Catecholaminergic contributions to the neuronal machinery of the olfactory bulb: aftoradiographic, immunohistochemical and evoked feild potential studies

Publisher Website
Google Scholar
Abstract
Aftographic exeperiments on the localization of radiolabeled noradrenaline, dopamine and dopa, as well as immunohistochemical studies on hydroxylase-like activity, are summarized and compared in both rat and turtle olfactory bulbs. Evoked field potential studies on effects of dopamine are also discussed. The histochemical studies suggest that dopaminergic periglomerular neurons are the most significant cellular component of the catecholaminergic system in the olfactory bulb of both species. Scattered fluorescent cell group was also present in the internal plexiform layer and superficial granule cell layer of the turtle olfactory bulb. Other fibres, not related to intrinsic bulbar neuronal cell bodies, were also labeled, mostly in the granule cell layer but also in the external plexiform layer. These might belong to a centrifugal catecholaminergic system from brain stem neurons. In the in vitro turtle olfactory bulb, dopamine and apomorphine depressed the amplitude of field potentials evoked by a single volley in the olfactory nerve or lateral olfactory tract, and reduced the depression and latency of reponses when paired volley were delivered. It is suggested that catecholaminergic systems play a key role in modulating mitral cell activity through actions in both superficial (glomerular) and deep (granule) layers. This may involve direct actions, or other, non-catecholaminergic interneurons.

This publication has 0 references indexed in Scilit: