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The Microbial Opsin Family of Optogenetic Tools: Cell
The Microbial Opsin Family of Optogenetic Tools: Cell
The capture and utilization of light is an exquisitely evolved process. The single-component microbial opsins, although more limited than multicomponent cascades in processing, display unparalleled compactness and speed. Recent advances in understanding microbial opsins have been driven by molecular engineering for optogenetics and by comparative genomics. Here we provide a Primer on these light-activated ion channels and pumps, describe a group of opsins bridging prior categories, and explore the convergence of molecular engineering and genomic discovery for the utilization and understanding of these remarkable molecular machines.
·cell.com·
The Microbial Opsin Family of Optogenetic Tools: Cell
Pfizer Scheme to Churn Out ‘Variant-Specific’ Vaccines Will Lead to More Variants, Experts Warn • Children's Health Defense
Pfizer Scheme to Churn Out ‘Variant-Specific’ Vaccines Will Lead to More Variants, Experts Warn • Children's Health Defense
Pfizer CEO Albert Bourla told Fox News the company has a system in place to turn around a variant-specific jab within 95 days in the likelihood a vaccine-resistant COVID strain emerges, but experts warn that strategy will backfire.
·childrenshealthdefense.org·
Pfizer Scheme to Churn Out ‘Variant-Specific’ Vaccines Will Lead to More Variants, Experts Warn • Children's Health Defense
Gq DREADD activation of CaMKIIa MnPO neurons stimulates nitric oxide activity | Journal of Neurophysiology
Gq DREADD activation of CaMKIIa MnPO neurons stimulates nitric oxide activity | Journal of Neurophysiology
Designer receptors exclusively activated by designer drugs (DREADDs) modify cellular activity following administration of the exogenous ligand clozapine-N-oxide (CNO). However, some reports indicate CNO may have off-target effects. The current studies investigate the use of Gq DREADDs in CaMKIIa-expressing neurons in the median preoptic nucleus (MnPO). Male Sprague-Dawley rats (250 g) anesthetized with isoflurane were stereotaxically microinjected in the MnPO with the Gq DREADD (AAV5-CaMKIIa-HM3D-mCherry) or control virus (AAV5-CaMKIIa-mCherry). Following a 2-wk recovery, rats were used for either immunohistochemical Fos analysis or in vitro patch-clamp electrophysiology. In Gq DREADD-injected rats, CNO induced significant increases in Fos staining in the MnPO and in regions that receive direct or indirect projections from the MnPO. In electrophysiological studies, CNO depolarized and augmented firing frequency in both Gq DREADD-positive neurons (Gq DREADD) as well as unlabeled MnPO neurons in slices from Gq DREADD-injected rats (Gq DREADDx). Gq DREADDx neurons also displayed increases in spontaneous postsynaptic current (sPSC) frequency in response to CNO. Additionally, CaMKIIa-positive MnPO neurons, which also express nitric oxide synthase (NOS), were treated with Nω-nitro-l-arginine (l-NNA; competitive inhibitor of NOS) and hemoglobin (NO scavenger) to assess the role of NO in Gq DREADDx neuron recruitment. Both l-NNA and hemoglobin blocked CNO-induced effects in Gq DREADDx neurons without affecting Gq DREADD neurons. These findings indicate that Gq DREADD-mediated activation of CaMKIIa/NOS expressing neurons in the MnPO can influence the activity of neighboring neurons. Future studies utilizing the use of Gq DREADDs will need to consider the potential recruitment of additional cell populations. NEW & NOTEWORTHY Rats were injected in the median preoptic nucleus (MnPO) with either an adeno-associated virus (AAV) and excitatory (Gq) designer receptor exclusively activated by designer drugs (DREADD) construct or a control AAV. In the Gq DREADD-injected rats only, clozapine-N-oxide (CNO) increased Fos staining in the MnPO and its targets and increased neuron action potential frequency. In electrophysiology experiments with slices with DREADD cells, unlabeled cells were activated and this was likely due to nitric oxide release by the DREADD cells.
