Thrombospondin 1 accelerates synaptogenesis in hippocampal neurons through neuroligin 1

In cultured rat hippocampal neurons, we found that thrombospondin 1 (TSP1) increased the speed of synapse formation in young neurons, but not the final density of synapses in mature neurons. TSP1 interacted with neuroligin 1 (NL1) and application of the NL1 extracellular domain blocked TSP1-induced synaptogenesis. Furthermore, knocking down endogenous NL1 inhibited TSP1's effect. Our results indicate that TSP1 accelerates the speed of synaptogenesis through NL1 in hippocampal neurons.