Map of spinal neurons activated by chemical stimulation in the nucleus raphe magnus of the unanesthetized rat.
The expression of the proto-oncogene c-fos was used as a cellular marker of spinal cord neurons activated by microinjection of kainic acid into the medullary nucleus raphe magnus of awake and drug-free Sprague-Dawley rats. The c-FOS protein was detected by immunocytochemistry. We found increased immunoreactivity bilaterally in laminae I-VI of the dorsal horn. The strongest c-FOS expression was observed within the inner layer of lamina II near its border with lamina III. In the ventral horn no c-FOS immunoreactivity was observed. Thus, the present results provide evidence for a descending excitation of neurons predominantly in inner lamina II, possibly mediating nucleus raphe magnus-induced inhibition of neurons in other laminae.
Bett
K
K
II. Physiologisches Institut, Universität Heidelberg, Germany.
Sandkühler
J
J
D000818:Animals; D016762:Genes, fos; D007608:Kainic Acid / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D008845:Microinjections; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011903:Raphe Nuclei / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000166:cytology* / Q000187:drug effects; D013268:Stimulation, Chemical
D007608:Kainic Acid