No abstract available.
Serotonergic Neurons*

No abstract available.
Fetus* ; Humans* ; Mesencephalon* ; Serotonergic Neurons*

No abstract available.
Animals ; Brain* ; Rats* ; Serotonergic Neurons*

No abstract available.
Brain Stem* ; Brain* ; Serotonergic Neurons*

No abstract available.
Animals ; Brain Stem* ; Cricetinae* ; Raphe Nuclei* ; Serotonergic Neurons*

The experimental study was performed to investigate the influence of carbon monoxide on the serotonergic neurons of the raphe nuclei in rat midbrain. For this study, Sprague Dawley rats were intoxicated with 2,000ppm carbon monoxide for 5 hours and serial sections of the midbrain were obtained and stained irnmunohistochemically using anti-serotonin anti sera. The changes in number of serotonergic neurons were analyzed. Total number of serotonergic neurons in rnidbrain of normal rats were 37,977 +/- 1,233.3 After carbon monoxide intoxication, the numbers of serotonergic neurons in midbrain nuclei were 28.138 +/- 3.321.8 CO-intoxication reduced the number of neurons in the midbrain nuclei by 25.9%. Especially diminished the number of B8 cell group by 32.6%.
Animals ; Carbon Monoxide* ; Carbon* ; Mesencephalon* ; Neurons ; Raphe Nuclei* ; Rats* ; Rats, Sprague-Dawley ; Serotonergic Neurons*

OBJECTIVES: Adrenergic alpha 1 and 2 receptors work as pathways to control the serotonergic neuron moderation and mirtazapine acts as antagonist of these receptors. The adrenoreceptor alpha 1a (ADRA1A) gene, which encodes adrenergic alpha 1 receptor, has Arg347Cys genetic polymorphism and the polymorphism has strong relationship with many neuro-psychiatric diseases. In this study, we explored the relationship between ADRA1A R347C polymorphism and mirtazapine treatment response in Koreans with major depression. METHODS: 352 patients enrolled in this study, and the symptoms were evaluated by 17-item Hamilton Depression Rating (HAMD-17) scale. After 1, 2, 4, 8, and 12 weeks of mirtazapine treatment, the association between ADRA1A R347C polymorphism and remission/response outcomes was evaluated. RESULTS: Treatment response to mirtazapine was significantly better in T allele carriers than C allele homozygotes after 12 weeks of mirtazapine monotherapy. The percentile decline of HAMD-17 score in T allele carriers was larger than that of C allele homozygotes. ADRA1A R347C genotypes were not significantly associated with remission. CONCLUSIONS: The result showed that treatment response to mirtazapine was significantly associated with ADRA1A R347C genetic polymorphism. T allele carriers showed better treatment response than C allele homozygotes. It can be supposed that T allele carriers have a trend of better treatment response to mirtazapine monotherapy.
Alleles ; Depression* ; Depressive Disorder, Major ; Genotype ; Homozygote ; Humans ; Polymorphism, Genetic ; Serotonergic Neurons

Alcohol abuse and cigarette smoking have been on the rise worldwide and it has been reported that alcohol and nicotine influence serotonergic neuronal activity in the dorsal raphe. Serotonin (5-hydroxytryptamine, 5-HT) has been implicated in the pathophysiology of various neuropsychiatric disorders. In the present study, the effects of alcohol and nicotine on the synthesis of 5-HT and the expression of tryptophan hydroxylase (TPH), the rate limiting enzyme of 5-HT synthesis, in the dorsal and median raphe of young rats were investigated via immunohistochemistry. The numbers of the 5-HT-positive and TPH-positive cells in raphe nuclei were reduced by alcohol and nicotine treatment, and these numbers were reduced more potently by co-administration of alcohol and nicotine. Based on the results, it can be suggested that the pathogenesis of alcohol- and nicotine-induced neuropsychological disorders involves alcohol- and nicotine-induced suppression of 5-HT synthesis and TPH expression in raphe, and that this may be of particular relevance in the consumption of alcohol and nicotine during adolescence.
Adolescent ; Alcoholism ; Animals ; Humans ; Immunohistochemistry ; Nicotine* ; Raphe Nuclei ; Rats* ; Serotonergic Neurons ; Serotonin* ; Smoking ; Tryptophan Hydroxylase* ; Tryptophan*

