Abstract
Background: Apart from functioning as a multimodal hematopoietic growth factor, granulocyte colony-stimulating factor (G-CSF) causes intense consequences on the brain. It has been viewed that G-CSF boosts the improvement from the neurologic deficits in rodent models of central nervous system diseases.

Aims and Objective: To evaluate the efficacy of G-CSF as an intervention for improving cognitive deficits commonly associated with aging.

Materials and Methods: In this study, male Wistar rats aged 21 months were treated for 2 weeks with G-CSF intraperitoneally at doses of 10, 50, and 70 mg/kg/day. The learning process was assessed by the reference memory task in the Morris water maze, by comparing the G-CSF–treated group with the control animals. All the rats received Morris water maze training (four trials/day for 5 days) in order to assess the hippocampal-dependent spatial learning and received a 60-s probe trial test of spatial memory retention 24 h after the twentieth trial.

Result: Over 5 days of training, G-CSF (10, 50, and70 mg/kg/day) significantly reduced the latency and path length to finding the escape platform (P < 0.01). In probe trials (without platform), on the last day of training, the G-CSF–treated group spent significantly longer time in the platform quadrant when compared with the control animals (P < 0.01). Among the treated groups, the 50-mg/kg dosage of G-CSF induced the best rehearsals memory.

Conclusion: The findings observed in this study support G-CSF as a promising therapeutic aid for cognitive enhancement in the aging phenomenon.