Abstracts / Drug and Alcohol Dependence 146 (2015) e34–e117
Conclusions: While findings affirmed the association between caffeine use and alcohol/other drug use and problems, the relationship was strongest in students consuming both coffee and energy drinks. Results should inform future prevention and intervention efforts. Financial support: NIH R37 AA011408* and RO1 DA026091. http://dx.doi.org/10.1016/j.drugalcdep.2014.09.673 Loss of serotonin (5-HT) 2C receptor (5-HT2CR) tone in the ventral tegmental area modulates cocaine-related behaviors Sarah E. Swinford-Jackson, Noelle C. Anastasio, Robert G. Fox, Sonja J. Stutz, Kathryn Cunningham Center for Addiction Research, UTMB, Galveston, TX, United States Aims: The mesocorticolimbic dopamine system is known to mediate the hyper- motive and reinforcing effects of cocaine. Serotonergic afferents to the VTA regulate dopamine transmission through the 5-HT2C R which exerts an overall inhibitory impact on VTA function. Although understudied, a few reports identified a role for VTA 5-HT2C R signaling such that intra-VTA microinfusion of a 5-HT2C R agonist has been shown to decrease cocaine-evoked hyperactivity and cocaine self-administration. Here, we employ a virally-mediated genetic knock- down strategy to expand upon these observations and test the hypothesis that diminished VTA 5-HT2C R tone alters cocaine-related behaviors. Methods: Male Sprague-Dawley rats were evaluated for basal motor activity and cocaine-evoked hyperactivity following genetic knockdown of 5-HT2C R in the VTA. We assessed hyperactivity after an injection of cocaine (10 mg/kg, i.p.) in VTA 5-HT2C R knockdown and control rats. Rats were then trained in daily 3-h sessions to self-administer a low dose (0.25 mg/kg/inf) of cocaine on an FR1-5 schedule; the cocaine dose-response (0.05, 0.125, 0.25 and 0.75 mg/kg/inf) relationship was then evaluated to interrogate differences in sensitivity to cocaine. Results: Rats with genetic knockdown of the 5-HT2C R in the VTA displayed enhanced cocaine-evoked hyperactivity (p < 0.05) but no difference in basal loco-motion relative to control rats. There was no difference in acquisition of cocaine self-administration or infusions earned during the cocaine dose-response sessions between VTA 5-HT2C R knockdown and control rats. Conclusions: These data suggest reduced VTA 5-HT2C R tone confers an increased sensitivity to the hypermotive response but not the reinforcing properties of cocaine. Investigation into the role of VTA 5-HT2C R tone on other cocaine-related behaviors, such as motivation to respond for cocaine or cocaine cue reactivity, are underway and will provide further insight into which facets of responsivity to cocaine are modulated by 5-HT2C R function in the VTA. Financial support: DA035620, DA06511, DA024157, DA033935, DA033374. http://dx.doi.org/10.1016/j.drugalcdep.2014.09.674
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Effects of intramuscular and oral buspirone on physiology and behavior in monkeys Kendall T. Szeliga, Susan E. Martelle, Michael A. Nader Physiology & Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, United States Aims: Buspirone has multiple actions in the brain including dopamine (DA) D2-like receptor antagonism. Recent data suggest that buspirone has higher affinity at the DA D3 receptor (DAD3) compared to the DA D2 receptor (DAD2) subtype; DAD3 has been a target for medications to treat drug addiction. One behavioral assay that has been used to assess DAD3 and DAD2 involves administration of the D2-like agonist quinpirole (QUIN). QUIN elicits yawning and the ascending limb of the dose-response curve is thought to be DAD3 mediated, while higher doses of QUIN result in fewer yawns and in hypothermia; the latter is thought to be DAD2 mediated. The goal of this study was to examine, in separate groups of monkeys, the effects of buspirone administered by different routes on behavior (QUIN-elicited yawning) and physiology (QUIN-induced hypothermia). Methods: In drug-naïve male rhesus monkeys (n = 3), QUIN (0.01–0.3 mg/kg, i.m.) elicited yawning that was characterized as an inverted U-shaped function of dose, with peak yawning following 0.1 mg/kg QUIN. In a second