Frequency-dependent expression of diaphorase staining and nNOS-immunoreactivity in rat dorsal horn neurones following C-fibre stimulation.
Recent evidence demonstrated that lesion-induced central nervous system changes are at least partly mediated by the action of the gaseous transmitter nitric oxide (NO). We investigated the hypothesis that the frequency of peripheral C-fibre stimulation determines the number of neurones in the dorsal horn that can be visualised immunohistochemically with antibodies to NO synthase (NOS) or using the NADPH-dependent diaphorase (NDP) reaction. C-fibre stimulation of the sciatic nerve at a frequency of 0.01 Hz was followed by a significant increase in NDP-cell number in the spinal segment L3, whereas 0.1 and 1 Hz stimulation resulted in a significant decrease. Neuronal NOS (nNOS)-immunoreactivity was significantly influenced only by 1 Hz stimulation and only on the ipsilateral side in L3. Here, the number of nNOS-immunoreactive (ir) neurones decreased significantly in the superficial dorsal horn. The results show that the system of NDP-neurones is capable of displaying a bidirectional response depending on the frequency of C-fibre input.
Hoheisel
U
U
Institut für Anatomie und Zellbiologie III, Heidelberg, Germany.
Kaske
A
A
Reinert
A
A
Mense
S
S
D000818:Animals; D000918:Antibody Specificity; D004558:Electric Stimulation; D008297:Male; D009252:NADPH Dehydrogenase / Q000032:analysis / Q000378:metabolism*; D009412:Nerve Fibers / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D009475:Neurons, Afferent / Q000737:chemistry / Q000201:enzymology* / Q000648:ultrastructure; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000276:immunology* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000166:cytology*; D013194:Staining and Labeling
D019001:Nitric Oxide Synthase; D009252:NADPH Dehydrogenase