Recommendations for the prevention and treatment of postpartum depression

Epidemiological data clearly indicate that depression is becoming an increasingly important health and social problem today. According to the World Health Organization (WHO), depression currently affects 350 million people worldwide and is considered the second most common cause of disability in Europe after ischemic heart disease. It is estimated that this health problem may affect as many as five million people in Poland. The gap between the reported number of patients treated and the prevalence of depression, highlights the scale of unmet needs. With the limited availability of specialists in psychiatric care, the most appropriate measures seem to be those aimed at increasing the competence of doctors of other specialties in the diagnosis and treatment of depression. Early detection and treatment results in faster remission, reduces relapses and mortality. The recommendations concerning prevention of depression were commissioned by the Polish Ministry of Health as a part of the Depression Prevention Program for 2016-2020. The Program has developed recommendations addressed to specialists in various fields of medicine, other than psychiatry, focusing on three risk groups: children and adolescents, women in the perinatal period and the elderly. These recommendations focus on the management of suspected postpartum depression and provide specific guidelines for medical staff having contact with pregnant and postpartum women (gynecologists, midwives, pediatricians).

Cost of Relapse Management in Patients with Schizophrenia in Italy and Spain: Comparison Between Lurasidone and Quetiapine XR

BACKGROUND AND OBJECTIVE

Schizophrenia is a low-prevalence mental disorder with a global age-standardized prevalence of 21 million people (2016). Second-generation antipsychotics (lurasidone and quetiapine XR) are recommended as the first-line treatment for schizophrenia. It is interesting to investigate how the results of clinical studies translate into direct medical costs. The objective of this analysis was to assess the direct medical costs related to pharmaceutical treatments and the management of relapses in patients affected with schizophrenia treated with lurasidone (74 mg) vs quetiapine XR (300 mg) assuming the Italian and Spanish National Health Service perspective.

METHODS

A health economic model was developed based on a previously published model. The analysis considered direct medical costs related to the pharmacological therapies and inpatient or outpatient management of relapses (direct medical costs referred to 2019). The probability of relapses and related costs were derived from two systematic reviews. A deterministic sensitivity analysis was implemented to test the robustness of the results.

RESULTS

The use of lurasidone (74 mg) compared with quetiapine XR (300 mg) would lead to a reduction in direct medical costs in Italy and Spain, with a lower cost per patient of - 163.7 € (- 9.0%) and - 327.2 € (- 22.7%), respectively. In detail, it would lead to an increase in the cost of therapy of + 53.8% and of + 30.5% in Italy and Spain, respectively, to a decrease in the cost of relapses with hospitalization of - 135.7%, and to an increase in the cost of relapses without hospitalization of + 24.5%.

CONCLUSIONS

The use of lurasidone (74 mg) for the treatment of patients affected with schizophrenia, compared with quetiapine XR (300 mg), would be a cost-saving strategy in the two contexts investigated assuming the National Health Service point of view.

Intergenerational implications of alcohol intake: metabolic disorders in alcohol-naïve rat offspring

Alcohol drinking may be associated with an increased risk of various metabolic diseases. Rat lines selectively bred for alcohol preference and alcohol avoidance constitute an interesting model to study inherited factors related to alcohol drinking and metabolic disorders. The aim of the present study was to compare the levels of selected laboratory biomarkers of metabolic disorders in blood samples from naïve offspring of Warsaw alcohol high-preferring (WHP), Warsaw alcohol low-preferring (WLP), and wild Wistar rats. Blood samples were collected from 3-month old (300–350 g) alcohol-naïve, male offspring of WHP (n = 8) and WLP rats (n = 8), as well as alcohol-naïve, male, wild Wistar rats. Markers of metabolic, hepatic, and pancreatic disorders were analysed (levels of homocysteine, glucose, total cholesterol, triglycerides and γ-glutamyl transferase (GGT), aspartate (AST), alanine aminotransferase (ALT), and amylase serum activities). Alcohol-naïve offspring of WHP, WLP, and wild Wistar rats differed significantly in the levels of triglycerides, total cholesterol, homocysteine, as well as in the activity of GGT, ALT, AST, and amylase enzymes. Most markers in the alcohol-naïve offspring of WHP rats were altered even thought they were never exposed to alcohol pre- or postnatally. This may suggest that parental alcohol abuse can have a detrimental influence on offspring vulnerability to metabolic disorders.

