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Cell Aug 2022Aedes aegypti mosquitoes are a persistent human foe, transmitting arboviruses including dengue when they feed on human blood. Mosquitoes are intensely attracted to body...
Aedes aegypti mosquitoes are a persistent human foe, transmitting arboviruses including dengue when they feed on human blood. Mosquitoes are intensely attracted to body odor and carbon dioxide, which they detect using ionotropic chemosensory receptors encoded by three large multi-gene families. Genetic mutations that disrupt the olfactory system have modest effects on human attraction, suggesting redundancy in odor coding. The canonical view is that olfactory sensory neurons each express a single chemosensory receptor that defines its ligand selectivity. We discovered that Ae. aegypti uses a different organizational principle, with many neurons co-expressing multiple chemosensory receptor genes. In vivo electrophysiology demonstrates that the broad ligand-sensitivity of mosquito olfactory neurons depends on this non-canonical co-expression. The redundancy afforded by an olfactory system in which neurons co-express multiple chemosensory receptors may increase the robustness of the mosquito olfactory system and explain our long-standing inability to disrupt the detection of humans by mosquitoes.
Topics: Aedes; Animals; Humans; Ligands; Odorants; Olfactory Receptor Neurons
PubMed: 35985288
DOI: 10.1016/j.cell.2022.07.024 -
Nature Methods Nov 2020The ability to directly measure acetylcholine (ACh) release is an essential step toward understanding its physiological function. Here we optimized the GRAB...
The ability to directly measure acetylcholine (ACh) release is an essential step toward understanding its physiological function. Here we optimized the GRAB (GPCR-activation-based ACh) sensor to achieve substantially improved sensitivity in ACh detection, as well as reduced downstream coupling to intracellular pathways. The improved version of the ACh sensor retains the subsecond response kinetics, physiologically relevant affinity and precise molecular specificity for ACh of its predecessor. Using this sensor, we revealed compartmental ACh signals in the olfactory center of transgenic flies in response to external stimuli including odor and body shock. Using fiber photometry recording and two-photon imaging, our ACh sensor also enabled sensitive detection of single-trial ACh dynamics in multiple brain regions in mice performing a variety of behaviors.
Topics: Acetylcholine; Animals; Animals, Genetically Modified; Behavior, Animal; Biosensing Techniques; Brain; Cholinergic Agents; Drosophila; Green Fluorescent Proteins; HEK293 Cells; Humans; Mice; Mushroom Bodies; Neurons; Olfactory Cortex; Receptor, Muscarinic M3; Somatosensory Cortex
PubMed: 32989318
DOI: 10.1038/s41592-020-0953-2 -
Biomolecules Jan 2021Lipoxygenases are widespread enzymes that catalyze oxidation of polyunsaturated fatty acids (linoleic, linolenic, and arachidonic acid) to produce hydroperoxides.... (Review)
Review
Lipoxygenases are widespread enzymes that catalyze oxidation of polyunsaturated fatty acids (linoleic, linolenic, and arachidonic acid) to produce hydroperoxides. Lipoxygenase reactions can be desirable, but also lipoxygenases can react in undesirable ways. Most of the products of lipoxygenase reactions are aromatic compounds that can affect food properties, especially during long-term storage. Lipoxygenase action on unsaturated fatty acids could result in off-flavor/off-odor development, causing food spoilage. In addition, lipoxygenases are present in the human body and play an important role in stimulation of inflammatory reactions. Inflammation is linked to many diseases, such as cancer, stroke, and cardiovascular and neurodegenerative diseases. This review summarized recent research on plant families and species that can inhibit lipoxygenase activity.
Topics: Animals; Arachidonate 15-Lipoxygenase; Arachidonate 5-Lipoxygenase; Arachidonic Acid; Fatty Acids; Fatty Acids, Unsaturated; Flowers; Humans; Hydrogen Peroxide; Inflammation; Inhibitory Concentration 50; Lipoxygenase; Lipoxygenase Inhibitors; Oxidation-Reduction; Oxygen; Plant Extracts; Plant Leaves; Polyphenols
PubMed: 33503885
DOI: 10.3390/biom11020152