SPINAL PROJECTION OF NEUROPEPTIDE Y-AND NEUROTENSIN-IMMUNOREACTIVE NEURONS TO THE PARABRACHIAL NUCLEUS IN THE RAT / 解剖学报

ABSTRACT

In this study a combination of HRP retrograde tract tracing and immunocytochemistry was employed to investigate the afferent projections of neuropeptide Y(NPY) -and neurotensin (NT)-immunoreactive(ir) neurons in the cervical, thoracic, lumbar and sacral spinal segments to the parabrachial nucleus in the rat. It was demonstrated that the retrogradely labeled neurons were scattered in bilateral laminae I, II, IV, V, VII, gray matter commissure dorsal to the central canal, lateral cervical nucleus and lateral spinal nucleus. The NPY-ir neurons were situated in bilateral lamina I, superficial portion of the lamina II, lateral cervical nucleus and lateral spinal nucleus. The NT-ir cells were seen in bilateral lamina I and lamina II of dorsal horn. In lamina I, lateral cervical nucleus and lateral spinal nucleus a few of NPY-HRP double labelled neurons could be observed. Individuals of NT-HRP double labeled neurons were identified only in lamina I. The results of this study suggest that NPY and NT neurons probably involved in the nociceptive transmission of the spino-parabrachial pathway.