Regulatory Circuits Research Articles

Supplementation with Amino Acid Sources Facilitates Fermentative Growth of Shewanella oneidensis MR-1 in Defined Media.

Shewanella oneidensis MR-1 is a facultative anaerobe that grows by respiration using a variety of electron acceptors. This organism serves as a model to study how bacteria thrive in redox-stratified environments. A glucose-utilizing engineered derivative of MR-1 has been reported to be unable to grow in glucose minimal medium (GMM) in the absence of electron acceptors, despite this strain having a complete set of genes for reconstructing glucose to lactate fermentative pathways. To gain insights into why MR-1 is incapable of fermentative growth, this study examined a hypothesis that this strain is programmed to repress the expression of some carbon metabolic genes in the absence of electron acceptors. Comparative transcriptomic analyses of the MR-1 derivative were conducted in the presence and absence of fumarate as an electron acceptor, and these found that the expression of many genes involved in carbon metabolism required for cell growth, including several tricarboxylic acid (TCA) cycle genes, was significantly downregulated in the absence of fumarate. This finding suggests a possibility that MR-1 is unable to grow fermentatively on glucose in minimal media owing to the shortage of nutrients essential for cell growth, such as amino acids. This idea was demonstrated in subsequent experiments that showed that the MR-1 derivative fermentatively grows in GMM containing tryptone or a defined mixture of amino acids. We suggest that gene regulatory circuits in MR-1 are tuned to minimize energy consumption under electron acceptor-depleted conditions, and that this results in defective fermentative growth in minimal media. IMPORTANCE It is an enigma why S. oneidensis MR-1 is incapable of fermentative growth despite having complete sets of genes for reconstructing fermentative pathways. Understanding the molecular mechanisms behind this defect will facilitate the development of novel fermentation technologies for the production of value-added chemicals from biomass feedstocks, such as electro-fermentation. The information provided in this study will also improve our understanding of the ecological strategies of bacteria living in redox-stratified environments.

Gene regulatory network inference in the era of single-cell multi-omics.

The interplay between chromatin, transcription factors and genes generates complex regulatory circuits that can be represented as gene regulatory networks (GRNs). The study of GRNs is useful to understand how cellular identity is established, maintained and disrupted in disease. GRNs can be inferred from experimental data - historically, bulk omics data - and/or from the literature. The advent of single-cell multi-omics technologies has led to the development of novel computational methods that leverage genomic, transcriptomic and chromatin accessibility information to infer GRNs at an unprecedented resolution. Here, we review the key principles of inferring GRNs that encompass transcription factor-gene interactions from transcriptomics and chromatin accessibility data. We focus on the comparison and classification of methods that use single-cell multimodal data. We highlight challenges in GRN inference, in particular with respect to benchmarking, and potential further developments using additional data modalities.

A speed-amplified tri-stable piezoelectric-electromagnetic-triboelectric hybrid energy harvester for low-frequency applications

This work proposes a new speed-amplified multi-stable tri-hybrid energy harvesting technique via the multi-stable nonlinearity enhanced frequency up-conversion and rack-pinion mechanisms to efficiently harness structural and biomechanical vibration energy. In the present design, two frequency up-conversion piezoelectric generators, an array-type electromagnetic generator and a sliding-mode triboelectric nanogenerator are integrated together to form a compact and interactive system. By utilizing the rack-pinion mechanism, the relative speed between the stators and the translators of the electromagnetic and triboelectric generators are both doubled. Meanwhile, the process of frequency up-conversion in the piezoelectric generators is also doubled per each cycle. This results in better performance under wideband and low-frequency vibration sources. For verification, a prototype of this design is tested by mechanical excitations and body-induced motions. In the shaker test, the prototype can generate a peak output power of 446.16 mW under an optimal resistance load, resulting in a normalized power density of 4.20 mW cm–3 g–2 at 5 Hz under 1 g. The prototype also exhibits exceptional performance under various human motion tests, it can drive 600 commercial light-emitting diodes simultaneously. Using a commercial DC/DC voltage regulator circuit, the proposed harvester can serve as a universal power source to charge commercial electronic devices, including smartphones and GPS sensors. The present design shows great potential as a sustainable power source for wearable/portable electronics as well as wireless monitoring systems.

