Neurotoxicity of crack cocaine exposure: evidence from a systematic review of in vitro and in vivo studies.

Several studies suggest that crack cocaine users exhibit higher prevalence of both psychiatric and psychosocial problems, with an aggressive pattern of drug use. Nevertheless, few experimental studies attempted to verify the neurotoxicity after crack cocaine exposure, especially when compared with other routes of cocaine administration. This systematic review aimed to verify whether in vitro and/or in vivo crack cocaine exposure is more neurotoxic than cocaine exposure (snorted or injected). A search was performed in the PubMed, EMBASE, Scopus, Web of Science, and LILACS databases for in vitro and in vivo toxicological studies conducted with either rats or mice, with no distinction with regard to sex or age. Other methods including BioRxiv, BDTD, Academic Google, citation searching, and specialist consultation were also adopted. Two independent investigators screened the titles and abstracts of retrieved studies and subsequently performed full-text reading and data extraction. The quality of the included studies was assessed by the Toxicological data Reliability assessment Tool (ToxRTool). The study protocol was registered with the Prospective Registry of Systematic Reviews (PROSPERO; CRD42022332250). Of the twelve studies included, three were in vitro and nine were in vivo studies. According to the ToxRTool, most studies were considered reliable either with or without restrictions, with no one being considered as not reliable. The studies found neuroteratogenic effects, decreased threshold for epileptic seizures, schizophrenic-like symptoms, and cognitive deficits to be associated with crack cocaine exposure. Moreover, both in vitro and in vivo studies reported a worsening in cocaine neurotoxic effect caused by the anhydroecgonine methyl ester (AEME), a cocaine main pyrolysis product, which is in line with the more aggressive pattern of crack cocaine use. This systematic review suggests that crack cocaine exposure is more neurotoxic than other routes of cocaine administration. However, before the scarcity of studies on this topic, further toxicological studies are necessary.

Impact of cannabidiol on brain glucose metabolism of C57Bl/6 male mice previously exposed to cocaine.

Despite evidence of the beneficial effects of cannabidiol (CBD) in animal models of cocaine use disorder (CUD), CBD neuronal mechanisms remain poorly understood. This study investigated the effects of CBD treatment on brain glucose metabolism, in a CUD animal model, using [18F]FDG positron emission tomography (PET). Male C57Bl/6 mice were injected with cocaine (20 mg/kg, i.p.) every other day for 9 days, followed by 8 days of CBD administration (30 mg/kg, i.p.). After 48 h, animals were challenged with cocaine. Control animals received saline/vehicle. [18F]FDG PET was performed at four time points: baseline, last day of sensitization, last day of withdrawal/CBD treatment, and challenge. Subsequently, the animals were euthanized and immunohistochemistry was performed on the hippocampus and amygdala to assess the CB1 receptors, neuronal nuclear protein, microglia (Iba1), and astrocytes (GFAP). Results showed that cocaine administration increased [18F]FDG uptake following sensitization. CBD treatment also increased [18F]FDG uptake in both saline and cocaine groups. However, animals that were sensitized and challenged with cocaine, and those receiving only an acute cocaine injection during the challenge phase, did not exhibit increased [18F]FDG uptake when treated with CBD. Furthermore, CBD induced modifications in the integrated density of NeuN, Iba, GFAP, and CB1R in the hippocampus and amygdala. This is the first study addressing the impact of CBD on brain glucose metabolism in a preclinical model of CUD using PET. Our findings suggest that CBD disrupts cocaine-induced changes in brain energy consumption and activity, which might be correlated with alterations in neuronal and glial function.

Prenatal caffeine consumption and neurobehavioral disorders - A systematic review.

