Glutamate and aspartate immunoreactivity in dorsal root ganglion cells supplying visceral and somatic targets and evidence for peripheral axonal transport

Abstract

Glutamate (Glu) is released by primary sensory neurons at their central synapses, although immunohistochemical studies have shown that only a proportion of these cell bodies are Glu-immunoreactive. Antisera raised against Glu or aspartate (Asp) were used to investigate whether neurons that store high levels of these substances have a unique neuropeptide content or target projection. In male rats, many lumbar and sacral dorsal root ganglion cells and their associated glia show high levels of Glu or Asp immunoreactivity, and fewer than half of these also express substance P or calcitonin gene-related peptide. Conversely, only a minority of peptide-containing neurons store high levels of excita..