[Abstract Title]. - Society for Neuroscience

Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 282.22/OO29
Topic: E.06.d. Cellular actions of stress
Title: The comparison of behavior and structural reorganization in motor cortex of rats after
immobilization
Authors: *V. N. MATS, I. LEVSHINA, N. PASIKOVA, N. SHUYKIN;
Inst. Higher, Moscow, Russian Federation
Abstract: INTRODUCTION:
While studying behavioral responses to the experimental stress in animals most researchers
prefer using emotional stress rather than any other physical or painful stimuli. Numerous data
about behavioral changes in stressed animals have been reported. However the influence of the
emotional stress on morphological status of brain structure has not been documented sufficiently.
We investigated behavioral changes in rats and accompanying morphological changes in their
motor cortex after the emotional stress.
Methods:
Wistar rats (n=20) were stressed by the interrupted immobilization, wich carried out for 7-8
hours a day during one week .“Open field” test was used to test behavior in experimental and
control rats before and after immobilization. In the end of experiment rats were decapitated, their
brains were fixed and frontal slices of forebrain were stained by Nissle method. The number of
neurons, neuroglia, and cells square in motor cortex were estimated.
Results:
No differences were found in size,and density of glial cells and neurons between experimental
and control animals. However, morphometric analyses showed significant increase of hypoxical
neurons density in motor cortex of stressed rats. After 1 week of immobilization, the number of
dark, stretched neurons with the corkscrew apical dendrite was estimated as 177% of those in
control rats. Hypoxical neurons were concentrated asymmetrically with those prevailing in the
left hemisphere in control rats and in the right hemisphere in stressed rats. Behavioral changes of
immobilized rats were characterized by increased horizontal and vertical locomotor activity and
duration of III and IV faze of grooming (comfortable grooming) in the “open field” test.
CONCLUSIONS:
Results showed the increased motor activity in animals despite the increase in concentration of
hypoxical neurons after immobilization.. Experimental rats are considered as a model of
redistribution of functional brain activity with preferential intensification of the left-brain
hemisphere.
Disclosures: V.N. Mats , None; I. Levshina, None; N. Pasikova, None; N. Shuykin, None.
Poster