Studies have suggested associations between gestational exposure to caffeine and adverse outcomes, however the evidence is still limited. Therefore, a systematic review was conducted to investigate the association between prenatal caffeine exposure and neurobehavioral disorders. The MEDLINE (PubMed), EMBASE, Scopus, Web of Science, and LILACS databases were searched. Observational studies involving women with documented caffeine consumption during pregnancy were eligible for inclusion. The outcomes evaluated were behavioral and intellectual development, Attention Deficit Hyperactivity Disorder, and related behaviors. The data were analyzed by qualitative synthesis. The ROBINS-I tool was employed to assess the risk of bias, and the certainty of evidence was evaluated using GRADE (PROSPERO: CRD42023421164). The search yielded fourteen studies that met the inclusion/exclusion criteria. The sample size among pregnant women ranged from 173 to 64,189, and among children ranged from 88 to 49,190. Maternal caffeine consumption during pregnancy ranged from 0 to 1000 mg/day, with the highest levels observed during mid-pregnancy. Seven studies indicated a potential association between prenatal caffeine exposure and neurobehavioral/neurodevelopment deficits, one study showed that prenatal caffeine exposure improved peer problems, and six studies did not show a significant effect of prenatal caffeine consumption on neurobehavioral disorders. The included studies were classified as moderate for the risk of bias and with very low certainty of evidence. Thus, the evidence is insufficient to confirm with certainty that the prenatal caffeine exposure leads to neurobehavioral disorders. Studies heterogenicity, as well as their variable quality and the presence of several confounding factors, generate uncertainty.

Effectiveness of epidural morphine for the treatment of cancer pain in patients with gastrointestinal neoplasm-a systematic review.

One-third of cancer pain patients do not experience adequate pain relief using analgesic ladder by the World Health Organization. Interventional procedures, such as epidural morphine, have been considered. This study aimed to review the literature comparing the effects of epidural administration of morphine with the oral route. This systematic review included randomized controlled trials (RCTs) conducted with patients with gastrointestinal neoplasm. A search was conducted on PubMed, EMBASE, Web of Science, Scopus, Cochrane Library, and CINAHL databases to identify studies published up to May 2023. The retrieved study was evaluated using the Risk of Bias 2 (RoB 2) tool and qualitatively synthesized. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach (Prospero: CRD42021264728). Only one RCT, a crossover trial, was included in this systematic review. The study was conducted with ten participants (one withdrawal) and reported a statistically significant difference between both subcutaneous and epidural morphine solutions and oral morphine. The adverse events were not described. The included study presents some concerns of bias and low certainty of evidence on the effectiveness and security of epidural morphine administration. The available literature does not suffice to elucidate whether morphine administration via the epidural route is more effective than other routes. Further RCTs are necessary to improve the level of evidence on the effectiveness and risk-benefit of epidural morphine in the management of cancer pain in gastrointestinal neoplasm patients.

Cost-effectiveness analysis of epidural morphine/ropivacaine treatment in patients with cancer pain.

BACKGROUND: Cancer pain is one of the main causes of human suffering, which can generate disabilities and compromise quality of life, giving rise to several psychosocial and economic consequences. AIMS: This quantitative study sought to perform a cost-effectiveness pharmacoeconomic analysis to assess the impact of implanting epidural morphine associated with ropivacaine treatment in gastrointestinal cancer patients with pain that is difficult clinical control, compared with conventional oral treatment. MATERIALS AND METHODS: The study population consisted of 24 patients with gastrointestinal neoplasia who underwent treatment for cancer pain that was difficult to clinically control. 12 patients each were recruited into the control and intervention groups, respectively. While patients in the control group were administered drug treatment orally, patients in the intervention group underwent a surgical procedure for subcutaneous implantation of a catheter that allowed epidural administration of morphine and ropivacaine. For pain assessment, the Visual Analogue Scale was applied. Data analysis had a descriptive character of costs, taking into account the costs for the year 2021. The study perspective was the Brazilian public healthcare provider, referred to as the Unified Health System (Sistema Único de-SUS in Portuguese). Costs were computed over the time horizon corresponding to the duration of treatment, from the first medical consultation (when the treatment was defined) to the end (end of treatment, disease progression, or death). Treatment duration was divided into three phases (first 60 days, support with palliative care, and end-of-life care). To assess the robustness of the economic analysis, sensitivity analyses were performed, considering the effectiveness of pain reduction on the Visual Analogue Scale, and a comparison of results using the median prices of pharmaceutical components used in the study. RESULTS: The mean age of patients was 59.3 years. The results from the cost-effectiveness analysis showed the epidural morphine/ropivacaine treatment to be more effective with regard to pain reduction on the pain scale, particularly for end-of-life care, when compared to the conventional oral treatment, however, at a significantly higher cost. DISCUSSION: From the accomplishment of this research, it was observed that the application of the pain assessment scale is a way to better interpret and understand the patient's pain, facilitating care planning and decision-making by health professionals, as well as monitoring the effectiveness of the proposed new treatment. CONCLUSION: To present a better cost-effectiveness ratio, a reduction in the cost of the new epidural technology or an increase in the value of the existing oral intervention would be required. However, the latter is not feasible and unlikely to occur. A value judgement to decide whether the incremental benefit associated with the use of the new intervention is worth the extra cost will have to be made by the healthcare provider. Interventions that can relieve cancer pain symptoms should be investigated continuously, in search of evidence to support clinical practice and promote better quality of life for patients.

