Fos and serotonin immunoreactivity in the raphe nuclei of the cat during carbachol-induced active sleep: a double-labeling study.
The microinjection of carbachol into the nucleus pontis oralis produces a state which is polygraphically and behaviorally similar to active sleep (rapid eye movement sleep). In the present study, using double-labeling techniques for serotonin and the protein product of c-fos (Fos), we sought to examine whether immunocytochemically identified serotonergic neurons of the raphe nuclei of the cat were activated, as indicated by their expression of c-fos, during this pharmacologically-induced behavioral state (active sleep-carbachol). Compared with control cats, which were injected with saline, active sleep-carbachol cats exhibited a significantly greater number of c-fos-expressing neurons in the raphe dorsalis, magnus and pallidus. Whereas most of the c-fos-expressing neurons in the raphe dorsalis were small, those in the raphe magnus were medium-sized and in the raphe pallidus they were small and medium-sized. The mean number of serotonergic neurons that expressed c-fos (i.e. double-labeled cells) was similar in control and active sleep-carbachol cats. These data indicate that there is an increased number of non-serotonergic, c-fos-expressing neurons in the raphe dorsalis, magnus and pallidus during the carbachol-induced state.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D002415:Cats; D004569:Electroencephalography / Q000187:drug effects; D007150:Immunohistochemistry; D008845:Microinjections; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D010477:Perfusion; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D011903:Raphe Nuclei / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*; D012890:Sleep / Q000187:drug effects / Q000502:physiology*; D016707:Tissue Fixation
D016760:Proto-Oncogene Proteins c-fos; D012701:Serotonin; D002217:Carbachol