Tracing of projection neurons from the cervical dorsal horn to the medulla with the anterograde tracer biotinylated dextran amine.

摘要: Abstract In addition to the well-defined role of dorsal horn neurons in pain transmission, superficial laminae also provide a rich source synaptic input cardiovascular and respiratory centers medullary reticular formation. this study, ascending projection from cervical enlargement were studied rat using anterograde tracer biotinylated dextran amine (BDA). Ipsilateral microinjection BDA into spinal cord (C6–C8) resulted extensive labeling I–V. Axons terminal processes cells projecting medulla present cuneate nucleus (Cu), solitary tract (NTS), lateral nucleus, (LRt) as well caudal rostral ventrolateral (VLM). The highest density was found ipsilaterally Cu, LRt, VLM, while moderate NTS area postrema (AP). Moderate-to-weak VLM contralateral injection. These results support existence spinomedullary pathway that transmits noxious innocuous Aδ C fiber-mediated sensory signals medulla. Neurons likely participate patterning autonomic responses evoked by or during exercise.