Critical Factors Associated with Morbimortality in COVID-19 Patients Attended at a Brazilian Public Hospital: a Cross-Sectional Study / Fatores Críticos Associados à Morbimortalidade em Pacientes com COVID-19 Atendidos em um Hospital Público Brasileiro: um Estudo Transversal

The association between death from Covid-19 and case management, especially in small and medium-sized municipalities, is still uncertain. To analyze sociodemographic, clinical, and pharmacological factors associated with death in patients with Coronavirus Disease 2019 (COVID-19), from a Brazilian referral public hospital. This is a cross-sectional study, with data from the hospital records of patients (≥ 18 years old) diagnosed with COVID-19, from March 2020 to March 2021. The sample was classified according to the clinical outcome into two groups (death and discharge), among which statistical associations were performed with the variables of interest, with a 5% significance level. Factors such as need for intensive care, use of mechanical ventilation, and total length of hospital stay was related to higher hospital mortality, as well as the permanence of changes in clinical laboratory testing, including lactic acid, D-dimer, markers of hepatic and renal function, C-Reactive protein, anemia, leukocytosis, lymphopenia, thrombocytopenia, pH, and blood oxygen saturation (SpO2) (P < 0.05). Medications used most frequently in the studied hospital for the treatment of COVID-19, such as enoxaparin, dexamethasone, ivermectin, acetylcysteine, chloroquine, and clarithromycin were correlated with morbimortality (P < 0.05). Clinical outcome was influenced by patient-related factors, such as age and comorbidities, however, therapeutic interventions and the choice of medication also impacted morbimortality. These results reinforce the need for preventive actions and adequate clinical protocols in the treatment of hospitalized COVID-19 patients.(AU)

A associação entre o óbito pela Covid-19 e o manejo dos casos, principalmente em municípios de pequeno e médio porte, ainda é incerta. Analisar os fatores sociodemográficos, clínicos e farmacológicos associados à morte em pacientes com a doença do Coronavírus 2019 (COVID-19) em um hospital público brasileiro de referência. Trata-se de um estudo transversal realizado com dados dos prontuários de pacientes (≥ 18 anos) diagnosticados com COVID-19 no período de março de 2020 a março de 2021. A amostra foi classificada de acordo com o desfecho clínico em dois grupos (óbito e alta) e foram realizados testes de associação estatística com as variáveis de interesse com nível de significância de 5%. Fatores como necessidade de terapia intensiva, uso de ventilação mecânica e tempo total de internação estiveram relacionados com maior mortalidade hospitalar, assim como a permanência de alterações nos exames laboratoriais clínicos, incluindo ácido lático, D-dímero, marcadores de função hepática e renal, proteína C reativa, anemia, leucocitose, linfopenia, trombocitopenia, pH e saturação de oxigênio no sangue (SpO2) (P < 0,05). Os medicamentos utilizados com maior frequência no hospital para o tratamento de COVID-19, como enoxaparina, dexametasona, ivermectina, acetilcisteína, cloroquina e claritromicina, foram correlacionados com morbimortalidade (P < 0,05). O desfecho clínico foi influenciado por fatores relacionados ao paciente, como idade e comorbidades, porém as intervenções terapêuticas e a escolha dos medicamentos também impactaram na morbimortalidade. Esses resultados reforçam a necessidade de ações preventivas e protocolos clínicos adequados no tratamento de pacientes hospitalizados com COVID-19.(AU)

Gestational lead exposure and its effects on fetal/infant development - A systematic review.

