Neuroscience journal最新文献

Rauwolfia vomitoria is a plant used for the treatment of insanity. The possible adverse effects of crude ethanolic root bark and leaf extract of the plant on Nissl substances of albino Wistar rat fetuses were studied using 25 mature female Wistar rats. The animals were divided equally into 5 groups, labeled A, B, C, D, and E. Group A was the control, while groups B, C, D, and E were the experimental. The female rats were mated with the males overnight, and the sperm positive day was designated as day zero of pregnancy. Oral doses of 150 mg/kg and 250 mg/kg body weight of the root bark extract were administered to groups B and C animals, respectively, while groups D and E animals received 150 mg/kg and 250 mg/kg body weight of the leaf extract, respectively, from day 7 to 11 of gestation. On day 20 of gestation, the rats were sacrificed, the fetuses brains extracted, and the cerebral cortices excised and routinely processed for Nissl substances using Cresyl fast violet staining method. Results showed reduced staining intensity of Nissl substances in the treated groups, especially those that received the root extract. Thus, the herbs may have adverse effects on protein synthesis within the cerebral cortex.

Aim. To evaluate the frequency of atypical and malignant meningiomas and analyze recurrence rate; to study the morbidity and mortality of these tumors compared to benign meningiomas. Methods. During 1992-2007, 16 patients with malignant and 16 patients with atypical meningioma were operated in Neurosurgery Department of Thessaloniki's Papanikolaou Hospital. We analyzed tumor histology, location, and extent of surgical resection with respect to tumor reappearance and patients' outcome and compared the behavior of benign versus nonbenign meningiomas. Results. Malignant meningiomas accounted for 4.4% (16 patients) and atypical meningiomas for another 4.4% of the series of patients (353) who were operated for intracranial meningioma at our department that period. Malignant meningiomas recurred at a rate of 75% and atypical meningiomas recurred at a rate of 41.6%. There was a significant association of the histological classification (benign, atypical, and malignant) with recurrence (P < 0.01). The recurrence rate after complete resection was 13.8%. The recurrence rate for incomplete resection was 46.7%. Extent of tumor removal was significant to recurrence (P < 0.001) for benign as well for atypical and malignant meningiomas. Tumor location (P > 0.05) was not significant to recurrence. Conclusions. Atypical and malignant meningiomas appeared at a rate of 8.8% of our series of intracranial meningiomas. They showed a significant predisposition to recur. These rare subtypes have higher morbidity and mortality rates than benign meningiomas. Recurrence depends primarily on the extent of surgical removal and on the histological characterization of the tumor as atypical or malignant.

Advanced ageing is associated with hippocampal deterioration and mild cognitive decline. The hippocampal subregion CA3 stratum lucidum (CA3-SL) receives neuronal inputs from the giant mossy fibre boutons of the dentate gyrus, but relatively little is known about the integrity of this synaptic connection with ageing. Using serial electron microscopy and unbiased stereology, we examined age-related changes in mossy fibre synapses on CA3 thorny excrescences within the CA3-SL of young adults (4-month-old), middle-aged (12-month-old), and old-aged (28-month-old) Wistar rats. Our data show that while there is an increase in CA3 volume with ageing, there is a significant (40-45%) reduction in synaptic density within the CA3-SL of 12- and 28-month-old animals compared with 4-month-old animals. We also present preliminary data showing that the CA3 neuropil in advanced ageing was conspicuously full of lipofuscin and phagolysosome positive, activated microglial cellular processes, and altered perivascular pathology. These data suggest that synaptic density in the CA3-SL is significantly impaired in ageing, accompanied by underlying prominent ultrastructural glial and microvascular changes.