Learning and memory are often correlated with cellular changes within the hippocampus, and drugs or environmental factors which affect learning and memory will thus often induce observable ...morphological changes in this structure. Like tetrahydrocannabinol (THC) itself, many synthetic cannabinoids such as the CB-1 receptor agonist WIN 55,212-2 will induce learning and memory changes. In the current study, we investigate whether or not these changes could be related to structural changes within the hippocampus. Adult male Sprague–Dawley rats were injected twice daily (12:00 and 0:00 h) subcutaneously with WIN 55,212-2 (2.0 mg/kg) in DMSO or DMSO for 21 days. On day 22, animals were perfused and stained immunochemically for the dendritic marker MAP-2, or with cresyl violet. Morphometric analysis showed dendritic rearrangement with increased staining of MAP-2 in CA3 and the lower blade of the dentate gyrus. However, a loss of staining was observed in CA1. Counting of cresyl violet stained sections showed an apparent increase in granule cell number in the lower blade of the dentate gyrus. This work shows the potential for cannabinoids to influence hippocampal morphology. The pattern of changes may be similar to that seen after ischemic or toxic damage, but may be opposite to changes seen in stress.
A general "one-pot" synthetic method is described for the preparation of phosphinodipeptides of type 1 , in 60-80% overall yield, allowing the variation of the substituents in f and/or g position to ...the phosphorus atom and also in f position to the nitrogen atom.
In this work we describe the main features of a Rb clock developed at INRIM and its preliminary industrialization approach made by Selex-ES. The clock operates at the Rb ground-state hyperfine ...frequency (6834 MHz) in pulsed regime; the pulsed optical pumping (POP) allows to make negligible the mutual interference between optical and microwave signals so that a frequency stability comparable to that of a passive H-maser has been achieved but with a much simpler system. The industrialization plan aims at investigating the possibility to reproduce the good results obtained by the INRIM laboratory prototype into a device suited to work in space.
Autism is classified as a pervasive developmental disorder, with several cardinal features including sensory disturbances, obsessive–compulsive-like behavior, lack of bonding to caregivers and motor ...disturbances. To date, there is a lack of an animal model of the disease. The current work is aimed at producing such a model by treating developing rat pups with a serotonergic agonist, 5-methoxytryptamine (5-MT; 1 mg/kg) during development (from gestational age 12 days to postnatal day 20), thus mimicking one of the hallmark neurochemical features of the illness—increases in the neurotransmitter, serotonin. Animals were then tested in behavioral paradigms that may resemble the human illness. Treated rat pups were found to be overreactive to auditory or tactile sensory stimuli, to display changes in the negative geotaxic test of motor development, to show lack of separation-induced vocalizations when their dam was removed and to show decreased alternation in the spontaneous alternation task. As well, the animals showed metabolic abnormalities in the brain using in vivo proton magnetic resonance spectroscopy, which are consistent with those observed in autistic children. In summary, the model we are proposing shows some of the behavioral and metabolic features of autism, as well as being produced through alteration of a neurochemical system known to be altered in autism.
S-100
β is a neurotrophic factor released by astroglial cells and localized to chromosome 21, within the region which is considered obligate for Down's syndrome (DS). S-100
β is increased in the ...postmortem brains of both DS and Alzheimer's disease. Transgenic mice, produced by insertion of the human gene for S-100
β, were examined for dendritic development at two ages, using an antibody against microtubule associated protein-2 (MAP-2). At the earliest stages, the density of dendrites within the hippocampus of transgenic animals exceeded that of controls. Also, MAP-2 immunostaining was evident in the region of the cell body. By 1 year of age, the transgenic animals had significant loss of dendrites compared to controls and the number of cells showing cell body staining was further increased. These pathological changes could be indicative of the presence of neurofibrillary tangles and cytoskeletal collapse. Behaviorally, younger transgenic animals could not perform in a learning task as well as controls. Together, these findings suggest that increased S-100
β in brain may lead to accelerated development, followed by increased aging. The pathological changes may prove useful as an animal model of Down's syndrome and Alzheimer's disease.
Hydrogen-free deuterated benzene C
6D
6 liquid scintillators are widely used for high resolution neutron capture cross-section measurements at time-of-flight facilities, using the total energy ...detection principle in combination with the Pulse Height Weighting Technique (PHWT). The quality of the data deduced from such measurements depends on the accuracy of the detector response that is used in the calculation of the weighting function and on the normalization procedure. In addition, for nuclei with small capture to scattering ratios, i.e. light and near neutron magic nuclei, a correction for the sensitivity of the capture detector to the scattered neutrons is required. The MCNP code was used to simulate both the γ-ray and neutron transport in a C
6D
6 detection system including its surroundings. The weighting functions and neutron sensitivity were then deduced from the simulations and validated by experiments. The simulations have also been used to identify the sources of uncertainties in performing capture cross-section measurements with C
6D
6 detectors.
A general one-pot synthesis is described for the preparation, in good overall yields, of phosphinopeptides as building blocks for peptide synthesis in the field of new enzyme inhibitors. This method, ...consisting of the addition of alkyl hypophosphites to imines and then in the Michael-addition of the resulting alkyl α-aminophosphonites on acrylates, affords the possibility of variations for the substituents in α and β position to the phosphorus atom and in α position to the nitrogen atom.
A one-pot procedure for the preparation, in good yields, of phosphinopeptides as building blocks for peptide synthesis in the field of new enzyme inhibitors is described. This method affords the possibility of variations for the substituents in α and β position to the phosphorus atom and in α position to the nitrogen atom.
A crash course in systems analysis Priest, S L; Borella, A B
Journal of healthcare information management,
1998-Fall, Letnik:
12, Številka:
3
Journal Article
PDF