Studies suggest that gestational exposure to lead (Pb) is related to spontaneous abortions, preterm birth, lower infant birth weight and length, and neurological dysfunctions. However, the evidence about its effects during pregnancy exposure on fetal and child development is still poor. Thus, the aim of this systematic review was to verify the association between prenatal exposure to Pb and the occurrence of neurobehavioral deficits, miscarriages, and child mortality. Observational studies with pregnant women exposed to Pb during pregnancy were included, without gender or ethnicity restrictions. The MEDLINE, Cochrane Library, EMBASE, Scopus, Web of Science, and LILACS databases were searched. The reading of titles and abstracts was conducted, followed by reading in full format and data extraction, that were performed independently by two reviewers. The included studies were evaluated by Downs and Black tool and qualitatively synthesized. Certainty of evidence was assessed by Grading of Recommendations Assessment, Development, and Evaluations (GRADE). The study protocol was registered with the Prospective Registry of Systematic Reviews (PROSPERO; CRD42022296750). Among twenty-one studies included, sixteen were classified as prospective cohort, two case-control, one nested case-control, one cohort, and one longitudinal study. No study that evaluated child mortality associated with gestational Pb exposure was found. There is a very low certainty of evidence in the association of gestational Pb exposure and neurobehavioral deficits or miscarriages. This systematic review reflects the poor evidence and the challenges of human toxicology studies, since it was not possible to associate gestational Pb exposure to neurobehavioral deficits, miscarriages, and child mortality.

Protective Effects of Kefir Against Unpredictable Chronic Stress Alterations in Mice Central Nervous System, Heart, and Kidney.

Kefir is a probiotic mixture with anxiolytic and antioxidant properties. Chronic stress can lead to anxiety disorders and increase oxidative damage in organs such as the heart and kidney. In this study, we examined whether kefir ameliorates the anxiety-like behavior of mice submitted to chronic unpredictable stress (CUS) by modulating brain-derived neurotrophic factor (BDNF) and corticosterone levels and whether kefir modifies the oxidative parameters in the heart and kidney of mice. Male Swiss mice received kefir (0.3 mL/100 g/day) or milk for 30 days (gavage). On the 10th day, the mice were submitted to CUS. Behavioral analysis was performed using the elevated plus maze and forced swimming tests. BDNF levels were analyzed in brain tissues. Heart and kidney superoxide dismutase (SOD), catalase, glutathione (GSH), thiobarbituric acid reactive substances (TBARS), 3-nitrotyrosine, metalloproteinase-2 (MMP-2), and plasma corticosterone were evaluated. Kefir reverted the CUS-induced decrease in the time spent in the open arms, the increase in grooming frequency, and decrease in the head dipping frequency, but not the reduced immobility time. CUS decreased the cerebellum BDNF levels and increased corticosterone levels, which were restored by Kefir. Neither catalase and SOD activities nor GSH, TBARS, 3-nitrotyrosine, and MMP-2 were modified by CUS in the heart. In the kidney, CUS increased 3-nitrotyrosine and MMP-2. Kefir increased the antioxidant defense in the heart and kidney of control and CUS mice. These results suggest that kefir ameliorated CUS-induced anxiety-like behavior by modulating brain BDNF and corticosterone levels. Kefir also increased the antioxidant defense of mice heart and kidney.

Oral pregabalin is effective as preemptive analgesia in abdominal hysterectomy-A randomized controlled trial.

Postoperative pain is one of the main negative symptoms resulting from surgery and the use of new methods to control this symptom is of ever-increasing relevance. Opioid-sparing strategies, such as multimodal analgesia, are trends in this scenario. Pregabalin is a well-established treatment for neuropathic pain; however, it is still controversial in the surgical context for postoperative analgesia. This study investigated the effect of pregabalin on postoperative analgesia in patients undergoing abdominal hysterectomy. It is a prospective, randomised, double-blind, placebo-controlled clinical trial. Female patients undergoing abdominal hysterectomy were randomised to use pregabalin (group P1), 300 mg orally 2 h before surgery, or identical placebo pills (group P0). The main outcome includes the postoperative pain index by visual analogue scale (VAS) and McGill's pain questionnaire. Secondary outcomes include opioid consumption and the presence of adverse effects. A value of p < 0.05 was used to reject type I error. Fifty-five patients were randomised amongst the groups. Patients in group P1 had lower pain rates by VAS scale, both at rest and in active motion, than group P0. In McGill's questionnaire, patients from group P1 also had lower pain rates (12 × 28.5). There was approximately twice as much opioid consumption amongst patients in group P0. Regarding side effects, there was a difference between the two groups only for dizziness, being more incident in group P1. This study suggests that pregabalin is an important adjuvant drug in treating postoperative pain in patients with abdominal hysterectomy.

Nicotine exposure through breastfeeding affects brain-derived neurotrophic factor and synaptic proteins levels in the brain of stressed adult female mice.

