Effect of G-CSF on the Spatial Arrangement of CA1 Hippocampal Pyramidal Neurons after Brain Ischemia in the male Rats.

Stroke is a leading cause of mortality and disability; Memory impairment occurs frequently after stroke and the pattern of hippocampal CA1 pyramidal neurons has important role in the signal transmission and memory forming. G-CSF (granulocyte-colony stimulating factor) is a novel treatment that exhibits neuroprotective and anti-apoptotic in the central nervous system. The aim of the present study was to determine the effects of G-CSF on the neurobehavioral outcome and spatial pattern of CA1 pyramidal neurons after focal cerebral ischemia in animals. Twenty one Sprague-Dawley adult male rats were randomly divided into three groups: The Sham group underwent surgery without middle cerebral artery occlusion (MCAO) and drug. The control and treatment groups after MCAO received vehicle or G-CSF (G-CSF 50 μg/kg) 6, 24, and 48 h after brain ischemia. Neurological deficit score and pole tests were performed, and 7 days after MCAO, the brain was removed and serially and coronally cut and finally stained by Nissl method. The infarct volume was evaluated and CA1 pyramidal neurons pattern was studied using Voronoi spatial tessellation in histological sections of the rat brain. The spatial pattern has been classified into regular, random, or clustered. G-CSF showed a significant effect on the weight, neurological deficit score, and Pole test and reduced infarct volume after stroke. Stroke also changed the spatial arrangement of CA1 hippocampal neurons into a random pattern, whereas treatment with G-CSF remained its regular spatial pattern. In conclusion, G-CSF had beneficial effects after cerebral ischemia on the neurological behavioral outcome, infarct volume and preserved the regular spatial distribution of CA1 hippocampal neurons.