Bidirectional modulation of P2X receptor-mediated response by divalent cations in rat dorsal motor nucleus of the vagus neurons

The modulatory effects of Zn(2+) and other divalent cations on the ATP-induced responses of preganglionic neurons acutely dissociated from the rat dorsal motor nucleus of the vagus (DMV) were examined using a nystatin-perforated patch technique under voltage-clamp. DMV neurons were identified by back-filling of DiI placed on the vagal bundle at the neck. Zn(2+) exerts a concentration-dependent effect on P2X receptor-mediated current (I(ATP)): a potentiation by low concentrations of Zn(2+) (< or = 50 microM) and an inhibition by high concentrations (> 50 microM). Inhibition of the ATP response was associated with a prolongation of the rising phase of I(ATP). Cu(2+) mimicked Zn(2+) regarding the biphasic modulation of I(ATP). On the other hand, Ni(2+) potentiated, but failed to inhibit, the ATP response even at a concentration of 3 mM. Quantitative RT-PCR revealed the similarity of P2X(2) mRNA expression between the DMV and superior cervical ganglion (SCG) but not in the dorsal root ganglion (DRG) and hypoglossal nucleus (XII). The results from the electrophysiological and molecular approaches suggest that functional P2X receptors expressed in DMV neurons are characterized mainly by the P2X(2) and P2X(2/6) subtype. DMV neurons possess similar P2X receptor characteristics to SCG neurons.     

The expression of chicken NOV, a member of the CCN gene family, in early stage development

The nephroblastoma overexpressed gene, NOV, is a member of the CCN gene family. We investigated the NOV gene expression pattern in the chicken during early stage embryogenesis. Several embryonic structures showed a distinct expression pattern. The initial expression was detected in Hensen's node (Hamburger and Hamilton stage (HH) 5). The expression was noted in the presumptive notochord and floor plate forming cells. The expression on the left side was more elongated posteriorly, a type of left-right asymmetry. Chicken NOV gene expression in the forming notochord and floor plate was observed until HH 18. The expression was also detected in the ventral area of the mesencephalon and isthmus at HH 14-16.     

Electrical activity in the vagus nerves and some medullary nuclei in rats: Changes induced by endotoxin action and hyperthermia evoked by an increase in ambient temperatures

Acute experiments on rats showed that intraperitoneal administration of 5 μg/kg of a bacterial toxin (pyrogenal) increases the afferent impulsation frequency in the cervical segments of vagus nerves, VN (multifiber recording), and frequency of the multineuronal activity in the solitary tract nucleus (STN); these changes were observed during the whole period of recording (10–160 min following toxin injection). Enhancement of the efferent impulsation in the VN and neuronal activity in the dorsal nucleus of the vagus nerve (DNVN) could be observed only 120–130 min after toxin administration. Under these conditions rectal temperature in experimental animals was 1.5° higher than that in control rats throughout the period of recording. Following subdiaphragmatic vagotomy, the afferent impulsation frequency in the cervical VN decreased about four times and kept on decreasing during the whole period of registration. Pyrogenal introduction evoked no changes in the direction of reactions to vagotomy. Under these conditions, body temperature of these animals was 2.5°C higher than in control vagotomized rats by the final stage of recording. Animal heating in a chamber caused no changes in the afferent impulsation frequency and resulted in a decrease in the frequency of VN efferent discharges. Involvement of the VN in the maintenance of temperature homeostasis during fever induced by the endotoxin action and by hyperthermia due to a rise in ambient temperature is discussed. Neirofiziologiya/Neurophysiology, Vol. 32, No. 2, pp. 112–119, March–April, 2000.     

Assisted Reproduction and Distributive Justice

The Canadian province of Quebec recently amended its Health Insurance Act to cover the costs of In Vitro Fertilization (IVF). The province of Ontario recently de‐insured IVF. Both provinces cited cost‐effectiveness as their grounds, but the question as to whether a public health insurance system ought to cover IVF raises the deeper question of how we should understand reproduction at the social level, and whether its costs should be a matter of individual or collective responsibility. In this article I examine three strategies for justifying collective provisions in a liberal society and assess whether public reproductive assistance can be defended on any of these accounts. I begin by considering, and rejecting, rights‐based and needs‐based approaches. I go on to argue that instead we ought to address assisted reproduction from the perspective of the contractarian insurance‐based model for public health coverage, according to which we select items for inclusion based on their unpredictability in nature and cost. I argue that infertility qualifies as an unpredictable incident against which rational agents would choose to insure under ideal conditions and that assisted reproduction is thereby a matter of collective responsibility, but only in cases of medical necessity or inability to pay. The policy I endorse by appeal to this approach is a means‐tested system of coverage resembling neither Ontario nor Quebec's, and I conclude that it constitutes a promising alternative worthy of serious consideration by bioethicists, political philosophers, and policy‐makers alike.     