Nicotine has been used during pregnancy and lactation as a tobacco harm reduction strategy. However, it is unclear whether nicotine exposure during a critical development period negatively impacts stress responses in adulthood. This study investigated how nicotine, administered via breastfeeding, affects the brain-derived neurotrophic factor (BDNF), synaptic proteins levels, and anxiety-like behavior in adult female mice subjected to stress. Female Swiss mice were exposed to saline or nicotine (8 mg/kg/day) through breastfeeding between their fourth and 17th postnatal days (P) via implanted osmotic mini pumps. The unpredictable chronic mild stress (UCMS) protocol was performed during their adulthood (P65) for 10 consecutive days, followed by the elevated plus maze (EPM) test 1 day after the protocol. Animals were euthanized and their blood, collected for plasma corticosterone measurements and their brain structures, dissected for BDNF and synaptic proteins analyses. We found no significant differences in corticosterone levels between groups (Saline/Non-stress, Nicotine/Non-stress, Saline/Stress, and Nicotine/Stress). The UCMS protocol hindered weight gain. Mice exposed to nicotine through breastfeeding with or without the UCMS protocol in adulthood showed higher grooming and head dipping frequency; decreased BDNF levels in cerebellum and striatum; increased postsynaptic density protein 95 (PSD-95), synapsin I, and synaptophysin levels in cerebellum; and decreased PSD-95 and synapsin I levels in brainstem. Our results indicate that nicotine exposure through breastfeeding leads to long-lasting behavioral effects and synaptic protein changes, most of which were independent of the UCMS protocol, even after a long nicotine-free period, highlighting the importance of further studies on nicotine exposure during development.

Ayahuasca, a psychedelic beverage, modulates neuroplasticity induced by ethanol in mice.

Alcohol use disorder needs more effective treatments because relapse rates remain high. Psychedelics, such as ayahuasca, have been used to treat substance use disorders. Our study aimed to evaluate the effects of ayahuasca on ethanol-induced behavioral sensitization (EIBS). Swiss mice received 2.2 g/kg ethanol or saline IP injections every other day across nine days (D1, D3, D5, D7, and D9), and locomotor activity was evaluated 10 min after each injection. Then, animals were treated daily with ayahuasca (corresponding to 1.76 mg/kg of N,N-dimethyltryptamine, DMT) or water by oral gavage for eight consecutive days. On the seventh day, mice were evaluated in the elevated plus maze. Then, mice were challenged with a single dose of ethanol to measure their locomotor activity. Dopamine receptors, serotonin receptors, dynorphin, and prodynorphin levels were quantified in the striatum and hippocampus by blot analysis. Repeated ethanol administration resulted in EIBS. However, those animals treated with ayahuasca had an attenuated EIBS. Moreover, ayahuasca reduced the anxiogenic response to ethanol withdrawal and prevented the ethanol-induced changes on 5-HT1a receptor and prodynorphin levels in the hippocampus and reduced ethanol effects in the dynorphin/prodynorphin ratio levels in the striatum. These results suggest a potential application of ayahuasca to modulate the neuroplastic changes induced by ethanol.

No effect of prior Dengue virus 1 infection in mouse dams on long-term behavioral profiles in offspring infected with Zika virus during gestation.

Zika virus (ZIKV) is a mosquito-borne Flavivirus structurally and antigenically related to Dengue virus (DENV). Zika virus has been associated with congenital anomalies and most ZIKV outbreaks have occurred in endemic areas of DENV. The present study investigated the effects of prior DENV serotype 1 (DENV1) immunity in immunocompetent female Swiss mice on gestational ZIKV infection in offspring. Physical/reflex development, locomotor activity, anxiety, visual acuity, and brain-derived neurotrophic factor (BDNF) levels were evaluated in offspring during infancy and adolescence. Anti-DENV1 and anti-ZIKV antibodies were detected in sera of the progenitors, whereas no ZIKV genomes were detected in the offspring brain. Pups from dams with only DENV1 immunity presented alterations of physical/reflex development. Pups from all infected dams exhibited time-related impairments in locomotor activity and anxiolytic-like behavior. Offspring from DENV/ZIKV-infected dams exhibited impairments in visual acuity during infancy but not during adolescence, which was consistent with morphometric analysis of the optic nerve. Pups from DENV1-, ZIKV-, and DENV/ZIKV-infected dams exhibited a decrease in BDNF levels during infancy and an increase during adolescence in distinct brain regions. In summary, we found no influence of prior DENV1 immunity on gestational ZIKV infection in offspring, with the exception of alterations of early visual parameters, and an increase in BDNF levels in the hippocampus during adolescence.

