Neurexin-1α regulates neurite growth of rat hippocampal neurons

The growth of neurites underlies the axonal pathfinding and synaptic formation during neuronal development and regeneration. Neurite growth is regulated by specific interactions between growth cone receptors and their ligands that function as molecular cues existing in microenvironments. Neurexins (NRXNs) are concentrated on growth cones and they may function to constrain axonal branches of invertebrate neurons. The present study explored the role of NRXN-1α in regulating neurite growth of mammalian neurons. Results showed that transfecting an effective NRXN-1α siRNA to cultured rat hippocampal neurons significantly increased neurite length. Adding NRXN-1α ligands including neuroligin (NLGN) peptide and/or α-latrotoxin (α-LTX) to the culture media largely decreased neurite growth of naïve neurons in a Ca²⁺-dependent manner, but had no effect on neurite growth of neurons transfected with NRXN-1α siRNA. Our results suggest that NRXN-1α regulates neurite development of mammalian neurons.