baseline scan, patients received eight outpatient treatment weeks with twice-weekly drug screens. Drug-use outcome groups were empirically defined based on cocaine-positive or missing urines averaged across the outpatient phase: GOOD (<40%), POOR (>85%), and Intermediate (INT, between 40% and 85%) outcomes. Differences of response to initial (Half1) and repeated (Half2) cues in a priori (cue-reactive) regions were tested between outcome groups (3 [Group] × 2 [Halves] ANOVA). An interaction was found in the brain response to drug (but not sex or aversive) cues, with a significant difference between the GOOD and POOR outcome groups in Half2, driven by a significant decrease in brain response by the GOOD outcome group and a sustained brain response by the POOR outcome group, to repeated cocaine cues. The brain response to repeated drug cues may be a useful predictor of future drug use, encouraging future intervention studies to restore a "healthy" (decreasing) response to the repeated presentation of drug cues., (© 2021 Society for the Study of Addiction.)

Topiramate, a GABA/glutamate modulator, is efficacious in reducing alcohol consumption, though the mechanisms underlying this effect are not well characterized. This study analyzed functional magnetic resonance imaging (fMRI) data from 22 heavy drinkers enrolled in a 12-week placebo-controlled, randomized clinical trial of topiramate to examine the effects of topiramate on alcohol cue-elicited brain responses, craving, and heavy drinking in individuals with DSM-5 alcohol use disorder. Patients were randomized to receive either topiramate (maximal daily dosage of 200 mg/day) or placebo and were administered an fMRI alcohol cue-reactivity task at baseline (before starting medication) and after 6 weeks of double-blind treatment. Analyses compared the topiramate (n = 12) and placebo (n = 8) groups on (1) the change in brain responses during alcohol cue exposure (vs non-alcohol cues) within five a priori regions of interest related to reward-the bilateral and medial orbitofrontal cortex (OFC) and bilateral ventral striatum (VS) and (2) change in craving and heavy drinking days (HDDs) from baseline and scan 2. Topiramate, relative to placebo, reduced alcohol cue-elicited activation of the left VS, bilateral OFC, and medial OFC, alcohol cue-elicited craving, and HDDs between baseline and 6 weeks of treatment. The reduction in alcohol cue-elicited activation in the medial OFC correlated with reductions in craving, and reduced activation in the right VS, right OFC, and medial OFC correlated with the reduction in HDD. This preliminary study provides evidence that topiramate's attenuation of alcohol cue-elicited brain activation and craving are key elements of the drug's neurobiological mechanism of action in reducing heavy drinking.

Background: Craving is a major contributor to drug-seeking and relapse. Although the ventral striatum (VS) is a primary neural correlate of craving, strategies aimed at manipulating VS function have not resulted in efficacious treatments. This incongruity may be because the VS does not influence craving in isolation. Instead, craving is likely mediated by communication between the VS and other neural substrates. Thus, we examined how striatal functional connectivity (FC) with key nodes of networks involved in addiction affects relief of craving, which is an important step in identifying viable treatment targets., Methods: Twenty-four nicotine-dependent non-abstinent women completed two resting-state (rs) fMRI scans, one before and one following smoking a cigarette in the scanner, and provided craving ratings before and after smoking the cigarette. A seed-based approach was used to examine rsFC between the VS, putamen and germane craving-related brain regions; the dorsolateral prefrontal cortex (dlPFC), the posterior cingulate cortex, and the anterior ventral insula., Results: Smoking a cigarette was associated with a decrease in craving. Relief of craving correlated with increases in right dlPFC- bilateral VS (r = 0.57, p = 0.003, corrected) as did increased right dlPFC-left putamen coupling (r = 0.62, p = 0.001, corrected)., Conclusions: Smoking-induced relief of craving is associated with enhanced rsFC between the dlPFC, a region that plays a pivotal role in decision making, and the striatum, the neural structure underlying motivated behavior. These findings are highly consistent with a burgeoning literature implicating dlPFC-striatal interactions as a neurobiological substrate of craving., (Copyright © 2021. Published by Elsevier B.V.)

Women experience more severe health consequences from smoking, have greater difficulty quitting, and respond less favorably to nicotine replacement therapy than men. The influence of fluctuating ovarian hormones, specifically estradiol (E) and progesterone (P), on brain and behavioral responses during exposure to smoking reminders (i.e., cues) may be a contributing factor. Results from our laboratory suggest that women in the late follicular phase of their menstrual cycle (MC) have enhanced smoking cue (SC) vulnerabilities and reduced functional connectivity in neurocircuitry underlying cognitive control, potentially placing them at greater risk for continued smoking and relapse. The primary aim of this study is to examine and link hormonal status with brain and behavioral responses to SCs over the course of three monthly MCs in naturally cycling women who are chronic cigarette smokers. This longitudinal, counterbalanced study collects brain and behavioral responses to SCs at three time points during a woman's MC. Participants complete psychological and physical examinations, biochemical hormonal verification visits, and at least three laboratory/neuroimaging scan visits. The scan visits include a 10-min SC task during blood oxygen level-dependent (BOLD) data acquisition and are timed to occur during the early follicular phase (low E and P), late follicular phase (high E, unopposed by P), and mid-luteal phase (high P, high E). The primary outcomes include brain responses to SCs (compared to non-SCs), subjective craving, E and P hormone levels, and behavioral responses to SCs. This study addresses a critical gap in our knowledge: namely, the impact of the natural hormonal milieu on brain and behavioral responses to SCs, a powerful relapse trigger. Additionally, this study will provide a roadmap for human sex differences researchers who are obliged to consider the often confounding cyclic hormonal fluctuations of women., Competing Interests: The authors declare no financial interests or conflicts of interest., (© 2021 Published by Elsevier Inc.)

