DENDRITIC CHANGES OF THE PYRAMIDAL NEURONS IN LAYER-V OF SENSORY-MOTOR CORTEX OF THE RAT-BRAIN DURING THE POSTRESUSCITATION PERIOD

Experiments were performed on 40 Wistar rats. Total brain ischemia was induced by 10 min clamping of the cardiac blood vessels. The brains w ere examined in control rats, after 90 min and after 1, 3, 7, 30 and 9 0 days during the postresuscitation period. Histological sections were stained with the Golgi method. Morphometrical parameters, 12, of dend ritic changes of the pyramidal neurons in layer V of sensory motor cor tex (SMC) in rat brain were studied at different intervals of the post resuscitation period. Reduction of the dendrites of the pyramidal neur ons due to the loss of the terminal branches of the oblique apical den drites in layers III-IV was detected from the first day after ischemia . The maximal dendritic change was detected 3 and 7 days after ischemi a. Decrease the volume of dendritic territory (54, 4%), the total dend ritic length of the whole dendritic territory (56, 0%) and branching o f dendrites, and decrease in the number of dendritic spines on apical dendrites in layers I-II (46, 1%) were the main changes during this pe riod. Reduction of the total length of dendrites occurred mostly due t o disappearance of the 2nd and 3rd order branches of the apical and ba sal dendrites. The change of dendrites neurons had returned to control levels after 30 days. By that time the diameter of the dendrites had increased, the varicosities on oblique apical and basal dendrites had disappeared, and the number of 2nd and 3rd order dendrites and of dend ritic spines had increased. (C) 1997 Elsevier Science Ireland Ltd.