In vivo and in vitro studies on the differential role of luteinizing hormone and follicle-stimulating hormone in regulating follicular function in the bonnet monkey (Macaca radiata) using specific gonadotropin antibodies

Although a distinct need for FSH in the regulation of follicular maturation in the primate is well recognized, it is not clear how FSH controls the functionality of different cellular compartments of the follicle. It is also not evident whether there is a requirement for LH in follicular maturation in the primate. In the first part of the present study, female bonnet monkeys were administered a well-characterized ovine (o) LH antiserum to neutralize endogenous monkey LH for different periods during the follicular phase, and the effect on the overall follicular maturation process was assessed by analyzing serum estrogen (E) and progesterone (P) profiles. Neither continuous LH deprivation from Day 8 of the cycle nor deprivation of LH on any one day between Days 6 and 10 had a significant effect on serum E and P profiles and the follicular maturation process. The period for which the antiserum was effective was dependent upon the dose injected; 1 ml of the antiserum given on Day 8 blocked ovulation but not follicular maturation. To assess the effect of deprivation of LH/FSH at the cellular level, animals were deprived in vivo of LH (on Days 8 and 9 of the cycle) or of FSH (on Day 6 of the cycle) by injection of highly characterized hCG and ovine (o) FSH antisera, respectively; the in vitro responsiveness of granulosa and thecal cells isolated on Day 10 from these animals was then determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential role of CB1 and TRPV1 receptors on anandamide modulation of defensive responses induced by nitric oxide in the dorsolateral periaqueductal gray

CB1, TRPV1 and NO can regulate glutamate release and modify defensive behaviors in regions related to defensive behavior such as the dorsolateral periaqueductal gray (dIPAG). A possible interaction between the endocannabinoid and nitrergic systems in this area, however, has not been investigated yet. The objective of the present work was to verify if activation of CB1 or TRPV1 receptors could interfere in the flight responses induced in rats by the injection of SIN-1, an NO donor, into the dIPAG. The results showed that local administration of a low dose (5 pmol) of anandamide (AEA) attenuated the flight responses, measured by the total distance moved and maximum speed in an open arena, induced by intra-dIPAG microinjection of SIN-1 (150 nmol). URB597 (0.1 nmol), an inhibitor of anandamide metabolism, produced similar effects. When animals were locally treated with the CB1 receptor antagonist AM251 the effective AEA dose (5 pmol) increased, rather than decreased, the flight reactions induced by SIN1-1. Higher (50-200 nmol) doses of AEA were ineffective and even tended to potentiate the SIN-1 effect. The TRPV1 antagonist capsazepine (CPZ, 30 nmol) prevented SIN-1 effects and attenuated the potentiation of its effect by the higher (200 nmol) AEA dose. The results indicate that AEA can modulate in a dual way the pro-aversive effects of NO in the dIPAG by activating CB1 or TRPV1 receptors. (C) 2012 Elsevier Ltd. All rights reserved.

A Differential Role of Volatiles from Conspecific and Heterospecific Competitors in the Selection of Oviposition Sites by the Aphidophagous Hoverfly Sphaerophoria rueppellii

The selection of oviposition sites by syrphids and other aphidophagous insects is influenced by the presence of con- and heterospecific competitors. Chemical cues play a role in this selection process, some of them being volatile semiochemicals. Yet, little is known about the identity and specificity of chemical signals that are involved in the searching behavior of these predators. In this study, we used olfactometer bioassays to explore the olfactory responses of gravid females and larvae of the syrphid Sphaerophoria rueppellii, focussing on volatiles from conspecific immature stages, as well as odors from immature stages of the competing coccinellid Adalia bipunctata. In addition, a multiple-choice oviposition experiment was conducted to study if females respond differently when they can also sense their competitors through visual or tactile cues. Results showed that volatiles from plants and aphids did not affect the behavior of second-instars, whereas adult females strongly preferred odors from aphid colonies without competitors. Odors from conspecific immature stages had a repellent effect on S. rueppellii adult females, whereas their choices were not affected by volatiles coming from immature heterospecific A. bipunctata. The results imply that the syrphid uses odors to avoid sites that are already occupied by conspecifics. They did not avoid the odor of the heterospecific competitor, although in close vicinity they were found to avoid laying eggs on leaves that had traces of the coccinellid. Apparently adult syrphids do not rely greatly on volatile semiochemicals to detect the coccinellid, but rather use other stimuli at close range (e. g., visual or non-volatile compounds) to avoid this competitor.

