Three-year efficacy of switching to dolutegravir plus lamivudine: A real-world study.

BACKGROUND: Dolutegravir (DTG) plus lamivudine (3TC) has proven highly efficacious as a switching strategy in virologically suppressed people with HIV (PWH). As this strategy was introduced relatively recently, real-world, long-term durability studies are lacking. METHODS: We performed a retrospective review of treatment-experienced patients who started DTG + 3TC in a cohort of PWH. HIV-RNA <50 copies/mL was analysed at 144 weeks in an intention-to-treat (ITT) analysis (missing = failure) and a per-protocol (PP) analysis (patients with missing data or changes for reasons other than virological failure were excluded). RESULTS: The study population comprised 358 PWH (19% women). Median age and time with HIV infection were 51.7 and 13.4 years, respectively. The median number of previous antiretroviral combinations was three. Previous virological failure was reported in 27.1% of patients, and the M184V resistance mutation was detected in 17 patients. At 144 weeks, the percentage of individuals with HIV-RNA <50 copies/mL was 77.4% (277/358) in the ITT analysis and 95.5% (277/290) in the PP analysis. A total of 68 participants were excluded from the PP analysis (data missing, 25, discontinuation due to toxicity, 19; other, 16; death, 8). Two people with virological failure selected resistance-associated mutations (M184V and M184V + R263K). HIV-RNA remained undetectable in 17 patients with a previous history of the M184V mutation. CONCLUSION: Our results confirm the real-world, long-term efficacy, tolerability and high genetic barrier of DTG + 3TC in treatment-experienced PWH. Although scarce, mutations causing resistance to nucleosides and integrase can emerge.

Clearance, biodistribution, and neuromodulatory effects of aluminum-based adjuvants. Systematic review and meta-analysis: what do we learn from animal studies?

Aluminum (Al) salts are commonly used as adjuvants in human and veterinary vaccines for almost a century. Despite this long history of use and the very large number of exposed individuals, data in the literature concerning the fate of these molecules after injection and their potential effects on the nervous system is limited. In the context of (i) an increase of exposure to Al salts through vaccination; (ii) the absence of safety values determined by health regulators; (iii) the lack of robustness of the studies used as references to officially claim Al adjuvant innocuity; (iv) the publication of several animal studies investigating Al salts clearance/biopersistence and neurotoxicity; we have examined in this review all published studies performed on animals and assessing Al adjuvants kinetics, biodistribution, and neuromodulation since the first work of A. Glenny in the 1920s. The diversity of methodological approaches, results, and potential weaknesses of the 31 collected studies are exposed. A large range of protocols has been used, including a variety of exposure schedule and analyses methods, making comparisons between studies uneasy. Nevertheless, published data highlight that when biopersistence, translocation, or neuromodulation were assessed, they were documented whatever the different in vivo models and methods used. Moreover, the studies pointed out the crucial importance of the different Al adjuvant physicochemical properties and host genetic background on their kinetics, biodistribution, and neuromodulatory effects. Regarding the state of the art on this key public health topic, further studies are clearly needed to determine the exact safety level of Al salts.

Gibbs thermodynamics and surface properties at the nanoscale.

Gibbs's classical thermodynamic framework approximates systems as infinitely large phases separated by infinitely thin surfaces. The range of validity of this classical framework naturally comes under scrutiny as we become interested in the properties of ever smaller systems. This Communication clarifies that while Gibbs's original framework of bulk phase thermodynamics did require modifications to describe the properties of very small (i.e., non-additive) phases, his classical framework remains fundamentally valid to describe the thermodynamic properties of surfaces. We explain why classical surface laws are applicable at the nanoscale, as suggested by simulations and confirmed by experiments. We also show that a generalized Gibbs-Tolman-Koenig-Buff equation and the resulting Tolman's law for surface tension are obtained from a classical thermodynamic analysis in the Tolman region, a region of interaction between the system and the environment.

2019 update of the European AIDS Clinical Society Guidelines for treatment of people living with HIV version 10.0.

