Functional connectivity in reward-related networks is associated with individual differences in gambling strategies in male Lister hooded rats

Individuals with gambling disorder display deficits in decision-making in the Iowa Gambling Task. The rat Gambling Task (rGT) is a rodent analogue that can be used to investigate the neurobiological mechanisms underlying gambling behaviour. The aim of this explorative study was to examine individual strategies in the rGT and investigate possible behavioural and neural correlates associated with gambling strategies. Thirty-two adult male Lister hooded rats underwent behavioural testing in the multivariate concentric square field™ (MCSF) and the novel cage tests, were trained on and performed the rGT and subsequently underwent resting-state functional magnetic resonance imaging (R-fMRI). In the rGT, stable gambling strategies were found with subgroups of rats that preferred the suboptimal safest choice as well as the disadvantageous choice, that is, the riskiest gambling strategy. R-fMRI results revealed associations between gambling strategies and brain regions central for reward networks. Moreover, rats with risky gambling strategies differed from those with strategic and intermediate strategies in brain functional connectivity. No differences in behavioural profiles, as assessed with the MCSF and novel cage tests, were observed between the gambling strategy groups. In conclusion, stable individual differences in gambling strategies were found. Intrinsic functional connectivity using R-fMRI provides novel evidence to support the notion that individual differences in gambling strategies are associated with functional connectivity in brain regions important for reward networks.

Atypical but not typical antipsychotic drugs ameliorate phencyclidine-induced emotional memory impairments in mice

Schizophrenia is associated with cognitive impairments related to hypofunction in glutamatergic N-methyl-D-aspartate receptor (NMDAR) transmission. Phencyclidine (PCP), a non-competitive NMDAR antagonist, models schizophrenia-like behavioral symptoms including cognitive deficits in rodents. This study examined the effects of PCP on emotional memory function examined in the passive avoidance (PA) task in mice and the ability of typical and atypical antipsychotic drugs (APDs) to rectify the PCP-mediated impairment. Pre-training administration of PCP (0.5, 1, 2 or 3 mg/kg) dose-dependently interfered with memory consolidation in the PA task. In contrast, PCP was ineffective when administered after training, and immediately before the retention test indicating that NMDAR blockade interferes with memory encoding mechanisms. The typical APD haloperidol and the dopamine D_2/3 receptor antagonist raclopride failed to block the PCP-induced PA impairment suggesting a negligible role of D₂ receptors in the PCP impairment. In contrast, the memory impairment was blocked by the atypical APDs clozapine and olanzapine in a dose-dependent manner while risperidone was effective only at the highest dose tested (1 mg/kg). The PCP-induced impairment involves 5-HT_1A receptor mechanisms since the antagonist NAD-299 blocked the memory impairment caused by PCP and the ability of clozapine to attenuate the impairment by PCP. These results indicate that atypical but not typical APDs can ameliorate NMDAR-mediated memory impairments and support the view that atypical APDs such as clozapine can modulate glutamatergic memory dysfunctions through 5-HT_1A receptor mechanisms. These findings suggest that atypical APDs may improve cognitive impairments related to glutamatergic dysfunction relevant for emotional memories in schizophrenia.

Spatial learning and long-term memory impairments in RasGrf1 KO, Pttg1 KO, and double KO mice

BACKGROUND

RasGrf1 is a guanine-nucleotide releasing factor that enhances Ras activity. Human PTTG1 is an oncoprotein found in pituitary tumors and later identified as securin, a protein isolated from yeast with a reported role in chromosome separation. It has been suggested that RasGrf1 is an important upstream component of signal transduction pathways regulating Pttg1 expression and controlling beta cell development and their physiological response. At memory formation level, there are contradictory data regarding the role of RasGrf1, while Pttg1 has not been previously studied. Both proteins are expressed in the mammalian hippocampus, which is one of the key brain areas for spatial learning and memory.

OBJECTIVE

The aim of this work was to study a potential link between RasGrf1 and Pttg1 in memory formation.