Chronic stress changes prepulse inhibition after amphetamine challenge: the role of the dopaminergic system

The goal of this research was to examine the influence of chronic mild stress (CMS) on prepulse inhibition (PPI). We used an amphetamine challenge to study the role of the dopaminergic system in limbic structures. Chronic stress caused a reduction in both sucrose preference and body weight. It was found that the initially strong response to amphetamine in the control rats was weakened after stress on both the behavioural and biochemical levels: improved PPI, decreased dopamine D2 receptor expression in the central nucleus of amygdala (CeA) and nucleus accumbens (NAC), and decreased dopamine and 3-MT (3-methoxytyramine) levels in NAC. We observed that the stress-evoked attenuation of amphetamine-induced stimulation was also paralleled by changes in corticosterone level. These effects were accompanied by a decrease in both glutamate and the glutamate/gamma-aminobutric acid (GABA) ratio in the NAC. The interpretation of these results is that prolonged stress induces compensatory mechanisms in the mesolimbic system which are responsible for psychostimulant (amphetamine) effects.

Catechol-O-Methyltransferase Val158Met Polymorphism and Clinical Response to Antipsychotic Treatment in Schizophrenia and Schizo-Affective Disorder Patients: a Meta-Analysis

BACKGROUND

The catechol-O-methyltransferase (COMT) enzyme plays a crucial role in dopamine degradation, and the COMT Val158Met polymorphism (rs4680) is associated with significant differences in enzymatic activity and consequently dopamine concentrations in the prefrontal cortex. Multiple studies have analyzed the COMT Val158Met variant in relation to antipsychotic response. Here, we conducted a meta-analysis examining the relationship between COMT Val158Met and antipsychotic response.

METHODS

Searches using PubMed, Web of Science, and PsycInfo databases (03/01/2015) yielded 23 studies investigating COMT Val158Met variation and antipsychotic response in schizophrenia and schizo-affective disorder. Responders/nonresponders were defined using each study's original criteria. If no binary response definition was used, authors were asked to define response according to at least 30% Positive and Negative Syndrome Scale score reduction (or equivalent in other scales). Analysis was conducted under a fixed-effects model.

RESULTS

Ten studies met inclusion criteria for the meta-analysis. Five additional antipsychotic-treated samples were analyzed for Val158Met and response and included in the meta-analysis (ntotal=1416). Met/Met individuals were significantly more likely to respond than Val-carriers (P=.039, ORMet/Met=1.37, 95% CI: 1.02-1.85). Met/Met patients also experienced significantly greater improvement in positive symptoms relative to Val-carriers (P=.030, SMD=0.24, 95% CI: 0.024-0.46). Posthoc analyses on patients treated with atypical antipsychotics (n=1207) showed that Met/Met patients were significantly more likely to respond relative to Val-carriers (P=.0098, ORMet/Met=1.54, 95% CI: 1.11-2.14), while no difference was observed for typical-antipsychotic-treated patients (n=155) (P=.65).

CONCLUSIONS

Our findings suggest that the COMT Val158Met polymorphism is associated with response to antipsychotics in schizophrenia and schizo-affective disorder patients. This effect may be more pronounced for atypical antipsychotics.

Pharmacogenetics of adverse events in schizophrenia treatment: comparison study of ziprasidone, olanzapine and perazine

The primary aim of the present study was to assess the possible associations between dopaminergic, serotonergic, and glutamatergic system-related genes and adverse events after antipsychotic treatment in paranoid schizophrenia patients. The second aim of the study was to compare the intensity of these symptoms between atypical (ziprasidone and olanzapine) and typical (perazine) antipsychotic drugs. One-hundred and ninety-one Polish patients suffering from paranoid schizophrenia were genotyped for polymorphisms of DRD2, DAT1, COMT, MAOA, SERT, 5HT2A, and GRIK3. The patients were randomized to treatment with perazine, olanzapine or ziprasidone monotherapy for 3 months. The intensity of side effects (changes in body weights and extrapyramidal symptoms (EPS)) was measured at baseline and after 12 weeks of antipsychotic treatment. After 3 months of therapy, the weight increase was the greatest in the group treated with olanzapine and the least in the group treated with ziprasidone. None of the examined gene polymorphisms was associated with the body weight changes. Perazine treatment was associated with the significantly highest intensity of EPS. None of the examined polymorphisms was associated with the changes in extrapyramidal adverse events after antipsychotic treatment. The selected polymorphisms are not primarily involved in changes in body weights and EPS related to antipsychotic treatment in paranoid schizophrenia patients.

ADN-1184 a monoaminergic ligand with 5-HT(6/7) receptor antagonist activity: pharmacological profile and potential therapeutic utility

BACKGROUND AND PURPOSE

Many dementia patients exhibit behavioural and psychological symptoms (BPSD) that include psychosis, aggressivity, depression and anxiety. Antipsychotic drugs are frequently prescribed but fail to significantly attenuate mood deficits, may interfere with cognitive function and are associated with motor and cardiac side effects, which are problematic in elderly patients. A need therefore exists for drugs that are better suited for the treatment of BPSD.