BACKGROUND: The European AIDS Clinical Society (EACS) Guidelines cover key aspects of HIV management with major updates every two years. GUIDELINE HIGHLIGHTS: The 2019 Guidelines were extended with a new section focusing on drug-drug interactions and other prescribing issues in people living with HIV (PLWH). The recommendations for treatment-naïve PLWH were updated with four preferred regimens favouring unboosted integrase inhibitors. A two-drug regimen with dolutegravir and lamivudine, and a three-drug regimen including doravirine were also added to the recommended initial regimens. Lower thresholds for hypertension were expanded to all PLWH and for cardiovascular disease prevention, the 10-year predicted risk threshold for consideration of antiretroviral therapy (ART) modification was lowered from 20% to 10%. Frailty and obesity were added as new topics. It was specified to use urine albumin to creatinine ratio to screen for glomerular disease and urine protein to creatinine ratio for tubular diseases, and thresholds were streamlined with the Kidney Disease: Improving Global Outcomes (KDIGO) recommendations. Hepatitis C virus (HCV) treatment recommendations were split into preferred and alternative treatment options. The algorithm for management of recently acquired HCV infection was updated and includes recommendations for early chronic infection management. Treatment of resistant tuberculosis (TB) was streamlined with the World Health Organization (WHO) recommendations, and new tables on immune reconstitution inflammatory syndrome, on when to start ART in the presence of opportunistic infections and on TB drug dosing were included. CONCLUSIONS: The EACS Guidelines underwent major revisions of all sections in 2019. They are available in four different formats including a new interactive web-based version and are translated into Chinese, French, German, Japanese, Portuguese, Russian and Spanish.

Determinants of blood telomere length in antiretroviral treatment-naïve HIV-positive participants enrolled in the NEAT 001/ANRS 143 clinical trial.

OBJECTIVES: Our aim was to investigate factors associated with baseline blood telomere length in participants enrolled in NEAT 001/ANRS 143, a randomized, open-label trial comparing ritonavir-boosted darunavir (DRV/r) plus raltegravir (RAL) with DRV/r plus tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in antiretroviral therapy (ART)-naïve HIV-positive adults. METHODS: A cross-sectional study of 201 randomly selected participants who had stored samples available was carried out. We measured telomere length (i.e. the relative telomere length, calculated as the telomere to single copy gene ratio) at baseline with monochrome quantitative multiplex polymerase chain reaction (PCR). We used multivariable predictive linear regression to calculate mean differences and 95% confidence intervals (CIs) for the association between baseline telomere length and baseline characteristics. RESULTS: The baseline characteristics of the 201 participants did not differ from those of the 805 participants in the parent trial population: 89% were male, the mean age was 39 years, 83.6% were Caucasian, 93% acquired HIV infection via sexual transmission, the mean estimated time since HIV diagnosis was 2.1 years, the mean HIV-1 RNA load was 4.7 log10 HIV-1 RNA copies/mL, the mean nadir and baseline CD4 counts were 301 and 324 cells/µL, respectively, and the mean CD4:CD8 ratio was 0.4. In the univariate analysis, shorter telomere length was associated with older age (per 10 years) (P < 0.001), HIV-1 RNA ≥ 100 000 copies/mL (P = 0.001), CD4 count < 200 cells/µL (P = 0.037), lower CD4:CD8 ratio (P = 0.018), statin treatment (P = 0.004), and current alcohol consumption (P = 0.035). In the multivariable analysis, older age (P < 0.001) and HIV RNA ≥ 100 000 copies/mL (P = 0.054) were independently associated with shorter telomere length. CONCLUSIONS: Both age and HIV RNA viral load correlated with shorter blood telomere length in untreated persons living with HIV. These results suggest that HIV infection and age have synergistic and independent impacts upon immunosenescence.

Arteriovenous malformations: a diagnostic and therapeutic challenge.

Many dermatologists are largely unfamiliar with arteriovenous malformations (AVMs). This is partly due to the low prevalence of these lesions and to the fact that they are generally managed by other specialists, in particular, interventional radiologists and pediatric, maxillofacial, and plastic surgeons. In this article, we review the recommended nomenclature for AVMs and look at their clinical manifestations and diagnosis, as well as the ideal type and time of treatment. AVMs should be managed from a multidisciplinary approach, and the dermatologist's primary goal should be to make a proper diagnosis and thereby avoid unnecessary treatments.

Size-dependent properties of magnetoferritin.