METHOD

Spatial learning and memory test in the Pttg1 KO, RasGrf1 KO, and Pttg1-RasGrf1 double KO and their correspondent WT mice using a Barnes maze.

RESULTS

In comparison with the WT control mice, Pttg1 KO mice learned how to solve the task in a less efficient way, suggesting problems in memory consolidation. RasGrf1 KO mice performance was similar to controls, and they learned to use the best searching strategy. Double KO mice reached a better spatial learning level than WT.

CONCLUSION

A role for Pttg1 in memory consolidation/formation is suggested, while our RasGrf1 KO mice do not show hippocampus associated memory defects.

Positive bias for European men in peer reviewed applications for faculty position at Karolinska Institutet

Background: Sweden is viewed as an egalitarian country, still most of the professors are Swedish and only 25% are women. Research competence is evaluated using peer review, which is regarded as an objective measure in the meritocracy system. Here we update the investigation by Wold & Wennerås (1997) on women researcher’s success rate for obtaining a faculty position, by examining factors (gender, nationality, productivity, etc.) in applications for an Assistant Professorship in 2014 at Karolinska Institutet.

Methods: Fifty-six applications, 26 Swedish and 21 women applicants, were scored both on merits and projects by six external reviewers. Additional variables, including grants and academic age, calculated as the number of years since PhD excluding parental or sick leave, were gathered. Productivity was assessed by calculating a composite bibliometric score based on six factors (citations, publications, first/last authorships, H-index, high impact publication).

Results: Overall, academic age was negatively correlated with scores on merits, as assessed by peer review, although not reaching statistical significance. In men, associations between scores on merits and productivity ( P-value=0.0004), as well as having received grants ( P-value=0.009) were seen. No associations were found for women. Moreover, applicants with a background from the Middle East were un-proportionally found in the lowest quartile (Fisher exact test P-value=0.007).

Conclusions: In summary, the gender inequality shown in peer review processes in Sweden 20 years ago still exists. Furthermore, a bias for ethnicity was found. In order to keep the best scientific competence in academia, more efforts are needed to avoid selection bias in assessments to enable equal evaluations of all researchers.

Nociceptin and the NOP receptor in aversive learning in mice

The endogenous neuropeptide nociceptin (N/OFQ), which mediates its actions via the nociceptin receptor (NOP), is implicated in multiple behavioural and physiological functions. This study examined the effects of the NOP agonists N/OFQ and the synthetic agonist Ro 64-6198, the antagonists NNN and NalBzoH, as well as deletion of the Pronociceptin gene on emotional memory in mice. The animals were tested in the passive avoidance (PA) task, dependent on hippocampal and amygdala functions. N/OFQ injected intraventricularly (i.c.v.) prior to training produced a biphasic effect on PA retention; facilitation at a low dose and impairment at higher doses. Ro 64-6198 also displayed a biphasic effect with memory facilitation at lower doses and impairment at a high dose. None of the agonists influenced PA training latencies. NNN did not significantly modulate retention in the PA task but antagonized the inhibitory effects of N/OFQ. NalBzoH facilitated memory retention in a dose-dependent manner and blocked the impairing effects of N/OFQ. However, neither NNN nor NalBzoH blocked the memory-impairing effects of Ro 64-6198. Finally, the Pnoc knockout mice exhibited enhanced PA retention latencies compared to the wild type mice. The biphasic effect of the natural ligand and Ro 64-6198 and the failure of the antagonists to block the action of Ro 64-6198 indicate complexity in ligand-receptor interaction. These results indicate that brain nociceptin and its NOP has a subtle role in regulation of mechanisms of relevance for treatment of disorders with processing disturbances of aversive events e.g. Alzheimer's disease, anxiety, depression and PTSD.

