TRANSNEURONAL VIRAL LABELING OF RAT-HEART LEFT-VENTRICLE CONTROLLING PATHWAYS

RETROGRADE transneuronal viral labelling and immunocytochemical method s were used for revealing neuronal networks controlling the left ventr icle myocardium of the rat heart. After injections of 1 mul pseudorabi es virus solution (3 x 10(6) PFU ml-1) into the left ventricle, infect ed orthosympathetic preganglionic cells were found in the intermediola teral cell groups of the first 6 thoracic spinal segments. Preganglion ic parasympathetic neurones were seen both in the nucleus ambiguus/ret ro-ambiguus area and the dorsal motor vagus nucleus. Large numbers of infected projecting interneurones were found in the rostral, caudal an d medial parts of the ventral medulla oblongata, the Kolliker-Fuse nuc leus and catecholaminergic cell group A5 and in the paraventricular hy pothalamic nucleus.