We report a detailed experimental study of maghemite nanoparticles, with sizes ranging from 1.6 to 6 nm, synthesized inside a biological mould of apoferritin. The structural characterization of the inorganic cores, using TEM and x-ray diffraction, reveals a low degree of crystalline order, possibly arising from the nucleation and growth of multiple domains inside each molecule. We have also investigated the molecular structure by means of atomic force microscopy in liquid. We find that the synthesis of nanoparticles inside apoferritin leads to a small, but measurable, decrease in the external diameter of the protein, probably associated with conformational changes. The magnetic response of the maghemite cores has been studied by a combination of techniques, including ac susceptibility, dc magnetization and Mössbauer spectroscopy. From the equilibrium magnetic response, we have determined the distribution of magnetic moments per molecule. The results show highly reduced magnetic moments. This effect cannot be ascribed solely to the canting of spins located at the particle surface but, instead, it suggests that magnetoferritin cores have a highly disordered magnetic structure in which the contributions of different domains compensate each other. Finally, we have also determined, for each sample, the distribution of the activation energies required for the magnetization reversal and, from this, the size-dependent magnetic anisotropy constant K. We find that K is enormously enhanced with respect to the maghemite bulk value and that it increases with decreasing size. The Mössbauer spectra suggest that low-symmetry atomic sites, probably located at the particle surface and at the interfaces between different crystalline domains, are the likely source of the enhanced magnetic anisotropy.

On the occurrence of Anaecypris hispanica, an extremely endangered Iberian endemism, in the Guadalquivir River basin.

The jarabugo Anaecypris hispanica, considered endemic to the Guadiana River basin, has been found in the Guadalquivir River. First genetic data showed a high degree of similarity to those of the Guadiana River populations. The genetic study recovered five different groups of haplotypes, the Guadalquivir River specimens belong to the largest and most widely extended group.

Epithelial-Mesenchymal Transition in a Case of Metastatic Thyroid Carcinoma in a Brown Bear (Ursus arctos).

A 20-year-old male brown bear (Ursus arctos) with a 20 × 25 cm necrotic mass adjacent to the trachea was diagnosed as having an anaplastic thyroid carcinoma. Metastases were observed in the lungs and one adrenal gland and, histologically, these had anaplastic and follicular carcinoma patterns, respectively. E-cadherin labelling was observed in the adrenal mass only, while N-cadherin immunolabelling was detected in the thyroid gland and lung masses. Thyroid-specific markers (thyroid transcription factor-1, thyroglobulin) were expressed in the adrenal gland metastasis. This case illustrates an example of a primary epithelial-mesenchymal transition (EMT) enabling metastasis to distant organ sites, followed by a mesenchymal-epithelial transition within the adrenal gland microenvironment, allowing invasion and reacquisition of thyroid epithelial cell features. EMTs help to understand the phenomenon of carcinoma cell plasticity in enabling colonization and growth of metastases.

Effects of acute sodium omission on insulin release, ionic flux and membrane potential in mouse pancreatic B-cells.

The effects of acute omission of extracellular Na+ on pancreatic B-cell function were studied in mouse islets, using choline and lithium salts as impermeant and permeant substitutes, respectively. In the absence of glucose, choline substitution for Na+ hyperpolarized the B-cell membrane, inhibited 86Rb+ and 45Ca2+ efflux, but did not affect insulin release. In contrast, Li+ substitution for Na+ depolarized the B-cell membrane and caused a Ca2+-independent, transient acceleration of 45Ca2+ efflux and insulin release. Na+ replacement by choline in the presence of 10 mM glucose and 2.5 mM Ca2+ again rapidly hyperpolarized the B-cell membrane. This hyperpolarization was then followed by a phase of depolarization with continuous spike activity, before long slow waves of the membrane potential resumed. Under these conditions, 86Rb+ efflux first decreased before accelerating, concomitantly with marked and parallel increases in 45Ca2+ efflux and insulin release. In the absence of Ca2+, 45Ca2+ and 86Rb+ efflux were inhibited and insulin release was unaffected by choline substitution for Na+. Na+ replacement by Li+ in the presence of 10 mM glucose rapidly depolarized the B-cell membrane, caused an intense continuous spike activity, and accelerated 45Ca2+ efflux, 86Rb+ efflux and insulin release. In the absence of extracellular Ca2+, Li+ still caused a rapid but transient increase in 45Ca2+ and 86Rb+ efflux and in insulin release. Although not indispensable for insulin release, Na+ plays an important regulatory role in stimulus-secretion coupling by modulating, among others, membrane potential and ionic fluxes in B-cells.