Altered explorative strategies and reactive coping style in the FSL rat model of depression

Modeling depression in animals is based on the observation of behaviors interpreted as analog to human symptoms. Typical tests used in experimental depression research are designed to evoke an either-or outcome. It is known that explorative and coping strategies are relevant for depression, however these aspects are generally not considered in animal behavioral testing. Here we investigate the Flinders Sensitive Line (FSL), a rat model of depression, compared to the Sprague-Dawley (SD) rat in three independent tests where the animals are allowed to express a more extensive behavioral repertoire. The multivariate concentric square field™ (MCSF) and the novel cage tests evoke exploratory behaviors in a novel environment and the home cage change test evokes social behaviors in the re-establishment of a social hierarchy. In the MCSF test, FSL rats exhibited less exploratory drive and more risk-assessment behavior compared to SD rats. When re-exposed to the arena, FSL, but not SD rats, increased their exploratory behavior compared to the first trial and displayed risk-assessment behavior to the same extent as SD rats. Thus, the behavior of FSL rats was more similar to that of SDs when the rats were familiar with the arena. In the novel cage test FSL rats exhibited a reactive coping style, consistent with the reduced exploration observed in the MCSF. Reactive coping is associated with less aggressive behavior. Accordingly, FSL rats displayed less aggressive behavior in the home cage change test. Taken together, our data show that FSL rats express altered exploratory behavior and reactive coping style. Reduced interest is a core symptom of depression, and individuals with a reactive coping style are more vulnerable to the disease. Our results support the use of FSL rats as an animal model of depression and increase our understanding of the FSL rat beyond the behavioral dimensions targeted by the traditional depression-related tests.

Prenatal exposure to carbamazepine reduces hippocampal and cortical neuronal cell population in new-born and young mice without detectable effects on learning and memory

Pregnant women with epilepsy have to balance maternal and fetal risks associated with uncontrolled seizures against the potential teratogenic effects from antiepileptic drugs (AEDs). Carbamazepine (CBZ) is among the four most commonly used AEDs for treatment of pregnant epileptic women. We previously reported that new-born children had a decreased head circumference after in utero CBZ exposure. This study investigates how prenatal exposure of CBZ influences the number of neurons in new-born and young mouse hippocampus, amygdala and cortex cerebri. Clinical studies describe inconclusive results on if prenatal CBZ treatment influences cognition. Here we investigate this issue in mice using two well characterized cognitive tasks, the passive avoidance test and the Morris water maze test. Prenatal exposure of CBZ reduced the number of neurons (NeuN-immunoreactive cells) in the new-born mouse hippocampus with 50% compared to non-exposed mice. A reduction of neurons (20%) in hippocampus was still observed when the animals were 5 weeks old. These mice also displayed a 25% reduction of neurons in cortex cerebri. Prenatal CBZ treatment did not significantly impair learning and memory measured in the passive avoidance test and in the Morris water maze. However, these mice displayed a higher degree of thigmotaxic behaviour than the control mice. The body weight of prenatally CBZ exposed five-week old mice were lower compared to control mice not exposed to CBZ (p = 0.001). In conclusion, prenatal exposure to CBZ reduces the number of neurons dramatically in areas important for cognition such as hippocampus and cortex, without severe impairments on learning and memory. These results are in line with some clinical studies, reporting that CBZ has minor negative effects on cognition. The challenge for future studies are to segment out what possible effects a reduction of neurons could have on different types of cognition, like intellectual ability and social interaction.

The monoamine stabilizer (-)-OSU6162 attenuates voluntary ethanol intake and ethanol-induced dopamine output in nucleus accumbens

BACKGROUND

New medications for alcohol use disorder (AUD) are needed. Long-term alcohol consumption leads to a dysregulated dopamine system. A novel approach to normalize these dysregulations might be treatment with "monoamine stabilizers," a novel class of compounds characterized by the ability to either suppress, stimulate, or not influence dopamine activity depending on the prevailing dopaminergic tone.

METHODS

The effects of the monoamine stabilizer (-)-OSU6162 (OSU6162) on voluntary ethanol intake and ethanol withdrawal symptoms were evaluated in rats voluntarily consuming ethanol for at least 3 months before testing. Furthermore, effects of OSU6162 on ethanol seeking behavior were evaluated with the progressive ratio and cue-induced reinstatement paradigms. Finally, the interaction of OSU6162 with ethanol on dopamine output and metabolism was studied with microdialysis.