EXPERIMENTAL APPROACH

We used in vitro cellular and in vivo behavioural tests to characterize ADN-1184, a novel arylsulfonamide ligand with potential utility for treatment of BPSD.

KEY RESULTS

ADN-1184 exhibits substantial 5-HT6 /5-HT7 /5-HT2A /D2 receptor affinity and antagonist properties in vitro. In tests of antipsychotic-like activity, it reversed MK-801-induced hyperactivity and stereotypies and inhibited conditioned avoidance response (MED = 3 mg·kg(-1) i.p.). Remarkably, ADN-1184 also reduced immobility time in the forced swim test at low doses (0.3 and 1 mg·kg(-1) i.p.; higher doses were not significantly active). Notably, up to 30 mg·kg(-1) ADN-1184 did not impair memory performance in the passive avoidance test or elicit significant catalepsy and only modestly inhibited spontaneous locomotor activity (MED = 30 mg·kg(-1) i.p.).

CONCLUSIONS AND IMPLICATIONS

ADN-1184 combines antipsychotic-like with antidepressant-like properties without interfering with memory function or locomotion. This profile is better than that of commonly used atypical antipsychotics tested under the same conditions and suggests that it is feasible to identify drugs that improve BPSD, without exacerbating cognitive deficit or movement impairment, which are of particular concern in patients with dementia.

The effect of selected polymorphisms of the dopamine receptor gene DRD2 and the ANKK-1 on the preference of concentrations of sucrose solutions in men with alcohol dependence

BACKGROUND

The aim of the study was to determine the influence of DRD2 gene polymorphisms in exon 8 G/A (rs 6276) in the promoter region -141 C Ins/Del (rs1799732) and the influence of ANKK-1 gene Taq-1A polymorphism (rs 1800497) on the preference of increasing sucrose concentrations in men with alcohol dependence.

SUBJECTS AND METHODS

63 male patients with alcohol dependence were genotyped for the above polymorphisms. Their preference for increasing sucrose concentrations was tested and their taste intensity perception of sucrose solutions was assessed. The patients were tested with the 'Sniffin' Sticks' olfactory test.

RESULTS

We found a statistically significant association between some alleles of ANKK 1 gene Taq 1A polymorphisms and sucrose preference in the subjects. The A1 Taq 1A allele determined hedonistic response to the two highest concentrations of sucrose. No association was found regarding the other two polymorphisms (in the promoter region and in the exon 8 of the DRD2 gene).

CONCLUSIONS

Study results suggest Taq-1A polymorphism plays a role in the preference to high concentrations of sucrose and its potential association with alcohol dependence pathogenesis.

Pharmacological characteristics of zolpidem-induced catalepsy in the rat

Zolpidem is a non-benzodiazepine hypnotic drug acting preferentially at α1-containing GABAA receptors expressed in various parts of the brain, including the basal ganglia. The aim of the present study was to provide preliminary characteristics of zolpidem-induced catalepsy in Wistar rats. Zolpidem (2.5-10.0mg/kg), but not diazepam and midazolam, produced dose-dependent cataleptic responses in the bar test, which were similar to those produced by a reference antipsychotic drug, haloperidol. Zolpidem-induced catalepsy was abolished by a benzodiazepine site antagonist, flumazenil (5.0mg/kg), D2/3 receptor agonist, quinpirole (1.0mg/kg), and a non-competitive NMDA receptor antagonist, MK-801 (0.1mg/kg), but not by a non-selective opioid receptor antagonist, naltrexone (3.0mg/kg). The present results indicate that systemic injections of zolpidem may produce short-lasting, neuroleptic-like catalepsy in the rat.

Mesh retraction correlates with vaginal pain and overactive bladder symptoms after anterior vaginal mesh repair

INTRODUCTION AND HYPOTHESIS

The aim of the present study was to determine possible correlations between mesh retraction after anterior vaginal mesh repair and de novo stress urinary incontinence (SUI), overactive bladder (OAB), and vaginal pain symptoms.

METHODS

One hundred and three women with symptomatic prolapse of the anterior vaginal wall, stages 3 and 4 based on the Pelvic Organ Prolapse Quantification (POP-Q) system, underwent Prolift anterior™ implantation. At a 6-month follow-up, the patients were interviewed for de novo SUI, OAB, and vaginal pain, and underwent an introital/transvaginal ultrasound examination to measure the mesh length in the midsagittal plane.

