Cytochemical characteristics of cat spinal neurons activated during fictive locomotion.
Using standard immunohistochemical and histochemical techniques, we have examined the neurochemical characteristics of a subpopulation of locomotor-related neurons as labeled by the activity-dependent marker c-fos. Results were compared to those obtained from a small sample of intracellularly labeled locomotor-related neurons. In the paralyzed, decerebrate cat, fictive locomotion was evoked by electrical stimulation of the mesencephalic locomotor region. Most c-fos-immunoreactive neurons were distributed in medial lamina VI and VII and in lamina VIII and X. Double labeling of c-fos with various cytochemical markers revealed that about one-third of the c-fos-immunoreactive neurons were choline acetyltransferase immunoreactive, about one-third were glutamate immunoreactive, and about one-third were aspartate immunoreactive. In addition, approximately 15% of the c-fos-labeled neurons contained NADPH-diaphrorase reaction product, while almost 40% appeared to receive close contacts from calcitonin gene-related peptide-immunoreactive fibers and boutons. Choline acetyltransferase- or aspartate immunoreactivity was observed in some intracellularly labeled neurons. These findings have implications regarding the putative neurotransmitters utilized by subpopulations of locomotor-related neurons in the cat spinal cord.
Carr
P A
PA
Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
Huang
A
A
Noga
B R
BR
Jordan
L M
LM
D000818:Animals; D015415:Biomarkers / Q000737:chemistry; D002415:Cats; D003655:Decerebrate State; D003911:Dextrans; D005260:Female; D005456:Fluorescent Dyes; D006651:Histocytochemistry; D007150:Immunohistochemistry; D008124:Locomotion / Q000502:physiology*; D008297:Male; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis*; D012235:Rhodamines; D013116:Spinal Cord / Q000737:chemistry / Q000166:cytology / Q000502:physiology*
D015415:Biomarkers; D003911:Dextrans; D005456:Fluorescent Dyes; C067661:Fluoro-Ruby; D016760:Proto-Oncogene Proteins c-fos; D012235:Rhodamines