Human chorionic gonadotropin attenuates amyloid-ß plaques induced by streptozotocin in the rat brain by affecting cytochrome c-ir neuron density.

OBJECTIVES: Amyloid ß plaques, in Alzheimer's disease, are deposits in different areas of the brain such as prefrontal cortex, molecular layer of the cerebellum, and the hippocampal formation. Amyloid ß aggregates lead to the release of cytochrome c and finally neuronal cell death in brain tissue. hCG has critical roles in brain development, neuron differentiation, and function. Therefore, we investigated the effect of hCG on the density of the congophilic Aß plaque and cytochrome c-ir neurons in the hippocampus, prefrontal cortex, and cerebellum of Streptozotocin (STZ)-treated rats. MATERIALS AND METHODS: Alzheimer model in rats (except the control group) was induced by streptozotocin (3 mg/kg, Intracerebroventricularly (ICV)). Experimental group rats received streptozotocin and then different doses of hCG (50, 100, and 200 IU, intraperitoneally) for 3 days. 48 hr after last drug injection and after histological processing, the brain sections were stained by congo red for congophilic amyloid ß plaques and cytochrome c in the hippocampus, prefrontal cortex, and cerebellum were immunohistochemically stained. RESULTS: Density of congophilic Aß plaques and cytochrome c-immunoreactive neurons was significantly higher in ICV STZ treated rats than controls. Treatment with three doses of hCG significantly decreased the density of congophilic Aß plaques and cytochrome c-immunoreactive neurons in the rat hippocampus, prefrontal cortex, and cerebellum in ICV STZ-treated rats (P<0.05). CONCLUSION: hCG can be useful in AD patients to prevent the congophilic Aß plaque formation and decrease cytochrome c-immunoreactive neuron density in the brain.

Ecstasy, anxiety and rat hippocampal astrocytes

Ecstasy (MDMA) is a popular drug a used recreationally with the rave culture and consumed in a high environment temperature. Repeated and prolonged MDMA ingestion is well known to cause depression, anxiety and aggression. The aim of this study was to evaluate the sub-chronic effects of MDMA on anxiety in Wistar rats and to determine astrocytes density in the rat hippocampus after anxiety. In this study, 28 adult male Wistar rats were used. The animals were distributed randomly in four groups, one sham group (receiving 1 ml/kg 0.9% saline solution) and three experimental groups: Exp. 1 (1.25 mg/kg/day MDMA), Exp. 2 (2.5 mg/kg/day MDMA), and Exp. 3 (5 mg/kg/day MDMA). The animals received Saline or MDMA for a week (sub-chronic period). An Elevated Plus Maze apparatus was used to examine anxiety levels in the rats. 24 h. after the last injection and behavioral test, the rat brains were withdrawn and fixed with 4% paraformaldehyde, and then - after histological processing - the slices of hippocampus were stained with PTAH for astrocytes. Our results showed that MDMA at 2.5 mg/kg/day for a week was most effective in causing anxiety. We found that the number of astrocytes was increased after this period. The greatest increase in astrocyte numbers was observed in the dentate gyrus of the5 mg/kg MDMA group. We concluded that the administration of MDMA over 7 days (sub-chronic period) can cause anxiety and can have an effect on the astrocyte density of the rat hippocampu (AU)

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Effects of Repeated Administration of 3,4-methylenedioxymethamphetamine (MDMA) on Avoidance Memory and Cell Density in Rats' Hippocampus.

INTRODUCTION: MDMA or ecstasy is a derivative of amphetamines used mostly by young people worldwide. Although the acute effects of this drug are known, the effect of chronic administration is not well studied. Therefor the aim of this study was to determine the effects of repeated (long term) administration of MDMA on rats' memory and their hippocampal cell density. METHOD: Young adult male Wistar rats 200 ± 20 g served as subjects. The rats were randomly distributed into three MDMA treated groups (3×2.5 mg/kg, 3×5 mg/kg, 3×10 mg/kg) and one control-saline group. All animals received MDMA intraperitoneally (3h apart; a challenge) 7th day of every week for consecutive 4 weeks. Animals were trained before and were tested after injections for their memory status using the standards passive avoidance method. Finally, 24hr after the memory test, rats were sacrificed and after tissue operations, the hippocampal astrocytes and neurons were counted. RESULTS: Results showed that the number of neurons in all experimental groups was lower than the control-saline group. The most decreased number of neurons was shown in 5 mg/kg MDMA group compared to control-saline in all the regions of hippocampus. Also we found that repeated administration of MDMA reduced the number of hippocampal astrocytes. DISCUSSION: It is concluded that repeated administration of MDMA can reduce density of neurons and astrocytes and this decrease is not dose dependence.