RESULTS

The OSU6162 attenuated several ethanol-mediated behaviors, including voluntary ethanol consumption, ethanol withdrawal symptoms, operant ethanol self-administration under progressive ratio schedule, and cue-induced reinstatement of ethanol seeking in rats that had voluntarily consumed ethanol for at least 3 months before treatment. In addition, OSU6162 blunted ethanol-induced dopamine output in nucleus accumbens of ethanol-naïve rats.

CONCLUSIONS

These results highlight the ability of OSU6162 to stabilize dopamine activity depending on the prevailing dopaminergic tone and indicate that OSU6162 might decrease ethanol intake by attenuating the acute rewarding properties of ethanol. In addition, OSU6162 might have potential to prevent relapse triggered by alcohol craving, alcohol related cues, and or an urge to relieve abstinence symptoms. The present study is to our knowledge the first indicating that OSU6162 might serve as a novel medication for AUD.

Student attitudes towards computer-aided testing

INTRODUCTION

  Computer-aided learning (CAL) is a viable alternative to traditional teaching methods. While CAL is used for teaching only, computer-aided testing (CAT) can be applied as a computer-based examination method. The aim of the present study was to evaluate students' attitude towards CAT as compared to written multiple choice tests.

MATERIALS AND METHODS

  Forty-one undergraduate dental students underwent a mock examination consisting of 15 written multiple choice questions and 15 questions delivered using the interactive MobiTed® system. A questionnaire based on an eight-item seven-point Likert scale was used to evaluate the students' attitude towards CAT. The students' performance in both tests was analysed using paired t-tests. Correlations between test performance and questionnaire were expressed by Pearson correlation coefficients.

RESULTS

  Despite study-design-related differences, students' test performance between written multiple choice and MobiTed® was comparable. No correlations between test results and questionnaire could be set up. Students rated MobiTed® to be equivalent to written multiple choice and had no difficulties with the CAT set up. The pre-defined sequence of questions with each question being shown only once was considered to be a major disadvantage of the CAT system. Complex questions should be displayed longer compared to short questions.

DISCUSSION

  Computer-aided testing appeared to be equivalent to written multiple choice tests not only in terms of student performance but also to their perception. This is consistent with previous studies.

CONCLUSIONS

  Interactive multiple choice tests may provide an alternative to written tests, but should allow examinees to have control over the sequence, as well as the length of time the questions are displayed.

Dental anxiety--an epidemiological study on its clinical correlation and effects on oral health

Pronounced dental anxiety could lead to avoidance strategies to evade dental visits. The aim of the present epidemiological study was to investigate the prevalence and related oral disease patterns of dental anxiety in young adult male soldiers. Therefore, the intensity and frequency of dental anxiety are presented and the correlation with oral clinical findings are evaluated. Three hundred seventy-four soldiers who underwent a compulsory dental check-up were randomly assigned to this study. Psychological parameters were collected based on a protocol integrating the Dental Anxiety Scale (DAS) and the Gatchell Fear Scale (GaFS). Patient-based measures included D3,4MF-scores for dental status and the Community Periodontal Index of Treatment Need (CPITN) for periodontal status. Thirty-two individuals (8.6%) showed DAS-scores of 13 or 14 (anxious), while 4.6% had a DAS-score > or = 15 (highly anxious/phobic). Highest DAS-values were measured among patients' aged 19-29 (n = 262). DMFS-values of anxious and less anxious patients showed only minor differences. However, anxious patients had significantly more carious lesions (P < 0.001). CPITN periodontal values showed no significant differences between both groups. 89.2% of less anxious individuals and 79.6% of anxious patients went for regular dental check-ups. Thus, every tenth patient was considered to have high dental anxiety. Anxiety results in avoidance behaviour, which can only be discovered upon compulsory examinations and which is associated with higher caries morbidity and need for oral rehabilitation. As anxiety has a direct influence on oral health, it should be detected and accounted for in a treatment concept integrating dental and cognitive-behavioural therapeutic approaches.

