Aim: To investigate the protective effects of kolaviron on brain weight and behavioural performance and the histology of the hippocampus of adult Wistar rats following methamphetamine challenge. Materials and Methods:Twenty four adult Wistar rats weighing between 150-200 g, randomly assigned into four groups of six each (Groups A, B, C, D) were used for this research. Group A served as control, while groups B and C were given single dose methamphetamine (10 mg/kg) intraperitoneally after group C was pre-treated with kolaviron (200 mg/kg) for 7 days and group D received cornoil (vehicle for kolaviron) only.Results: High level of methamphetamine-induced stereotypic movement was observed, and the onset was delayed by kolaviron administration. Animals administered methamphetamine only, showed significantly poor behavioural performance on the water maze after treatment when compared to the other groups (P<0.05). Histological analysis revealed neuronal destruction of the pyramidal layer of the hippocampus following methamphetamine administration. Kolaviron to some extent prevented destruction of pyramidal cells of the hippocampus in pre-treated rats. Conclusion:The present findings show the neuro-destructive effects of methamphetamine on hippocampal neurons and its ability to negatively affect behaviour and that kolaviron could prevent such behavioural deficit and also afford some protection to the hippocampus.

BackgroundNicotine is a subject of continuous research because of its likely ameliorative effects on neurologic and neurodegenerative disorders.PurposeThis study examined the effects of its chronic subcutaneous administration on hippocampal and striatal microstructure in both female and male rats.MethodsForty adult female and male Wistar rats were divided into 4 groups. Three experimental groups were administered nicotine via subcutaneous injections at doses of 0.25, 2 and 4 mg/kg body weight for 28 days. Control groups received normal saline. Following administration, routine processing of brain tissues was carried out. Sections obtained were stained using routine H&E methods for general histological appearance, Cresyl violet methods for nissl substances, and Bielschwolsky silver impregnation method for neuritic plaques and neurofibrillary tangles.ResultsThe study showed significant increase in percentage of neurons showing degenerating features in the hippocampus and striatum of both female and male rats following the higher doses of nicotine treatment. Only female rats showed positive agyrophilic (black-coloured) aggregations in the hippocampal and striatal regions after nicotine treatment.ConclusionThe present study indicates that higher dose of chronic nicotine administration may induce hippocampal and striatal neurodegenerative changes. However, further studies using more specific method for studying neurodegeneration within brain regions is recommended.

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BackgroundNicotine has shown potential therapeutic value for neurodegenerative diseases though there are concerns that it may induce behavioural deficits.PurposeThe present study sought to determine the effect of chronic nicotine administration on overall motor functions and coordination.MethodsForty adult female and male Wistar rats were randomly grouped into 4 groups. Treated groups were administered nicotine via subcutaneous injections at doses of 0.25, 2 and 4 mg/kg body weight for 28 days. Control groups received normal saline. All animals were monitored for the first few minutes after each injection for any observed immediate effect of drug administration. Motor associated behavioural tests performed include: open field test, string test for grip strength and limb impairment, movement initiation and step test.ResultsNicotine induced muscular convulsions within the first 1-5 minutes following daily subcutaneous injections, throughout the period of administration. This was observed to be more severe in females. Nicotine did not produce major alterations in overall motor functions and coordination in both females and males.ConclusionThe present study shows chronic nicotine treatment produces muscular convulsion but no major deficit in overall motor function and coordination and that any observed alterations may just be transient effects.

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