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Your search keyword '"Serotonergic innervation"' showing total 5 results
Start Over Descriptor "Serotonergic innervation" Topic serotonin
5 results on '"Serotonergic innervation"'

1. Serotonergic innervation of the striatum in a nonhuman primate model of Parkinson's disease.

Author

Jiménez-Sánchez L, Blesa J, Del Rey NL, Monje MHG, Obeso JA, and Cavada C

Subjects
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine administration & dosage, Administration, Intravenous, Animals, Corpus Striatum chemistry, Corpus Striatum pathology, Macaca fascicularis, Parkinsonian Disorders chemically induced, Parkinsonian Disorders pathology, Primates, Serotonergic Neurons chemistry, Serotonergic Neurons pathology, Corpus Striatum metabolism, Parkinsonian Disorders metabolism, Serotonergic Neurons metabolism, Serotonin metabolism
Abstract

Parkinson's disease (PD) is characterized by dopaminergic neurodegeneration in the substantia nigra and dopamine depletion in the striatum. Non-dopaminergic systems are also affected, including the serotonergic system. Enhanced striatal serotonergic innervation is a proposed compensatory mechanism for the dopaminergic deficit. Meanwhile a serotonergic deficit has been suggested as preceding the nigrostriatal dopaminergic pathology in PD. Our aim was to assess the serotonergic innervation of the striatum in a model of progressive experimental parkinsonism in macaques, from pre-symptomatic to symptomatic stages. The neurotoxin 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) was administered to adult macaque monkeys using a slow intoxication protocol. The intoxicated animals were classified into asymptomatic, recovered, moderate and severe parkinsonian, based on their motor behavior. The serotonergic innervation was studied by immunohistochemistry against serotonin (5-HT). In the striatum, the density of 5-HT-immunoreactive (5-HT+) axons was estimated with stereology. Images of the striatum in the immunostained sections were taken to compare the distribution patterns of the serotonergic innervation between groups. These patterns were apparently similar among the groups. Axonal density estimations showed no differences in striatal 5-HT+ innervation between the intoxicated groups and the control group. Accordingly, this study fails to find significant changes in the striatal serotonergic axonal innervation in MPTP-treated monkeys, coinciding with previous biochemical findings in our model. However, it is possible that alterations in the serotonergic system in PD could be independent of axonal density changes. Consequently, the proposed role for striatal serotonin serving as a compensatory mechanism for dopaminergic denervation merits further study. This article is part of the special issue entitled 'Serotonin Research: Crossing Scales and Boundaries'., Competing Interests: Declaration of competing interest None., (Copyright © 2019. Published by Elsevier Ltd.)

Published
2020
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2. Biochemical evidence for the presence of serotonin transporters in the rat cochlea

Author

Vicente-Torres, M. Angeles, Dávila, David, Bartolomé, M. Visitación, Carricondo, Francisco, and Gil-Loyzaga, Pablo

Subjects
*COCHLEA, *HAIR cells, *SEROTONIN, *MESSENGER RNA
Abstract

Cochlear serotonergic innervation is constituted by efferent fibers projecting both to the area below the inner and the outer hair cells. Previous detection of serotonin (5-HT) metabolites and 5-HT receptor mRNAs suggests the existence of serotonergic synaptic activity in the cochlea. The present study explores this possibility through the effect of 6-nitroquipazine (6-NQ), a 5-HT selective reuptake inhibitor, on the basal turnover of 5-HT. The concentrations of 5-HT and its metabolite 5-hydroxyindole-3-acetic acid (5-HIAA) were quantified by high performance liquid chromatography with electrochemical detection in blood-free cochleae of rats treated with 6-NQ or saline and kept under silent conditions. Treatment with 6-NQ induced a significant increase of the cochlear concentration of 5-HT and a significant reduction of 5-HIAA concentration with respect to saline treatment. These findings could indicate that 6-NQ induced the blockade of the 5-HT selective reuptake to the cochlear serotonergic fibers. This suggests that plasma membrane 5-HT transporters are present in cochlear serotonergic fibers. Even though the role of serotonergic innervation on cochlear physiology remains unknown, the existence of cochlear serotonergic synaptic activity is strongly supported by present contributions. [Copyright &y& Elsevier]

Published
2003
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3. Perturbation of Serotonin Homeostasis during Adulthood Affects Serotonergic Neuronal Circuitry

Author

Alessandro Usiello, Sara Migliarini, Francesco Napolitano, Marta Pratelli, Massimo Pasqualetti, Barbara Pelosi, Pratelli, Marta, Migliarini, Sara, Pelosi, Barbara, Napolitano, Francesco, Usiello, Alessandro, Pasqualetti, Massimo, Pratelli, M, Migliarini, S, Pelosi, B, Napolitano, F, and Pasqualetti, M.