RESULTS

Mesh retraction was significantly larger in a subgroup of patients (n = 20; 19.4 %) presenting de novo OAB symptoms on the follow-up assessment compared with those without this complication (5.0 cm vs. 4.3 cm; p < 0.05). Mesh retraction was also significantly larger in a subgroup of patients (n = 23; 22.3 %) reporting postoperative vaginal pain compared with the women who did not report any postoperative vaginal pain (5.3 cm vs. 4.2 cm; p < 0.01). A significant correlation was found between mesh retraction and the severity of vaginal pain (R = 0.4, p < 0.01). Mesh retraction did not differ between patients with de novo SUI symptoms and those without this complication.

CONCLUSIONS

Mesh retraction assessed on ultrasound examination after anterior vaginal mesh repair may correlate with de novo OAB symptoms and vaginal pain.

Increased ethanol intake and preference in cyclin D2 knockout mice

Inhibitory effects of passive ethanol exposure on brain neurogenesis have been extensively documented in animal models. In contrast, a role of brain neurogenesis in ethanol self-administration has not been addressed, as yet. The aim of this study was to assess intake of, and preference for, ethanol solutions [2-16% (v/v)] in a mouse model of adult neurogenesis deficiency based on permanent knockout (KO) of cyclin D2 (Ccnd2). Wild type (WT) and Ccnd2 KO mice did not differ in 2% and 4% ethanol intake. The KO group consumed significantly more ethanol in g/kg when offered with 8% or 16% ethanol as compared with the WT controls. The WT and KO mice did not differ in 2% ethanol preference, but the KO group showed a significantly higher preference for 4-16% ethanol. Animal and human studies have suggested that the low level of response to the sedative/hypnotic effects of alcohol is genetically associated with enhanced alcohol consumption. However, in this study, there were no between-genotype differences in ethanol-induced loss of righting reflex. Previous reports have also suggested that high ethanol intake is genetically associated with the avidity for sweets and better acceptance of bitter solutions. However, the KO and WT mice consumed similar amounts of saccharin solutions and the KOs consumed less quinine (i.e. bitter) solutions as compared with the WTs. In conclusion, these results may indicate that Ccnd2 and, possibly, brain neurogenesis are involved in central regulation of ethanol intake in mice.

Neonatal administration of thimerosal causes persistent changes in mu opioid receptors in the rat brain

Thimerosal added to some pediatric vaccines is suspected in pathogenesis of several neurodevelopmental disorders. Our previous study showed that thimerosal administered to suckling rats causes persistent, endogenous opioid-mediated hypoalgesia. Here we examined, using immunohistochemical staining technique, the density of μ-opioid receptors (MORs) in the brains of rats, which in the second postnatal week received four i.m. injections of thimerosal at doses 12, 240, 1,440 or 3,000 μg Hg/kg. The periaqueductal gray, caudate putamen and hippocampus were examined. Thimerosal administration caused dose-dependent statistically significant increase in MOR densities in the periaqueductal gray and caudate putamen, but decrease in the dentate gyrus, where it was accompanied by the presence of degenerating neurons and loss of synaptic vesicle marker (synaptophysin). These data document that exposure to thimerosal during early postnatal life produces lasting alterations in the densities of brain opioid receptors along with other neuropathological changes, which may disturb brain development.

Reliability and clinical validity of a Polish version of the CONTILIFE: a quality of life questionnaire for urinary incontinence

INTRODUCTION AND HYPOTHESIS

The primary aim of the study was to translate and validate a Polish version of the CONTILIFE, a quality of life questionnaire. The clinical validity of the CONTILIFE was assessed against the number of urinary leaks, Valsalva leak point pressure (VLPP), and maximum urethral closure pressure (MUCP).

METHODS

One hundred women with stress urinary incontinence completed a Polish version of the CONTILIFE twice with a 4-day interval.

RESULTS

Internal consistency (Cronbach's alpha= 0.94) and test-retest reliability of the instrument (ICC = 0.96) were very good. A significant relationship was found between all the CONTILIFE dimension scores, the CONTILIFE global score, and the number of urinary leaks per week. A less significant relationship was found between VLPP, MUCP, and CONTILIFE dimension and global scores.

CONCLUSIONS

A Polish version of the CONTILIFE can be a reliable measure of quality of life in stress urinary incontinence patients.

