207OBSERVED MICROSTRUCTURAL CHANGES IN THE CEREBELLAR CORTEX OF ADULT WISTAR RATS FOLLOWING MANGANESE DICHLORIDE EXPOSURESome effects of manganese which is an essential trace element for both animals and man, on nissl substances in the cerebellar cortex of adult Wistar rats were investigated. Twenty eight adult wistar rats of both sexes weighing between 950 – 200g were separated into four groups, each containing seven rats. The rats in group D (control) received equal volume of distilled water as contained in experimental doses. Treated rats group A, B and C respectively received MnCl2 at a dose of 5, 15 and 25 mg/kg body weight orally for 21 consecutive days. The rats were sacrificed by cervical dislocation on the 26th day of the treatment. The cerebellum of each rat was removed and fixed in 10% normal saline for routine histological procedures. The findings showed more intensely and distinctly stained nissl substances in the cerebellar cortex of the control rats compared with less intensely stained and degenerated nissl substances in the cerebellar cortex of the treated rats. The observed decreased staining intensity and degenerated nissl substances in the cerebellar cortex may adversely affect protein synthesis in relation to neuronal function in the treated rats.adeshinaajibade@yahoo.co.ukResearch422013Manganese dichloride,Intensely stained,Nissl substances,Cerebellar cortexAjibade J,Fakunle P.B,Fatoba O.O,Ajani R.ADepartment of Anatomy Ladoke Akintola University of Technology Ogbomoso, Oyo State, Nigeria.,Department of Anatomy Ladoke Akintola University of Technology Ogbomoso, Oyo State, Nigeria.,Department of Anatomy Ladoke Akintola University of Technology Ogbomoso, Oyo State, Nigeria.,Department of Biochemistry, Ladoke Akintola University of Technology Ogbomoso, Oyo State, Nigeria.