[Fluorohistochmical studies on localization of 5-hydroxytryptamine neurons in the rat brain following administration of thiopental sodium].
The localization of 5-hydroxytryptamine (5-HT) neurons in the rat brain was studied by the fluorescence histochemical method of Falck and Hillarp. A model experiment and tissue experiment were used to measure the characteristics of wave length of 5-HT fluorophor and we decided 420 mmu for excitation maxima and 520 mmu for emission maxima. The 5-HT neurons both in frontal and sagittal sections of the brain from reserpine-nialamide-treated rats were observed fluorohistochemically. The brain was divided into 5 portions; medulla oblonga, pons, midbrain, diencephalon and telencephalon. In frontal sections, from B1 to B8 cell groups were localized in raphe nuclei, in the region of 200 mu width on both sides from the central plane, excluding most of B2 cells and cells of B9 group which were situated on both side apart from the central plane. Microphotographs taken from about 34 areas of a sagittal section were composed to determine the interrelationship between B cell groups of 5-HT neurons. The frontal sections untreated with reserpine-nialamide showed a faint fluorescence of 5-HT neurons, however, after the administration of thiopental sodium 80 mg/kg i.p. the fluorescence of 5-HT neurons was increased in intensity and the observable cells were increased in number, especially in the B7 cell group. The yellow fluorescence of 5-HT nerve terminals in nuc suprachiasmaticus in the sagittal section was increased in intensity and varicosities of the terminals were readily observed. These results verified the increase of 5-HT in 5-HT neurons after the administration of thiopental and suggest that the 5-HT neuron may play a role in the mechanism of the central action of a thiopental.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008856:Microscopy, Fluorescence; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D012701:Serotonin / Q000378:metabolism*; D013874:Thiopental / Q000494:pharmacology*
D012701:Serotonin; D013874:Thiopental; D009638:Norepinephrine