Neonatal administration of a vaccine preservative, thimerosal, produces lasting impairment of nociception and apparent activation of opioid system in rats

Thimerosal (THIM), an organomercury preservative added to many child vaccines is a suspected factor in pathogenesis of neurodevelopmental disorders. We examined the pharmacokinetics of Hg in the brain, liver and kidneys after i.m. THIM injection in suckling rats and we tested THIM effect on nociception. THIM solutions were injected to Wistar and Lewis rats in a vaccination-like mode on PN days 7, 9, 11 and 15 in four equal doses. For Wistar rats these were: 12, 48, 240, 720, 1440, 2160, 3000 microg Hg/kg and for Lewis: 54, 216, 540 and 1080 microg Hg/kg. Pharmacokinetic analysis revealed that Hg from THIM injections accumulates in the rat brain in significant amounts and remains there longer than 30 days after the injection. At the 6th week of age animals were examined for pain sensitivity using the hot plate test. THIM treated rats of both strains and sexes manifested statistically significantly elevated pain threshold (latency for paw licking, jumping) on a hot plate (56 degrees C). Wistar rats were more sensitive to this effect than Lewis rats. Protracted THIM-induced hypoalgesia was reversed by naloxone (5 mg/kg, i.p.) injected before the hot plate test, indicative of involvement of endogenous opioids. This was confirmed by augmented catalepsy after morphine (2.5 mg/kg, s.c.) injection. Acute THIM injection to 6-week-old rats also produced hypoalgesia, but this effect was transient and was gone within 14 days. Present findings show that THIM administration to suckling or adult rats impairs sensitivity to pain, apparently due to activation the endogenous opioid system.

The effects of fatty acid amide hydrolase inhibitors on maintenance of cocaine and food self-administration and on reinstatement of cocaine-seeking and food-taking behavior in rats

Some empirical evidence suggests that the endocannabinoids (eCB) (e.g. anandamide) may play an important role in cocaine addiction. The eCB act as a retrograde messengers activating CB receptors at the presynaptic membrane and are degraded by enzymatic actions of fatty acid amide hydrolase (FAAH). The present study aimed to examine the effect of the FAAH inhibitors, phenylmethylsulphonyl fluoride (PMSF; i.p.) or cyclohexylcarbamic acid 3-carbamoyl biphenyl-3-yl ester (URB597; i.p.) on the cocaine- or food-maintained self-administration as well as on the cocaine-seeking or food-taking behaviors in rats. Male Wistar rats were implanted with a catheter (iv.) and trained to self-administer cocaine (0.5 mg/kg/infusion) on a fixed ratio 5 schedule of reinforcement with a conditioned stimulus (tone+light). After self-administration stabilized, extinction/reinstatement procedures were carried out during which the rats were tested for the response reinstatement induced by cocaine (10 mg/kg, ip) or a cue (light+tone). The food (sweetened milk) self-administration and extinction/reinstatement procedures were conducted in a manner resembling cocaine self-administration. Neither PMSF (30-120 mg/kg) nor URB597 (0.1-3 mg/kg) affected cocaine self-administration. PMSF, 60 mg/kg, significantly reduced cocaine-induced reinstatement and at 120 mg/kg (combined with the challenge dose of cocaine) it evoked behavioral disruption. PMSF (60-120 mg/kg) dose-dependently inhibited cue-induced reinstatement. URB597 (1-3 mg/kg) attenuated both cocaine- and cue-induced drug-seeking behaviors. PMSF (60 mg/kg) decreased food self-administration. Toward reinstatement of food-taking behavior PMSF (60-120 mg/kg) and URB597 (3 mg/kg) showed inhibitory effects. Our results indicate that FAAH inhibitors could be potent modulators of motivational and conditioned aspects of goal-directed behaviors with less prominent effects on consumatory behaviors.

A protein synthesis inhibitor, cycloheximide does not alter cue-induced reinstatement of saccharin seeking

A large body of evidence indicates that reactivation of aversive memories leads to protein synthesis-dependent memory reconsolidation which can be disrupted by cycloheximide and other protein synthesis inhibitors. The aim of the present study was to investigate whether cycloheximide would alter reconsolidation of the associations involving discrete cues paired with a sweet reward in an appetitive instrumental task. Rats trained to lever press for 0.1% saccharin were repeatedly tested for cue-induced reinstatement of non-reinforced responding for saccharin. CHX (3 mg/kg, s.c.) or its vehicle was injected immediately after each reinstatement session. The protein synthesis inhibitor did not alter the ability of the saccharin-paired cues to reinstate saccharin seeking. The present results suggest that passive re-exposure to saccharin-paired discrete cues in the reinstatement procedure does not lead to any cycloheximide-sensitive reconsolidation of the original associations.