Obesity and cigarette smoking are two of the leading preventable causes of death in the United States. Research suggests that overlapping pathophysiology may contribute to obesity and nicotine use disorder (NUD), yet no studies have investigated the effect of obesity on neural response to reward stimuli in NUD. This study used arterial spin-labeled perfusion functional magnetic resonance imaging (fMRI) to examine neural responses during exposure to smoking versus nonsmoking cues in 79 treatment-seeking participants with NUD, 26 with normal weight, 28 with overweight, and 25 with obesity. Given that deficits in behavioral inhibitory control have been associated with both obesity and NUD, participants completed an affect-congruent Go/NoGo task to assess the effect of body mass index (BMI) on this construct in NUD. Analyses revealed that BMI was negatively associated with activation in the right dorsolateral prefrontal cortex (dlPFC) in response to smoking cues, with significantly reduced response in smokers with overweight and smokers with obesity compared with normal-weight smokers. In addition, greater commission errors on the Go/NoGo task were correlated with reduced neural response to smoking cues in the right dlPFC only among those with obesity. Together, these findings provide evidence that obesity in treatment-seeking NUDs is related to neurobiological alterations in inhibitory control over cue-potentiated behaviors, suggesting that smoking cessation may be more difficult in individuals with comorbid NUD and obesity than in those without, requiring treatment strategies tailored to meet their unique needs., (© 2019 Society for the Study of Addiction.)

Cigarette smoking continues to be a leading cause of preventable morbidity and mortality. Although the majority of smokers report making a quit attempt in the past year, smoking cessation rates remain modest. Thus, developing accurate, data-driven methods that can classify and characterize the neural features of nicotine use disorder (NUD) would be a powerful clinical tool that could aid in optimizing treatment development and guide treatment modifications. This investigation applied support vector machine-based classification to resting-state functional connectivity (rsFC) data from individuals diagnosed with NUD (n = 108; 63 male) and matched nonsmoking controls (n = 108; 63 male) and multi-dimensional scaling to visualize the heterogeneity of NUD in individual smokers based on rsFC measures. Machine-based learning models identified five resting-state networks that played a role in distinguishing smokers from controls: the posterior and anterior default mode networks, the sensorimotor network, the salience network and the right executive control network. The classification method constructed classifiers with an average correct classification rate of 88.1 percent and an average area under the curve of 0.93. Compared with controls, individuals with NUD had weaker functional connectivity measures within these networks (P < 0.05, false discovery rate corrected). Further, multi-dimensional scaling visualization demonstrated that controls were similar to each other whereas individuals with NUD had less similarity to controls and to other individuals with NUD. Our findings build upon previous literature demonstrating that machine learning-based approaches to classifying rsFC data offer a valuable technique to understanding network-level differences in nicotine-related neurobiology and extend previous findings by improving classification accuracy and demonstrating the heterogeneity in resting-state networks of individuals with NUD., (© 2018 Society for the Study of Addiction.)

Background: The preclinical literature identifies the ventral striatum (VS) as a key player in drug-conditioned responses, guiding hypotheses examining neural substrates involved in human drug cue reactivity, including the study of sex differences. Men show a replicable response that includes the VS, while women's responses have been weaker and variable. New evidence suggests that the hormonal milieu modulates women's responses to drug cues in the dorsal striatum (DS), specifically, in the putamen. Here we tested the hypothesis that the hormonal milieu affects neural responses to smoking cues (SCs) in the putamen in women cigarette smokers., Methods: We re-examined our three previous neuroimaging studies of the influence of sex and menstrual cycle (MC) phase effects on SC neuroactivity, incorporating the DS as a region of interest., Results: As previously shown, men exhibited increased ventral medial prefrontal cortex (vmPFC) and VS/V pallidum responses, and women showed increased vmPFC responses that were greater in women during the follicular phase (high estradiol), compared to the luteal phase (high progesterone). Reducing the statistical threshold within luteal phase women revealed select deactivation of the putamen., Conclusions: These preliminary findings shed light upon factors that may modulate drug cue reactivity in women, specifically the influence of hormones on DS responses. Emerging literature suggests that manipulating the hormonal milieu may open a fundamental window into sex-specific treatment targets. More rigorous study of the brain substrates involved in drug cue reactivity and other reward-related behavior that may be influenced by sex and the hormonal milieu is imperative., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Introduction: Research indicates that overnight nicotine abstinence disrupts neural activity in the mesocorticolimbic reward network; however, less is known about the time course of abstinence-induced brain changes. To examine the potential neural effects of early abstinence, we used arterial spin labeling perfusion fMRI, to measure regional cerebral blood flow (rCBF) changes in the resting brain induced by 4h of nicotine abstinence., Methods: In a repeated measures design, 5min of resting perfusion fMRI data were acquired in awake nicotine-dependent individuals (eyes open) during 'smoking as usual' (SMK) and following 4h of monitored nicotine abstinence (ABS) conditions (N=20). Conditions were compared using a paired t test in SPM8. Craving was assessed prior to each condition., Results: Compared to SMK, ABS significantly increased craving and reduced rCBF in select regions, including the hippocampus and ventral striatum (cluster corr, α=0.01, 943 contiguous voxels). The magnitude of the abstinence-induced change in rCBF correlated with the magnitude of the change in craving across conditions in select regions, including the medial and lateral orbitofrontal cortices and the anterior ventral insula (r values ranging from 0.59-0.74)., Conclusions: Results show that as few as 4h of abstinence can reduce resting rCBF in multiple nodes of the brain's mesocorticolimbic network, disrupting neural processing. Identifying early withdrawal treatment targets has far-reaching implications, which include thwarting relapse proclivities. Results parallel those of the extant human literature and are in agreement with an extensive preclinical literature showing compromised mesolimbic dopaminergic function and impairments in reward function during nicotine withdrawal., (Copyright © 2017. Published by Elsevier B.V.)

Drug-reward cues trigger motivational circuitry, a response linked to drug-seeking in animals and in humans. Adverse life events have been reported to increase sensitivity to drug rewards and to bolster drug reward signaling. Therefore, we hypothesized that cocaine-dependent individuals with prior emotional, physical and sexual abuse might have a heightened mesolimbic brain response to cues for drug reward in a new brief-cue probe. Cocaine-dependent human individuals (N = 68) were stabilized in an inpatient setting and then completed an event-related blood-oxygen-level dependent functional magnetic resonance imaging task featuring 500-ms evocative (cocaine, sexual, aversive) and comparator (neutral) cues. Responses to three questions about emotional, physical and sexual abuse from the Addiction Severity Index were used to divide the patients into subgroups (history of Abuse [n = 40] versus No Abuse [n = 28]). When subjects were grouped by the historical presence or absence of emotional, physical or sexual abuse, the Abuse group showed a heightened midbrain, thalamic, caudate, and caudal orbitofrontal cortex response to cocaine cues; a similar result was found in other evocative cues, as well. These findings are the first reported for a 500-ms cocaine-cue probe, and they highlight the ability of very brief evocative cues to activate the brain's motivational circuitry. Although all participants had severe cocaine use disorders, individuals reporting prior abuse had a heightened mesolimbic response to evocative cues. To our knowledge, this is the first study in humans linking a history of abuse to a brain vulnerability (heightened mesolimbic response to drug cues) previously shown to contribute to drug-seeking., (© 2016 Society for the Study of Addiction.)

