The topographical distribution of serotoninergic terminals in the spinal cord of the cat: quantitative radioautographic studies.

摘要: In vitro uptake of labeled serotonin (5-HT) has allowed the radioautographic detection serotoninergic fibers in cat spinal cord at thoracic and lumbar levels. The specificity labeling was ensured by conditions incubation ([3H]5-HT 10(-7) M) test control experiments with concomitant 10(-6) M NA or 2 X fluoxetine which led respectively to an unmodified a negative pattern. Macroscopic radioautography [14C]5-HT gave framework for analysis 5-HT innervation this level appeared dense grey matter more scattered white except periphery. structures histological as randomly oriented fibers. They displayed enlargements were identified electron microscopy varicosities (mean diameter 0.7 micrometer) containing clear large granular vesicles. To estimate density matter, semi-automatic counting performed on radioautographs, using image analyzer. Maximal concentrations boutons found periependymal region, sympathetic lateral column, whole dorsal horn motor neuron area ventral horn. densely innervated number estimated be least 2.65 10(6)/cu.mm. longitudinally periphery obliquely other regions, funiculus, where they nearly absent. Previous histofluorescence biochemical data are confirmed completed results approach displays several advantages resolution, sensitivity possibilities automated quantification. Moreover owing dynamic abilities method, provides good model study properties (namely axonal flow) functions neurons.