Evidence for calcitonin gene-related peptide contacts on a population of lamina I projection neurons.
Using double-labeling techniques, we evaluated small diameter primary afferent input, as indicated by calcitonin gene-related peptide-immunoreactive varicosities, to a population of lamina I projection neurons in the rat lumbar spinal cord. About one third of the lamina I neurons labeled after injections of a retrograde tracer into the region surrounding the brachium conjunctivum received contacts from immunoreactive varicosities. Significantly fewer immunoreactive varicosities were in apposition to fusiform neurons than pyramidal or flattened neurons. A positive correlation was found between the size of the retrogradely labeled neuron and the number of contacts received. This study demonstrates that a known population of nociceptive lamina I neurons received direct input from presumed nociceptive primary afferents.
Nahin
R L
RL
Neurobiology and Anesthesiology Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892.
Humphrey
E
E
Hylden
J L
JL
D000344:Afferent Pathways / Q000033:anatomy & histology* / Q000166:cytology / Q000502:physiology; D000818:Animals; D001370:Axonal Transport; D001921:Brain / Q000033:anatomy & histology* / Q000166:cytology; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis*; D002772:Cholera Toxin; D006735:Horseradish Peroxidase; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000166:cytology* / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins
D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; D002772:Cholera Toxin; D006735:Horseradish Peroxidase; D015740:Calcitonin Gene-Related Peptide