Classical studies using bovine chromaffin granules have defined the physiologic and pharmacologic properties of the vesicular amine transporter that packages monoamine transmitters into intracellular vesicles for subsequent regulated release. The recent isolation of two distinct but closely related cDNA clones encoding vesicular amine transport suggests that the activity expressed in the brain (synaptic vesicle amine transporter or SVAT) may differ significantly from the previously described adrenal gland activity (chromaffin granule amine transporter or CGAT). A direct comparison of the two transporters now shows that SVAT has a higher affinity than CGAT for monoamine substrates, in particular for histamine. In addition, SVAT shows approximately 10-fold greater sensitivity to tetrabenazine than CGAT. [3H]Dihydrotetrabenazine shows no detectable binding to CGAT but does bind to SVAT, accounting for the differential sensitivity. Furthermore, methamphetamine preferentially inhibits transport by SVAT relative to CGAT, apparently by competing at the site of amine recognition rather than by disrupting the vesicular pH gradient. These previously unsuspected differences in the storage of monoamine transmitter in the central nervous system and the adrenal gland may help to account for several classic pharmacological observations.
Download full-text PDF |
Source |
---|
Background: The locus coeruleus (LC), is the first brain region to develop hyperphosphorylated tau (ptau) inclusions in Alzheimer's disease (AD) and undergoes catastrophic degeneration in later stages of the disease. Importantly, the LC is the main noradrenergic nucleus in the brain and source of NE in the forebrain, and dysregulation of the neurotransmitter norepinephrine (NE) is associated with AD symptoms, as its release in the forebrain regulates attention, arousal, stress response, and learning and memory. Moreover, the LC may transmit pathogenic tau to the forebrain via its extensive projections.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Emory University School of Medicine, Atlanta, GA, USA.
Background: Early stages of Alzheimer's disease (AD) are characterized by neuropsychiatric symptoms such as anxiety, apathy, compulsivity, and sleep disturbances, which manifest years before cognitive deficits. It has been hypothesized that dysregulation of the locus coeruleus-norepinephrine (LC-NE) system contributes to these symptoms because (1) the LC is the first site where hyperphosphorylated 'pretangle' tau can be detected in the human brain and (2) NE influences physiological processes such as mood, stress responses, and arousal. To investigate causal relationships between LC tau pathology and neuropsychiatric symptoms, we developed a translationally-relevant model where pathogenic tau is exclusively expressed in mouse LC to recapitulate the 'LC-first' phenomenon.
View Article and Find Full Text PDFNat Commun
January 2025
The Institute of Technological Sciences, Wuhan University, Wuhan, China.
Flexible perovskite solar cells (F-PSCs) are appealing for their flexibility and high power-to-weight ratios. However, the fragile grain boundaries (GBs) in perovskite films can lead to stress and strain cracks under bending conditions, limiting the performance and stability of F-PSCs. Herein, we show that the perovskite film can facilely achieve in situ bifacial capping via introducing 4-(methoxy)benzylamine hydrobromide (MeOBABr) as the precursor additive.
View Article and Find Full Text PDFNat 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 PDFNeuropsychiatr Dis Treat
December 2024
Department of Medicine and Surgery, Kore University of Enna, Enna (EN), Italy.
Background: Currently available antipsychotics, mainly targeting the dopaminergic pathway, fail to address the complexity of schizophrenic symptoms and can lead to burdening adverse events. The need for innovative pharmacological options remains critical and research is now focusing on the development of non-dopaminergic antipsychotics. This review aims to summarize the current literature on the most promising non-dopaminergic new APs (muscarinic agonists, Trace Amine Associated Receptor 1 agonists, Glycine Transporter Type 1 inhibitors and 5-HT2A antagonists) and provide a clinically oriented overview of their efficacy, safety and potential use in schizophrenia.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!