Search

Objectives: To evaluate the hypoglycemic and anti-diabetic activity of chloroform extract of Calotropis gigantea leaves and flowers in normal rats and streptozotocin induced diabetes.Methods: The hypoglycemic activity in normal rats was carried out by treatment using chloroform extract of Calotropis gigantea leaf and flower 10, 20 and 50 mg/kg, orally. The oral glucose tolerance test was carried out by administering glucose (2 g/kg, p.o), to non-diabetic rats treated with leaf and flowers extracts at oral doses 10, 20 and 50 mg/kg, p.o and glibenclamide 10 mg/kg. The serum glucose was then measured at 0, 1.5, 3 and 5 hr after administration of extracts/drug. Streptozotocin-induced diabetic rats were administered the same doses of leaf and flower extracts, and standard drugs glibenclamide was given to the normal rats or 0.5 ml of 5�0Tween-80, for 27 days. The blood sample from all groups collected by retro-orbital puncture on 7, 14, 21 and 27th days after administration of the extracts/drug and used for the estimation of serum glucose levels using the glucose kit.Results: The Calotropis gigantea leaves and flowers extracts were effective in lowering serum glucose levels in normal rats. Improvement in oral glucose tolerance was also registered by treatment with Calotropis gigantean. The administration of leaf and flower extracts to streptozotocin-induced diabetic rats showed a significant reduction in serum glucose levels.Conclusion: It is concluded that chloroform extracts of Calotropis gigantea leaves and flowers have significant anti-diabetic activity.

Modern techniques that enable identification and targeted manipulation of neuron groups are frequently used to bolster theories that attribute specific behavioral functions to specific neuron types. These same techniques can also be used, however, to highlight limitations of such attribution, and to develop the argument that the question "what is the function of these neurons?" is ill-posed in the absence of temporal and network constraints. Here we do this, first reviewing evidence that neural responses are dynamic at multiple time scales, making the point that such changes in firing rates imply changes in what the neuron is doing. Studies involving brief perturbations of neural populations confirm this point, showing that the functions in which these populations participate change across seconds and even milliseconds. Based on these studies, we suggest that it is inappropriate to assign function to sets of neurons without contextualizing that assignment to specific times and network conditions., Competing Interests: Declaration of interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Background: Working memory deficits are key cognitive symptoms of schizophrenia. Elevated delta oscillations, which are uniquely associated with the presence of the illness, may be the proximal cause of these deficits. Spatial working memory (SWM) is impaired by elevated delta oscillations projecting from thalamic nucleus reuniens (RE) to the hippocampus (HPC); these findings imply a role of the RE-HPC circuit in working memory deficits in schizophrenia, but questions remain as to whether the affected process is the encoding of working memory, recall, or both. Here, we answered this question by optogenetically inducing delta oscillations in the HPC terminals of RE axons in mice during either the encoding or retrieval phase (or both) of an SWM task., Methods: We transduced cells in RE to express channelrhodopsin-2 through bilateral injection of adeno-associated virus, and bilaterally implanted optical fibers dorsal to the hippocampus (HPC). While mice performed a spatial memory task on a Y-maze, the RE-HPC projections were optogenetically stimulated at delta frequency during distinct phases of the task., Results: Full-trial stimulation successfully impaired SWM performance, replicating the results of the previous study in a mouse model. Task-phase-specific stimulation significantly impaired performance during retrieval but not encoding., Conclusions: Our results indicate that perturbations in the RE-HPC circuit specifically impair the retrieval phase of working memory. This finding supports the hypothesis that abnormal delta frequency bursting in the thalamus could have a causal role in producing the WM deficits seen in schizophrenia., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Many sensory neural circuits exhibit response normalization, which occurs when the response of a neuron to a combination of multiple stimuli is less than the sum of the responses to the individual stimuli presented alone. In the visual cortex, normalization takes the forms of cross-orientation suppression and surround suppression. At the onset of visual experience, visual circuits are partially developed and exhibit some mature features such as orientation selectivity, but it is unknown whether cross-orientation suppression is present at the onset of visual experience or requires visual experience for its emergence. We characterized the development of normalization and its dependence on visual experience in female ferrets. Visual experience was varied across the following three conditions: typical rearing, dark rearing, and dark rearing with daily exposure to simple sinusoidal gratings (14-16 h total). Cross-orientation suppression and surround suppression were noted in the earliest observations, and did not vary considerably with experience. We also observed evidence of continued maturation of receptive field properties in the second month of visual experience: substantial length summation was observed only in the oldest animals (postnatal day 90); evoked firing rates were greatly increased in older animals; and direction selectivity required experience, but declined slightly in older animals. These results constrain the space of possible circuit implementations of these features. SIGNIFICANCE STATEMENT The development of the brain depends on both nature-factors that are independent of the experience of an individual animal-and nurture-factors that depend on experience. While orientation selectivity, one of the major response properties of neurons in visual cortex, is already present at the onset of visual experience, it is unknown whether response properties that depend on interactions among multiple stimuli develop without experience. We find that the properties of cross-orientation suppression and surround suppression are present at eye opening, and do not depend on visual experience. Our results are consistent with the idea that a majority of the basic properties of sensory neurons in primary visual cortex are derived independent of the experience of an individual animal., (Copyright © 2018 the authors 0270-6474/18/382656-15$15.00/0.)