Background: Biological sex influences cigarette smoking behavior. More men than women smoke, but women have a harder time quitting. Sex differences in smoking cue (SC) reactivity may underlie such behavioral differences. However, the influence of sex on brain reactivity to SCs has yielded inconsistent findings suggesting the need for continued study. Here, we investigated the effect of sex on SC reactivity across two sites using different imaging modalities and SC stimulus types., Methods: Pseudo-continuous arterial spin-labeled (pCASL) perfusion functional magnetic resonance imaging (fMRI) was used to assess brain responses to SC versus non-SC videos in 40 smokers (23 females) at the University of Pennsylvania. BOLD fMRI was used to assess brain responses to SC versus non-SC still images in 32 smokers (18 females) at McLean Hospital. Brain reactivity to SCs was compared between men and women and was correlated with SC-induced craving., Results: In both cohorts, males showed higher SC versus non-SC reactivity compared to females in reward-related brain regions (i.e., ventral striatum/ventral pallidum, ventral medial prefrontal cortex). Brain activation during SC versus non-SC exposure correlated positively with SC-induced subjective craving in males, but not females., Conclusions: The current work provides much needed replication and validation of sex differences in SC-reactivity. These findings also add to a body of literature showing that men have greater reward-related brain activation to drug cues across drug classes. Such sex differences confirm the need to consider sex not only when evaluating SC-reactivity but when examining nicotine dependence etiology and treatment., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Sex differences in tobacco-related morbidity and mortality exist, with women experiencing more severe health consequences and greater difficulty with smoking cessation than men. One factor that likely contributes to these sex differences is menstrual cycle phase and associated neural and cognitive changes associated with ovarian hormone fluctuations across the menstrual cycle. Previously, we showed that naturally cycling, cigarette-dependent women in the follicular phase of their menstrual cycle showed greater reward-related neural activity and greater craving during smoking cue exposure. To better understand our results and the observed sex differences in smoking behavior and relapse, we explored potential menstrual cycle phase differences in resting-state functional connectivity (rsFC) in naturally cycling, cigarette-dependent women. Understanding how menstrual cycle phase affects neural processes, cognition, and behavior is a critical step in developing more efficacious treatments and in selecting the best treatment option based on a patient's needs., Methods: Resting-state functional connectivity analyses were used to examine connectivity strength differences between naturally cycling, premenopausal, cigarette-dependent women who were in the follicular phase (FPs; n = 22) and those in the luteal phase (LPs, n = 16) of their menstrual cycle. We also explored associations between connectivity strength and attentional bias to smoking cues., Results: Compared with LPs, FPs showed decreased rsFC between the dorsal anterior cingulate cortex (dACC) and the subgenual anterior cingulate cortex, medial orbitofrontal cortex (mOFC), and ventral striatum. Among FPs, rsFC strength between the dACC and the bilateral dorsolateral prefrontal cortex (DLPFC), the bilateral dorsal striatum, and the left temporal gyrus was inversely correlated with attentional bias to smoking cues., Conclusions: This is the first study to explore menstrual cycle phase differences in rsFC among cigarette-dependent women, and results suggest that FPs show differences in rsFC underlying cognitive control, which could place them at greater risk for continued smoking and relapse. These findings provide new insights toward individualized treatment strategies.

Cigarette smoking continues to be the leading cause of preventable morbidity and mortality. Similar to other addictive substances, the prevalence of cigarette smoking is greater among men than women, yet women are less successful at quitting smoking. Preclinical and clinical research suggests that ovarian hormones (i.e., estradiol and progesterone), which fluctuate over the course of the menstrual cycle, may contribute to these sex differences. Specifically, research suggests that progesterone may protect against cigarette smoking and nicotine addiction; whereas estradiol may underlie enhanced vulnerability. In this review, we discuss new research on ovarian hormone and menstrual cycle phase effects on smoking-related responses and behavior in women, including studies examining neural responses to smoking cues, hormonal influences on medication-assisted smoking cessation, and acute smoking abstinence. We highlight innovative studies with strong research methodology and provide suggestions for future research that may allow evidence-based knowledge for immediate translation to the clinic to guide novel, hormonally-informed treatment strategies. Thus, rigorous scientific study holds the potential to reduce relapse rates, thus improving the health and saving the lives of the many thousands of women who unfortunately do not respond to current treatments.

Addiction theories posit that addiction is the result of a progressive transition from voluntary to habitual, compulsive drug use-changes that have been linked, in animals, to a shift from ventral to dorsal striatal control over drug-seeking behavior. Thus, we hypothesized that early-onset (EOs) cannabis users versus late-onset (LOs) cannabis users might exhibit, respectively, greater dorsal versus ventral striatal response to drug cues. We used functional magnetic resonance imaging and an event-related blood oxygen level-dependent backward-masking task to evaluate striatal responses to backward-masked cannabis cues (vs. neutral cues) in EOs (<16 years old, n = 15) and LOs (≥16 years old, n = 26) with similar recent cannabis use patterns. Direct comparisons revealed that EOs showed greater response to cannabis cues in the dorsal striatum than LOs ( p < 0.01, k > 50 voxels). Within-group analyses revealed that EOs showed greater neural response to cannabis cues in the dorsal striatum, whereas LOs exhibited greater neural response to cannabis cues in the ventral striatum. Although cross-sectional, these findings are consistent with recent addiction theories suggesting a progressive shift from ventral to dorsal striatal control over drug-seeking behavior and highlight the importance of age of onset of cannabis use on the brain and cognition., Competing Interests: Author Disclosure Statement No competing financial interests exist.