History of cocaine self-administration alters morphine reinforcement in the rat

It has been shown repeatedly that cocaine pre-exposure may sensitise neurochemical and behavioural responses to opioid drugs. The aim of the present study was to investigate effects of a prior history of cocaine self-administration on morphine reinforcement in the rat. Male Sprague-Dawley rats were allowed to acquire intravenous cocaine self-administration (0.3 mg/kg/infusion) for 20 days. When operant responding for cocaine had stabilised, morphine was introduced instead of cocaine in the next self-administration session. One group of cocaine-exposed rats was allowed to respond for 0.56 mg/kg/infusion of morphine (i.e. the dose which was willingly self-administered by drug-naive controls). The second group was allowed to respond for 0.056 mg/kg/infusion of morphine (i.e. the dose which did not maintain self-administration behaviour in the drug-naive rats). The subjects with the history of cocaine self-administration, in contrast to the drug-naive group, did not maintain operant responding for 0.56 mg/kg/infusion of morphine. These rats easily self-administered the ten times lower dose of the opioid (0.056 mg/kg/infusion). An opioid receptor antagonist, naltrexone (1 mg/kg i.p.) restored the positive reinforcing properties of the higher dose of morphine in the cocaine-exposed rats. Concluding, the present results suggest that prior history of cocaine self-administration sensitises rats to the positive reinforcing properties of morphine.

Rapid and robust protection against cocaine-induced lethality in rats by the bacterial cocaine esterase

There is no approved means to prevent the toxic actions of cocaine. Cocaine esterase (CocE) is found in a rhodococcal strain of bacteria that grows in the rhizosphere soil around the coca plant and has been found to hydrolyze cocaine in vitro. The esteratic activity of CocE (0.1-1.0 mg, i.v.) was characterized and confirmed in vivo by assessing its ability to prevent cocaine-induced convulsions and lethality in the rat. The therapeutic efficiency of the enzyme was demonstrated by the increasing dose of cocaine (100-1000 mg/kg, i.p.) required to produce toxic effects after a single intravenous injection of CocE. The enzyme demonstrated rapid kinetics for cocaine degradation in rat and human serum. Two catalytically inactive mutants of CocE (S117A or Y44F) failed to protect rats from the toxic effects of cocaine, confirming the protective effects are due to hydrolytic activity. However, butyrylcholinesterase, an endogenous cocaine-hydrolyzing enzyme, was inactive (1.3-13 mg, i.v.) in this rat toxicity procedure. Furthermore, CocE did not block the lethality of WIN-35065-2 (560 mg/kg, i.p.), a cocaine analog that lacks the benzoyl ester moiety targeted by CocE. This characterization of CocE provides preliminary evidence that the enzyme could serve as a suitable antidote to cocaine toxicity in humans.

Cycloheximide impairs acquisition but not extinction of cocaine self-administration

The aim of the present study was to assess the role of de novo protein synthesis in the acquisition and extinction of cocaine self-administration. In a first experiment, rats were trained to respond for intravenous cocaine infusions (0.3 mg/kg) and a protein synthesis inhibitor, cycloheximide (CHX; 3 mg/kg, s.c.) was injected immediately after each self-administration session. In a second experiment, rats were allowed to acquire cocaine self-administration and CHX was injected immediately after subsequent extinction sessions. CHX impaired the acquisition, but not extinction, of cocaine self-administration. In control experiments, CHX (3 mg/kg) blocked c-Fos protein expression after foot-shock stress and impaired the acquisition of conditioned freezing but did not inhibit spontaneous locomotor activity and sucrose drinking. Our results suggest that: i) the acquisition and extinction of cocaine-reinforced behaviour have a different molecular basis; and ii) only the former process requires de novo protein synthesis.

A prospective study of the financial costs of multiple sclerosis at different stages of the disease

The aim of our study was to estimate the costs of multiple sclerosis (MS) in Poland according to severity of disease. Total, direct and indirect costs were compared in 148 patients divided into three groups categorized by disease severity: stage I Expanded Disability Status Scale (EDSS <3.5), stage II (EDSS 4.0-6.0) and stage III (EDSS >6.5). Cost evaluation was performed from the societal perspective and covered the 5-month period. Simple sensitivity analysis was performed by varying the tariffs and valuing caregiving at 40% of the average wage. The mean total cost/patient for 5 months was estimated at 10,955, 15, 603 and 18, 464 PLN for stage I, II and III, respectively [exchange rate: 4 PLN=1 EUR; purchasing power pariety: 1 EUR=2.05 PLN] (P <0.0001). Regardless of EDSS stage indirect costs exceeded direct costs. Both direct and indirect costs increased with MS progression. For indirect cost the main item was productivity loss. This study confirms that MS represents a high economic burden, with indirect costs greatly exceeding direct costs. As costs increase with disease progression, treatment efforts should focus on patients in the early stages of MS.

