Morris water maze test on neuroprotective effects of ethanolic extract of oyster mushroom (Pleurotus ostreatus) against neurotoxicity of mercury chloride in albino rats (Rattus norvegicus)

The neuroprotective effects of ethanolic extract of Pleurotus ostreatus against neurotoxicity of mercury on albino rats was studied using the spatial memory test (morris water maze test), this was conducted in order to know the extent of spatial memory impairments caused by mercury toxicity, and also to ascertain the neuroprotective effects of the mushroom against this toxicity. The study was conducted to determine the ability of the animal groups to identify and easily trace the location of an escape platform with the help of a spatial cues. Twenty four rats were distributed into six groups of four animals each. Group 1 (control), group 2 (250 mg/kg mushroom alone), group 3 (250 mg mushroom and 50 µg/kg mercury), group 4 (250 mg mushroom and 100 µg/kg mercury), group 5 (50 µg/kg mercury alone) and group 6 (100 µg/kg mercury alone). These animal groups were administered their respective treatments for a period of one month. Thereafter, the anti-depression and spatial memory test (Morris water maze) was carried out. The result indicated that, groups 1, 2, 3, 4, 5 and 6 had mean values of 41.73±12.24, 14.88±11.12, 22.76±17.34, 26.29±13.14, 47.88±14.11, and 80.26±82.15 seconds respectively. These showed that mercury can be implicated as neuro-toxicant having caused high degree of depression with poor response abilities in the animals with mercury doses alone (groups 5 and 6) as against those administered mercury and mushrooms (groups 3 and 4). It was also seen that group 2 which was given mushroom alone had the best response, even better than the control. This concludes that P. ostreatus improves neuro function in animals against neurotoxicity of mercury