SPINAL PROJECTIONS TO THE PARABRACHIAL NUCLEUS IN THE RAT——HRP AND FLUOROGOLD RETROGRADE TRACT TRACING STUDY / 解剖学报

ABSTRACT

By introducing a mixture of WGA-HRP and HRP or fluorogold into the parabrachial nucleus, the cell origin of the spinoparabrachial projections in the rat have been carefully examined. The labelled neurons were found in bilateral spinal gray matter, lateral spinal nucleus and lateral cervical nucleus with contralateral predominance. They were mainly located in lamina I, lamina II, lamina IV, lamina V and lamina VII of the gray matter and also in the gray matter commissure posterior to the central canal. Comparing the distribution patterns of the projection neurons in the cervical, thoracic, lumbar and sacral segments, we did not find any distinct differences. The fact that the parabrachial nucleus receives a wide extensive projections form the spinal segments suggests that the spino-parabrachial pathways are possibly involved in the transmission of multiple sensory inputs.