Elizabeth Finbarrs-Bello, , Ignatius Ikemefuna Ozor, Vivian Onyinye Atuadu, Epete Michael Arinze
Abstract: Ketamine has been known to produce psychotic symptoms like delusion and hallucination in rodents and humans. Chlorpromazine (CPZ) a dopamine receptor antagonist of the typical anti-psychotic drug is used to treat schizophrenia. This study investigated the neuroprotective effect of chlorpromazine on hippocampus of ketamine-induced psychotic rat model. Twenty (20) rats were divided intoexperimental and control groups. The control (n=5) received 0.1ml saline (p.o) while psychosis was induced in experimental rats (n=15) using 25mg/kg of ketamine (i.p) for 7days. On the eight (8th) day the psychotic model rats (n=15) were subdivided into three groups 1, 2and3of five ketamine induced rats each.The control and Group 1 were sacrificed, then groups 2 and 3 were treated with 25mg/kg of chlorpromazine (p.o) and 0.1ml of saline (p.o) respectively for 21days. On the 22nd daythe rats were anaesthetized by 50mg/kg of thiopental sodium, aortic perfusion was performed and the brain was dissected. Deparaffinized tissue sections were processed and stained. The H & E stained section of the control group showed normal neurons, untreated model shows features of cytoplasmic vacuolation, and chlorpromazine treated model showed relatively normal neuronal cells, while the saline treated model group showed shrunken cytoplasm.TheGolgi silver stained hippocampal sections revealed numerous granular cells with accumulation of silver deposit in the untreated model, chlorpromazine treated model had few granular cells with silver depositsand Saline treated model shows cell with moderate granular cells with silver deposits. The Nissl bodies stained by Cresyl fast violet method decreased in the untreated and saline treated models, while itincreased in the model treated with chlorpromazine. This result put together we conclude that chlorpromazine an antipsychotic drug has neuroprotective effect on the hippocampus in ketamine-induced psychosis in rat.
Keywords: Ketamine, Psychosis, Chlorpromazine, Hippocampus, Nissl Bodies, Silver Stain