Cognitive mediation of panic severity: The role of catastrophic misinterpretation of bodily sensations and panic self-efficacy

This study examined the differential role of negative and positive cognitions in mediating treatment outcome in CBT for Panic Disorder through comparison of a Standard CBT (n = 36) versus a Waitlist Condition (n = 24). Regression analyses indicated that, relative to the Waitlist Condition, patients in the Standard CBT condition reported significantly greater shifts both towards higher panic self-efficacy and lower catastrophic misinterpretation of bodily sensations during treatment, as well as a significantly lower level of panic severity at posttreatment. Changes in catastrophic misinterpretation of bodily sensations and panic self-efficacy contributed significantly more to prediction of panic severity than did assignment to either Standard CB T or a Waitlist Condition. Results are discussed in terms of the importance of including both negative and positive cognitions in demonstrating cognitive mediation.

The role of alcohol expectancy and drinking refusal self-efficacy beliefs in university student drinking

Aims: University student alcohol misuse is a considerable problem. Alcohol expectancy research has contributed significantly to our understanding of problem drinking in young adults. Most of this research has investigated positive expectancy alone. The current study utilized two measures of alcohol expectancy, the alcohol expectancy questionnaire (AEQ) and the drinking expectancy profile [consisting of the drinking expectancy questionnaire (DEQ) and the drinking refusal self-efficacy questionnaire] to predict severity of alcohol dependence, frequency of drinking, and the quantity of alcohol consumed per occasion. Methods: Measures of drinking behaviour and alcohol expectancy were completed by 174 undergraduate university students. Results: Positive alcohol expectancy factors accounted for significant variance in all three drinking indices, with the DEQ adding additional variance to AEQ scores on frequency and severity of alcohol dependence indices. Negative expectancy did not add incremental variance to the prediction of drinking behaviour in this sample. Drinking refusal self-efficacy and dependence beliefs added additional variance over positive and negative expectancies in the prediction of all three drinking parameters. Conclusions: Positive expectancy and drinking refusal self-efficacy were strongly related to university student drinking. The incorporation of expectancy as a means of informing prevention approaches in tertiary education shows promise.

Immunomodulation using agonists and antagonists: potential clinical applications

Introduction: Extensive studies have gone into understanding the differential role of the innate and adaptive arms of the immune system in the context of various diseases. Receptor-ligand interactions are responsible for mediating cross-talk between the innate and adaptive arms of the immune system, so as to effectively counter the pathogenic challenge. While TLRs remain the best studied innate immune receptor, many other receptor families are now coming to the fore for their role in various pathologies. Research has focused on the discovery of novel agonists and antagonists for these receptors as potential therapeutics. Areas covered: In this review, we present an overview of the recent advances in the discovery of drugs targeting important receptors such as G-protein coupled receptors, TRAIL-R, IL-1 beta receptor, PPARs, etc. All these receptors play a critical role in the modulation of the immune response. We focus on the recent paradigms applied for the generation of specific and effective therapeutics for these receptors and their status in clinical trials. Expert opinion: Non-specific activation by antagonist/agonist is a difficult problem to dodge. This demands innovation in ligand designing with the use of strategies such as allosterism and dual-specific ligands. Rigorous preclinical and clinical studies are required in transforming a compound to a therapeutic.

Synapsin- and actin-dependent frequency enhancement in mouse hippocampal mossy fiber synapses

The synapsin proteins have different roles in excitatory and inhibitory synaptic terminals. We demonstrate a differential role between types of excitatory terminals. Structural and functional aspects of the hippocampal mossy fiber (MF) synapses were studied in wild-type (WT) mice and in synapsin double-knockout mice (DKO). A severe reduction in the number of synaptic vesicles situated more than 100 nm away from the presynaptic membrane active zone was found in the synapsin DKO animals. The ultrastructural level gave concomitant reduction in F-actin immunoreactivity observed at the periactive endocytic zone of the MF terminals. Frequency facilitation was normal in synapsin DKO mice at low firing rates (approximately 0.1 Hz) but was impaired at firing rates within the physiological range (approximately 2 Hz). Synapses made by associational/commissural fibers showed comparatively small frequency facilitation at the same frequencies. Synapsin-dependent facilitation in MF synapses of WT mice was attenuated by blocking F-actin polymerization with cytochalasin B in hippocampal slices. Synapsin III, selectively seen in MF synapses, is enriched specifically in the area adjacent to the synaptic cleft. This may underlie the ability of synapsin III to promote synaptic depression, contributing to the reduced frequency facilitation observed in the absence of synapsins I and II.

