Fig 3. Photomicrographs of seminiferous tubule sections of rats from CTR group (A), MPH 2.5 group (B) and the MPH 5.0 group (C) stained by toluidine blue. Increase in the space between seminiferous tubules (ST) in the MPH groups and comparison with the CTR group. Scale = 50 µm. CTR: distilled water; MPH 2.5: methylphenidate 2.5 mg/kg; MPH 5.0: methylphenidate 5.0 mg/kg.