Effects on development.

This chapter will review the effects produced on neural development by maternal consumption of cannabinoids during gestation and lactation, with emphasis in the maturation of several neurotransmitter systems (dopamine, serotonin, opioids, cannabinoids, etc.) and possible modifications in their functional expression at the behavioral or neuroendocrine levels. In addition, we have analyzed the possible existence of a sexual dimorphism in these ontogenic effects of cannabinoids, as well as the possible molecular mechanism underlying such effects. In general, the results discussed support the view that exposure to cannabinoids during critical periods of development produces marked modifications in the functional expression of diverse neuronal systems in adulthood. Furthermore, the functions of endocannabinoids in the brain are large not only in adulthood, but also in the period of prenatal and postnatal development. Thus, endocannabinoids have been reported to be present in early ages and to play a role in the process of brain development: neural proliferation and migration, axonal elongation, synaptogenesis and/or myelogenesis.

[Macronutrients intake in school teenagers in Soria capital]. / Ingesta de macronutrientes en adolescentes escolarizados en Soria capital.

OBJECTIVES: To study the macronutrients intake in Soria teenagers from 10 to 19 years, as well as their body mass index (BMI). METHODS: A seven-day diet questionnaire filled in by an accidental sample of teenagers (54 boys and 56 girls) from public schools in the capital. Working out the average daily intake of energy, carbohydrates, lipids and proteins by the software of "Alimentación y Salud" which also gives values of individual recommended dietary allowances (RDAs) related to each individual's particular characteristics. Use of Student's t-test to compare the average values of the estimated intakes of different nutrients and their RDAs. RESULTS: In general, the intakes of energy, proteins and lipids are statistically significant over the RDAs, while the carbohydrates intake is under the recommendations. With reference to the type of lipids, the intake is over the RDAs for cholesterol, monounsaturated fatty acids, and saturated fatty acids, but not for polyunsaturated fatty acids. Among girls from 13 years of age more than 12% have a higher BMI than 26 kg/m2, but between 10 and 12 years of age more than 20% of the students have this parameter under 16 kg/m2. CONCLUSIONS: According to the results, it would be useful to implement some nutritional intervention among the adolescents in Soria capital to promote a healthy feeding in order to avoid possible disorders (obesity, anorexia, etc.).

Nutrient insulin secretagogues decrease 45Ca2+ efflux from islet cells by a mechanism other than the inhibition of the Na+-Ca2+ countertransport.

The mechanism whereby nutrient insulin secretagogues decrease 45Ca2+ efflux from islet cells is controversial. It was studied with mouse islets perifused with Ca2+-free solutions. In the presence of Na+, glucose and ketoisocaproate inhibited 45Ca2+ efflux by about 50%. Substitution of choline+ salts for Na+ salts decreased the efflux rate by 45%, but did not prevent glucose from decreasing it further. Ketoisocaproate also inhibited 45Ca2+ efflux, but less markedly than in an Na+ medium. Omission of Na+ decreased the efflux rate even when it was already lowered by glucose or ketoisocaproate. It is thus clear that nutrient insulin secretagogues decrease 45Ca2+ efflux from islet cells by a mechanism other than the inhibition of the Na+-Ca2+ countertransport, possibly by increasing sequestration of the ion in cellular organelles.

Comparisons between brain dopaminergic neurons of juvenile and aged rats: sex-related differences.

It is known that several aspects of dopaminergic neurotransmission deteriorate with advanced age. In the present report, we have studied the possible existence of sexual differences in these aging-induced changes. Thus, we measured several pre- and postsynaptic biochemical parameters, indicative of the activity of dopaminergic neurons, in striatum, limbic forebrain and hypothalamic-anterior pituitary area of aged (24-26 months) and young (2 months) rats of both sexes. Tyrosine hydroxylase (TH) activity, as well as the number of D2-dopaminergic receptors, decreased in the striatum of aged rats, especially in the males in which the decrease in the number of receptors was associated with an increase in their affinity. In addition, the ratio between dopamine (DA) and its intraneuronal metabolite, L-3,4-dihydroxyphenyl-acetic acid (DOPAC), which can be used as an index of neurotransmitter turnover, was increased in aged females in parallel with a decreased DA content. In the limbic forebrain, TH activity was also decreased during aging, but only in males, whereas the DOPAC/DA ratio was increased in females, although in parallel with an increased DOPAC production. Finally, in the hypothalamic-anterior pituitary area, aging only affected the females, in which increased plasma prolactin levels were observed. This effect might be the result of a low responsiveness of pituitary lactotrophs to DA released from hypothalamic neurons, in spite of high prolactin levels producing a constant, although ineffective, stimulation of the activity of these neurons, as reflected by the high DOPAC content and DOPAC/DA ratio observed in the medial basal hypothalamus. In summary, these data allow us to suggest that the activity of brain dopaminergic neurons is modified with aging and there are significant differences as a function of sex and brain area.

