Crucial role of α4 and α6 nicotinic acetylcholine receptor subunits from ventral tegmental area in systemic nicotine self-administration

The identification of the molecular mechanisms involved in nicotine addiction and its cognitive consequences is a worldwide priority for public health. Novel in vivo paradigms were developed to match this aim. Although the beta2 subunit of the neuronal nicotinic acetylcholine receptor (nAChR) has been shown to play a crucial role in mediating the reinforcement properties of nicotine, little is known about the contribution of the different alpha subunit partners of beta2 (i.e., alpha4 and alpha6), the homo-pentameric alpha7, and the brain areas other than the ventral tegmental area (VTA) involved in nicotine reinforcement. In this study, nicotine (8.7-52.6 microg free base/kg/inf) self-administration was investigated with drug-naive mice deleted (KO) for the beta2, alpha4, alpha6 and alpha7 subunit genes, their wild-type (WT) controls, and KO mice in which the corresponding nAChR subunit was selectively re-expressed using a lentiviral vector (VEC mice). We show that WT mice, beta2-VEC mice with the beta2 subunit re-expressed exclusively in the VTA, alpha4-VEC mice with selective alpha4 re-expression in the VTA, alpha6-VEC mice with selective alpha6 re-expression in the VTA, and alpha7-KO mice promptly self-administer nicotine intravenously, whereas beta2-KO, beta2-VEC in the substantia nigra, alpha4-KO and alpha6-KO mice do not respond to nicotine. We thus define the necessary and sufficient role of alpha4beta2- and alpha6beta2-subunit containing nicotinic receptors (alpha4beta2*- and alpha6beta2*-nAChRs), but not alpha7*-nAChRs, present in cell bodies of the VTA, and their axons, for systemic nicotine reinforcement in drug-naive mic

Perfuorooctane Sulfonate (PFOS), Perfluorooctanoic Acid (PFOA), Brominated Dioxins (PBDDs) and Furans (PBDFs) in Wild and Farmed Organisms at Different Trophic Levels in the Mediterranean Sea

The present study shows the results of perfuorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), brominated dioxins (PBDDs) and furans (PBDFs) measured in several marine fish and seafood of commercial interest at different trophic levels of the food chain. The aims were to investigate the level of the contamination in Mediterranean aquatic wildlife, and in farmed fish, to assess human exposure associated to fishery products consumption. Samples of wild fish were collected during three different sampling campaigns in different Food and Agriculture Organization (FAO) 37 areas of the Mediterranean Sea. In addition, farmed fish (gilthead sea bream and European sea bass) from off-shore cages from different marine aquaculture plants. Results showed contamination values of PFOS and PFOA were lower than those detected in sea basins other than the Mediterranean Sea. Concentration values of PFOS were generally higher than those of PFOA; moreover, levels in farmed fish were lower than in wild samples from the Mediterranean Sea. Intake of PFOS and PFOA through fishery products consumption was estimated to be 2.12 and 0.24 ng/kgBWday, respectively, for high consumers (95th percentile). Results of 2,3,7,8-substituted congeners of PBDDs and PBDFs were almost all below the limit of detection (LOD), making it difficult to establish the contribution of these compounds to the total contamination of dioxin-like compounds in fish and fishery products

Comparing the hierarchy of keywords in on-line news portals

The tagging of on-line content with informative keywords is a widespread phenomenon from scientific article repositories through blogs to on-line news portals. In most of the cases, the tags on a given item are free words chosen by the authors independently. Therefore, relations among keywords in a collection of news items is unknown. However, in most cases the topics and concepts described by these keywords are forming a latent hierarchy, with the more general topics and categories at the top, and more specialised ones at the bottom. Here we apply a recent, cooccurrence-based tag hierarchy extraction method to sets of keywords obtained from four different on-line news portals. The resulting hierarchies show substantial differences not just in the topics rendered as important (being at the top of the hierarchy) or of less interest (categorised low in the hierarchy), but also in the underlying network structure. This reveals discrepancies between the plausible keyword association frameworks in the studied news portals

The use of visual methods to explore how children construct and assign meaning to the ''self'' within two urban communities in the Western Cape, South Africa

This study aimed to explore how children construct and assign meaning to the ''self'' within two urban communities of Cape Town in South Africa. Using a child participation methodological framework data were collected using Photovoice and community maps with 54 participants between the ages of 9 and 12. Feelings of safety, social connectedness, and children's spaces were found to be central to the ways in which the participants constructed and assigned meaning to the ''self.'' The study provides implications for intervention programmes aimed at improving children's well-being to be inclusive of activities aimed at improving children's self-concept, including the construction of safe spaces for children to play, learn, and form meaningful relationships