Subjects
Messenger, Tryptophan Hydroxylase, Inbred C57BL, Transgenic, Serotonergic innervation, 5-Hydroxytryptophan, chemistry.chemical_compound, Mice, 0302 clinical medicine, Serotonin Agents, Neural Pathways, Homeostasis, Neurotransmitter, Serotonin Plasma Membrane Transport Proteins, 0303 health sciences, Serotonergic Neuron, 5-hydroxytryptophan, serotonergic innervations, serotonin, serotonin homeostasis, tryptophan hydroxylase 2, Animals, Brain-Derived Neurotrophic Factor, Gene Expression Regulation, Green Fluorescent Proteins, Mice, Inbred C57BL, Mice, Transgenic, Midline Thalamic Nuclei, Nerve Net, RNA, Messenger, Serotonergic Neurons, Serotonin, Signal Transduction, General Neuroscience, Medicine (all), General Medicine, New Research, Serotonin homeostasi, medicine.anatomical_structure, Serotonin Agent, Serotonin Plasma Membrane Transport Protein, Biology, Development, Serotonergic, Green Fluorescent Protein, 03 medical and health sciences, Neural Pathway, Homeostasi, medicine, 030304 developmental biology, Brain-derived neurotrophic factor, Animal, chemistry, RNA, Neuron, Neuroscience, 030217 neurology & neurosurgery
Abstract

Visual Abstract, Growing evidence shows that the neurotransmitter serotonin (5-HT) modulates the fine-tuning of neuron development and the establishment of wiring patterns in the brain. However, whether serotonin is involved in the maintenance of neuronal circuitry in the adult brain remains elusive. Here, we use a Tph2fl°x conditional knockout (cKO) mouse line to assess the impact of serotonin depletion during adulthood on serotonergic system organization. Data show that the density of serotonergic fibers is increased in the hippocampus and decreased in the thalamic paraventricular nucleus (PVN) as a consequence of brain serotonin depletion. Strikingly, these defects are rescued following reestablishment of brain 5-HT signaling via administration of the serotonin precursor 5-hydroxytryptophan (5-HTP). Finally, 3D reconstruction of serotonergic fibers reveals that changes in serotonin homeostasis affect axonal branching complexity. These data demonstrate that maintaining proper serotonin homeostasis in the adult brain is crucial to preserve the correct serotonergic axonal wiring.

Published
2017

5. Lack of brain serotonin affects postnatal development and serotonergic neuronal circuitry formation

Author

Barbara Pelosi, Massimo Pasqualetti, G. Lunardi, Sara Migliarini, and Giulia Pacini

Subjects
Serotonin, Neurogenesis, Central nervous system, Green Fluorescent Proteins, Longevity, Hippocampus, Tryptophan Hydroxylase, Serotonergic, neural development, Cellular and Molecular Neuroscience, Mice, Genes, Reporter, Tph2, Neural Pathways, medicine, Neurites, Animals, Body Size, Gene Knock-In Techniques, Transgenes, BDNF, neurodevelopmental disorders, serotonergic innervation, serotonin, Molecular Biology, Growth Disorders, Brain-derived neurotrophic factor, Brain Chemistry, TPH2, Brain-Derived Neurotrophic Factor, Brain, Tryptophan hydroxylase, Mice, Inbred C57BL, Psychiatry and Mental health, medicine.anatomical_structure, Phenotype, Psychology, Neuroscience, Serotonergic Neurons
Abstract

Despite increasing evidence suggests that serotonin (5-HT) can influence neurogenesis, neuronal migration and circuitry formation, the precise role of 5-HT on central nervous system (CNS) development is only beginning to be elucidated. Moreover, how changes in serotonin homeostasis during critical developmental periods may have etiological relevance to human mental disorders, remains an unsolved question. In this study we address the consequences of 5-HT synthesis abrogation on CNS development using a knock-in mouse line in which the tryptophan hydroxylase 2 (Tph2) gene is replaced by the eGFP reporter. We report that lack of brain 5-HT results in a dramatic reduction of body growth rate and in 60% lethality within the first 3 weeks after birth, with no gross anatomical changes in the brain. Thanks to the specific expression of the eGFP, we could highlight the serotonergic system independently of 5-HT immunoreactivity. We found that lack of central serotonin produces severe abnormalities in the serotonergic circuitry formation with a brain region- and time- specific effect. Indeed, we observed a striking reduction of serotonergic innervation to the suprachiasmatic and thalamic paraventricular nuclei, while a marked serotonergic hyperinnervation was found in the nucleus accumbens and hippocampus of Tph2∷eGFP mutants. Finally, we demonstrated that BDNF expression is significantly up-regulated in the hippocampus of mice lacking brain 5-HT, mirroring the timing of the appearance of hyperinnervation and thus unmasking a possible regulatory feedback mechanism tuning the serotonergic neuronal circuitry formation. On the whole, these findings reveal that alterations of serotonin levels during CNS development affect the proper wiring of the brain that may produce long-lasting changes leading to neurodevelopmental disorders.

Published
2012

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