Modeling neuropathologic syndromes by creating generators of pathologically enhanced excitation in the hypothalamus of rabbits

In the experiments on free behavior rabbits, tetanus toxin was injected into "pacemaker" motivational emotiogenic regions of the hypothalamus to form generators of pathologically enhanced excitation; this produced stable, long-term disorders in motivational-emotional behavior. The changes were manifested by intensification of the feeding behavior activity, including increase of the "secondary motivational reactions", intensification of the motor activity, excessive number of automatic masticatory movements, appearance of aggression, fear reaction and corresponding vegetative changes. The character of these reactions depended on the site of the toxin administration and on its dose. Formation of long-term generators of the pathologically enhanced excitation in the "pacemaker" motivational-emotiogenic centers of the hypothalamus by tetanus toxin can be used the modelling of psychopathological states in animals. The data obtained on the new model have confirmed the theory of generative mechanisms of neuropathological syndromes characterized by hyperactivity of the systems.     

Electrical and adaptive properties of rod photoreceptors in bufo marinus. I. Effects of altered extracellular Ca(2+) levels

The effects of altering extracellular Ca(2+) levels on the electrical and adaptive properties of toad rods have been examined. The retina was continually superfused in control (1.6 mM Ca(2+)) or test ringer’s solutions, and rod electrical activity was recorded intracellularly. Low-calcium ringer’s (10(-9)M Ca(2+)) superfused for up to 6 min caused a substantial depolarization of the resting membrane potential, an increase in light-evoked response amplitudes, and a change in the waveform of the light-evoked responses. High Ca(2+) ringer’s (3.2 mM) hyperpolarized the cell membrane and decreased response amplitudes. However, under conditions of either low or high Ca(2+) superfusion for up to 6 min, in both dark-adapted and partially light-adapted states, receptor sensitivity was virtually unaffected; i.e., the V-log I curve for the receptor potential was always located on the intensity scale at a position predicted by the prevailing light level, not by Ca(2+) concentration. Thus, we speculate that cytosol Ca(2+) concentration is capable of regulating membrane potential levels and light-evoked response amplitudes, but not the major component of rod sensitivity. Low Ca(2+) ringer’s also shortened the period of receptor response saturation after a bright but nonbleaching light flash, hence accelerating the onset of both membrane potential and sensitivity recovery during dark adaptation.

Exposure of the retina to low Ca(2+) (10(-9)M) ringer’s for long periods (7-15 min) caused dark-adapted rods to lose responsiveness. Response amplitudes gradually decreased, and the rods became desensitized. These severe conditions of low Ca(2+) caused changes in the dark-adapted rod that mimic those observed in rods during light adaptation. We suggest that loss of receptor sensitivity during prolonged exposure to low Ca(2+) ringer’s results from a decrease of intracellular (intradisk) stores of Ca(2+); i.e., less Ca(2+) is thereby released per quantum catch.

     

Acceptor of action results as a structural functional basis of dynamic stereotype activities of the brain

The system mechanisms of brain dynamic stereotypes formation are considered. The brain dynamic stereotypes are shown to be formed on the structures of acceptor of action results by dominating motivations and reinforcements. Acceptors of action results are widely spread in brain structures. They are presented in functional systems which form behavioral acts of animals with spreading neural excitations in collaterals of axons of pyramidal tract. Reinforcing excitations form specific architectonic of acceptors of action results, which include brain structures corresponding to modalities of parameters of reinforcements. Dominating motivations, which predict future events, excite molecular engrams of action results which were formed by previous reinforcements.     

Gastrin in the mechanisms of genetic determination of feeding behavior in rabbits

Spreading of a dominant motivation to the molecular intracellular mechanisms of genetic memory was studied. Blockage of protein synthesis in the nervous system selectively abolishes food motivation in rabbits during stimulation of the lateral hypothalamus but exerts no noticeable effect on avoidance responses during stimulation of the ventromedial hypothalamus. During protein synthesis blockage, food motivation returns to normal upon pentagastrin intracerebroventricular (i.c.v.) injection. Intracerebroventricular administration of antigastrin immunoglobulin inhibits feeding reaction to lateral hypothalamic stimulation but not avoidance response to ventromedial hypothalamic stimulation. It was concluded that feeding motivation translates into feeding behavior in the following stages: motivational excitation, gene activation, mRNA synthesis, formation of a gastrin-like peptide, and expression of feeding behavior.     

A statistical test that supports a human/chimpanzee clade based on noncoding DNA sequence data

Using the aligned DNA sequence data of Miyamoto et al. and Maeda et al., all noncoding genetic material, and a simple statistical test, we show that a Homo/Pan clade is supported at approximately the 3% level of significance. The method accommodates polymorphism and different evolutionary rates for different sites. All assumptions on which the statistical study is based are made explicit. (See the Note added in proof, which--adding recently published data--improves the significance level to about 1%.      

Reflooding the Faguibine floodplain system,northern Mali: potential benefits and challenges

The Faguibine system, northern Mali, consists of a series of interconnected floodplains of which the flooded surface area declined from about 1 000 km² in the late 19th century to only some 90 km² in 2010. Flood extent depends on the height of the Niger River flood peak at Diré. Satellite imagery analysis indicated that a phase shift may have occurred in the year 2000, probably as a delayed consequence of the Sahelian drought of the 1970s compounded by the collapse of societal controls on water use during recent civil conflict. An economic evaluation of the system in 2011 showed US$100 000 per year of net income per flooded km² in Lake Faguibine, allowing vulnerable people to practise recession agriculture, to fish and to graze livestock. An intensive investment phase, combined with an approach of rebuilding local governance systems and environmental management capacity, could yield net benefits to the user communities of the order of ten times the maintenance costs, contributing to human well-being. The system is currently threatened by the building of the Fomi Dam in Guinea and by the planned expansion of irrigation upstream. There is also a risk of the return of a prolonged drought linked to the Atlantic multi-decadal oscillation index.     

Zerumbone induced apoptosis in liver cancer cells via modulation of Bax/Bcl-2 ratio

Background  

Zerumbone is a cytotoxic component isolated from Zingiber zerumbet Smith, a herbal plant which is also known as lempoyang. This new anticancer bioactive compound from Z. zerumbet was investigated for its activity and mechanism in human liver cancer cell lines.     

耐甲氧西林金黄色葡萄球菌在动物流行病学中的研究进展

葡萄球菌是动物中重要的机会性病原体,耐甲氧西林金黄色葡萄球菌（MRSA）因其多药耐药的特征日益成为动物和公众健康的主要威胁。由于动物与动物及人畜间存在相互传染的风险,在控制MRSA感染的整个体系中,分析MRSA在动物中的流行显得尤为重要。