The endocannabinoid system and Huntington's disease.

The research in Huntington's disease (HD) has been growing exponentially during the last decade, since the discovery of the genetic basis that leads to neurodegeneration. HD is one of several progressive neurodegenerative disorders, in which the underlying mutation is a CAG expansion encoding a polyglutamine tract in a specific protein, which in the case of HD, is called huntingtin. The first clinical symptoms of HD are generally psychiatric abnormalities, most commonly depression and mood disturbances. Involuntary choreiform movements and dementia develop over the next 15-20 years, and death generally results from complications derived from immobility. There is currently no cure, or even an effective therapy to offset the decline in mental and motor capabilities suffered by those affected by HD, but recent studies have started to examine the usefulness of different classes of new compounds. Among these, plant-derived, synthetic or endogenous cannabinoids have been proposed to have therapeutic value for the treatment of HD, since they act on cannabinoid CB(1) receptors located in the basal ganglia circuitry, that is affected by the striatal atrophy typical of HD. Recent studies have characterized the changes in these receptors, as well as their endogenous ligands, in the basal ganglia in a variety of animal models of HD. The results are indicative that the endocannabinoid system becomes hypofunctional in this disease, which could be related to the hyperkinesia typical of the earliest phases of this disease. In addition, it has been proposed that the loss of these receptors might be involved in the process of pathogenesis itself. This, together with the well-known protective properties of cannabinoid-related compounds, suggest that, in addition to a symptomatic usefulness, cannabinoids might also serve to delay or to arrest the development of this disease. The present article will review all recent data dealing with the biochemical, pharmacological and therapeutic bases that support a potential role of cannabinoids in the pathogenesis and/or therapeutic treatment of this motor disorder.

Possible role of the cytochrome P450-linked monooxygenase system in preventing delta 9-tetrahydrocannabinol-induced stimulation of tuberoinfundibular dopaminergic activity in female rats.

The administration of delta 9-tetrahydrocannabinol (THC) or related cannabinoids markedly affected neurobehavioral and neuroendocrine indices in male rodents but usually failed to affect those indices in females. We examined whether inhibition of the cytochrome P450-linked monooxygenase system in female rats is able to elicit the effects of THC on one of the most characteristic targets of cannabinoid action, tuberoinfundibular dopaminergic neurons, whose activity is known to increase after cannabinoid exposure in males. It was found that the administration of THC to ovariectomized rats acutely replaced with estradiol (to discard problems derived from differences in the estrogenic status) did not affect either dopamine and L-3,4-dihydroxyphenylacetic acid (DOPAC) contents and tyrosine hydroxylase activity in the medial basal hypothalamus or the density of D2-dopaminergic receptors in the anterior pituitary. However, the administration of THC to estrogen-replaced ovariectomized rats that had been pretreated with two separately administered inhibitors of cytochrome P450, piperonyl butoxide or metyrapone, significantly increased DOPAC content in the medial basal hypothalamus, with no changes in the other parameters. Collectively, these results indicate that the metabolism of THC to inactive compounds might play a protective role in females, counteracting the effects of this cannabinoid on tuberoinfundibular dopaminergic activity because pharmacological inhibition of cytochrome P450-linked monooxygenase system elicited a significant stimulation of these neurons by THC.

Effects of cannabinoids on prolactin and gonadotrophin secretion: involvement of changes in hypothalamic gamma-aminobutyric acid (GABA) inputs.