Introduction: Neonatal respiratory disorders are a leading cause of perinatal mortality due to complications resulting from premature births and prenatal exposure to drugs of abuse, but optimal treatments for these symptoms are still unclear due to a variety of confounds and risk factors. Mouse models present an opportunity to study the underlying mechanisms and efficacy of potential treatments of these conditions with controlled variables. However, measuring respiration in newborn mice is difficult and commercial components are expensive and often require modification, creating a barrier and limiting our understanding of the short and long-term effects of birth complications on respiratory function., Methods: Here, we present an inexpensive and simple flow through pneumotachograph and face mask design that can be easily scaled for parallel, high-throughput assays measuring respiration in neonatal mouse pups. The final apparatus consists of three main parts: a water-jacketed chamber, an integrated support tray for the pup, and a pneumotachograph consisting of a two side-arm air channel that is attached to a pressure transducer., Results: The pneumotach showed a linear response and clean, steady respiratory traces in which apneas and sighs were clearly visible. Administration of caffeine in P0.5 CD1 wildtype neonates resulted in an increase in tidal volume, minute ventilation, and minute ventilation normalized to oxygen consumption as well as a decrease in periodic instability., Discussion: The described methods offer a relatively simple and inexpensive approach to constructing a pneumotachograph for non-invasive measurements of neonatal mouse respiration, enhancing accessibility and enabling the high-throughput and parallel characterizations of neonatal respiratory disorders and potential pharmacological therapies., (Copyright © 2017 Elsevier Inc. All rights reserved.)

A goal of current schizophrenia (SZ) research is to understand how multiple risk genes work together with environmental factors to produce the disease. In schizophrenia, there is elevated delta frequency EEG power in the awake state, an elevation that can be mimicked in rodents by N-methyl-d-aspartate receptor (NMDAR) antagonist action in the thalamus. This thalamic delta can be blocked by dopamine D2 receptor antagonists, agents known to be therapeutic in SZ. Experiments suggest that these oscillations can interfere with brain function and may thus be causal in producing psychosis. Here we evaluate the question of whether well-established schizophrenia risk genes may interact to affect the delta generation process. We identify 19 risk genes that can plausibly work in a synergistic fashion to generate delta oscillations., Competing Interests: John Lisman received speaker’s honoraria from Pfizer Pharmaceuticals and Roche Pharmaceuticals. Edwin A. Richard, Elizaveta Khlestova and Roshan Nanu report no potential conflicts of interest., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In order to make adequate provision for staffing and staff training in leagane (long-term residential care institutions for preschool age children in Romania) a postal survey was conducted in the autumn of 1991 to ascertain the demographic characteristics, job titles and educational attainment of directors and staff, staffing needs and the kinds of positions currently filled, the numbers of directors and staff exposed to continuing education programmes within the last 2 years, and the opinions of directors and staff regarding their most important continuing educational needs. The bulk of the direct care workforce was less than 50 years old. Thirty-four per cent of the direct care staff had less than a high-school education. Sixty-seven per cent of the staff were health professionals or health care workers. There were few psychologists, physical therapists, teachers or social workers. In the last 2 years, directors and other physicians had been mostly exposed to courses in the areas of psycho-social care/management and paediatric medical care. Nurses had attended professional development courses. Infirmiera (nursing assistants) had also attended professional development courses such as those offered by foreign non-governmental organizations on the care of institutionalized children. Educators (teaching assistants) had attended courses in child development and rehabilitation. Directors and staff expressed clear opinions regarding their needs and preferences for additional training.