Background: Resting-state functional connectivity is a noninvasive, neuroimaging method for assessing neural network function. Altered functional connectivity among regions of the default-mode network have been associated with both nicotine and cannabis use; however, less is known about co-occurring cannabis and tobacco use., Methods: We used posterior cingulate cortex (PCC) seed-based resting-state functional connectivity analyses to examine default mode network (DMN) connectivity strength differences between four groups: (1) individuals diagnosed with cannabis dependence who do not smoke tobacco (n=19; ages 20-50), (2) cannabis-dependent individuals who smoke tobacco (n=23, ages 21-52), (3) cannabis-naïve, nicotine-dependent individuals who smoke tobacco (n=24, ages 21-57), and (4) cannabis- and tobacco-naïve healthy controls (n=21, ages 21-50), controlling for age, sex, and alcohol use. We also explored associations between connectivity strength and measures of cannabis and tobacco use., Results: PCC seed-based analyses identified the core nodes of the DMN (i.e., PCC, medial prefrontal cortex, inferior parietal cortex, and temporal cortex). In general, the cannabis-dependent, nicotine-dependent, and co-occurring use groups showed lower DMN connectivity strengths than controls, with unique group differences in connectivity strength between the PCC and the cerebellum, medial prefrontal cortex, parahippocampus, and anterior insula. In cannabis-dependent individuals, PCC-right anterior insula connectivity strength correlated with duration of cannabis use., Conclusions: This study extends previous research that independently examined the differences in resting-state functional connectivity among individuals who smoke cannabis and tobacco by including an examination of co-occurring cannabis and tobacco use and provides further evidence that cannabis and tobacco exposure is associated with alterations in DMN connectivity., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Preclinical and clinical research indicates that there are sex differences in how men and women initiate, progress, respond to, and withdraw from cannabis use; however, neurophysiological differences, such as neural responses to cannabis cues, are not well understood. Using functional MRI and an event-related blood oxygen level-dependent backward-masking task, we compared neural responses to backward-masked cannabis cues to neutral cues in treatment-seeking, cannabis-dependent adults (N = 44; 27 males) and examined whether sex differences exist. In addition, functional MRI findings were correlated with cannabis craving. Backward-masked cannabis cues elicited greater neural responses than neutral cues in reward-related brain regions, including the striatum, hippocampus/amygdala, insula, anterior cingulate cortex, and lateral orbitofrontal cortex, p < .01, k > 121 voxels. Although no significant sex differences in neural responses to cannabis cues emerged, women showed a positive correlation between neural responses to cannabis cues in the bilateral insula and cannabis craving and an inverse correlation between neural responses to cannabis cues in the left lateral orbitofrontal cortex and cannabis craving. Men, however, showed a positive correlation between neural responses to cannabis cues in the striatum and cannabis craving. Given that cues and craving are important triggers and the focus on many behavioral treatment approaches, these findings suggest that treatment-seeking, cannabis-dependent men and women may benefit from sex-specific and tailored cannabis use disorder treatments., ((c) 2015 APA, all rights reserved).)

Background: Structural magnetic resonance imaging techniques are powerful tools for examining the effects of drug use on the brain. The nicotine and cannabis literature has demonstrated differences between nicotine cigarette smokers and cannabis users compared to controls in brain structure; however, less is known about the effects of co-occurring cannabis and tobacco use., Methods: We used voxel-based morphometry to examine gray matter volume differences between four groups: (1) cannabis-dependent individuals who do not smoke tobacco (Cs); (2) cannabis-dependent individuals who smoke tobacco (CTs); (3) cannabis-naïve, nicotine-dependent individuals who smoke tobacco (Ts); and (4) healthy controls (HCs). We also explored associations between gray matter volume and measures of cannabis and tobacco use., Results: A significant group effect was observed in the left putamen, thalamus, right precentral gyrus, and left cerebellum. Compared to HCs, the Cs, CTs, and Ts exhibited larger gray matter volumes in the left putamen. Cs also had larger gray matter volume than HCs in the right precentral gyrus. Cs and CTs exhibited smaller gray matter volume than HCs in the thalamus, and CTs and Ts had smaller left cerebellar gray matter volume than HCs., Conclusions: This study extends previous research that independently examined the effects of cannabis or tobacco use on brain structure by including an examination of co-occurring cannabis and tobacco use, and provides evidence that cannabis and tobacco exposure are associated with alterations in brain regions associated with addiction., (© The Author 2015. Published by Oxford University Press on behalf of CINP.)

Introduction: Functional magnetic resonance imaging (fMRI) has been used extensively in an attempt to understand brain vulnerabilities that mediate maladaptive responses to drug cues. Using perfusion fMRI, we have consistently shown reward-related activation (medial orbitofrontal cortex/ventral striatum) to smoking cues (SCs). Because preclinical and clinical studies generally show that progesterone may reduce reward and craving, we hypothesized that females in the follicular phase of the cycle (FPs; when progesterone levels are low) would have greater reward-related neural responses to SCs compared with females in the luteal phase (LPs)., Methods: Sated cigarette-dependent premenopausal naturally cycling females underwent pseudo-continuous arterial spin-labeled perfusion fMRI during exposure to 10-min audio visual clips of appetitive SCs and non-SCs. Brain responses to SCs relative to non-SCs were examined among females grouped according to menstrual cycle (MC) phase at the time of scanning (22 FPs, 15 LPs). Craving scores were acquired pre- and post-SC exposure., Results: FPs showed increased neural responses to SCs compared with non-SCs in the medial orbitofrontal cortex (p ≤ .05 corrected), whereas LPs did not. FPs reported SC-elicited craving (p ≤ .005), whereas LPs did not. Within FPs, SC-induced craving correlated with increased neural responses in the anterior insula (r = 0.73, p < .0001)., Conclusions: FPs may be more vulnerable to relapse during appetitive SC exposure than LPs. Because the influence of MC phase on drug cue neural activity has not been examined, these results contribute to our knowledge of the neurobiological underpinnings of responses to drug cues, and they highlight the importance of monitoring menstrual cycle phase in all areas of addiction research., (© The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Cigarette smoke contains nicotine and toxic chemicals and may cause significant neurochemical and anatomical brain changes. Voxel-based morphometry studies have examined the effects of smoking on the brain by comparing gray matter volume (GMV) in nicotine dependent individuals (NDs) to nonsmoking individuals with inconsistent results. Although sex differences in neural and behavioral features of nicotine dependence are reported, sex differences in regional GMV remain unknown. The current study examined sex differences in GMV in a large sample of 80 NDs (41 males) and 80 healthy controls (41 males) using voxel-based morphometry. Within NDs, we explored whether GMV was correlated with measures of cigarette use and nicotine dependence. High-resolution T1 structural scans were obtained from all participants. Segmentation and registration were performed in SPM8 using the optimized DARTEL approach. Covariates included age and an estimate of total global GMV. Differences were considered significant at p≤0.001, with a whole brain FWE-corrected cluster probability of p<0.025. Among NDs compared to Controls less GMV was observed in the thalamus and bilateral cerebellum and greater GMV was observed in the bilateral putamen and right parahippocampus. Lower thalamic GMV was observed in both female and male NDs compared to Controls. Female NDs also had lower GMV in the left cerebellum and in the ventral medial and orbitofrontal cortices with no areas of greater GMV. Male NDs had lower GMV in bilateral cerebellum and greater GMV in bilateral parahippocampus and left putamen. Within male NDs, GMV in the left putamen was correlated with number of pack years. This study, conducted in a large cohort, contributes to our knowledge of brain morphology in nicotine addiction and provides additional evidence of sex-specific effects on GMV in NDs. Identifying brain vulnerabilities with respect to sex provides a methodological framework for personalized therapies to improve relapse rates for both sexes.