Effects of morphine on gene expression in the rat amygdala

Influence of morphine self-administration on gene expression in the rat amygdala was studied using rat genome DNA arrays U34A from Affymetrix. Animals were trained to self-administer morphine, each having two 'yoked' control animals, receiving passive injections of either morphine or saline. After 40 sessions of self-administration, amygdalae were removed, total RNA was isolated and used to prepare probes for Genechip arrays. The treatment was found to significantly change abundance of 29 transcripts. Analysis by means of reverse transcription real-time PCR showed significant changes in abundance of five transcripts: gamma protein kinase C (PKC), upstream binding factor 2 (UBF2), lysozyme, noggin and heat shock protein 70 (hsp70). After 30 days of forced abstinence from morphine self-administration, abundance of hsp70 and lysozyme returned to basal levels. Changes in abundance of UBF2 persisted, and abundance of three additional genes, namely nuclear factor I/A, gamma1 subunit of GABAA receptor and the neuronal calcium sensor 1, changed. Additionally, acute as well as chronic intraperitoneal morphine administration changed the abundance of PKC gamma, gamma1 subunit of GABAA and hsp70 genes.

Time-dependent changes in alcohol-seeking behaviour during abstinence

Exposure of alcohol addicts to alcohol-related environmental cues may elicit alcohol-seeking behaviour even after protracted abstinence. The purpose of the present study was to assess time-dependent changes in alcohol-seeking behaviour in rats trained to respond for alcohol. The rats were re-exposed to alcohol-associated stimuli after 1, 28 or 56 days of withdrawal. During the re-exposure session, the rats were first allowed to respond in extinction. Then, reinstatement of alcohol-seeking behaviour was evoked by a complex of discrete alcohol-associated cues (auditory and light cues combined with taste and smell of alcohol). Extinction behaviour depended on abstinence duration with maximal responding after 28-day abstinence. Reinstatement of alcohol-seeking behaviour evoked by the discrete cues was highest after 56-day abstinence. No correlations were found between individual alcohol intakes, extinction behaviour and cue-induced reinstatement. These results suggest that: (i) alcohol-seeking behaviour may become more intense after long-term imposed abstinence; (ii) alcohol self-administration, extinction behaviour, and reinstatement of alcohol-seeking behaviour may be regulated by separate neural mechanisms.

Dissociation of ethanol and saccharin preference in fosB knockout mice

The Fos family of transcription factors may play a key role in various forms of brain plasticity. Among different genes coding Fos proteins is the fosB gene. Protein products of the fosB gene are thought to be critically involved in neural adaptations produced by chronic treatment with drugs of abuse. fosB gene transcription leads to accumulation of full-length FosB as well as its truncated form, deltafosB. Stable isoforms of deltafosB called chronic FRAs accumulate in the brain after chronic administration of various drugs of abuse. The purpose of the present study was to evaluate the role of the fosB gene in two-bottle choice ethanol self-administration. For this aim, ethanol (2-8% v/v) intake and preference was assessed in fosB mutant (n=17) and wild-type (WT) mice (n=16). For comparison, consumption of saccharin (0.05-0.8% w/v) and quinine (15-960 microM) solutions was assessed in the same animals. Ethanol preference in both groups varied from around 50% for the lowest to 20% for the highest ethanol concentration. Neither ethanol intake (g/kg) nor preference differed between the two genotypes. In contrast, saccharin preference, but not intake, was higher in the fosB mutants. Only slight and inconsistent between-group differences were observed in terms of quinine preference. The present results suggest that permanent elimination of fosB gene products does not alter ethanol intake but may enhance preference for sweet solutions in mice.

Ethanol-reinforced behaviour predicts acquisition but not extinction of cocaine self-administration in the rat

AIMS

The aim of the present study was to evaluate the relationship between operant oral ethanol self-administration and intravenous (i.v.) cocaine self-administration in male Wistar rats.

METHODS

Twenty-four rats were trained to lever press for 8% v/v ethanol in the sucrose-fading procedure. The subjects with the highest (high ethanol responders [HER], n = 7) and lowest (low ethanol responders [LER], n = 7) ethanol intakes were selected for further experiments. After a wash-out period, during which i.v. catheters were implanted, the HER and LER were trained to nose-poke for cocaine infusions (0.33 mg/kg/infusion, a FR1 schedule) for nine daily sessions.

RESULTS

The HER emitted more 'active' nose-pokes and obtained more cocaine infusions during sessions 2-4. Drug-seeking behaviour in the absence of cocaine reinforcement was then assessed for three consecutive extinction sessions. No between-group differences were found in terms of extinction of cocaine seeking. Locomotor responses to a novel environment were also similar in both groups.

CONCLUSIONS

The present results suggest that a propensity to self-administer ethanol predicts more rapid acquisition of cocaine self-administration behaviour but does not influence subsequent behaviour during extinction.