Enhanced amygdala–cingulate connectivity associates with better mood in both healthy and depressive individuals after sleep deprivation

Sleep loss robustly disrupts mood and emotion regulation in healthy individuals but can have a transient antidepressant effect in a subset of patients with depression. The neural mechanisms underlying this paradoxical effect remain unclear. Previous studies suggest that the amygdala and dorsal nexus (DN) play key roles in depressive mood regulation. Here, we used functional MRI to examine associations between amygdala- and DN-related resting-state connectivity alterations and mood changes after one night of total sleep deprivation (TSD) in both healthy adults and patients with major depressive disorder using strictly controlled in-laboratory studies. Behavioral data showed that TSD increased negative mood in healthy participants but reduced depressive symptoms in 43% of patients. Imaging data showed that TSD enhanced both amygdala- and DN-related connectivity in healthy participants. Moreover, enhanced amygdala connectivity to the anterior cingulate cortex (ACC) after TSD associated with better mood in healthy participants and antidepressant effects in depressed patients. These findings support the key role of the amygdala-cingulate circuit in mood regulation in both healthy and depressed populations and suggest that rapid antidepressant treatment may target the enhancement of amygdala-ACC connectivity.

1625-P: Osteoprotection by FNIP1 Signaling in Skeletal Muscle

Obesity is increasingly recognized to exert negative impact on bone mass. Skeletal muscle and bone are closely related throughout life, and muscle dysfunction can cause osteoporosis. Understanding of the crosstalk between muscle and bone could have implications for maintaining bone fitness in various disease states such as obesity. FNIP1 is emerging as key regulator of muscle metabolism acting via AMPK. However, the role of muscle FNIP1 in bone mass control is unknown. Using both gain- and loss-of function muscle-specific genetic models, we show that in addition to the known role in the regulation of mitochondrial function muscle fiber type, FNIP1 participates in muscle programs that govern bone homeostasis. FNIP1 KO mice showed a decrease in trabecular bone volume and bone mineral density, whereas muscle specific restoration of FNIP1 expression in KO mice (FNIP1Tg/KO) reversed the bone loss phenotypes. Femoral bending tests revealed a marked decrease in elastic modulus and maximum force in FNIP1 KO mice but increase in FNIP1 TgKO mice. Consistent with these findings, muscle cell-specific deletion of FNIP1 resulted in a pronounced bone structural and mechanical dysfunction. Using AMPKα1/α2 KO lines, we show that muscle FNIP1 exerts control actions upon bone homeostasis independently of AMPK. Through comprehensive RNA-seq and genomic analyses, we reveal that muscle FNIP1 deficiency induces IGF2 secretion, thereby driving an IGF2-depenent osteoclast program. Importantly, we also found that the muscle FNIP1-IGF2 regulatory circuit is associated with osteoporosis in humans. Thus, muscle FNIP1 is a critical safeguard of bone mass. These findings provide new therapeutic opportunities for enhancing muscle fitness to combat a variety of metabolic and musculoskeletal diseases. Disclosure M.Yan: None. Z.Xu: None. Y.Yin: None. T.Fu: None. Z.Zhou: None. L.Yang: None. Z.Gan: None.

Parameters self-learning of solenoid valve for wheel pressure estimation

As the most important component of the braking pressure regulation circuit, apply valve directly affect the accuracy of pressure control and estimation, which in turn affects the performance of vehicle dynamics control. However, the not exactly same parameters in the manufacturing and the parameters change with wear and tear will introduce large errors in the model-based pressure estimation. In this paper, the electromagnetic model and hydraulic model of apply valve are proposed and illustrated, which is the basis for pressure estimation and air gap learning. The particle swarm optimization (PSO) is presented for the self-learning of apply valve air gap, and the pressure estimation algorithm is presented based on the learned air gap. The proposed model and the algorithm are verified in the vehicle test and Amesim simulation. The results show that the proposed algorithm achieves the estimation of air gap within the error of [Formula: see text], and thus reduces pressure estimation error to smaller than [Formula: see text].

