Granule cells in the hippocampal dentate gyrus are generated throughout adulthood of mammals, and recent studies indicate that they are incorporated into neural circuitry and mature into functional neurons. To determine whether newly generated granule cells form dendritic growth cones during this process of synaptogenesis, we used the immunocytochemical method to localize doublecortin, a protein associated with microtubules in newborn neurons. Here we show that both dendritic growth cones and recurrent basal dendrites are common features of newly generated granule cells. This study is the first to show dendritic growth cones in the dentate gyrus of the adult nervous system and suggests that dendrites in adult brains grow in a similar way as those found in immature brains