Pyrrolidine dithiocarbamate reduces alloxan-induced kidney damage by decreasing nox4, inducible nitric oxide synthase, and metalloproteinase-2.

We examined the effect of the NFκB inhibitor pyrrolidine-1-carbodithioic acid (PDTC) on inducible nitric oxide synthase (iNOS), matrix metalloproteinase-2 (MMP-2) activity, and oxidative and inflammatory kidney damage in alloxan-induced diabetes. Two weeks after diabetes induction (alloxan-130 mg/kg), control and diabetic rats received PDTC (100 mg/kg) or vehicle for 8 weeks. Body weight, glycemia, urea, and creatinine were measured. Kidney changes were measured in hematoxylin/eosin sections and ED1 by immunohistochemistry. Kidney thiobarbituric acid reactive substances (TBARS), superoxide anion (O2-), and nitrate/nitrite (NOx) levels, and catalase and superoxide dismutase (SOD) activities were analyzed. Also, kidney nox4 and iNOS expression, and NFkB nuclear translocation were measured by western blot, and MMP-2 by zymography. Glycemia and urea increased in alloxan rats, which were not modified by PDTC treatment. However, PDTC attenuated kidney structural alterations and macrophage infiltration in diabetic rats. While diabetes increased both TBARS and O2- levels, PDTC treatment reduced TBARS in diabetic and O2- in control kidneys. A decrease in NOx levels was found in diabetic kidneys, which was prevented by PDTC. Diabetes reduced catalase activity, and PDTC increased catalase and SOD activities in both control and diabetic kidneys. PDTC treatment reduced MMP-2 activity and iNOS and p65 NFκB nuclear expression found increased in diabetic kidneys. Our results show that the NFκB inhibitor PDTC reduces renal damage through reduction of Nox4, iNOS, macrophages, and MMP-2 in the alloxan-induced diabetic model. These findings suggest that PDTC inhibits alloxan kidney damage via antioxidative and anti-inflammatory mechanisms.

Environmental Tobacco Smoke During the Early Postnatal Period of Mice Interferes With Brain 18 F-FDG Uptake From Infancy to Early Adulthood - A Longitudinal Study.

Exposure to environmental tobacco smoke (ETS) is associated with high morbidity and mortality, mainly in childhood. Our aim was to evaluate the effects of postnatal ETS exposure in the brain 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) uptake of mice by positron emission tomography (PET) neuroimaging in a longitudinal study. C57BL/6J mice were exposed to ETS that was generated from 3R4F cigarettes from postnatal day 3 (P3) to P14. PET analyses were performed in male and female mice during infancy (P15), adolescence (P35), and adulthood (P65). We observed that ETS exposure decreased 18F-FDG uptake in the whole brain, both left and right hemispheres, and frontal cortex in both male and female infant mice, while female infant mice exposed to ETS showed decreased 18F-FDG uptake in the cerebellum. In addition, all mice showed reduced 18F-FDG uptake in infancy, compared to adulthood in all analyzed VOIs. In adulthood, ETS exposure during the early postnatal period decreased brain 18F-FDG uptake in adult male mice in the cortex, striatum, hippocampus, cingulate cortex, and thalamus when compared to control group. ETS induced an increase in 18F-FDG uptake in adult female mice when compared to control group in the brainstem and cingulate cortex. Moreover, male ETS-exposed animals showed decreased 18F-FDG uptake when compared to female ETS-exposed in the whole brain, brainstem, cortex, left amygdala, striatum, hippocampus, cingulate cortex, basal forebrain and septum, thalamus, hypothalamus, and midbrain. The present study shows that several brain regions are vulnerable to ETS exposure during the early postnatal period and these effects on 18F-FDG uptake are observed even a long time after the last exposure. This study corroborates our previous findings, strengthening the idea that exposure to tobacco smoke in a critical period interferes with brain development of mice from late infancy to early adulthood.

Endocannabinoid-Like Lipid Neuromodulators in the Regulation of Dopamine Signaling: Relevance for Drug Addiction.

