Morphological Changes and Characteristics of the Expression of Serine Racemase in the Hippocampus of Rats Exposed to Multiple Negative Gravitational Overloads

Neuroscience and Behavioral Physiology - Objectives. To study the morphometric parameters and levels of expression of serine racemase in the hippocampus of rats repeatedly exposed to gravitational...     

HPLC Determination of Aloenin in Leaves and Preparations of Aloe arborescens Mill.

Pharmaceutical Chemistry Journal - Amethod for quantitative determination of aloenin by microcolumn reversed-phase HPLC with UV detection (306 nm) using a KAH-6-80-4 column (2 × 80 mm,...     

Functional and Morphological Changes in the Pyramidal Layer of the Hippocampus in Rats with Encephalopathy Induced by Prolonged Exposure to Gravitational Overloading

Neuroscience and Behavioral Physiology - Studies of morphofunctional changes in the hippocampus using a model of impaired cerebral hemodynamics are needed for understanding the mechanisms of...     

Fatty Acid Profile and Antioxidant Activity of Nigella Sativa Fatty Oil

Pharmaceutical Chemistry Journal - The chemical composition of Nigella sativa L. (black cumin) fatty oil was studied by gas chromatography with mass-selective detection in a search for promising...     

Developing methods for qualitative and quantitative analysis of <Emphasis Type="Italic">Chelidonium majus</Emphasis> herbs

A pure compound has been isolated and identified as coptisine on the basis of UV and NMR spectroscopy data using preparative separation of the extract from greater celandine (Chelidonium majus L.) herbs by column chromatography over short columns of silica gel. Qualitative and quantitative estimation of the total alkaloid contents in C. majus is performed using TLC analysis and spectrophotometry (analytical wavelength 360 nm). The need for using a state standard sample of coptisine is validated. The total content of alkaloids in C. majus herbs varies within 0.90–1.75% (calculated as coptisine). The relative error of the determination of the total alkaloid content using the proposed method at a confidence probability of 0.95 does not exceed ±4.40%. Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 42, No. 11, pp. 30–33, November, 2008.     

Directional asymmetry in vertical smooth-pursuit and cancellation of the vertical vestibulo-ocular reflex in juvenile monkeys

Young primates exhibit asymmetric eye movements during vertical smooth-pursuit across a textured background such that upward pursuit has low velocity and requires many catch-up saccades. The asymmetric eye movements cannot be explained by the un-suppressed optokinetic reflex resulting from background visual motion across the retina during pursuit, suggesting that the asymmetry reflects most probably, a low gain in upward eye commands (Kasahara et al. in Exp Brain Res 171:306–321, 2006). In this study, we examined (1) whether there are intrinsic differences in the upward and downward pursuit capabilities and (2) how the difficulty in upward pursuit is correlated with the ability of vertical VOR cancellation. Three juvenile macaques that had initially been trained only for horizontal (but not vertical) pursuit were trained for sinusoidal pursuit in the absence of a textured background. In 2 of the 3 macaques, there was a clear asymmetry between upward and downward pursuit gains and in the time course of initial gain increase. In the third macaque, downward pursuit gain was also low. It did not show consistent asymmetry during the initial 2 weeks of training. However, it also exhibited a significant asymmetry after 4 months of training, similar to the other two monkeys. After 6 months of training, these two monkeys (but not the third) still exhibited asymmetry. As target frequency increased in these two monkeys, mean upward eye velocity saturated at ∼15°/s, whereas horizontal and downward eye velocity increased up to ∼40°/s. During cancellation of the VOR induced by upward whole body rotation, downward eye velocity of the residual VOR increased as the stimulus frequency increased. Gain of the residual VOR during upward rotation was significantly higher than that during horizontal and downward rotation. The time course of residual VOR induced by vertical whole body step-rotation during VOR cancellation was predicted by addition of eye velocity during pursuit and VOR x1. These results support our view that the directional asymmetry reflects the difference in the organization of the cerebellar floccular region for upward and downward directions and the preeminent role of pursuit in VOR cancellation.