Tyrosine hydroxylase and cholecystokinin mRNA levels in the substantia nigra, ventral tegmental area, and locus ceruleus are unaffected by acute and chronic haloperidol administration

1990 ◽  
Vol 10 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Sandra L. Cottingham ◽  
David Pickar ◽  
Thomas K. Shimotake ◽  
Pascale Montpied ◽  
Steven M. Paul ◽  
...  
Keyword(s):  
Tyrosine Hydroxylase ◽  
Substantia Nigra ◽  
Ventral Tegmental Area ◽  
Locus Ceruleus ◽  
Mrna Levels ◽  
Chronic Haloperidol ◽  
Ventral Tegmental

scholarly journals Understanding the Mechanism of Antidepressant-Related Sexual Dysfunction: Inhibition of Tyrosine Hydroxylase in Dopaminergic Neurons after Treatment with Paroxetine but Not with Agomelatine in Male Rats

2019 ◽  
Vol 8 (2) ◽  
pp. 133 ◽  
Author(s):  
Yanira Santana ◽  
Angel Montejo ◽  
Javier Martín ◽  
Ginés LLorca ◽  
Gloria Bueno ◽  
...  
Keyword(s):  
Sexual Behavior ◽  
Tyrosine Hydroxylase ◽  
Sexual Dysfunction ◽  
Substantia Nigra ◽  
Ventral Tegmental Area ◽  
Median Eminence ◽  
Zona Incerta ◽  
Mediobasal Hypothalamus ◽  
Ventral Tegmental ◽  
Serotonergic Antidepressant

Antidepressant-related sexual dysfunction is a frequent adverse event caused by serotonergic activation that intensely affects quality of life and adherence in depressed patients. The dopamine system has multiple effects promoting sexual behavior, but no studies have been carried out to confirm dopaminergic changes involved in animal models after antidepressant use. Methods: The sexual behavior-related dopaminergic system in the rat was studied by comparing two different antidepressants and placebo for 28 days. The antidepressants used were paroxetine (a serotonergic antidepressant that causes highly frequent sexual dysfunction in humans) and agomelatine (a non-serotonergic antidepressant without associated sexual dysfunction). The tyrosine hydroxylase immunoreactivity (THI) in the substantia nigra pars compacta, the ventral tegmental area, the zona incerta, and the hypothalamic arcuate nucleus, as well as the dopaminergic projections to the striatum, hippocampus, cortex, and median eminence were analyzed. Results: The THI decreased significantly in the substantia nigra and ventral tegmental area after treatment with paroxetine, and the labeling was reduced drastically in the zona incerta and mediobasal hypothalamus. The immunoreactive axons in the target regions (striatum, cortex, hippocampus, and median eminence) almost disappeared only in the paroxetine-treated rats. Conversely, after treatment with agomelatine, a moderate reduction in immunoreactivity in the substantia nigra was found without appreciable modifications in the ventral tegmental area, zona incerta, and mediobasal hypothalamus. Nevertheless, no sexual or copulatory behavior was observed in any of the experimental or control groups. Conclusion: Paroxetine but not agomelatine was associated with important decreased activity in dopaminergic areas such as the substantia nigra and ventral tegmental areas that could be associated with sexual performance impairment in humans after antidepressant treatment.

Reversibility of functionally injured neurotransmitter systems with shunt placement in hydrocephalic rats: implications for intellectual impairment in hydrocephalus

1998 ◽  
Vol 88 (4) ◽  
pp. 709-717 ◽  
Author(s):  
Yuzuru Tashiro ◽  
James M. Drake
Keyword(s):  
Tyrosine Hydroxylase ◽  
Ventral Tegmental Area ◽  
Locus Ceruleus ◽  
Intellectual Impairment ◽  
Content Type ◽  
Shunt Placement ◽  
Cholinergic Basal Forebrain ◽  
Ventral Tegmental ◽  
Immunohistochemical Techniques ◽  
Fine Print

