THE RELATIONSHIP OF TERMINALS CONTAINING NEUROPEPTIDE-Y LIKE IMMUNOREACTIVITY TO LUMBAR SYMPATHETIC VASOCONSTRICTOR NEURONS IN THE RABBIT

Abstract

The distributions of preganglionic neurones retrogradely labelled with horseradish peroxidase and of immunohistochemically identified varicose axons reactive for neuropeptide Y (NPY-IR) in the intermediate zone of rabbit lumbar spinal segments have been compared. Neurones projecting in the caudal lumbar sympathetic chain (LSC), which are mainly vasoconstrictor, were located laterally, associated with dense accumulations of NPY-IR terminals in mid L3 to caudal L4. In all other regions of the lumbar intermediate zone, there was relatively little correlation between the location of either LSC neurones, or those projecting to the pelvic viscera, and aggregations of NPY-IR axons. Most of these ax..