CB1 cannabinoid receptors are located in hypothalamic nuclei and their activation alters several hypothalamic neurotransmitters resulting in, among other things, decreased prolactin (PRL) and luteinizing hormone (LH) secretion from the anterior pituitary gland. In the present study, we addressed two related objectives to further explore this complex regulation. First, we examined whether changes in gamma-aminobutyric acid (GABA) and/or dopamine (DA) inputs in the medial basal hypothalamus might occur in parallel to the effects resulting from the activation of CB1 receptors on PRL and gonadotrophin secretion in male rats. Thus, the acute administration of (-)-delta9-tetrahydrocannnabinol (delta9-THC) produced, as expected, a marked decrease in plasma PRL and LH levels, with no changes in follicle-stimulating hormone (FSH) levels. This was paralleled by an increase in the contents of GABA, but not of DA, in the medial basal hypothalamus and, to a lesser extent, in the anterior pituitary gland. The co-administration of delta9-THC and SR141716, a specific antagonist for CB1 receptors, attenuated both PRL and LH decrease and GABA increase, thus asserting the involvement of the activation of CB1 receptors in these effects. As a second objective, we tested whether the prolonged activation of these receptors might induce tolerance with regard to the decrease in PRL and LH release, and whether this potential tolerance might be related to changes in CB1-receptor binding and/or mRNA expression. The chronic administration of R-methanandamide (AM356), a more stable analog of anandamide, the putative endogenous cannabinoid ligand, produced a marked decrease in plasma PRL and LH levels, with no changes in FSH. The decreases were of similar magnitude to those caused by a single injection of this cannabimimetic ligand, thus suggesting the absence of tolerance. In parallel, the analysis of CB1-receptor binding and mRNA expression in several hypothalamic structures proved that the acute or chronic administration of AM356 did not affect either the binding or the synthesis of these receptors. In summary, the activation of CB1 receptors in hypothalamic nuclei produced the expected decrease in PRL and LH secretion, an effect which might be related to an increase in GABAergic activity in the hypothalamus-anterior pituitary axis. The prolonged activation of these receptors for five days did not elicit tolerance in terms of an attenuation in the magnitude of the decrease in PRL and LH, and, accordingly, did not alter CB1-receptor binding and mRNA levels in the hypothalamic nuclei examined.

Effects of perinatal exposure to delta 9-tetrahydrocannabinol on the fetal and early postnatal development of tyrosine hydroxylase-containing neurons in rat brain.

The exposure of pregnant rats to delta 9-tetrahydrocannabinol (delta 9-THC), the main psychoactive constituent of Cannabis sativa, during the perinatal period affects the gene expression and the activity of tyrosine hydroxylase (TH) in the brains of their offspring at peripubertal and adult ages. In the present work we explored whether these effects also appear during fetal and early neonatal periods, when TH expression plays an important role in neural development. To this end, the mRNA amounts for TH and the amounts and activity of this enzyme, in addition to catecholamine (CA) contents, were analyzed in the brain of fetuses at different gestational days (GD) and of newborns at two postnatal ages, which had been daily exposed to delta 9-THC or vehicle from d 5 of gestation. Results were as follows. The exposure to delta 9-THC markedly affected the expression of the TH gene in the brain of fetuses at GD 14. Thus, the amounts of its mRNA at this age were higher in delta 9-THC-exposed fetuses than in controls. This corresponded with a marked rise in the amounts of TH protein and in the activity of this enzyme at this age. Normalization was found in these parameters at GD16. However, a marked sexual dimorphism in the response of TH gene to cannabinoid exposure appeared from GD18 and was particularly evident at GD21, when TH-mRNA amounts increased in developing female brains, but decreased in developing male brains exposed to delta 9-THC, effects that were mostly prolonged to early postnatal ages. However, these changes did not correspond always with parallel changes in the amounts and activity of TH and in CA contents, as occurred in GD14, suggesting that delta 9-THC would not be affecting the basal capability to synthesize CAs in TH-containing neurons, but would affect the responsiveness of TH gene. We found only a marked increase in the production of L-3,4-dihydroxyphenylacetic acid, the main intraneuronal dopamine metabolite, in female newborns exposed to delta 9-THC. Collectively, our results support the belief that the perinatal exposure to delta 9-THC affects the expression of the TH gene and, sometimes, the activity of this enzyme in brain catecholaminergic neurons in certain critical periods of fetal and early neonatal brain development. These results support the notion that cannabinoids are able to affect the gene expression of specific key proteins for catecholaminergic development, and that these alterations might be the origin of important long-term neurobehavioral effects caused by perinatal cannabinoid exposure at peripubertal and adult ages.

