A method of improving cognitive function or treating cognitive dysfunction is provided. The method is based on activating a kainate receptor or a glutamate GluR6 receptor by kainate or a glutamate GluR6 receptor activator such as an agonist. Additionally, a method of enhancing a learning ability by activating a kainate receptor such as the glutamate GluR6 receptor via kainate or a glutamate GluR6 receptor activator such as an agonist is provided.