ACUTE AND CHRONIC IMMOBILIZATION STRESS;

Morphometric study of Purkinje cells of vermal cerebellar cortex of young male rats.

Abstract

ABSTRACT…Objective: To compare the morphological changes induced by acute and chronic immobilization in vermal cerebellar
cortex 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 male
Sprague Dawley rats were taken and divided equally in two groups (n=60 in each). Both these groups were divided further into two
subgroups (n=30 in each) control acute (CA), immobilized acute (IA), control chronic (CC) and immobilized chronic (IC). ‘Immobilized
acute’ group IA was kept in restrainer for 24 hours continuously while ‘immobilized chronic’ group IC was kept in restrainer for 2 hours
daily for fourteen days, one rat per restrainer separately. Sections stained with Hematoxylin and Eosin were studied under light
microscope for observations and data was recorded. Results of experimental acute group were compared with those of experimental
chronic’. SSPS version 10 was used for data analysis. Results: Changes in the shape and size of the soma and nucleus of the Purkinje
cells were noted. The cells were looking like dried raisins in both experimental groups but these changes were more marked in acute
experimental group as compared to controls. The size of the soma and nucleus of the Purkinje cells was reduced in both acute and chronic
immobilized stressed groups’ however; this reduction in the size of the soma and nucleus of the Purkinje cells was more pronounced in
acute stressed group as compared to animals exposed to chronic stress. Total cell count and cell size was significantly decreased in both
experimental groups as compared to their controls; however, it was more pronounced in acute stressed group as compared to animals
exposed to chronic stress. Conclusions: Immobilization stress may act as a factor causing an imbalance in the metabolic activity of the
neurons which can result in neuronal injury. The Purkinje neurons were affected more under the effect of acute stress as compared to
chronic. The lesser effect in chronic stress is probably due to role of the phenomena of adaptation.