Rôle des circuits cortico-striataux dans la planification et l'exécution de règles lexicales

Des recherches, autant chez l’homme que chez l’animal, proposent qu’il existerait, au sein des réseaux cérébraux, une organisation anatomique parallèle de circuits qui coordonne l’activité des structures qui participent à la planification et à l’exécution d’une action. Dans cette foulée, un modèle émerge qui attribue au cortex préfrontal (CPF) latéral une spécificité anatomo-fonctionnelle basée sur les niveaux de traitement en mémoire de travail (MT). Il s’agit du modèle « niveaux de traitement-dépendant », qui accorde un rôle important au CPF latéral dans l’acquisition et la représentation de règles guidant nos comportements. Des études en neuroimagerie fonctionnelle, utilisant le Wisconsin Card Sorting Task (WCST) ont permis de corroborer ce modèle et de dissocier trois niveaux de traitement en MT non seulement au sein du CPF latéral mais encore aux structures sous- corticales, les ganglions de la base (GB). Ces études suggèrent que certains noyaux des GB seraient topographiquement organisés avec le CPF latéral et contriburaient, sous certaines conditions, à des processus cognitifs et moteurs semblables à leur homologue cortical. Le but de notre étude est d'explorer la généralisation de la contribution des GB et du CPF au modèle niveaux de traitement-dépendant afin de voir si ce dernier est indépendant de la nature des stimuli en mémoire de travail. À cet effet, nous avons modifié le WCST en l’appliquant à un autre domaine, celui du langage. Nous avons remplacé les pictogrammes par des mots et modifié les règles formes, couleurs, nombres, par des règles sémantiques et phonologiques. L’analyse des résultats a démontré que différentes parties des GB de concert avec différentes régions du CPF se différencient quant aux niveaux de traitement en MT et ce, indépendamment de la nature des stimuli. Une deuxième analyse a permis d’évaluer les patrons d’activations liés aux conditions sémantiques et phonologiques. Ces résultats ont mis en évidence que les réseaux préfrontaux semblent liés aux processus exécutifs nécessaires à la réalisation de la tâche, indépendamment de la condition tandis que les aires associatives se dissocient davantage et contiennent des réseaux propres à la sémantique et à la phonologie.

Contrasting phylogenetic signals and evolutionary rates in floral traits of Neotropical lianas

The diversity of floral forms has long been considered a prime example of radiation through natural selection. However, little is still known about the evolution of floral traits, a critical piece of evidence for the understanding of the processes that may have driven flower evolution. We studied the pattern of evolution of quantitative floral traits in a group of Neotropical lianas (Bignonieae, Bignoniaceae) and used a time-calibrated phylogeny as basis to: (1) test for phylogenetic signal in 16 continuous floral traits; (2) evaluate the rate of evolution in those traits; and (3) reconstruct the ancestral state of the individual traits. Variation in floral traits among extant species of Bignonieae was highly explained by their phylogenetic history. However, opposite signals were found in floral traits associated with the attraction of pollinators (calyx and corolla) and pollen transfer (androecium and gynoecium), suggesting a differential role of selection in different floral whorls. Phylogenetic independent contrasts indicate that traits evolved at different rates, whereas ancestral character state reconstructions indicate that the ancestral size of most flower traits was larger than the mean observed sizes of the same traits in extant species. The implications of these patterns for the reproductive biology of Bignonieae are discussed. (C) 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102, 378-390.

International technological dynamics in production sectors: An empirical analysis

A new methodology is proposed for evaluating the economic development opportunities associated with the different industries making up a country’s economic structure. To this end, neo-Schumpeterian concepts are used to reinterpret the tools afforded by the “product space” literature in an attempt to assess the technological pervasiveness and sophistication of different production sectors. The ultimate objective is to develop a description of today’s techno-productive paradigm and the differential role that the various sectors play in it. An analysis of export data from 113 countries and territories for 2005-2009 indicates that the key sectors in the world economy are: industrial machinery, scientific and medical instruments, and pharmaceuticals. The strong performance of sectors based on mature technologies suggests that key sectors originating in different stages in history can survive and overlap one another, much like geological strata, owing to the persistence of older technological systems.