study, drug-naïve female cynomolgus monkeys (n = 4) were surgically implanted with indwelling telemetry transmitters (D70-PCT; Data Sciences International, St. Paul, MN). QUIN (0.1 mg/kg, i.m.) induced significant hypothermia. Results: Irrespective of route, buspirone (0.1, i.m. and 0.3–1.0 mg/kg, p.o.) attenuated 0.1 mg/kg QUIN-elicited yawning. Intramuscular (0.1–0.56 mg/kg) but not oral (1.0–5.6 mg/kg) buspirone attenuated QUIN-induced hypothermia. Conclusions: The present data support the hypothesis that oral buspirone is primarily a DAD3 antagonist. If DAD3 is a viable target for addiction medications, then additional studies using oral buspirone are warranted. Financial support: DA012460 and DA010584. http://dx.doi.org/10.1016/j.drugalcdep.2014.09.675 Lower oxidative stress in umbilical blood cord of newborns exposed to crack during pregnancy Claudia M. Szobot 1 , Maria Zavaschi 1 , V. Mardini 1 , F. Kapczinski 1 , Márcia Kauer-Sant’anna 1 , Gabriela Colpo 1 , Bianca Aguiar 1 , Gabrielle Cunha 1 , L. Manna 1 , Anna Rose Childress 2 , Daniel Langleben 2 , K.M. Cereser 1 , L.A. Rohde 1 1 Federal University of Rio Grande do Sul, Porto Alegre, Brazil 2 Treatment Research Center, Philadelphia, PA, United States
Aims: The use of crack-cocaine is a major health concern in several countries. Among its users, pregnant women and their newborns, exposed to crack-cocaine intrautero, deserve special attention. One of the toxic mechanisms of crack-cocaine consists of oxidative stress (OS), which plays an important role in the embryonic development, neonatal and pregnancy-related disorders. Little is known about OS in babies exposed to crack-cocaine during pregnancy. The aim of this study was to compare the levels of OS in newborns exposed to crack during pregnancy (EN) and nonexposed newborns (NEN).
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Abstracts / Drug and Alcohol Dependence 146 (2015) e34–e117
Methods: A cross-sectional study in which the levels of lipid peroxidation and oxidative damage to proteins, measured, respectively, by Thiobarbituric Acid Reactive Substances (TBARS) and carbonil in the umbilical cord blood – UCB) were compared among 48 EN and 83 NEN. Demographic data, presence of psychopathology and use of other substances were assessed in the mothers. Results: After adjustment for maternal psychopatology, newborn weight and alcohol use by mothers, the mean levels of TBARS were significant lower in the group of EN (26.64, CI95% = 20.35–34.88) in comparison to NEN (92.99, CI95% = 90.48–107.44, P < 0.001). There were no significant differences on carbonil levels between groups (0.02065, 0.001160–0.344170 in EN, vs. 0.0189, 0.0076–2.17091 in NEN, P = 0.33). Conclusions: The exposed babies had lower OS, probably induced by Cocaine and Amphetamine Regulated Transcript (CART), which stimulates antioxidant routes. Since both low and high OS are associated to embryotoxicity, the long term effects of these very early adjustments require further investigations. Financial support: This study was funded by Coordenac¸ão de Aperfeic¸oamento de Pessoal de Nível Superior (CAPES), Fundac¸ão de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS) e do Fundo de Incentivo à Pesquisa e Eventos (FIPE) do Hospital de Clínicas de Porto Alegre (HCPA). All Brazilian institutions. http://dx.doi.org/10.1016/j.drugalcdep.2014.09.676 Methamphetamine self-administration in rats is diminished by wheel access in the prior 22 h Michael A. Taffe, Shawn M. Aarde, Kevin Creehan, Sophia A. Vandewater CNAD, The Scripps Research Institute, La Jolla, CA, United States Aims: Prior studies found that a 6 week interval of access to an activity wheel reduces the intravenous self-administration of cocaine and methamphetamine in rodent models. Such models confounded prior wheel exposure with the acute effects of wheel activity in the home cage during self-administration training. A recent study found that ∼22 h of wheel access prior to sessions, without any extended prior exposure, was sufficient to reduce cocaine self-administration in a between-groups design. The present study sought to determine if ∼22 h access to a wheel reduces methamphetamine (MA) self-administration. Methods: