Panic-like defensive behavior but not fear-induced antinociception is differently organized by dorsomedial and posterior hypothalamic nuclei of Rattus norvegicus (Rodentia, Muridae)

The hypothalamus is a forebrain structure critically involved in the organization of defensive responses to aversive stimuli. Gamma-aminobutyric acid (GABA)ergic dysfunction in dorsomedial and posterior hypothalamic nuclei is implicated in the origin of panic-like defensive behavior, as well as in pain modulation. The present study was conducted to test the difference between these two hypothalamic nuclei regarding defensive and antinociceptive mechanisms. Thus, the GABA A antagonist bicuculline (40 ng/0.2 µL) or saline (0.9% NaCl) was microinjected into the dorsomedial or posterior hypothalamus in independent groups. Innate fear-induced responses characterized by defensive attention, defensive immobility and elaborate escape behavior were evoked by hypothalamic blockade of GABA A receptors. Fear-induced defensive behavior organized by the posterior hypothalamus was more intense than that organized by dorsomedial hypothalamic nuclei. Escape behavior elicited by GABA A receptor blockade in both the dorsomedial and posterior hypothalamus was followed by an increase in nociceptive threshold. Interestingly, there was no difference in the intensity or in the duration of fear-induced antinociception shown by each hypothalamic division presently investigated. The present study showed that GABAergic dysfunction in nuclei of both the dorsomedial and posterior hypothalamus elicit panic attack-like defensive responses followed by fear-induced antinociception, although the innate fear-induced behavior originates differently in the posterior hypothalamus in comparison to the activity of medial hypothalamic subdivisions.

New perspective on the pathophysiology of panic: merging serotonin and opioids in the periaqueductal gray

Panic disorder patients are vulnerable to recurrent panic attacks. Two neurochemical hypotheses have been proposed to explain this susceptibility. The first assumes that panic patients have deficient serotonergic inhibition of neurons localized in the dorsal periaqueductal gray matter of the midbrain that organize defensive reactions to cope with proximal threats and of sympathomotor control areas of the rostral ventrolateral medulla that generate most of the neurovegetative symptoms of the panic attack. The second suggests that endogenous opioids buffer normal subjects from the behavioral and physiological manifestations of the panic attack, and their deficit brings about heightened suffocation sensitivity and separation anxiety in panic patients, making them more vulnerable to panic attacks. Experimental results obtained in rats performing one-way escape in the elevated T-maze, an animal model of panic, indicate that the inhibitory action of serotonin on defense is connected with activation of endogenous opioids in the periaqueductal gray. This allows reconciliation of the serotonergic and opioidergic hypotheses of panic pathophysiology, the periaqueductal gray being the fulcrum of serotonin-opioid interaction.

Chronic kidney disease in disadvantaged populations

The increased burden of chronic kidney disease (CKD) in disadvantaged populations is due to both global factors and population-specific issues. Low socioeconomic status and poor access to care contribute to health care disparities and exacerbate the negative effects of genetic or biological predisposition. Provision of appropriate renal care to these populations requires a two-pronged approach: expanding the reach of dialysis through development of low-cost alternatives that can be practiced in remote locations, and implementation and evaluation of cost-effective prevention strategies. Kidney transplantation should be promoted by expansion of deceased donor transplant programs and use of inexpensive, generic immunosuppressive drugs. The message of World Kidney Day 2015 is that a concerted attack against the diseases that lead to end-stage renal disease, by increasing community outreach, better education, improved economic opportunity, and access to preventive medicine for those at highest risk, could end the unacceptable relationship between CKD and disadvantage in these communities.