Blunted Vagal Cocaine- and Amphetamine-Regulated Transcript Promotes Hyperphagia and Weight Gain

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Vagus Nerve Stimulation as a Tool to Induce Plasticity in Pathways Relevant for Extinction Learning

Extinction describes the process of attenuating behavioral responses to neutral stimuli when they no longer provide the reinforcement that has been maintaining the behavior. There is close correspondence between fear and human anxiety, and therefore studies of extinction learning might provide insight into the biological nature of anxiety-related disorders such as post-traumatic stress disorder, and they might help to develop strategies to treat them. Preclinical research aims to aid extinction learning and to induce targeted plasticity in extinction circuits to consolidate the newly formed memory. Vagus nerve stimulation (VNS) is a powerful approach that provides tight temporal and circuit-specific release of neurotransmitters, resulting in modulation of neuronal networks engaged in an ongoing task. VNS enhances memory consolidation in both rats and humans, and pairing VNS with exposure to conditioned cues enhances the consolidation of extinction learning in rats. Here, we provide a detailed protocol for the preparation of custom-made parts and the surgical procedures required for VNS in rats. Using this protocol we show how VNS can facilitate the extinction of conditioned fear responses in an auditory fear conditioning task. In addition, we provide evidence that VNS modulates synaptic plasticity in the pathway between the infralimbic (IL) medial prefrontal cortex and the basolateral complex of the amygdala (BLA), which is involved in the expression and modulation of extinction memory.     

The containment of the radical right in Western Europe: a response to Carvalho

Do extreme right parties in contemporary Europe shape policy in meaningful ways? Carvalho's book charts complicated intellectual terrain, and the author demonstrates that while radical right parties have made a modest political impact in some states, they have achieved much less than one might have expected in their central policy area (immigration). After reviewing the strengths and weaknesses of Carvalho's analysis, I suggest that his findings are consistent with the general ‘containment’ (as opposed to ‘contagion’) of the radical right in (Western) Europe. The notion that the populist right has been ‘contained’ in Europe may seem odd at first blush, but a comparison with the USA suggests that it may be a fruitful theoretical starting point.     

Are radical right-wing parties the black holes in party space? Implications and limitations in impact assessment of radical right-wing parties

Radical right-wing parties have been a constant force in party systems of Western Europe since the late 1980s, despite cycles of development and support. Still, measurement of their impact has proven difficult. Scholars assessing the impact of radical right-wing parties in recent years have produced mixed findings in terms of whether effects tend to be direct or indirect and more or less salient. The recent book by Carvalho engages existing literature on impact assessment examining the cases of the UK, France and Italy. His findings caution against overstatement of impacts on immigration policy, suggesting that effects are contingent on party system competition and mainstream party agency. This article considers the mixed results pointing to a lack of existing tools for measuring indirect party impacts. It contends that existing theory on party impact struggles to conceptualize empty spaces in political ideology, attributing agency to moving parties and not to others that may be pushing them.     

Left‐right asymmetry in the light of TOR: An update on what we know so far

The internal left‐right (LR) asymmetry is a characteristic that exists throughout the animal kingdom from roundworms over flies and fish to mammals. Cilia, which are antenna‐like structures protruding into the extracellular space, are involved in establishing LR asymmetry during early development. Humans who suffer from dysfunctional cilia often develop conditions such as heterotaxy, where internal organs appear to be placed randomly. As a consequence to this failure in asymmetry development, serious complications such as congenital heart defects (CHD) occur. The mammalian (or mechanistic) target of rapamycin (mTOR) pathway has recently emerged as an important regulator regarding symmetry breaking. The mTOR pathway governs fundamental processes such as protein translation or metabolism. Its activity can be transduced by two complexes, which are called TORC1 and TORC2, respectively. So far, only TORC1 has been implicated with asymmetry development and appears to require very precise regulation. A number of recent papers provided evidence that dysregulated TORC1 results in alterations of motile cilia and asymmetry defects. In here, we give an update on what we know so far of mTORC1 in LR asymmetry development.     

Does disappearance mean extirpation? The case of right whales off Namibia

Right whales off Namibia were severely depleted by early 19th century whaling, and rarely featured in modern whaling catches in the 1920s. Aerial surveys of the Namibian coastline from 1978 and onwards revealed increasing numbers of right whales, but few cow‐calf pairs. Aerial surveys off South Africa since 2009 showed a major decline in the availability of animals without calves. Twenty individual matches were made between 94 whales photographed off Namibia/Northern Cape in 2003–2012 and 1,677 photographed off South Africa in 1979–2012. Eight were adult females that calved in South African waters, but only one was also seen with a calf off Namibia. Twelve out of 13 individuals off Namibia with distinctive dorsal pigmentation were first seen as calves off South Africa. These results strongly indicate connectivity between the two regions, while the presence off Namibia of three adult females from the South African population in the season in which they are believed to conceive suggests that there is unlikely to be any genetic differentiation between the two areas. We conclude that the reappearance of right whales off Namibia represents range expansion from South Africa rather than the survival of a few remnants of an originally separate stock.