Relapse is a widely recognized and difficult to treat feature of the addictions. Substantial evidence implicates cue-triggered activation of the mesolimbic dopamine system as an important contributing factor. Even drug cues presented outside of conscious awareness (i.e., subliminally) produce robust activation within this circuitry, indicating the sensitivity and vulnerability of the brain to potentially problematic reward signals. Because pharmacological agents that prevent these early cue-induced responses could play an important role in relapse prevention, we examined whether baclofen-a GABAB receptor agonist that reduces mesolimbic dopamine release and conditioned drug responses in laboratory animals-could inhibit mesolimbic activation elicited by subliminal cocaine cues in cocaine-dependent individuals. Twenty cocaine-dependent participants were randomized to receive baclofen (60 mg/d; 20 mg t.i.d.) or placebo. Event-related BOLD fMRI and a backward-masking paradigm were used to examine the effects of baclofen on subliminal cocaine (vs neutral) cues. Sexual and aversive cues were included to examine specificity. We observed that baclofen-treated participants displayed significantly less activation in response to subliminal cocaine (vs neutral) cues, but not sexual or aversive (vs neutral) cues, than placebo-treated participants in a large interconnected bilateral cluster spanning the ventral striatum, ventral pallidum, amygdala, midbrain, and orbitofrontal cortex (voxel threshold p < 0.005; cluster corrected at p < 0.05). These results suggest that baclofen may inhibit the earliest type of drug cue-induced motivational processing-that which occurs outside of awareness-before it evolves into a less manageable state.

Although several sex differences in nicotine dependence have been identified, the neural mechanisms underlying these sex differences are not clear. The present study examines sex differences in resting-state brain activity using an arterial spin labeling (ASL) perfusion imaging technique. Fifty-one (31 males) sated nicotine-dependent cigarette smokers underwent perfusion functional magnetic resonance imaging during the resting state. Using functionally defined hippocampus/amygdala (HIP/AMY) seed regions, we observed sex differences in correlation strength between the HIP/AMY and the bilateral anterior insula, rostral anterior cingulate cortex, and inferior parietal lobule with females showing stronger functional coupling than males. This pattern of synchronous variations in dynamic cerebral blood flow is consistent with recent models of nicotine dependence, and as such, our findings provide a novel perspective on the neural mechanisms that may contribute to sex differences in nicotine dependence., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Rationale: Addiction theories posit that drug-related cues maintain and contribute to drug use and relapse. Indeed, our recent study in cocaine-dependent patients demonstrated that subliminally presented cocaine-related stimuli activate reward neurocircuitry without being consciously perceived. Activation of reward neurocircuitry may provoke craving and perhaps prime an individual for subsequent drug-seeking behaviors., Objectives: Using an equivalent paradigm, we tested whether cannabis cues activate reward neurocircuitry in treatment-seeking, cannabis-dependent individuals and whether activation was associated with relevant behavioral anchors: baseline cannabis craving (drug-seeking behavior) and duration of use (degree of conditioning)., Methods: Twenty treatment-seeking, cannabis-dependent individuals (12 males) underwent event-related blood oxygen level-dependent functional magnetic resonance imaging during exposure to 33-ms cannabis, sexual, and aversive cues presented in a backward-masking paradigm. Drug use history and cannabis craving were assessed prior to imaging., Results: Participants showed increased activity to backward-masked cannabis cues in regions supporting reward detection and interoception, including the left anterior insula, left ventral striatum/amygdala, and right ventral striatum. Cannabis cue-related activity in the bilateral insula and perigenual anterior cingulate cortex was positively associated with baseline cannabis craving, and cannabis cue-related activity in the medial orbitofrontal cortex was positively correlated with years of cannabis use. Neural responses to backward-masked sexual cues were similar to those observed during cannabis cue exposure, while activation to aversive cues was observed only in the left anterior insula and perigenual anterior cingulate cortex., Conclusions: These data highlight the sensitivity of the brain to subliminal reward signals and support hypotheses promoting a common pathway of appetitive motivation.

