Dopamine Synthesis in the Nigrostriatal Dopaminergic System in Patients at Risk of Developing Parkinson's Disease at the Prodromal Stage.

Parkinson's disease (PD) is diagnosed by the onset of motor symptoms and treated long after its onset. Therefore, the development of the early diagnosis of PD is a priority for neurology. Advanced methodologies for this include (1) searching for patients at risk of developing prodromal PD based on premotor symptoms; (2) searching for changes in the body fluids in these patients as diagnostic biomarkers; (3) verifying the diagnosis of prodromal PD and diagnostic-value biomarkers using positron emission tomography (PET); (4) anticipating the development of motor symptoms.

The prevalence of hookah smokers among Belarussian children and adolescents.

Introduction: The purpose of this survey was to assess the prevalence of hookah smokers among children and adolescents aged 12-16 years in Belarus.

Methods: This survey involved 3485 people, including 1737 girls and 1726 boys, and included 6 questions from the main questionnaire of the GYTS aimed at hookah consumption. The statistical processing was performed using the SUDAAN software package; a 95% confidence interval was calculated to calculate weighted prevalence estimates and standard errors.

Development of the Periventricular Nucleus as a Brain Center, Containing Dopaminergic Neurons and Neurons Expressing Individual Enzymes of Dopamine Synthesis.

We have recently shown that the periventricular nucleus (PeVN) of adult rats is a "mixed dopaminergic (DAergic) center" containing three thousand neurons: DAergic neurons and those expressing one of the dopamine (DA)-synthesizing enzymes. This study aims to evaluate the development of the PeVN as a mixed DAergic center in rats in the perinatal period, critical for brain morphogenesis. During this period, the PeVN contains DAergic neurons and monoenzymatic neurons expressing individual enzymes of DA synthesis: tyrosine hydroxylase (TH) or aromatic L-amino acid decarboxylase (AADC).

Striatal Neurons Partially Expressing a Dopaminergic Phenotype: Functional Significance and Regulation.

Since the discovery of striatal neurons expressing dopamine-synthesizing enzymes, researchers have attempted to identify their phenotype and functional significance. In this study, it was shown that in transgenic mice expressing green fluorescent protein (GFP) under the tyrosine hydroxylase (TH) gene promoter, (i) there are striatal neurons expressing only TH, only aromatic L-amino acid decarboxylase (AADC), or both enzymes of dopamine synthesis; (ii) striatal neurons expressing dopamine-synthesizing enzymes are not dopaminergic since they lack a dopamine transporter; (iii) monoenzymatic neurons expressing individual complementary dopamine-synthesizing enzymes produce this neurotransmitter in cooperation; (iv) striatal nerve fibers containing only TH, only AADC, or both enzymes project into the lateral ventricles, providing delivery pathways for L-3,4-dihydroxyphenylalanine and dopamine to the cerebrospinal fluid; and (v) striatal GFP neurons express receptor genes for various signaling molecules, i.e.

The Periventricular Nucleus as a Brain Center Containing Dopaminergic Neurons and Neurons Expressing Individual Enzymes of Dopamine Synthesis.

Since the 1980s, the concept of dopamine-rich brain centers as clusters of only dopaminergic neurons has been fundamentally revised. It has been shown that, in addition to dopaminergic neurons, most of these centers contain neurons expressing one of the enzymes of dopamine synthesis: tyrosine hydroxylase (TH) or aromatic L-amino acid decarboxylase (AADC). We have obtained convincing evidence that in rats, the hypothalamic periventricular nucleus (PeVN) is one of the largest dopamine-rich centers, containing dopaminergic and monoenzymatic neurons.