Children’s discourses of natural spaces: considerations for children’s subjective well-being

Based on the evidence provided in the literature, it is manifest that increased time spent in nature increases various aspects of children’s well-being. Using discourse analysis on focus group interviews with 28 children between the ages of 12 and 14 years old from three socio-economically diverse communities in the Western Cape of South Africa, the study aimed to explore how children construct and assign meaning to natural spaces. More specifically the study explored how children use specific discursive resources and repertoires to construct and assign meaning to their engagement with natural spaces, and the extent to which this influences their subjective well-being. Several pertinent discourses emerged from the participants’ accounts within four themes of: Safety and natural spaces, Appreciation for natural spaces, Degradation of Nature: Thinking environmentally, acting pro-environmentally, and Natural spaces and children’s subjective well-being. The study highlights the critical role that children’s engagement in natural spaces has on their subjective well-being, and how these benefits can be harnessed to better children’s overall quality of life.IS

Brain tumor location influences the onset of acute psychiatric adverse events of levetiracetam therapy: an observational study.

To explore possible correlations among brain lesion location, development of psychiatric symptoms and the use of antiepileptic drugs (AEDs) in a population of patients with brain tumor and epilepsy. The medical records of 283 patients with various types of brain tumor (161 M/122 F, mean age 64.9 years) were analysed retrospectively. Patients with grade III and IV glioma, previous history of epileptic seizures and/or psychiatric disorders were excluded. Psychiatric symptoms occurring after initiation of AED therapy were considered as treatment emergent psychiatric adverse events (TE-PAEs) if they fulfilled the following conditions: (1) onset within 4 weeks after the beginning of AED therapy; (2) disappearance on drug discontinuation; (3) absence of any other identified possible concurrent cause. The possible influence of the following variables were analysed: (a) AED drug and dose; (b) location and neuroradiologic features of the tumor, (c) location and type of EEG epileptic abnormalities, (d) tumor excision already or not yet performed; (e) initiation or not of radiotherapy. TE-PAEs occurred in 27 of the 175 AED-treated patients (15.4%). Multivariate analysis showed a significant association of TE-PAEs occurrence with location of the tumor in the frontal lobe (Odds ratio: 5.56; 95% confidence interval 1.95-15.82; p value: 0.005) and treatment with levetiracetam (Odds ratio: 3.61; 95% confidence interval 1.48-8.2; p value: 0.001). Drug-unrelated acute psychiatric symptoms were observed in 4 of the 108 AED-untreated patients (3.7%) and in 7 of the 175 AED-treated patients (4%). The results of the present study suggest that an AED alternative to levetiracetam should be chosen to treat epileptic seizures in patients with a brain tumor located in the frontal lobe to minimize the possible onset of TE-PAEs