Cigarette-dependent smokers automatically and involuntarily orient attention toward smoking cues (SCs). This attentional bias is clinically significant, as it may contribute to relapse. Thus, identifying neural and genetic correlates of attentional bias is critical for improving interventions. Our previous studies show that the dopamine transporter (DAT) SLC6A3 genotype exerts profound effects on limbic responses to SCs. One potential mechanism underlying these effects is greater attentional bias for SCs. Here, we explored associations between attentional bias for SCs and neural responses to SCs among 'sated' smokers genotyped for the SLC6A3 polymorphism. Pseudo-continuous arterial spin-labeled perfusion functional magnetic resonance imaging images were acquired during SC exposure in 35 smokers genotyped for the SLC6A3 variable number of tandem repeats polymorphism (n = 16, 9-repeats; n = 19, 10/10-repeats). Participants completed a visual dot-probe attentional bias task, which contained pictures of smoking and non-smoking pictures, to examine whether genetic variation in DAT influences attentional bias and to investigate relationships between attentional bias and neural responses to SCs. Although attentional bias to smoking pictures was not significantly different between 9-repeats and 10/10-repeats, 9-repeats showed a positive correlation between attentional bias and increased SC-induced brain activity in the amygdala, whereas 10/10-repeats showed an inverse correlation in the medial orbitofrontal cortex (mOFC). In group comparisons, 9-repeats exhibited positive correlations between attentional bias and SCs in the mOFC and amygdala, relative to 10/10-repeats. Findings suggest that genetic variation in the DAT gene influences brain responses associated with attentional bias; thus, providing additional support for a SC-vulnerable endophenotype., (Published 2012. This article is a U.S. Government work and is in the public domain in the USA.)

Background: Anecdotal and clinical theories purport that females are more responsive to smoking cues, yet few objective, neurophysiological examinations of these theories have been conducted. The current study examines the impact of sex on brain responses to smoking cues., Methods: Fifty-one (31 males) cigarette-dependent sated smokers underwent pseudo-continuous arterial spin-labeled perfusion functional magnetic resonance imaging during exposure to visual smoking cues and non-smoking cues. Brain responses to smoking cues relative to non-smoking cues were examined within males and females separately and then compared between males and females. Cigarettes smoked per day was included in analyses as a covariate., Results: Both males and females showed increased responses to smoking cues compared to non-smoking cues with males exhibiting increased medial orbitofrontal cortex and ventral striatum/ventral pallidum responses, and females showing increased medial orbitofrontal cortex responses. Direct comparisons between male and female brain responses revealed that males showed greater bilateral hippocampal/amygdala activation to smoking cues relative to non-smoking cues., Conclusions: Males and females exhibit similar responses to smoking cues relative to non-smoking cues in a priori reward-related regions; however, direct comparisons between sexes indicate that smoking cues evoke greater bilateral hippocampal/amygdalar activation among males. Given the current literature on sex differences in smoking cue neural activity is sparse and incomplete, these results contribute to our knowledge of the neurobiological underpinnings of drug cue reactivity.

Objective: : Determining the brain substrates underlying the motivation to abuse addictive drugs is critical for understanding and treating addictive disorders. Laboratory neuroimaging studies have demonstrated differential activation of limbic and motivational circuitry (eg, amygdala, hippocampus, ventral striatum, insula, and orbitofrontal cortex) triggered by cocaine, heroin, nicotine, and alcohol cues. The literature on neural responses to marijuana cues is sparse. Thus, the goals of this study were to characterize the brain's response to marijuana cues, a major motivator underlying drug use and relapse, and determine whether these responses are linked to self-reported craving in a clinically relevant population of treatment-seeking marijuana-dependent subjects., Methods: : Marijuana craving was assessed in 12 marijuana-dependent subjects using the Marijuana Craving Questionnaire-Short Form. Subsequently, blood oxygen level dependent functional magnetic resonance imaging data were acquired during exposure to alternating 20-second blocks of marijuana-related versus matched nondrug visual cues., Results: : Brain activation during marijuana cue exposure was significantly greater in the bilateral amygdala and the hippocampus. Significant positive correlations between craving scores and brain activation were found in the ventral striatum and the medial and lateral orbitofrontal cortex (P < 0.0001)., Conclusions: : This study presents direct evidence for a link between reward-relevant brain responses to marijuana cues and craving and extends the current literature on marijuana cue reactivity. Furthermore, the correlative relationship between craving and brain activity in reward-related regions was observed in a clinically relevant sample (treatment-seeking marijuana-dependent subjects). Results are consistent with prior findings in cocaine, heroin, nicotine, and alcohol cue studies, indicating that the brain substrates of cue-triggered drug motivation are shared across abused substances.

Voxel-based morphometry (VBM) studies have interpreted longitudinal medication- or behaviorally induced changes observed on T1-weighted magnetic resonance images (MRIs) as changes in neuronal structure. Although neurogenesis or atrophy certainly occurs, the use of T1-weighted scans to identify change in brain structure in vivo in humans has vulnerability: the T1 relaxation time for arterial blood and gray matter are not clearly distinguishable and therefore, apparent reported structural findings might be at least partially related to changes in blood flow or other physiological signals. To examine the hypothesis that apparent structural modifications may reflect changes introduced by additional mechanisms irrespective of potential neuronal growth/atrophy, we acquired a high-resolution T1-weighted structural scan and a 5-min perfusion fMRI scan (a measurement of blood flow), before and after administration of an acute pharmacological manipulation. In a within-subject design, 15 subjects were either un-medicated or were administered a 20 mg dose of baclofen (an FDA-approved anti-spastic) approximately 110 min before acquiring a T1-weighted scan and a pseudo continuous arterial spin labeled perfusion fMRI scan. Using diffeomorphic anatomical registration through exponentiated lie algebra within SPM7, we observed macroscopic, and therefore implausible, baclofen-induced decreases in VBM 'gray matter' signal in the dorsal rostral anterior cingulate (family wise error corrected at p<0.04, T = 6.54, extent: 1,460 voxels) that overlapped with changes in blood flow. Given that gray matter reductions are unlikely following a single dose of medication these findings suggest that changes in blood flow are masquerading as reductions in gray matter on the T1-weighted scan irrespective of the temporal interval between baseline measures and longitudinal manipulations. These results underscore the crucial and immediate need to develop in vivo neuroimaging biomarkers for humans that can uniquely capture changes in neuronal structure dissociable from those related to blood flow or other physiological signals.

