Despite intense research efforts, the specific pathogenic mechanisms that underlie the link between respiratory syncytial virus (RSV) and childhood asthma remain unclear.1,2 Recent researches suggest that changes in the structure and function of the nerves themselves in response to changing conditions, a phenomenon known as neuronal plasticity, may also contribute to the pathophysiology of airway diseases.3 Therefore in the present study we developed a model of RSV infection in Sprague-Dawley (SD) rats and measured the neuronal plasticity and the airway responsiveness after a period of the viral infection. We also assessed the protective effect of a polyclonal antibody specific for the rat nerve growth factor (NGF) against RSV-induced neuronal plasticity and the airway responsiveness. Finally, we compared the expression of key substances of neuronal plasticity, synaptophysin (SYN) and neurofilament (NF), with airway responsiveness.