The family of lipid neuromodulators has been rapidly growing, as the use of different -omics techniques led to the discovery of a large number of naturally occurring N-acylethanolamines (NAEs) and N-acyl amino acids belonging to the complex lipid signaling system termed endocannabinoidome. These molecules exert a variety of biological activities in the central nervous system, as they modulate physiological processes in neurons and glial cells and are involved in the pathophysiology of neurological and psychiatric disorders. Their effects on dopamine cells have attracted attention, as dysfunctions of dopamine systems characterize a range of psychiatric disorders, i.e., schizophrenia and substance use disorders (SUD). While canonical endocannabinoids are known to regulate excitatory and inhibitory synaptic inputs impinging on dopamine cells and modulate several dopamine-mediated behaviors, such as reward and addiction, the effects of other lipid neuromodulators are far less clear. Here, we review the emerging role of endocannabinoid-like neuromodulators in dopamine signaling, with a focus on non-cannabinoid N-acylethanolamines and their receptors. Mounting evidence suggests that these neuromodulators contribute to modulate synaptic transmission in dopamine regions and might represent a target for novel medications in alcohol and nicotine use disorder.

Early postnatal tobacco smoke exposure triggers anxiety-like behavior and decreases synaptic proteins even after a long exposure-free period in mice.

Although environmental tobacco smoke (ETS) is mainly associated to cardiorespiratory disease, clinical and preclinical studies have showed that ETS induces behavioral disorders and deleterious effects in the brain. Our aim was to investigate the effects of ETS during the early postnatal period on locomotor activity and anxiety and in the presynaptic proteins and brain-derived neurotrophic factor (BDNF) in distinct brain regions. BALB/c mice were exposed to ETS generated from 3R4F reference research cigarettes from the third to the fourteenth days of life. Behavioral and biochemical analyzes were performed during infancy, adolescence, and adulthood. ETS exposure induced a decrease in the locomotor activity in both female and male mice during infancy and in male mice during adolescence. Mice exposed to ETS showed lower distance traveled in the open arms of the elevated plus maze than control group. We also observed a decrease in synapsin levels in the cerebellum and striatum during infancy and adolescence, which persisted during the adulthood only in the cerebellum. Synaptophysin levels were low in all brain regions studied during the infancy, which remained reduced in the cerebellum and prefrontal cortex during adolescence and in the prefrontal cortex during adulthood. BDNF levels were reduced in the striatum and prefrontal cortex during infancy. These behavioral and biochemical data indicate that exposure to ETS during a critical development period leads to anxiety-like behavior and blunted synaptic proteins levels in different regions of the brain. More important, several of these effects were not reversed even after a long exposure-free period.

Exposure to tobacco smoke during the early postnatal period modifies receptors and enzymes of the endocannabinoid system in the brainstem and striatum in mice.

Environmental tobacco smoke (ETS) exposure during brain development has been associated with several disorders, such as depression, anxiety, sudden infant death syndrome, and the predisposition to addiction. The endocannabinoid system plays an essential role in neuronal development. We investigated the effects of early postnatal ETS exposure on the endocannabinoid system in different brain regions. C57BL/6 J mice were exposed to ETS that was generated from 3R4F cigarettes from postnatal day 3 (P3) to P14. Receptors and enzymes of the endocannabinoid system were assessed in infancy, adolescence, and adulthood by Western blot. In the brainstem, ETS exposure decreased cannabinoid 1 (CB1) receptor, CB2 receptor, N-arachidonoyl phosphatidyl ethanol-specific phospholipase D (NAPE-PLD), and fatty acid amino hydrolase (FAAH) levels and increased in diacylglycerol lipase (DAGL) and monoacylglycerol lipase (MAGL) levels during infancy and decreased CB2 and FAAH levels during adulthood. In the striatum, ETS decreased in the NAPE-PLD and MAGL levels and increased FAAH levels during infancy, increased FAAH levels during adolescence, and decreased NAPE-PLD levels during adulthood. The present findings indicate that exposure to ETS during a critical period of brain development can disturb the endocannabinoid system in the brainstem and striatum, regions that are involved in the pathogenesis of sudden infant death syndrome and the susceptibility to addiction.

Anhydroecgonine methyl ester, a cocaine pyrolysis product, may contribute to cocaine behavioral sensitization.