Quantifying and Maximising the Benefits of Crops After Rice

At the time this project was conceived, rising watertables and subsequent salinisation were considered to be the major threats to the sustainability of irrigated agriculture in the rice growing areas of southern NSW. The biggest threat to sustainability at present is the reduced availability and higher cost of water as a result of the water reforms, and more recently prolonged drought. The hypothesis of this project was that growing crops immediately after rice would increase water use efficiency and profitability of rice-based cropping systems while reducing net recharge. Field experiments were conducted from 1998 to 2000 on two soil types to evaluate the effect of non-irrigated wheat after rice on watertables and net recharge. Rainfall during the wheat season was reasonably similar in all 3 years (270-318 mm) and higher than average (220 mm). Yield and biomass production of early sown (24 April) wheat were higher than yield of late wheat (29 June) (grain yield 4.7 vs 3.8 t/ha at 12% moisture). In the absence of irrigation, the soil profile remained wet in fallow areas, whereas there was considerable drying in areas planted to wheat. The drying created capacity in the soil profile to capture and use winter rainfall. There was a general increase in depth to the watertable during the first half of the season where non-irrigated wheat was grown after rice, but not in the fallow areas. However, in all situations, the watertable rose around the time of rice sowing each year due to a rise in the regional groundwater level. The lumped water balance studies suggested net discharge of about 1 ML/ha between the time of sowing and harvesting wheat after rice in each of the three years, mostly due to higher upflow due to crop water use. In the fallow, net discharge/recharge was close to zero. The CERES Wheat and SWAGMAN® Destiny models performed very well in simulating a wide range of crop and soil water parameters, although the validation data sets were limited in that the yield range was smaller than desirable. Consistent with the field studies, yield of nonirrigated early sown wheat (median 3.8 t/ha) was usually much higher than yield of late sown wheat (median 1.8 t/ha). With one or two irrigations yields of both early and late sown wheat almost always increased, by around 1 t/ha with one irrigation at heading, and an additional 0.5 t/ha with a second irrigation during grain filling. It was only with frequent irrigation (whenever cumulative ETo-rain since the previous irrigation reached 60 mm) that yields of late sown wheat matched (or surpassed) yields of early sown wheat. However, the irrigation requirement for late wheat irrigated at ETo-rain 60 mm was almost always much higher than for early wheat with the same irrigation management (by >100 mm in most years). While irrigation increased yield, it also increased net recharge, with final watertables generally higher by 0.5 to 0.8 m for wheat after rice (wet initial soil) with irrigation at ETo-rain 60 mm compared with no irrigation. The model simulations showed that with wheat after rice, there was net discharge in almost all years, regardless of initial watertable depth (0.5-1.5 m). In comparison, net recharge occurred in 18 to 48% of years with fallow after rice, the amount of recharge increase as initial depth to the watertable increased. For non-irrigated wheat after rice, salinity of the watertable was 2 important where the watertable was shallow (0.5 m), with yield reductions in excess of 1 t/ha in most years. However for deeper watertables, there was no effect of watertable salinity for non-irrigated wheat. With irrigation, watertable salinity had no impact on yields. Growing wheat immediately after rice was financially beneficial, with an increase in Net Present Value (NPV) ranging from 31 to 126 $/ha/yr depending on the rotation. Assuming that the rate of adoption is doubled over 20 years as a result of the project, the NPV of benefits was estimated to be$5.6 million compared with costs of $1.1 million, resulting in a benefit cost ratio of 5.3

Quantifying and Maximising the Benefits of Crops After Rice

At the time this project was conceived, rising watertables and subsequent salinisation were considered to be the major threats to the sustainability of irrigated agriculture in the rice growing areas of southern NSW. The biggest threat to sustainability at present is the reduced availability and higher cost of water as a result of the water reforms, and more recently prolonged drought. The hypothesis of this project was that growing crops immediately after rice would increase water use efficiency and profitability of rice-based cropping systems while reducing net recharge. Field experiments were conducted from 1998 to 2000 on two soil types to evaluate the effect of non-irrigated wheat after rice on watertables and net recharge. Rainfall during the wheat season was reasonably similar in all 3 years (270-318 mm) and higher than average (220 mm). Yield and biomass production of early sown (24 April) wheat were higher than yield of late wheat (29 June) (grain yield 4.7 vs 3.8 t/ha at 12% moisture). In the absence of irrigation, the soil profile remained wet in fallow areas, whereas there was considerable drying in areas planted to wheat. The drying created capacity in the soil profile to capture and use winter rainfall. There was a general increase in depth to the watertable during the first half of the season where non-irrigated wheat was grown after rice, but not in the fallow areas. However, in all situations, the watertable rose around the time of rice sowing each year due to a rise in the regional groundwater level. The lumped water balance studies suggested net discharge of about 1 ML/ha between the time of sowing and harvesting wheat after rice in each of the three years, mostly due to higher upflow due to crop water use. In the fallow, net discharge/recharge was close to zero. The CERES Wheat and SWAGMAN® Destiny models performed very well in simulating a wide range of crop and soil water parameters, although the validation data sets were limited in that the yield range was smaller than desirable. Consistent with the field studies, yield of nonirrigated early sown wheat (median 3.8 t/ha) was usually much higher than yield of late sown wheat (median 1.8 t/ha). With one or two irrigations yields of both early and late sown wheat almost always increased, by around 1 t/ha with one irrigation at heading, and an additional 0.5 t/ha with a second irrigation during grain filling. It was only with frequent irrigation (whenever cumulative ETo-rain since the previous irrigation reached 60 mm) that yields of late sown wheat matched (or surpassed) yields of early sown wheat. However, the irrigation requirement for late wheat irrigated at ETo-rain 60 mm was almost always much higher than for early wheat with the same irrigation management (by >100 mm in most years). While irrigation increased yield, it also increased net recharge, with final watertables generally higher by 0.5 to 0.8 m for wheat after rice (wet initial soil) with irrigation at ETo-rain 60 mm compared with no irrigation. The model simulations showed that with wheat after rice, there was net discharge in almost all years, regardless of initial watertable depth (0.5-1.5 m). In comparison, net recharge occurred in 18 to 48% of years with fallow after rice, the amount of recharge increase as initial depth to the watertable increased. For non-irrigated wheat after rice, salinity of the watertable was 2 important where the watertable was shallow (0.5 m), with yield reductions in excess of 1 t/ha in most years. However for deeper watertables, there was no effect of watertable salinity for non-irrigated wheat. With irrigation, watertable salinity had no impact on yields. Growing wheat immediately after rice was financially beneficial, with an increase in Net Present Value (NPV) ranging from 31 to 126 $/ha/yr depending on the rotation. Assuming that the rate of adoption is doubled over 20 years as a result of the project, the NPV of benefits was estimated to be$5.6 million compared with costs of $1.1 million, resulting in a benefit cost ratio of 5.3

