Immunohistochemical identification of two types of dopamine neuron in the rat olfactory bulb as seen by serial sectioning.

Several neurons around the glomeruli in the rat olfactory bulb contain the enzyme tyrosine hydroxylase as revealed by light and electron microscopic immunohistochemistry. Electron microscopic analysis of serial sections reveal that both superficial tufted cells and small periglomerular neurons were labelled. These results give further support for the view that dopamine neurons in the rat olfactory bulb, from a neuroanatomical point of view, do not represent a homogeneous cell population. Furthermore, taken together with previous results in the literature our findings indicate that, from a transmitter histochemical point of view, neither tufted cells nor periglomerular neurons represent a homogeneous cell population.