Intellectual impairment has been related to alteration of neuronal innervation in the following regions: cholinergic basal forebrain nuclei (Ch1–Ch6, learning and memory), dopaminergic ventral tegmental area (emotional control), and noradrenergic locus ceruleus (cognition). Recent studies have implicated neuronal injury in the pathogenesis of hydrocephalus. Object. The authors used immunohistochemical techniques to investigate functional injury in these regions in animals with progressive hydrocephalus, following shunt placement for cerebrospinal fluid (CSF) drainage. Methods. Hydrocephalus was induced in 20 Wistar rats by intracisternal injection of 0.05 ml of 25% kaolin solution. Four control animals (Group 1) received the same volume of saline. Ventriculoperitoneal shunts were inserted in eight rats at 2 and 4 weeks after kaolin injection and the animals were killed at 8 weeks (Group 2). The other 12 hydrocephalic animals were killed at 2, 4, and 8 weeks without undergoing shunt placement (Group 3). Immunoreactive (IR) neurons to choline acetyltransferase (ChAT) in Ch1–Ch6, tyrosine hydroxylase (TH) in the ventral tegmental area, and dopamine B-hydroxylase (DBH) in the locus ceruleus, as well as IR projection fibers in the terminal areas, were compared between groups. The number of ChAT- and TH-IR neurons in rats with and without shunt placement was counted for quantitative analysis. The number of ChAT-IR neurons was progressively reduced during the development of hydrocephalus in Ch1, Ch2, Ch3, and Ch4 (p < 0.05). Tyrosine-hydroxylase-immunoreactive neurons were also reduced in number, and demonstrated decreased projection fibers and terminals. Early shunting (at 2 weeks) restored ChAT and TH immunoreactivity to control levels, but late shunting (at 4 weeks) did not (p < 0.05). The DBH—IR neurons in the locus ceruleus were remarkably compressed by the dilated fourth ventricle, and diminished immunoreactivity was observed in the terminal areas. Shunt placement for CSF also restored the immunoreactivity in this system. Conclusions. These findings indicate that a progressive functional injury occurs in the cholinergic, dopaminergic, and noradrenergic systems as a result of hydrocephalus. This may contribute to intellectual impairment and might be prevented by early treatment with shunt placement.

A simple and fast densitometric method for the analysis of tyrosine hydroxylase immunoreactivity in the substantia nigra pars compacta and in the ventral tegmental area

2005 ◽  
Vol 16 (1-3) ◽  
pp. 58-64 ◽  
Author(s):  
Léder Leal Xavier ◽  
Giordano Gubert Viola ◽  
Anete Curte Ferraz ◽  
Claudio Da Cunha ◽  
Janyana Marcela Doro Deonizio ◽  
...  
Keyword(s):  
Tyrosine Hydroxylase ◽  
Substantia Nigra ◽  
Ventral Tegmental Area ◽  
Substantia Nigra Pars Compacta ◽  
Ventral Tegmental

scholarly journals Programming of Dopaminergic Neurons by Neonatal Sex Hormone Exposure: Effects on Dopamine Content and Tyrosine Hydroxylase Expression in Adult Male Rats

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Pedro Espinosa ◽  
Roxana A. Silva ◽  
Nicole K. Sanguinetti ◽  
Francisca C. Venegas ◽  
Raul Riquelme ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Tyrosine Hydroxylase ◽  
Substantia Nigra ◽  
Ventral Tegmental Area ◽  
Dopaminergic Neurons ◽  
Dopamine Release ◽  
Male Rats ◽  
Midbrain Dopaminergic Neurons ◽  
Dopamine Content ◽  
Ventral Tegmental

We sought to determine the long-term changes produced by neonatal sex hormone administration on the functioning of midbrain dopaminergic neurons in adult male rats. Sprague-Dawley rats were injected subcutaneously at postnatal day 1 and were assigned to the following experimental groups: TP (testosterone propionate of 1.0 mg/50 μL); DHT (dihydrotestosterone of 1.0 mg/50 μL); EV (estradiol valerate of 0.1 mg/50 μL); and control (sesame oil of 50 μL). At postnatal day 60, neurochemical studies were performed to determine dopamine content in substantia nigra-ventral tegmental area and dopamine release in nucleus accumbens. Molecular (mRNA expression of tyrosine hydroxylase) and cellular (tyrosine hydroxylase immunoreactivity) studies were also performed. We found increased dopamine content in substantia nigra-ventral tegmental area of TP and EV rats, in addition to increased dopamine release in nucleus accumbens. However, neonatal exposure to DHT, a nonaromatizable androgen, did not affect midbrain dopaminergic neurons. Correspondingly, compared to control rats, levels of tyrosine hydroxylase mRNA and protein were significantly increased in TP and EV rats but not in DHT rats, as determined by qPCR and immunohistochemistry, respectively. Our results suggest an estrogenic mechanism involving increased tyrosine hydroxylase expression, either by direct estrogenic action or by aromatization of testosterone to estradiol in substantia nigra-ventral tegmental area.

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