Crack cocaine has a high potential to induce cocaine addiction and its smoke contains cocaine's pyrolysis product anhydroecgonine methyl ester (AEME), a partial agonist at M1- and M3-muscarinic acetylcholine receptor and an antagonist at the remaining subtypes. No reports have assessed AEME's role in addiction. Adult male Wistar rats were intraperitoneally administered with saline, 3mg/kg AEME, 15mg/kg cocaine, or a cocaine-AEME combination on every other day during a period of 9 days. After a 7-days withdrawal period, a challenge injection of the respective drugs was performed on the 17th day. The locomotor activity was evaluated on days 1, 3, 5, 7, 9 and 17, as well as dopamine levels (9th day) and dopaminergic receptors proteins (D1R and D2R on the 17th day) in the caudate-putamen (CPu) and nucleus accumbens (NAc). AEME was not able to induce the expression of behavioral sensitization, but it substantially potentiates cocaine-effects, with cocaine-AEME combination presenting higher expression than cocaine alone. An increase in the dopamine levels in the CPu in all non-saline groups was observed, with the highest levels in the cocaine-AEME group. There was a decrease in D1R protein level in this brain region only for cocaine and cocaine-AEME groups. In the NAc, an increase in the dopamine levels was only observed for cocaine and cocaine-AEME groups, with no changes in both D1R and D2R protein levels. These behavioral and neurochemical data indicate that AEME alone does not elicit behavioral sensitization but it significantly potentiates cocaine effects when co-administered, resulting in dopamine increase in CPu and NAc, brain regions where dopamine release is mediated by cholinergic activity.

Anhydroecgonine methyl ester, a cocaine pyrolysis product, may contribute to cocaine behavioral sensitization

Crack cocaine has a high potential to induce cocaine addiction and its smoke contains cocaine's pyrolysis product anhydroecgonine methyl ester (AEME), a partial agonist at M-1- and M-3-muscarinic acetylcholine receptor and an antagonist at the remaining subtypes. No reports have assessed AEME's role in addiction. Adult male Wistar rats were intraperitoneally administered with saline, 3 mg/kg AEME, 15 mg/kg cocaine, or a cocaine-AEME combination on every other day during a period of 9 days. After a 7-days withdrawal period, a challenge injection of the respective drugs was performed on the 17th day. The locomotor activity was evaluated on days 1, 3, 5, 7, 9 and 17, as well as dopamine levels (9th day) and dopaminergic receptors proteins (D1R and D2R on the 17th day) in the caudate-putamen (CPu) and nucleus accumbens (NAc). AEME was not able to induce the expression of behavioral sensitization, but it substantially potentiates cocaine-effects, with cocaine-AEME combination presenting higher expression than cocaine alone. An increase in the dopamine levels in the CPu in all non-saline groups was observed, with the highest levels in the cocaine-AEME group. There was a decrease in D1R protein level in this brain region only for cocaine and cocaine-AEME groups. In the NAc, an increase in the dopamine levels was only observed for cocaine and cocaine-AEME groups, with no changes in both D1R and D2R protein levels. These behavioral and neurochemical data indicate that AEME alone does not elicit behavioral sensitization but it significantly potentiates cocaine effects when co-administered, resulting in dopamine increase in CPu and NAc, brain regions where dopamine release is mediated by cholinergic activity.

M1 and M3 muscarinic receptors may play a role in the neurotoxicity of anhydroecgonine methyl ester, a cocaine pyrolysis product.

The smoke of crack cocaine contains cocaine and its pyrolysis product, anhydroecgonine methyl ester (AEME). AEME possesses greater neurotoxic potential than cocaine and an additive effect when they are combined. Since atropine prevented AEME-induced neurotoxicity, it has been suggested that its toxic effects may involve the muscarinic cholinergic receptors (mAChRs). Our aim is to understand the interaction between AEME and mAChRs and how it can lead to neuronal death. Using a rat primary hippocampal cell culture, AEME was shown to cause a concentration-dependent increase on both total [(3)H]inositol phosphate and intracellular calcium, and to induce DNA fragmentation after 24 hours of exposure, in line with the activation of caspase-3 previously shown. Additionally, we assessed AEME activity at rat mAChR subtypes 1-5 heterologously expressed in Chinese Hamster Ovary cells. l-[N-methyl-(3)H]scopolamine competition binding showed a preference of AEME for the M2 subtype; calcium mobilization tests revealed partial agonist effects at M1 and M3 and antagonist activity at the remaining subtypes. The selective M1 and M3 antagonists and the phospholipase C inhibitor, were able to prevent AEME-induced neurotoxicity, suggesting that the toxicity is due to the partial agonist effect at M1 and M3 mAChRs, leading to DNA fragmentation and neuronal death by apoptosis.