Augmented acquisition of cocaine self-administration and altered brain glucose metabolism in adult female but not male rats exposed to a cannabinoid agonist during adolescence

Marijuana consumption during adolescence has been proposed to be a stepping stone for adult cocaine addiction. However, experimental evidence for this hypothesis is missing. In this work we chronically injected male and female Wistar rats with either the cannabinoid agonist CP 55,940 (CP; 0.4 mg/kg) or its corresponding vehicle. Adult acquisition (seven 30 min daily sessions) and maintenance (fourteen 2 h daily sessions) of cocaine self administration (1 mg/kg), food reinforced operant learning under conditions of normal (ad libitum access to food), and high motivation (food restriction schedule) were measured. Additionally, brain metabolic activity was analyzed by means of [18F] fluorodeoxyglucose positron emission tomography. During the acquisition phase, female CP treated rats showed a higher rate of cocaine self administration as compared to vehicle treated females and males; no differences were found between both male groups. This effect disappeared in the maintenance phase. Moreover, no differences among groups were evident in the food reinforced operant task, pointing to the cocaine specific nature of the effect seen in self administration rather than a general change in reward processing. Basal brain metabolic activity also changed in CP treated females when compared to their vehicle treated counterparts with no differences being found in the males; more specifically we observed a hyper activation of the frontal cortex and a hypo activation of the amygdalo entorhinal cortex. Our results suggest that a chronic exposure to cannabinoids during adolescence alters the susceptibility to acquire cocaine self administration, in a sex specific fashion. This increased susceptibility could be related to thechanges in brain metabolic activity induced by cannabinoids during adolescenceThis work was supported by Grants FIS G03/05 (Red de Trastornos Adictivos), BSO2001-1099, FIS 01-05-01, Plan Nacional sobre Drogas (PNSD) 2001–2003, PNSD 2004–2007, GR-SAL/0260/2004 to EA and Grants INT/2012/ 2002, CB06/01/0079, and CENIT (2006–2009) to MDPublicad

Natural course of behavioral addictions: A 5-year longitudinal study

BACKGROUND: Resolving the theoretical controversy on the labeling of an increasing number of excessive behaviors as behavioral addictions may also be facilitated by more empirical data on these behavioral problems. For instance, an essential issue to the classification of psychiatric disorders is information on their natural course. However, longitudinal research on the chronic vs. episodic nature of behavioral addictions is scarce. The aim of the present study, therefore, was to provide data on prevalence, substance use comorbidity, and five-year trajectories of six excessive behaviors—namely exercising, sexual behavior, shopping, online chatting, video gaming, and eating. METHODS: Analyses were based on the data of the Quinte Longitudinal Study, where a cohort of 4,121 adults from Ontario, Canada was followed for 5 years (2006 to 2011). The response rate was 21.3%, while retention rate was 93.9%. To assess the occurrence of each problem behavior, a single self-diagnostic question asked people whether their over-involvement in the behavior had caused significant problems for them in the past 12 months. To assess the severity of each problem behavior reported, the Behavioral Addiction Measure was administered. A mixed design ANOVA was used to investigate symptom trajectories over time for each problem behavior and whether these symptom trajectories varied as a function of sex. RESULTS: The large majority of people reported having problematic over-involvement for just one of these behaviors and just in a single time period. A main effect of time was found for each problem behavior, indicating a moderately strong decrease in symptom severity across time. The time x sex interaction was insignificant in each model indicating that the decreasing trend is similar for males and females. The data also showed that help seeking was very low in the case of excessive sexual behavior, shopping, online chatting, and video gaming but substantially more prevalent in the case of excessive eating and exercising. CONCLUSIONS: The present results indicate that self-identified excessive exercising, sexual behavior, shopping, online chatting, video gaming, and/or eating tend to be fairly transient for most people. This aspect of the results is inconsistent with conceptualizations of addictions as progressive in nature, unless treated. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12888-015-0383-3) contains supplementary material, which is available to authorized users