olfactory bulb glomerular layer

Most superficial of the layers of the olfactory bulb, the glomerular layer contains three elements: the dendritic arborisations of mitral cells, which form the glomeruli themselves, incoming olfactory nerve fibres, and periglomerular cells. The convergence here is considerable, since each mitral cell is contacted by at least a thousand olfactory nerve fibres. Periglomerular cells contact multiple mitral cell dendrites within the glomeruli and supply lateral inhibition to neighbouring glomeruli while permitting excitation of one specific mitral cell dendritic tree, a wiring pattern that sharpens the distinction between activated and neighbouring glomeruli. In topographic terms the layer occupies the tissue between the primary olfactory fibre layer and the external cellular layer of the bulb.