Neuronal Receptors (s) having Paired recordings in slices showed excitatory transmission mediated solely by transmitter spillover between mitral cells. Dendritic glutamate release causes self-excitation via local activation of NMDA receptors, and generates NMDA receptor-mediated responses in neighbouring cells. It is suggested that this simultaneous activation of neighbouring cells by a diffuse action of glutamate provides a mechanism for synchronizing olfactory principal cells as Publication facts