Intranasal delivery of nerve growth factor for cognitive dysfunction after traumatic brain injury in rats

Objective Cognitive dysfunction frequently occurs after traumatic brain injury(TBI).This article aims to study the effect of intranasally delivered nerve growth factor(NGF) on cognitive dysfunction in rats with TBI.Methods TBI models were established in healthy adult SD rats using the modified method of Feeney′s weight-drop and then randomly divided into a sham,a control and a treatment group.The rats in the control group were given phosphate-buffered saline,and those in the treatment group intranasally administered NGF.The cognitive function of the three groups of rats was assessed by the Morris water maze test,the surviving neurons in the hippocampus identified by Nissl staining,the concentration of Aβ42 in the injured ipsilateral hippocampus measured by ELISA,and the expression of Aβ42 in the hippocampus detected by immunohistochemistry.Results Cognitive dysfunction was significantly milder in the treated than in the control rats(P0.05).There were significantly fewer surviving neurons in the hippocampus in treatment and control groups than in the sham group(P0.05),and more in the treatment than in the control group(P0.05).The expression of Aβ42 was significantly higher in the control and treated rats than in the sham group(P0.05),even higher in the treatment than in the control group(P0.05).ConclusionIntranasal delivery of NGF can increase the survival rate of hippocampal neurons,regulate the overproduction of Aβ42,and thus improve the cognitive function after brain injury in rats.