Groups of male Sprague Dawley rats were trained to stably self-administer MA (0.05 mg/gk/infusion, i.v.) and then subjected to wheel access/no access conditions when in the vivarium. Intake of MA was significantly lower on sessions following ∼22 h of access to the wheel compared with sessions which followed ∼22 h of normal housing. Effects of the wheel were observed within-subject in an ABAB design as well as between groups. Results: Metamphetamine self-administration was reduced in sessions following 22 h of wheel access both within and between subjects. Conclusions: These data provide evidence that a suppressive effect of wheel activity that had previously been attributed to sustained, multi-week wheel access is instead due to acute wheel activity in the day prior. Thus, brain plasticity mechanisms that require 6 weeks of chronic activity to produce are unlikely to be related to the suppressive effect of activity on drug selfadministration. This study also has important implications for using exercise as an adjunct to human drug cessation therapy because an extended interval of escalated activity may not be required. The
study also shows that consistent daily activity may be required for maximum effect. Financial support: These studies supported by USPHS Grants DA024705 and DA02410. http://dx.doi.org/10.1016/j.drugalcdep.2014.09.677 Brain biomarkers of alcohol abuse at autopsy Mehran Taherian 1 , Joseph Jones 2 , Caroline Williams 1 , Linda Duque 1 , Deborah C. Mash 1 1 Neurology, UM Miller Medical School, Miami, FL, United States 2 US Drug Testing Lab, Des Plaines, IL, United States
Aims: Identification of chronic excessive alcohol consumption in living and deceased individuals is a fundamental task in forensic pathology, because antemortem reports are often unreliable. Alcohol abuse is widely recognized as an important background factor in motor vehicle accidents, occupational accidents, homicides and suicides. In clinical practice, several blood markers are used, but these are not applicable for identifying alcohol exposure at autopsy. Carbohydrate deficient transferrin in serum is a reliable indirect marker of recent alcohol use, but the application to postmortem brain measurement is problematic. We studied phosphatidylethanol (PEth) and ethyl glucoronide (EtG), two direct biomarkers of ethanol consumption. PEth is an abnormal phospholipid formed only in the presence of ethanol. EtG is a direct minor metabolite of ethanol that serves as an antemortem marker of alcohol ingestion. Methods: PEth and EtG were analyzed in social drinkers who died suddenly (n = 12) and heavy drinkers (n = 24) who by report were either abusing alcohol at the time of death or recently abstinent with negative blood alcohol concentrations (BAC) at autopsy. Human brain tissues were obtained and frozen at −80 ◦ C until solid phase extraction. The concentration of PEth and EtG in the cerebellum was determined using LC–MS/MS (Agilent 6460). The limit for detection of PEth and EtG were 4 ng/g and 3 ng/g, respectively. Results: In social drinkers that had negative BAC at autopsy, 8–9 out of 12 subjects tested positive for PEth (13.1–1307.2 ng/g) and/or EtG (6.0–57.0 ng/g). In alcoholics who had negative BAC at autopsy, 11 out of 12 tested positive for PEth (5.93 ng/g–9887.0 ng/g) and 10 out of 12 for EtG (19.5–402.4 ng/g). The mean concentration of PEth was 3012.41 ± 683.7 ng/g in the 12 active alcoholics (BAC 0.24 ± 0.04%). For the chronic alcohol abusers with negative BAC, the biomarker sensitivity for PEth and EtG was 91% and 83%, respectively. Conclusions: EtG and PEth are useful surrogate markers for detecting excessive alcohol drinking, providing a longer detection window and good sensitivity. Financial support: NIDA DA06227-19. http://dx.doi.org/10.1016/j.drugalcdep.2014.09.678 A trans-generational ripple: How a puff during early development led to a global huff in MicroRNA profiles as well as grand-offspring addictive behavior in Caenorhabditis elegans Faten A. Taki, Xiaoping Pan, Baohong Zhang Biology, East Carolina University, Greenville, NC, United States Aims: We employed C. elegans to study the effect of postembryonic nicotine exposure on parental global miRNA expression