Role of the paraventricular nucleus in the projection from the nucleus of the solitary tract to the olfactory bulb.

Electrophysiological experiments were performed on anesthetized rats to determine the effects of lesions of the paraventricular nucleus on the amplitude of evoked potentials recorded in the periglomerular layer of the olfactory bulb after nucleus of the solitary tract electrical stimulation. Lesions of the paraventricular nucleus enhance the amplitude of both the positive and negative components of the evoked potential in the olfactory bulb. The pathway from the paraventricular nucleus to the olfactory bulb seems to exert a suppressive influence over the projection from the nucleus of the solitary tract to the olfactory bulb under these conditions.