·journals.physiology.org·
Gq DREADD activation of CaMKIIa MnPO neurons stimulates nitric oxide activity | Journal of Neurophysiology
Cheyenna Layne Weber
Cheyenna Layne Weber
Cheyenna Layne Weber is a Brooklyn-based writer, community organizer, and educator pursuing art and activism that elevates the needs of people and the planet over profit. She provides strategic nonprofit communications, organizational development, community-based research, and collective and coopera
·cheyennaweber.com·
Cheyenna Layne Weber
Changing the locks | Feature | Chemistry World
Changing the locks | Feature | Chemistry World
Designer receptors help understand cellular signals and could treat epilepsy and Parkinson's disease, but need new tools, finds Andy Extance
·chemistryworld.com·
Changing the locks | Feature | Chemistry World
Compound 21, a two-edged sword with both DREADD-selective and off-target outcomes in rats
Compound 21, a two-edged sword with both DREADD-selective and off-target outcomes in rats
Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) represent a technical revolution in integrative neuroscience. However, the first used ligands exhibited dose-dependent selectivity for their molecular target, leading to potential unspecific effects. Compound 21 (C21) was recently proposed as an alternative, but in vivo characterization of its properties is not sufficient yet. Here, we evaluated its potency to selectively modulate the activity of nigral dopaminergic (DA) neurons through the canonical DREADD receptor hM4Di using TH-Cre rats. In males, 1 mg.kg-1 of C21 strongly increased nigral neurons activity in control animals, indicative of a significant off-target effect. Reducing the dose to 0.5 mg.kg-1 circumvented this unspecific effect, while activated the inhibitory DREADDs and selectively reduced nigral neurons firing. In females, 0.5 mg.kg-1 of C21 induced a transient and residual off-target effect that may mitigated the inhibitory DREADDs-mediated effect. This study raises up the necessity to test selectivity and efficacy of chosen ligands for each new experimental condition.
·journals.plos.org·
Compound 21, a two-edged sword with both DREADD-selective and off-target outcomes in rats
DREADDs: The Power of the Lock, the Weakness of the Key. Favoring the Pursuit of Specific Conditions Rather than Specific Ligands | eNeuro
DREADDs: The Power of the Lock, the Weakness of the Key. Favoring the Pursuit of Specific Conditions Rather than Specific Ligands | eNeuro
DREADDs (designer receptors exclusively activated by designer drugs) are a powerful and tremendous new technique for selectively manipulating a specific neuronal (or non-neuronal) subpopulation. Recent studies indicate, however, that ligands used for DREADDs, such as clozapine- N -oxide or its parent compound clozapine, are not as selective as expected, even at reasonable concentrations. Although the new generation of ligands specifically developed for DREADDs or alternative chemogenetic receptors may present some improvements, the absence of potential off-target effects remains to be fully demonstrated. Together, indications from the recent literature on DREADDs should warn current and future users about some weaknesses of this expanding technique in the field of integrative neuroscience and encourage them to take some specific precautions to avoid important pitfalls with DREADDs, which remain a promising and complementary approach to optogenetics with the relevant controls. Over the past decade, chemogenetic and optogenetic techniques have revolutionized integrative neuroscience by providing new tools to reversibly manipulate the activity of specific populations or neurotransmitter systems with greater selectivity (Sternson and Roth, 2014; Roth, 2016; Wiegert et al., 2017). Compared with optogenetics, which allow fast and phasic neuronal modulation with high temporal resolution, chemogenetics allow more extended modulation of systems, which is particularly useful for studies focusing on tonic phenomena (e.g., investigation of the implication of dopamine in motivational processes; Whissell et al., 2016). Among chemogenetic tools, designer receptors exclusively activated by designer drugs (DREADDs) are widely used and are referred to as a biological “lock-and-key” system for selective manipulation of cell activity through G-protein signaling pathways. First developed very elegantly by the Roth’s group (Armbruster et al., 2007), this G-protein-coupled receptor (GPCR) is a muscarinic receptor: the lock, which was mutated to respond only to clozapine- N -oxide (CNO), the …
·eneuro.org·
DREADDs: The Power of the Lock, the Weakness of the Key. Favoring the Pursuit of Specific Conditions Rather than Specific Ligands | eNeuro
donee in a sentence - donee sentence
donee in a sentence - donee sentence
donee in a sentence - Use donee in a sentence and its meaning 1. The most common donee beneficiary contract is a life insurance policy. 2. He did not in fact deliver the deed to the donee. click for more sentences of donee...
·eng.ichacha.net·
donee in a sentence - donee sentence
1769-P: Microglial Activation and Inactivation via Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) Alters Peripheral Glucose Homeostasis | Diabetes
1769-P: Microglial Activation and Inactivation via Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) Alters Peripheral Glucose Homeostasis | Diabetes
Obesity, a condition affecting more than one in three American adults, is associated with hypothalamic neuronal injury, inflammation, and gliosis- a process cha
·diabetes.diabetesjournals.org·
1769-P: Microglial Activation and Inactivation via Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) Alters Peripheral Glucose Homeostasis | Diabetes