Background: Preclinical and clinical evidence show that the GABA B agonist, baclofen is a promising treatment for addictive disorders; however, until recently its mechanism of action in the human brain was unknown. In previous work we utilized a laboratory model that included a medication versus placebo regimen to examine baclofen's actions on brain circuitry. Perfusion fMRI [measure of cerebral blood flow (CBF)] data acquired 'at rest' before and on the last day of the 21-day medication regimen showed that baclofen diminished CBF bilaterally in the VS, insula and medial orbitofrontal cortex (mOFC). In the present study, we hypothesized that a single dose of baclofen would have effects similar to repeated dosing., Methods: To test our hypothesis, in a crossover design, CBF data were acquired using pseudo continuous arterial spin labeled (pCASL) perfusion fMRI. Subjects were either un-medicated or were administered a 20mg dose of baclofen approximately 110 min prior to scanning., Results: Acute baclofen diminished mOFC, amygdala, and ventral anterior insula CBF without causing sedation (family-wise error corrected at p=0.001)., Conclusions: Results demonstrate that similar to repeated dosing, an acute dose of baclofen blunts the 'limbic' substrate that is hyper-responsive to drugs and drug cues. Smokers often manage their craving and can remain abstinent for extended periods after quitting, however the risk of eventual relapse approaches 90%. Given that chronic medication may not be a practical solution to the long-term risk of relapse, acute baclofen may be useful on an 'as-needed' basis to block craving during 'at risk' situations., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Background: Preclinical studies confirm that the GABA B agonist, baclofen blocks dopamine release in the reward-responsive ventral striatum (VS) and medial prefrontal cortex, and consequently, blocks drug motivated behavior. Its mechanism in humans is unknown. Here, we used continuous arterial spin labeled (CASL) perfusion fMRI to examine baclofen's effects on blood flow in the human brain., Methods: Twenty-one subjects (all smokers, 12 females) were randomized to receive either baclofen (80 mg/day; N=10) or placebo (N=11). A five minute quantitative perfusion fMRI resting baseline (RB) scan was acquired at two time points; prior to the dosing regimen (Time 1) and on the last day of 21 days of drug administration (Time 2). SPM2 was employed to compare changes in RB from Time 1 to 2., Results: Baclofen diminished cerebral blood flow (CBF) in the VS and mOFC and increased it in the lateral OFC, a region involved in suppressing previously rewarded behavior. CBF in bilateral insula was also blunted by baclofen (T values ranged from -11.29 to 15.3 at p=0.001, 20 contiguous voxels). CBF at Time 2 was unchanged in placebo subjects. There were no differences between groups in side effects or cigarettes smoked per day (at either time point)., Conclusions: Baclofen's modulatory actions on regions involved in motivated behavior in humans are reflected in the resting state and provide insight into the underlying mechanism behind its potential to block drug-motivated behavior, in preclinical studies, and its putative effectiveness as an anti-craving/anti-relapse agent in humans., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Previously we demonstrated profound effects of dopamine transporter (DAT) SLC6A3 genotype on limbic responses to smoking cues (SCs). Probands carrying at least one copy of the 9-repeat allele (9-repeat carriers) had greater neural responses to SCs in the anatomically interconnected rostral ventral striatum/medial orbitofrontal cortex (VS/mOFC), compared with homozygotes for the 10-repeat allele (10/10-repeats). To test the reliability of the initial findings, we examined perfusion functional magnetic resonance images acquired during SC exposure in a new cohort of smokers (N=26) who were genotyped for the SLC6A3 polymorphism. In smokers overall, activity was enhanced in the VS/mOFC (t=3.77). Contrasts between allelic groups revealed that 9-repeat carriers had a greater response to SCs in the VS (t=3.12) and mOFC (t=3.19). In separate groups, 9-repeat carriers showed increased activity in the VS (t=5.47) and mOFC (T=4.96), while no increases were observed in 10-repeats. Subjective reports of craving correlated with increased activity in reward-related structures including the extended amygdala, insula and post-central gyrus, and decreased activity in the dorsolateral prefrontal cortex, and were DAT-genotype dependent (r=0.63-0.96). In secondary analyses, we found that The Fagerström Test for Nicotine Dependence scores correlated with enhanced SC-induced perfusion in 10/10-repeats in the insula, mOFC, medial temporal and superior frontal gyri (r=0.50-0.82), while correlations were absent in 9-repeat carriers. Despite heterogeneity introduced by a host of factors, including variance in other genes involved in smoking behavior, we confirm that DAT genotype predicts the direction and location of neural responses to SCs., (© 2011 The Authors, Addiction Biology © 2011 Society for the Study of Addiction.)

The surge in dopamine in ventral striatal regions in response to drugs of abuse and drug-associated stimuli is a final common pathway of addiction processes. GABA B agonists exert their effects indirectly, by quieting dopaminergic afferents. The ability of the GABA B agonist, baclofen to ameliorate nicotine and drug motivated behavior is established within the animal literature, however its potential to do so in humans is understudied, particularly with respect to its possible utility as a smoking cessation agent. We conducted a nine-week double-blind placebo-controlled pilot trial of baclofen for smoking reduction (N=30/group) in smokers contemplating, but not quite ready to quit. Baclofen was titrated upwards to 20mg q.i.d. over a period of twelve days. The primary outcome measure was the number of cigarettes smoked per day (CPD). A significant group by time effect of medication was observed. Baclofen was superior to placebo in reducing CPD (beta=0.01, t=1.97, p<0.05). The most common side effect reported during baclofen treatment is transient drowsiness, however there were no differences between groups in mild, moderate, or severe sedation. Craving was significantly lowered at end of treatment in all smokers (p<0.02). Retention did not differ between groups. In line with a multitude of preclinical studies examining the effects of baclofen on drug-motivated behavior, baclofen reduced CPD. In agreement with other studies examining craving and drug use, reductions in CPD were accompanied by a reduction in craving, a major motivator underlying continued smoking and relapse. These preliminary results demonstrate provisional evidence of the utility of baclofen to aid in smoking cessation and indicate further investigation.