These experiments were performed to investigate the effect of photoperiod and melatonin on serotonergic immunoreactivity in rat brain stem. The animals were injected with melatonin (1 mg/kg, i.p.) after light and dark treatment. The results by immunohistochemical method were as follows; 1. Immunohistochemical serotonin intensity in brain stem (dorsal raphe nucleus of midbrain, nucleus tractus solitarius and dorsal raphe nucleus of vagus nerve in medulla) appeard weakly in medium in control group compared with light and dark treated group. It suggest that enhanced effect in single injection (light or dark) was canceled by complex mechanism when two factors (light and dark) bring about together. 2. Serotonin immunoreactive neurons in brain stem (dorsal raphe nucleus of midbrain, nucleus tractus solitarius and dorsal raphe nucleus of vagus nerve in medulla) were significantly increased in light and dark treated group compared with control group. These results show that serotonin pathways are more important in mediating the effects of retinally perceived light in the rat. 3. Serotonin immunoreactive neurons in brain stem (dorsal raphe nucleus of midbrain, nucleus tractus solitarius and dorsal raphe nucleus of vagus nerve in medulla) were incresesed in melatonin treated group compared with melatonin non-treated group in light and dark. These results indicated that melatonin injection during photo and dark period enhanced serotonergic neurons activity and then light control influenced the development of serotonergic systems in brain stem including dorsal raphe nucleus of midbrain, nucleus tractus solitarius and dorsal nucleus of vagus nerve in medulla.
Animals ; Brain Stem* ; Brain* ; Melatonin* ; Mesencephalon ; Negotiating ; Neurons ; Photoperiod* ; Raphe Nuclei ; Rats* ; Serotonergic Neurons ; Serotonin ; Solitary Nucleus ; Vagus Nerve

This study was designed to clarify the cytotoxic effects of 5, 7-dihydroxytryptamine (5, 7-DHT) on the serotonergic neurons in the dorsal raphe nucleus, and to investigate the glial reaction during the neurodegenerative changes by light and electron microscopy. Adult male rats (Sprague-Dawley strain) weighing from 250 g to 350 g each were used as experimental animal. 5, 7-DHT (200 microgram dissolved in 0.9% NaCl) was injected into the lateral ventricle of the rat brain with the Hamiton syringe fixed on stereotaxic apparatus. The control rats were given with the similar volume of 0.9% NaCl. The rats were sacrified on the 1st, 3rd, 5th, 10th and 20th day after the injection of 5, 7-DHT. The results were as follows : The cytotoxicity of 5, 7-DHT resulted in severe neurodegenerations of the serotonergic neurons. Most degenerated cells mainly showed necrotic findings, but a few of them exhibited apoptotic features. That is, in early stage of this experiment, the degenerated cells showed edematic changes of cytoplasm, but their nuclei were relatively seen intact. In late stage, the cells showed dark degenerative changes both in their cytoplasm and nuclei. Thereafter the cells were autolysed or phagocytosed by neighboring glial cells. Based on the results, author thought that 5, 7-DHT act as a specific neurotoxin to serotonergic neurons in DRN, and induces severe neurodegenerative changes. The glial reactions in DRN are activated during the neurodegerative changes, and show characteristic patterns of glial reactions.
Adult ; Animals ; Brain ; Cytoplasm ; Humans ; Lateral Ventricles ; Male ; Microscopy, Electron ; Neuroglia ; Raphe Nuclei* ; Rats* ; Serotonergic Neurons* ; Syringes