Comparison between computer-aided testing and traditional multiple choice: an equivalence study

AIMS

Computer-aided learning (CAL) is a viable alternative to traditional teaching methods. While CAL is used for teaching only, computer-aided testing (CAT) can be applied as a computer-based examination method. The aim of the present study was to compare the performance of undergraduate students in computer-interactive tests and traditional multiple choice tests and to evaluate the influence of question length and language skills on test results.

MATERIALS AND METHODS

Fifty-two native German-speaking students and five non-native speaking students were randomly assigned to two groups. They were required to answer 20 conventional multiple choice questions and 20 questions using the interactive MobiTed system. An analysis of variance and t-tests (alpha = 0.05) were used to compare scores.

RESULTS

Non-native speakers scored significantly lower on the interactive test compared with the native speaking students (P = 0.048 for long questions and P = 0.003 for short questions). There were no significant group differences on the conventional multiple choice test (P = 0.052 for long questions and P = 0.089 for short questions). Based on the results of the native speaking students neither test method nor question length had an influence on overall performance.

CONCLUSION

Interactive multiple choice tests may provide an alternative to written tests, especially when considering time expenditure. Language skills and question length should be taken into account when setting time limits for examination.

Changes in neurophysiologic parameters in a patient with dental anxiety by hypnosis during surgical treatment

It was hypothesized that dental anxiety, which leads to neurophysiologic alterations in heart rate, respiratory rate and blood pressure prior, during and subsequent to dental treatment, can be influenced by medical hypnosis. We report the positive impact from non-invasive hypno-sedation during dental implant surgery on a 54-year-old female patient who experienced neurophysiologic reactions as a result of the psychosomatic process of dental anxiety (dental anxiety scale value = 13). The neurophysiologic changes during dental surgery performed with and without hypnosis were compared after the patient underwent the same surgical treatment protocol. This case report was part of a study designed to evaluate hypnosis as a non-invasive therapy for dental-anxious patients over six sessions using subjective experience and objective parameters, which included electroencephalogram, electrocardiogram, heart rate, blood pressure, oxygen saturation of the blood, respiration rate, salivary cortisol concentration and body temperature.

Expression of interleukin 1-beta, transforming growth factor beta-1, and vascular endothelial growth factor in soft tissue over the implant before uncovering

BACKGROUND

Overexpression of inflammatory cytokines interleukin 1-beta (IL-1beta), transforming growth factor beta-1 (TGF-beta1), and vascular endothelial growth factor (VEGF) may cause healing impairment following implant insertion, jeopardizing success especially in patients previously irradiated. Limited data is available regarding expression pattern of inflammatory cytokines in peri-implant soft tissue caused by the surgical intervention itself.

STUDY DESIGN

This study examined 21 patients receiving dental implants. Biopsies of peri-implant tissue were harvested at re-entry 4 months after initial surgery. Eight patients underwent probing of untreated mucosa. Three groups were created (group 1: regular peri-implant mucosa; group 2: patients with irradiated peri-implant mucosa, radiation treatment due to oral squamous cell cancer; group 3: control). Immunohistochemical staining was performed for TGFss1, IL-1ss, and VEGF.

RESULTS

Following the placement of dental implants (group 1 vs group 3) a significant increase (P > .05) in TGF-beta1, IL-1beta, and VEGF expression in the peri-implant mucosa was demonstrated. No alteration of this distinct pattern was found for previously irradiated tissue (group 1 vs. group 2).

CONCLUSIONS

The study highlights the fundamental involvement of TGF-beta1, IL-1beta, and VEGF during the regeneration of peri-implant soft tissue structures. The use of extended interim solutions may be one clinical implication of these prolonged tissue remodeling processes.