We previously demonstrated differential activation of the mesocorticolimbic reward circuitry in response to cigarette cues independent of withdrawal. Despite robust effects, we noted considerable individual variability in brain and subjective responses. As dopamine (DA) is critical for reward and its predictive signals, genetically driven variation in DA transmission may account for the observed differences. Evidence suggests that a variable number of tandem repeats (VNTRs) polymorphism in the DA transporter (DAT) SLC6A3 gene may influence DA transport. Brain and behavioral responses may be enhanced in probands carrying the 9-repeat allele. To test this hypothesis, perfusion fMR images were acquired during cue exposure in 19 smokers genotyped for the 40 bp VNTR polymorphism in the SLC6A3 gene. Contrasts between groups revealed that 9-repeat (9-repeats) had a greater response to smoking (vs nonsmoking) cues than smokers homozygous for the 10-repeat allele (10/10-repeats) bilaterally in the interconnected ventral striatal/pallidal/orbitofrontal cortex regions (VS/VP/OFC). Activity was increased in 9-repeats and decreased in 10/10-repeats in the VS/VP/OFC (p<0.001 for all analyses). Brain activity and craving was strongly correlated in 10/10-repeats in these regions and others (anterior cingulate, parahippocampal gyrus, and insula; r(2)=0.79-0.86, p<0.001 in all regions). Alternatively, there were no significant correlations between brain and behavior in 9-repeats. There were no differences in cigarette dependence, demographics, or resting baseline neural activity between groups. These results provide evidence that genetic variation in the DAT gene contributes to the neural and behavioral responses elicited by smoking cues.

Background and Objective: The deleterious health consequences of smoking are even more severe for women, yet ironically, they have more difficulty quitting than men. Identifying relapse predictors for women and implementing strategies to increase their chances of successfully quitting and remaining abstinent are important goals. Clinicians and researchers suggest that women could achieve greater success in smoking cessation interventions if the initial quit attempt coincided with the follicular phase (i.e., preovulatory phase) of their menstrual cycle (MC) rather than the luteal phase (i.e., premenstrual). However, no experimental data have been published to support this claim. Our objective was to determine whether MC phase affected smoking status in premenopausal female smokers participating in a smoking cessation treatment trial., Methods: Data from 102 treatment-seeking smokers who participated in an 8-week nicotine replacement therapy (NRT) plus behavioral intervention smoking cessation study were examined retrospectively. NRT began the day subjects attempted to quit smoking (quit date). For analyses, smokers were grouped according to sex, and women were subdivided by MC phase at quit date into follicular (FF, days 1-14, n = 16) and luteal (LF, days 15-30, n = 21) groups., Results: Smoking status was examined on the third day after the quit date (day 3) and at 1 week posttreatment (week 9). On day 3, 52% of LFs reported smoking compared with 19% of FFs (p < 0.04), and at week 9, 71% of LFs reported smoking compared with 31% of FFs (p < 0.02). In a comparison group of men (n = 65), 25% were smoking at day 3 and 68% at week 9. Self-report at week 9 was verified by urine cotinine levels., Conclusions: These data support the supposition that better treatment outcomes can be achieved by scheduling quit dates to coincide with the follicular phase of the MC in female smokers.

Exposure to cigarette smoking cues can trigger physiological arousal and desire to smoke. The brain substrates of smoking cue-induced craving (CIC) are beginning to be elucidated; however, it has been difficult to study this state independent of the potential contributions of pharmacological withdrawal from nicotine. Pharmacological withdrawal itself may have substantial effects on brain activation to cues, either by obscuring or enhancing it, and as CIC is not reduced by nicotine replacement strategies, its neuro-anatomical substrates may differ. Thus, characterizing CIC is critical for developing effective interventions. This study used arterial spin-labeled (ASL) perfusion fMRI, and newly developed and highly appetitive, explicit smoking stimuli, to examine neural activity to cigarette CIC in an original experimental design that strongly minimizes contributions from pharmacological withdrawal. Twenty-one smokers (12 females) completed smoking and nonsmoking cue fMRI sessions. Craving self-reports were collected before and after each session. SPM2 software was employed to analyze data. Blood flow (perfusion) in a priori-selected regions was greater during exposure to smoking stimuli compared to nonsmoking stimuli (p<0.01; corrected) in ventral striatum, amygdala, orbitofrontal cortex, hippocampus, medial thalamus, and left insula. Perfusion positively correlated with intensity of cigarette CIC in both the dorsolateral prefrontal cortex (r2=0.54) and posterior cingulate (r2=0.53). This pattern of activation that includes the ventral striatum, a critical reward substrate, and the interconnected amygdala, cingulate and OFC, is consistent with decades of animal research on the neural correlates of conditioned drug reward.

This article examines conceptual, methodological, and analytic issues in research on relapse to alcohol and other drug use. The review notes the continued move in relapse research from a primary reliance on retrospective assessment of factors surrounding the onset of relapse episodes to an increased focus on the use of new technologies to obtain "near real time" data on proximal factors in relapses. Recent advances in neurobiology have yielded important gains in our understanding of vulnerability to relapse in alcohol and other drug abusers. New statistical techniques are also available to analyze data on relapse. From a theoretical standpoint, there has been an increasing appreciation for the complicated and dynamic interplay of distal and proximal factors in the relapse process. At this point, the strongest and most detailed data on factors in the onset and course of relapse have been generated by studies of smoking relapses that have made use of Ecological Momentary Assessment (EMA) technology. However, there is still limited "near real" time data on proximal factors in alcohol and other drug relapses, and no such data on factors that influence the course of these relapses, once they have begun. Nevertheless, important methodological advances have been and continue to be made in the study of relapse, and our knowledge about the nature and process of relapse has increased considerably over the past 10 years.

Cigarettes acquire reinforcing properties from nicotine and from cues associated with their intake. However, smoking in males and females may be reinforced differentially. Smoking in females is posited to be influenced more by cues whereas male smoking is influenced predominantly by the direct pharmacological actions of nicotine in the brain. Menstrual cycle phase may contribute to some of the sex differences observed in smokers. We hypothesized that females may report more intense craving to smoking cue exposure than males and, further, that female craving scores may be influenced by menstrual cycle phase. Thus, we reexamined previously collected cue exposure data with respect to sex and cycle phase. Self-report measures were collected from subjects prior to and immediately following exposure to visual smoking stimuli. The study included 69 male and 41 female treatment-seeking subjects who smoked more than 15 cigarettes per day for more than 10 years. Females were grouped according to cycle phase. Of the female subjects, 17 were classified as follicular phase females (FFemales) and 24 were classified as luteal phase females (LFemales). Change scores were calculated from the subjective data collected before and after stimulus presentation. Contrary to our hypothesis, overall, males and all females did not differ in their level of cue-induced craving; however, when females were separated into groups by cycle phase, FFemales reported significantly less craving than either males or LFemales (p<.05). The suppressed craving response in FFemales suggests an influence of cycle phase on cue-induced craving.