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Watts, M.

Publications and source records attributed to Watts, M..

4 recordsLinked to original sources

A transcriptomic and spatial map of serotonin autoreceptor expression in Drosophila

Serotonin is an evolutionarily ancient neurotransmitter that modulates an array of behaviors such as mood, sleep, and appetite across species. Serotonin acts primarily by binding to serotonin receptors, which are expressed in post-synaptic neurons (heteroreceptors) and serotonergic neurons themselves (autoreceptors). Serotonin autoreceptors modulate serotonergic tone, the foundational principles of which have been excellently demonstrated in vertebrate and invertebrate models. However, many aspects of the mechanisms and contexts in which this modulation occurs are still unclear. Drosophila melanogaster is a powerful model organism that can provide unique insights into autoreceptor function by the ability to perform precise spatial and temporal genetic manipulation with structural and functional readouts / behaviors of serotonin systems. However, a systematic characterization of serotonin autoreceptor expression in Drosophila has not been conducted. Here we use single-cell sequencing and genetic labeling to show that all five serotonin receptors are expressed in serotonergic neurons and map their expression at both the larval and adult stages of development. This is the first evidence of 5-HT2A and 5-HT7 expression in serotonergic neurons in any organism. Moreover, the unique combinations of autoreceptor expression in specific neuronal clusters will aid in the development of novel hypotheses for autoreceptor function, and demonstrates the utility of Drosophila as a model organism to study the function of serotonin autoreceptors.

neuroscience↗

Cardiac-specific Kv1.1 deficiency alters cardiomyocyte electrophysiology without modifying overall cardiac function or arrhythmia susceptibility

The leading cause of epilepsy-related mortality is sudden unexpected death in epilepsy (SUDEP), resulting from seizure-induced cardiorespiratory arrest by mechanisms that remain unresolved. Mutations in ion channel genes expressed in both brain and heart represent SUDEP risk factors because they can disrupt neural and cardiac rhythms, providing a unified explanation for seizures and lethal arrhythmias. However, the relative contributions of brain-driven mechanisms, heart-intrinsic processes, and seizures to cardiac dysfunction in epilepsy remain unclear. Here, we investigated the heart-specific role of the Kcna1 gene, which encodes Kv1.1 voltage-gated potassium channel -subunits expressed in both neurons and cardiomyocytes, where they shape action potential firing and influence seizure and arrhythmia susceptibility. We generated cardiac-specific Kcna1 conditional knockout (cKO) mice lacking Kv1.1 selectively in cardiomyocytes and assessed their cardiac function using in vitro and in vivo electrophysiology. Cardiac Kv1.1 deficiency prolonged action potentials in atrial, but not ventricular, cardiomyocytes, demonstrating a direct role for Kv1.1 in atrial repolarization. Despite these cellular effects, cKOs exhibited normal lifespans, electrocardiographic features, heart rate variability, pacing-induced arrhythmia susceptibility, contractility, seizure susceptibility, and seizure-induced mortality. Thus, while loss of cardiac Kv1.1 was sufficient to impair atrial repolarization, it did not reproduce the broader cardiac abnormalities seen in global Kcna1 knockouts. Given the higher mortality rates of global compared with neural-specific knockouts in our previous studies, cardiac Kv1.1 deficiency, while not lethal alone, may increase vulnerability to seizure-related death when combined with neural deficiency, consistent with a brain-heart dyssynergy that lowers the threshold for fatal events.

physiology↗

MicroRNA-210 Knockout Alters Dendritic Density and Behavioural Flexibility

MicroRNAs exert post-transcriptional control over eukaryotic genomes and are integral for regulating complex functions in neurodevelopment, neuroplasticity and cognitive processing. The microRNA-210 (miR-210) is a highly-conserved, hypoxia-regulated miRNA that has been shown to be dysregulated in Alzheimers Disease. We have recently also identified a significant enrichment of neurodegenerative diseases among miR-210 targets within the human transcriptome. To further elucidate the role of miR-210 in neuronal function and cognitive behaviour, we utilised conditional miR-210 knockout mice to characterise miR-210 regulation and function in primary hippocampal neurons and measured visual discrimination and reversal learning using rodent touchscreen assays. We found that miR-210 expression was induced by neuronal activation and loss of neuronal miR-210 increased oxidative metabolism and ROS production as well as dendritic density and branching in vitro. We also found that loss of miR-210 in knockout mice increased behavioural flexibility and reduced perseverative responding during reversal learning which required updating of information and feedback. These data support a conserved, activity-dependent role for miR-210 in cognitive function through modulation of neuronal metabolism.

neuroscience↗

Minimum Information for Reusable Arthropod Abundance Data (MIReAAD)

Introduction Introduction Discussion Conclusion References Arthropods play a dominant role in the dynamics of practically all natural and human-modified terrestrial ecosystems1-3, and have significant economic and health effects. For example, certain insects provide significant economic benefits (e.g. pollination) exceeding $57 billion a year to the United States alone4. Meanwhile, invasive insects cost an estimated $70 billion dollars per year globally5 and insect pests may reduce agricultural harvests by up to 16%, with an equal amount of further losses of harvested goods6. Particularly noteworthy is a subset of arthropods that are disease vectors, transmitting pathogens to and between animals as well as plan ...

ecology↗