We have studied the responsibility of tissue serotonin reserves in the excito-motor effects induced by DOPA and dopamine on the isolated rat duodenum in vitro in certain experimental conditions. Two groups of experiments have been performed: first the determination of serotonin endogenous stores after administration of repeated high doses of DOPA and dopamine in the organ bath, secondly the evaluation of motor effects of DOPA and dopamine on rat duodenums experimentally depleted of their endogenous serotonin stores. Serotonin levels were lowered after DOPA and the excito-motor effect of this compound was suppressed in serotonin-depleted duodenums. After dopamine, serotonin tissue levels were not significantly lowered, and the excito-motor effect was observed whatever the serotonin stores may be, depleted or not. Our results are consistent with a relationship between the excito-motor effects of DOPA and serotonin release from endogenous stores; but, concerning dopamine, experimental proofs supporting this hypothesis have not been obtained.
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http://dx.doi.org/10.3109/13813457809055927 | DOI Listing |
Neurosci Lett
January 2025
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico. Electronic address:
Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive loss of dopaminergic neurons in the substantia nigra pars compacta, leading to significant motor and non-motor symptoms. Beta oscillations in cortical areas are a pathognomonic sign. Here we ask whether these oscillations can be recorded in in vitro cortical tissue despite severing the cortico-basal ganglia-thalamo-cortical loop.
View Article and Find Full Text PDFIn the later stages of Parkinson's disease (PD), patients often manifest levodopa-induced dyskinesia (LID), compromising their quality of life. The pathophysiology underlying LID is poorly understood, and treatment options are limited. To move toward filling this treatment gap, the intrinsic and synaptic changes in striatal spiny projection neurons (SPNs) triggered by the sustained elevation of dopamine (DA) during dyskinesia were characterized using electrophysiological, pharmacological, molecular and behavioral approaches.
View Article and Find Full Text PDFZhejiang Da Xue Xue Bao Yi Xue Ban
January 2025
School of Medicine, Hangzhou City University, Zhejiang Provincial Key Laboratory of Novel Targets and Drug Study for Neural Repair, Hangzhou 310015, China.
Objectives: To investigate the protective effects and underlying mechanisms of extract on motor dysfunction in mouse model of Parkinson's disease (PD).
Methods: Eighty C57BL/6 male mice were randomly divided into five groups: control group, PD model group, levodopa treatment group (positive control group), low-dose GP treatment group (LD-GP group), and high-dose GP treatment group (HD-GP group), with 16 mice per group. The PD model was induced by injection of 6-hydroxydopamine into the substantia nigra pars reticulata in mice of last 5 groups.
Narra J
December 2024
Department of Nutrition, Faculty of Medicine Science, Universitas Brawijaya, Malang, Indonesia.
Velvet bean is a native Indonesian legume containing L-dopa, yet it remains underutilized. The aim of this study was to analyze the effects of different types of tempe (soybean, velvet bean, and their combination) on cognitive function, brain histology, dopamine levels, and serum β-amyloid in rats, as well as to identify the parameters most influencing cognitive function, including brain mass and volume, hippocampal neuron count, and dopamine and β-amyloid levels. An experimental study was conducted using a completely randomized design with one factor: the protein source of diet.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemistry, Chungnam National University, Daejeon 34134, Republic of Korea.
Bioinspired coatings that mimic the adhesive properties of mussels have received considerable attention for surface modification applications. While polydopamine chemistry has been widely used to develop functional coatings, 3,4-dihydroxyphenyl-l-alanine (l-DOPA), a key component of mussel adhesive proteins, has received less attention because, compared to dopamine, it is relatively difficult to form effective coatings on solid substrates in mildly alkaline solutions. Although several methods have been explored to improve the efficiency of l-DOPA coatings, there is still a need to expand the l-DOPA-based surface chemistry.
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