ACUTE AND CHRONIC IMMOBILIZATION STRESS;

Abstract

ABSTRACT…Objective: To compare the morphological changes induced by acute and chronic immobilization in vermal cerebellarcortex of young male sprague dawley rats with special reference to Purkinje cells. Study design: It was experimental. Setting:Department of Anatomy CPSP Reional Centre, Islamabad. Period: 2005 to 2007. Material and method: A total of 120 young maleSprague Dawley rats were taken and divided equally in two groups (n=60 in each). Both these groups were divided further into twosubgroups (n=30 in each) control acute (CA), immobilized acute (IA), control chronic (CC) and immobilized chronic (IC). ‘Immobilizedacute’ group IA was kept in restrainer for 24 hours continuously while ‘immobilized chronic’ group IC was kept in restrainer for 2 hoursdaily for fourteen days, one rat per restrainer separately. Sections stained with Hematoxylin and Eosin were studied under lightmicroscope for observations and data was recorded. Results of experimental acute group were compared with those of experimentalchronic’. SSPS version 10 was used for data analysis. Results: Changes in the shape and size of the soma and nucleus of the Purkinjecells were noted. The cells were looking like dried raisins in both experimental groups but these changes were more marked in acuteexperimental group as compared to controls. The size of the soma and nucleus of the Purkinje cells was reduced in both acute and chronicimmobilized stressed groups’ however; this reduction in the size of the soma and nucleus of the Purkinje cells was more pronounced inacute stressed group as compared to animals exposed to chronic stress. Total cell count and cell size was significantly decreased in bothexperimental groups as compared to their controls; however, it was more pronounced in acute stressed group as compared to animalsexposed to chronic stress. Conclusions: Immobilization stress may act as a factor causing an imbalance in the metabolic activity of theneurons which can result in neuronal injury. The Purkinje neurons were affected more under the effect of acute stress as compared tochronic. The lesser effect in chronic stress is probably due to role of the phenomena of adaptation.