Unlike other monoamine neurotransmitters, the mechanism by which the brain's histamine content is regulated remains unclear. In mammals, vesicular monoamine transporters (VMATs) are expressed exclusively in neurons and mediate the storage of histamine and other monoamines. We have studied the visual system of Drosophila melanogaster in which histamine is the primary neurotransmitter released from photoreceptor cells. We report here that a novel mRNA splice variant of Drosophila VMAT (DVMAT-B) is expressed not in neurons but rather in a small subset of glia in the lamina of the fly's optic lobe. Histamine contents are reduced by mutation of dVMAT, but can be partially restored by specifically expressing DVMAT-B in glia. Our results suggest a novel role for a monoamine transporter in glia that may be relevant to histamine homeostasis in other systems.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2570955PMC
http://dx.doi.org/10.1371/journal.pgen.1000245DOI Listing

Publication Analysis

Top Keywords

vesicular monoamine
8
monoamine transporter
8
visual system
8
histamine
6
glial variant
4
variant vesicular
4
monoamine
4
transporter required
4
required store
4
store histamine
4

Similar Publications

Drug inhibition and substrate transport mechanisms of human VMAT2.

Nat Commun

January 2025

Shanghai Fifth People's Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China.

Vesicular monoamine transporter 2 (VMAT2) is crucial for packaging monoamine neurotransmitters into synaptic vesicles, with their dysregulation linked to schizophrenia, mood disorders, and Parkinson's disease. Tetrabenazine (TBZ) and valbenazine (VBZ), both FDA-approved VMAT2 inhibitors, are employed to treat chorea and tardive dyskinesia (TD). Our study presents the structures of VMAT2 bound to substrates serotonin (5-HT) and dopamine (DA), as well as the inhibitors TBZ and VBZ.

View Article and Find Full Text PDF

Introduction: Chorea is a motor manifestation of Huntington's disease (HD), which can lead to decreased functional independence and falls. Even though multiple classes of medications have been used to treat this symptom, only the vesicular monoamine transporter 2 (VMAT2) inhibitors tetrabenazine, deutetrabenazine, and valbenazine have been approved by the FDA for this indication.

Areas Covered: This article reviews the pharmacological properties, clinical efficacy, safety, and tolerability of valbenazine in the treatment of chorea in HD.

View Article and Find Full Text PDF

Reversal of the motivational effects of tetrabenazine by NMDA receptor blockade.

Neuropharmacology

December 2024

- Department of Psychopharmacology, Valdman Institute of Pharmacology, Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russia. Electronic address:

Background: Apathy is a syndrome of decreased goal-directed activity, one of the main features of different brain disorders. Despite its high prevalence and life-threatening potential, there are currently very few options for its pharmacological treatment, which may be related to the lack of valid animal models.

Aims: The vesicular monoamine transporter 2 inhibitor tetrabenazine (TBZ) was used in this study to model apathy-related behavior in pathologies linked to a depletion of dopamine.

View Article and Find Full Text PDF

The quantitative analysis of vesicular neurotransmitters in neurons in situ is paramount for investigating neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease (PD). Unfortunately, a direct approach for monitoring neurotransmitter chemistry in single vesicles in fresh brain tissue has remained inaccessible so far. Here, we introduce an innovative platform of single-vesicle electrochemistry (SVE) in fresh brain tissue, enabling the quantification of neurotransmitters at the single-vesicle level for both soma and varicosity.

View Article and Find Full Text PDF

Vesicular monoamine transporter 2 inhibitors (VMAT2i) are currently Food and Drug Administration-approved for the treatment of Huntington disease chorea and tardive dyskinesia. Additionally, they are often used for other hyperkinetic movement disorders in clinical practice. Due to a lack of head-to-head clinical trials, management of VMAT2i in the clinical setting may be unclear and rely on the clinical experience of the practitioner.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!