Tramadol Causes Weight, Nissl Substance, and Astrocytic Changes in the Hippocampal Formation's Structures

Tramadol hydrochloride is a centrally acting synthetic opioid which is used to treat moderate to moderately severe pain and is reported  to have neurotoxic potential. Therefore, this study investigated the effects of tramadol on weight, Nissl bodies and astrocytic changes in  the structures of the hippocampal formation. 2ml/kg of distilled water was given to the control group and 50mg/kg tramadol to group 2  orally for 21 days. The weight of the rats was taken before and after the experiment. The rats were euthanized, brains harvested and  weighed. The harvested brains were fixed in 10% formol saline, and processed routinely, stained with Cresyl fast violet (CFV) for  demonstration of Nissl substance and glial fibriliary acidic protein (GFAP) for demonstration of astrocytes expression. CFV stain revealed  a reduced staining intensity of these regions with pathological changes in the tramadoltreated group. GFAP showed numerous reactive  astrocyte processes; overlapping and interdigitation of astrocyte processes; astrocyte proliferation; astrocyte cell body hypertrophy and  thickening of astrocyte processes. This study's findings revealed changes in weight, Nissl bodies and hippocampal formation  histopathology.