Bone apposition and surface treatment in dental implants: histomorphometric pilot evaluation in rabbits

The surface of dental implants is an important factor for osseointegration process and different methods of surface treatment have been described. Objective: To investigate the bone apposition in implant surface treated with sandblasting and acid-etching. Material and methods: Ten rabbits were selected and received one implant treated with method I in the left tibia and one implant treated with method II in the right tibia. Then, twenty implants were divided in two groups, according to methods of sandblasting and acid-etching (method I and method II). After 7, 14, 30, 45 and 60 days, tibias were retrieved and submitted to histotechnical procedures. The percentages of bone–implant contact (BIC) and bone area between threads (BABT) were determined throughout histomorphometric analysis and bone apposition was detected in implants of both groups. Results: In BABT measurements, an increase was observed after 45 and 60 days in the method II, compared to method I and no differences were found after 7, 14 and 30 days. In BIC measurements, an increase was detected with method II at 45 days when compared to method I. No differences between groups in BIC values were observed after 7, 14, 30 and 60 days. Conclusion: Our data demonstrated that implants treated with the method II presented increase in the contact between bone and implant after 45 days compared to method I. Moreover, with concern to bone area between threads, it was observed an increased in the method II after 45 and 60 days. However, both groups can be successfully used as a therapeutic strategy to rehabilitation of edentulous patients. Then, further experiments are needed to evaluate, in depth, the putative differential role of each surface treatment.

Intrahippocampal injection of brain-derived neurotrophic factor increases anxiety-related, but not panic-related defensive responses: involvement of serotonin

Changes in brain-derived neurotrophic factor (BDNF)mediated signaling in the hippocampus have been implicated in the etiology of depression and in the mode of action of antidepressant drugs. There is also evidence from animal studies to suggest that BDNF-induced changes in the hippocampus may play a role in another stress-related pathology: anxiety. However, it is still unknown whether this neurotrophin plays a differential role in defensive responses associated with distinguished subtypes of anxiety disorders found in the clinic, such as generalized anxiety and panic disorder. In the present study, we investigated the effect of an acute BDNF injection into the rat dorsal hippocampus (DH) on inhibitory avoidance acquisition and escape expression measured in the elevated T-maze (ETM). We also assessed whether serotonergic neurotransmission may account for such effects. Intra-DH BDNF injection (200 pg) facilitated inhibitory avoidance in ETM. BDNF was equally anxiogenic in the light/dark transition test. Preadministration of the 5-HT1A receptor antagonist WAY-100635 fully counteracted the anxiogenic effect of BDNF in both tests. Intra-DH midazolam administration (10 nmol) impaired avoidance acquisition in ETM, suggesting an anxiolytic effect. Therefore, in the DH, facilitation of BDNF signaling seems to enhance 5-HT1A receptor-mediated neurotransmission to exert an anxiogenic effect associated with generalized anxiety. Behavioural Pharmacology 23:80-88 (C) 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Serotonin-2C receptors in the basolateral nucleus of the amygdala mediate the anxiogenic effect of acute imipramine and fluoxetine administration

A growing body of evidence indicates that facilitation of serotonin-2C receptor (5-HT2CR)-mediated neurotransmission in the basolateral nucleus of the amygdala (BLA) is involved in anxiety generation. We investigated here whether BLA 5-HT(2C)Rs exert a differential role in the regulation of defensive behaviours related to generalized anxiety (inhibitory avoidance) and panic (escape) disorders. We also evaluated whether activation of BLA 5-HT(2C)Rs accounts for the anxiogenic effect caused by acute systemic administration of the antidepressants imipramine and fluoxetine. Male Wistar rats were tested in the elevated T-maze after intra-BLA injection of the endogenous agonist 5-HT, the 5-HT2CR agonist MK-212 or the 5-HT2CR antagonist SB-242084. This test allows the measurement of inhibitory avoidance acquisition and escape expression. We also investigated whether intra-BLA administration of SB-242084 interferes with the acute anxiogenic effect caused by imipramine and fluoxetine in the Vogel conflict test, and imipramine in the elevated T-maze. While intra-BLA administration of 5-HT and MK-212 facilitated inhibitory avoidance acquisition, suggesting an anxiogenic effect, SB-242084 had the opposite effect. None of these drugs affected escape performance. Intra-BLA injection of a sub-effective dose of SB-242084 fully blocked the anxiogenic effect caused either by the local microinjection of 5-HT or the systemic administration of imipramine and fluoxetine. Our findings indicate that 5-HT(2C)Rs in BLA are selectively involved in the regulation of defensive behaviours associated with generalized anxiety, but not panic. The results also provide the first direct evidence that activation of BLA 5-HT(2C)Rs accounts for the short-term aversive effect of antidepressants.