ABSTRACT
BACKGROUND:Chemotherapy drugs have been shown to penetrate the blood-brain barrier and cause neurotoxicity,further damaging nerve cells.OBEJCTIVE:To investigate the changes in the expression and morphology of hippocampal neurons in chemobrain,and to investigate the underlying mechanism of nerve regeneration in chemobrain.METHODS:The brain specimens were obtained from the six patients undergoing cancer chemotherapy and six patients without chemotherapy,and were then subdivided into two groups:＜ 60 years and ＞ 60 years groups (n=3 per group).Immunofluorescence staining with specific antibodies was used to detect the changes in the morphology and number of neurons in the hippocampus CA1,CA2 and CA3.RESULTS AND CONCLUSION:The number of neurons positive for NeuN,DCX and PV in the hippocampal CA1,CA2 and CA3 in the chemotherapy group was significantly lower than that in the non-chemotherapy group.Moreover,the neurons positive for PV were smaller,with less and shorter nervous processes.Immunofiuorescence staining findings showed that the ＜ 60 years old patients in the chemotherapy group had less neurons positive for NeuN and DCX than that in the non-chemotherapy;for ＞ 60 years old patients,there was no significant difference between two groups.These findings suggest that chemotherapy can downregulate the expression of immature neurons in the hippocampus and reduce the number of neurons in the hippocampus.Moreover,chemotherapy can change the morphology and reduce the number of PV neurons.