Intravenous self-administration of morphine and cocaine: a comparative study

The aim of the present study was to estimate differences between patterns of morphine and cocaine use in Sprague-Dawley rats. This was done by first developing a set of conditions under which both drugs would be consistently self-administered over time. Subsequently rats were studied in groups of three, with only one rat actively self-administering morphine or cocaine while others two receiving yoked injections of either the drug or saline. With the exception of the 0.056, 0.1, 0.3 and 1.0 mg/kg/inj. training-dose regimens, intravenous (i..v.)self-administration of morphine was acquired at the dose of 0.56 mg/kg/inj. and subsequently maintained by rats. In contrast to morphine self-administration, rats rapidly acquired cocaine self-administration behavior at either the 0.3 or 0.56 injection dose and showed typical inverted U-shaped dose-response curves with maximal responding occurring at the injection dose of 0.3 mg/kg. With the "yoked" pairs of subjects, the rate of responding of the animal actually self-administering the drug was significantly higher than that of a paired animal which passively received injection whenever the first animal self-administered the drug. Thus, both morphine and cocaine served as a positive reinforcer of self-administration behavior under the fixed ratio 5 schedule of reinforcement. However, the 0.56 mg/kg injection dose of morphine resulted in an acquisition curve that was markedly, temporally delayed relative to the injection dose of cocaine. Finally, cocaine maintained higher rates of responding for its delivery than morphine. These differences between self-administration patterns of morphine and cocaine may provide significant information about the nature of drug reinforcement and dependence.

Chorda tympani nerve transection does not alter operant oral self-administration of ethanol in the rat

In experimental conditions, it has been suggested that taste factors may contribute to ethanol preference in rodents. The aim of the current study was to assess the effects of transection of a gustatory branch of the seventh cranial nerve, the chorda tympani (CT), on operant self-administration of ethanol in rats. Male Wistar rats were trained to lever press for 8% [volume/volume (vol./vol.)] ethanol solution. When 8% ethanol intake stabilized, the CT nerve was transected bilaterally in six subjects. Another group received sham operations. There were no between-group differences in terms of self-administration of 8% ethanol, either before or after surgery. In addition, self-administration of 2% and 4% ethanol, measured after surgery, did not differ between the groups. In a control experiment, two-bottle consumption of as well as preference for 0.625% [weight/volume (wt./vol.)] sucrose were significantly decreased in the lesioned subjects. The results may indicate that gustatory input of the CT nerve is not necessary for maintenance of operant oral self-administration of ethanol.

Frequency of His1069Gln and Gly1267Lys mutations in Polish Wilson's disease population

Wilson's disease is an autosomal recessive disorder. More than 60 mutations of the Wilson's disease gene have been described so far. We have analysed 148 Polish Wilson's disease patients from 95 families for His1069Gln and Gly1267Lys mutations and correlated this finding with age and clinical form of the disease at presentation. To identify these mutations, single strand conformation polymorphism analysis was performed. In our group there were 94 patients with neurological presentation, 28 with hepatic presentation, whilst 26 were in a pre-clinical stage of the disease. His1069Gln mutation was present on 171 (57%) of the 296 studied chromosomes, and Gly1267Lys mutation was present on 27 chromosomes (9.1%). Most of our patients were homozygous or heterozygous for His1069Gln mutation (39.9% and 30.4%, respectively); 4% of the patients were homozygous for Gly1267Lys mutation and 5.4% had both of these described mutations on their chromosomes. His1069Gln and Gly1267Lys mutations occurred often in our Wilson's disease patient population but we did not find any relationship between investigated mutations and the clinical form of Wilson's disease or age of first symptoms.

Cold water stress induced analgesia in unilateral inflammation of the hindpaw in hypertensive and normotensive rats

Analgesia induced by cold water stress (CWS) was tested in the model of monolateral inflammation in spontaneously hypertensive (SHR), renal hypertensive (RHR) and normotensive Wistar (NR) and Wistar Kyoto (WKY) rats. Unilateral hind paw inflammation was induced by Freund's complete adjuvant (FCA). Four days after inoculation all tested rats exhibited profound analgesia following CWS in both inflamed and non-inflamed paws which reached a maximum immediately after CWS and returned to control values within 15 min. The activity of naloxone was tested both by systemic and local injection. Baseline pain thresholds of SHR rats were significantly higher than those of NR, WKY and RHR. Hyperalgesia following systemic intraperitoneal administration of naloxone applied ten minutes before CWS was higher in RHR and WKY than in NR and SHR. When administered directly into the inflamed paw, naloxone did not antagonize CWS-induced analgesia in RHR, in contrast to weak antagonism in NR, while more evident in SHR and WKY. Our results probably reflect biological and genetic variability of intrinsic opioid and inflammatory mechanisms in hypertension.