Massage-like stroking influences plasma levels of gastrointestinal hormones, including insulin, and increases weight gain in male rats

The aim of the present study was to investigate the effects of repeated massage-like stroking on plasma levels of some gastrointestinal hormones, insulin included, glucose and weight gain. For this purpose, male rats were exposed to stroking on the ventral side of the abdomen for 3 or 14 times. The treatments were given every second day. Control rats were picked up at the same time but received no stroking. Body weight was measured regularly. Rats were decapitated 10 min after the last treatment. Hormone levels were radioimmunoassayed and glucose was measured by spectrophotometry. In rats exposed to 3 sessions of massage-like stroking plasma levels of insulin (p<0.05) and somatostatin (p<0.01) were significantly decreased 10 min after the last treatment. After 14 treatments of massage-like stroking, decreased plasma levels of insulin (p<0.01) and gastrin (p<0.01) as well as increased glucose levels (p<0.01) were observed 10 min after the last treatment. In addition, weight gain was significantly increased (ANOVA p<0.0001) in rats exposed to 14 treatments. In conclusion, repeated massage-like stroking decreased plasma levels of gastrin, insulin and somatostatin, increased plasma levels of glucose and promoted weight gain. The effects were influenced by the number of treatments.

Postnatal oxytocin treatment and postnatal stroking of rats reduce blood pressure in adulthood

The aim of the present study was to investigate the effects of postnatal oxytocin (OT) treatment and postnatal stroking on blood pressure and heart rate in adult rats. For this purpose, rats were treated subcutaneously with OT (1 mg/kg) once a day on days 1-14 after birth, or exposed to stroking on the ventral side of the abdomen for 5 min once a day on days 1-7 after birth. Blood pressure and heart rate were measured at the age of 7-8 months. The OT-treated male rats had a significantly reduced diastolic blood pressure in adulthood (p < 0.001), and in the female rats, both systolic (p < 0.01) and diastolic blood pressures (p < 0.001) were significantly lower compared to controls given saline postnatally. OT reduced blood pressure also in prenatally stressed female rats, which had a significantly higher blood pressure in adulthood compared to control rats that had not been exposed to prenatal stress. Also, the postnatal stroking reduced diastolic blood pressure in adulthood (p < 0.05). No changes in heart rate were found. In conclusion, both postnatal OT treatment and postnatal stroking reduced blood pressure in adulthood. In addition, in female rats, OT reduced the increase in blood pressure caused by prenatal stress.

Indole-3-pyruvic and -propionic acids, kynurenic acid, and related metabolites as luminophores and free-radical scavengers

Chemiluminescence associated with oxidation by free radicals was investigated in an alkaline, hemin-catalysed hydrogen peroxide system, using the following tryptophan metabolites as radical scavengers: indole-3-pyruvic, indole-3-propionic, kynurenic, xanthurenic and quinaldic acids and 4-hydroxy-quinoline. Light emission from oxidation of the indolic compounds was only partially inhibited by the hydroxyl-radical scavenger DMSO, but strongly suppressed by the superoxide-anion scavenger Tiron, whereas chemi-luminescence generated from kynurenic acid was strongly inhibited by either of these compounds. Light emission from oxidation of kynurenic acid lasts for a surprisingly long period of time: At 0.4 mM and 20 degrees C, luminescence increased for 5 hours and continued at a high rate for more than a day. Comparison of structural analogues indicated that the 4-hydroxyl and carboxyl groups of kynurenic acid are essential for effective light emission, and that an additional 8-hydroxyl residue leading to an intramolecular hydrogen bond diminishes the reaction rate.

Fulguration-ablation of atypical accessory urethra

A male adolescent presented with perineal dribbling during voiding. Evaluation revealed an accessory urethra originating from the prostatic urethra. There was persistent anatomical and functional dominance of the dorsal orthotopic urethra, constituting a reversal of the arrangement most commonly described for urethral duplication. Successful ablation of the accessory urethra was accomplished by electrofulguration. The salient features of urethral duplication are reviewed.

Pyelo-choledochal fistula accompanying operative cholangiography

Fistulous communications between the biliary system and the urinary tract are encountered infrequently and, routinely, they are associated with operative dissections involving both systems. We report a case of opacification of the right renal collecting system during cholangiography following uneventful cholecystectomy. Prompt spontaneous resolution was verified by subsequent excretory urography.