Perinatal cannabinoid exposure modifies the sociosexual approach behavior and the mesolimbic dopaminergic activity of adult male rats.

In the present work, we attempted to study whether hashish exposure during perinatal development affects sociosexual approach behavior in adult rats. To this end, we subjected adult female and male rats that had been perinatally exposed to hashish extracts to a sociosexual approach behavior test, completed with a dark-light emergence test and with a social interaction test. It was found that adult males perinatally exposed to hashish extracts exhibited marked changes in the behavioral patterns executed in the sociosexual approach behavior test; these changes did not exists in females. Thus, control males first visited the incentive male and took longer to visit the incentive female, whereas hashish-exposed males followed the opposite pattern. Moreover, hashish-exposed males spent more time in the vicinity of the incentive female, whereas they decreased their frequency of visits to, and the time spent in, the male incentive area. This behavior was observed early on, during the first third of the test, but became normalized and even inverted later on during the last two-thirds. Additionally, in the social interaction test, the normal reduction in the time spent in active social interaction following the exposure to a neophobic situation (high light levels) in controls did not occur in hashish-exposed males, although these exhibited a response in the dark-light emergence test similar to that of their corresponding controls. No changes were seen in spontaneous locomotor activity in both tests. These behavioral alterations observed in hashish-exposed males were paralleled by a significant decrease in L-3,4-dihydroxyphenylacetic acid contents in the limbic forebrain; this suggests a decreased activity of mesolimbic dopaminergic neurons. No effects were seen in females. Collectively, these results show that in the rat, perinatal cannabinoid exposure affects the sociosexual approach behavior and the mesolimbic dopaminergic activity in adulthood, although the effects were sexually dimorphic because they only appeared in the males.

An acute dose of delta 9-tetrahydrocannabinol affects behavioral and neurochemical indices of mesolimbic dopaminergic activity.

Cannabinoid consumption has been reported to affect several neurotransmitter systems and their related behaviors. The present study has been designed to examine cannabinoid effects on certain behaviors, which have been currently located in the limbic forebrain, in parallel to their effects on mesolimbic dopaminergic neurons. To this end, male rats treated with an oral dose of delta 9-tetrahydrocannabinol (THC) or vehicle were used 1 h after treatment for two different behavioral tests or neurochemical analyses of mesolimbic dopaminergic activity. Treatments, behavioral tests and sacrifice were performed in the dark phase of photoperiod because it corresponds to the maximum behavioral expression in the rat. Behavioral tests were a dark-light emergence test, which allows measurements of emotional reactivity, and a socio-sexual approach behavior test, which allows measurements of sexual motivation and also of spontaneous and stereotypic activities. Neurochemical analyses consisted of measurements of dopamine (DA) and L-3,4-dihydroxyphenylacetic acid (DOPAC) contents, tyrosine hydroxylase activity, in vitro DA release and number and affinity of D1 receptors in the limbic forebrain. Results were as follows. THC exposure markedly altered the pattern executed by the animals in both tests. Concretely, THC-exposed animals exhibited a low number of visits to an incentive female in addition to high time spent in the vicinity of an incentive male, both observed in the socio-sexual approach behavior test, and an increased emergence latency to go out of a dark compartment in the dark-light emergence test. However, the fact that THC also decreased spontaneous activity and the frequency of rearing and self-grooming behaviors, in addition to the observations of either low total number of visits to both incentive sexual areas or high escape latency to go out of a light compartment, when the animal is placed in this compartment, also suggest the possible existence of an accompanying motor deficit. These behavioral effects were accompanied by increases in DA and DOPAC contents and in D1 receptor density in the limbic forebrain and to a slight decrease in the pattern of K(+)-evoked DA release in vitro from perifused limbic fragments, with no changes in the remaining neurochemical parameters. Collectively, these results allow us to conclude that acute THC markedly altered the behavioral pattern executed by the animals in a socio-sexual approach behavior test and in a dark-light emergence test, presumably indicating loss of sexual motivation and increased emotionality, although also accompanied by motor deficiencies.(ABSTRACT TRUNCATED AT 400 WORDS)