Prions: the danger of biochemical weapons

The knowledge of biotechnology increases the risk of using biochemical weapons for mass destruction. Prions are unprecedented infectious pathogens that cause a group of fatal neurodegenerative diseases by a novel mechanism. They are transmissible particles that are devoid of nucleic acid. Due to their singular characteristics, Prions emerge as potential danger since they can be used in the development of such weapons. Prions cause fatal infectious diseases, and to date there is no therapeutic or prophylactic approach against these diseases. Furthermore, Prions are resistant to food-preparation treatments such as high heat and can find their way from the digestive system into the nervous system; recombinant Prions are infectious either bound to soil particles or in aerosols. Therefore, lethal Prions can be developed by malicious researchers who could use it to attack political enemies since such weapons cause diseases that could be above suspicion.

Variation of some chemical and functional properties of Bambara groundnut (Voandzeia Subterranean L. Thouars) during sort time storage

Abstract The storage susceptibility of Bambara groundnut (B. G.) (Voandzeia Subterranean (L.) Thouars) to Callosobruchus maculatus and chemical and functional properties of 11 varieties form Far-North of Cameroon were investigate using standard analytical methods. Storage susceptibility shown that, after five months within treatment, C. maculatus destroy 10 to 50% of grains. The chemical characteristics of none attack grains of 11 varieties were range to 18.64 at 21.08%, 6.85 at 7.44%, 49.75 at 52.68% and to 6.05 at 7.55% respectively for protein, fat, starch and free carbohydrate. These chemical characteristics significantly (p < 0.05) decreases form attacks varieties. For the functional parameters, the none attacks grains was range of 130 at 135%, 19.15 at 20.91%, 18.20 at 21.13%, 2.76 at 3.21% and of 8.54 at 10.14% respectively for water capacity absorption, solubility index, gel length, ash and humidity. The results of this study indicated that storage susceptibility, chemical and functional properties of B. G. be dependant to the varieties.

Avaliação do relacionamento entre danos mecânicos e vigor, em sementes de milho, por meio da análise de imagens

A possibilidade de utilização da técnica de análise de imagens, para a determinação de danos mecânicos em sementes, é promissora; é um método de precisão, onde as sementes podem ser examinadas individualmente em imagens ampliadas e capazes de indicar, com detalhes, a área danificada, a localização e a extensão do dano. Por se tratar de método não destrutivo, as sementes em análise podem ser submetidas a testes fisiológicos e, desta forma, permitir o estabelecimento de relações entre os danos mecânicos e os prejuízos causados à qualidade. Assim, o presente trabalho teve o objetivo de estudar os efeitos dos danos mecânicos sobre o vigor de sementes de milho, utilizando a referida técnica. Cinqüenta sementes de cada um dos cultivares estudados (CO 32, AG 6690 e Attack) foram selecionadas visualmente, de tal maneira que a amostra fosse constituída por sementes íntegras e com danos mecânicos de intensidades variáveis. Em seguida, as sementes foram radiografadas, fotografadas (faces ventral e dorsal) e destinadas ao teste de frio (método do rolo de papel com terra). As plântulas normais, anormais e sementes mortas provenientes do teste de frio foram, também, fotografadas. As imagens obtidas foram disponibilizadas em computador de tal maneira que, examinadas simultaneamente na tela do monitor, pudessem ser buscadas relações de causa e efeito nas imagens anteriores e posteriores ao teste de frio. Os resultados obtidos indicam que o método estudado permite relacionar o dano mecânico com eventuais prejuízos ocasionados ao vigor das sementes de milho.

As razões do laissez-faire: uma análise do ataque ao mercantilismo e da defesa da liberdade econômica na Riqueza das Nações

The reasons of the laissez-faire: an analysis of the attack to mercantilism and of the defense of economic liberty in The Wealth of Nations. The main reasons presented in The Wealth of Nations to advocate the system of economic liberty and reject mercantilism are analyzed. These two systems are evaluated considering basically their impact on the annual product, and the degree of liberty and justice they engender. Based on his views of man and of capital hierarchy, Smith defends the superiority of economic liberty in what concerns the growth of the annual product. This system is also considered superior to mercantilism in terms of justice since it does not privilege any sector of society and allows a great level of liberty to the individuals.