Glucose Transport in Escherichia coli: From Basics to Transport Engineering.

Escherichia coli is the best-known model for the biotechnological production of many biotechnological products, including housekeeping and heterologous primary and secondary metabolites and recombinant proteins, and is an efficient biofactory model to produce biofuels to nanomaterials. Glucose is the primary substrate used as the carbon source for laboratory and industrial cultivation of E. coli for production purposes. Efficient growth and associated production and yield of desired products depend on the efficient sugar transport capabilities, sugar catabolism through the central carbon catabolism, and the efficient carbon flux through specific biosynthetic pathways. The genome of E. coli MG1655 is 4,641,642 bp, corresponding to 4702 genes encoding 4328 proteins. The EcoCyc database describes 532 transport reactions, 480 transporters, and 97 proteins involved in sugar transport. Nevertheless, due to the high number of sugar transporters, E. coli uses preferentially few systems to grow in glucose as the sole carbon source. E. coli nonspecifically transports glucose from the extracellular medium into the periplasmic space through the outer membrane porins. Once in periplasmic space, glucose is transported into the cytoplasm by several systems, including the phosphoenolpyruvate-dependent phosphotransferase system (PTS), the ATP-dependent cassette (ABC) transporters, and the major facilitator (MFS) superfamily proton symporters. In this contribution, we review the structures and mechanisms of the E. coli central glucose transport systems, including the regulatory circuits recruiting the specific use of these transport systems under specific growing conditions. Finally, we describe several successful examples of transport engineering, including introducing heterologous and non-sugar transport systems for producing several valuable metabolites.

Comments on several review eBooks promoting a novel kinetic modelling framework of metabolic processes and of genetic regulatory circuits in living cells

The aim of the articles was to disseminate trends emerging in the production of sustainable cosmetics. For thousands of years, people have been looking for new ways to improve their appearance. Wanting to take care of their beauty, women and men all over the world, in addition to using the best cosmetics and treatments, want to introduce a sustainable beauty routine to mitigate the negative impact of consumerism on the environment. One of the most noticeable trends is the development of pro-environmental solutions applied in everyday life, but also in industry. Manufacturers are emphasising the production of more environmentally friendly raw materials. Conscious consumers, they choose cosmetics whose production is based on sustainability (Figure 1). The results that have been collected in this article show how to use waste from other industries to produce cosmetics. Consumer awareness on the manufacturer of cosmetics that are safe not only for human health, but also for the environment.

EPEN-11. CHARACTERIZATION OF THE SPATIAL ARCHITECTURE OF INTRATUMORAL CELL STATES IN PEDIATRIC HIGH-RISK EPENDYMOMA

Abstract By single-cell analyses, we previously uncovered distinct intratumoral transcriptomic ependymoma (EPN) cell states and developmental trajectories correlating with molecular subtype and biological behavior. However, the relation of these cell states to characteristic EPN tissue architecture and tumor microenvironment remains widely unknown. We aimed to characterize the spatial architecture and elucidate regulatory circuits in EPN via spatial transcriptomics (10X Visium) of tumor specimens matching our previously generated single-cell transcriptome data spanning all EPN subtypes (ZFTA, YAP1, PFA, PFB). We investigated whether spatially restricted cell-cell interactions correlate with our previously identified cell states. Analyses revealed distinct spatially resolved cell populations in supratentorial and posterior fossa EPN. All subgroups showed several (5-9) spatially discrete cell clusters. Via non-negative matrix factorization (NMF), cell-specific spatial clusters emerged correlating with previous single-cell programs. ZFTA EPN highly correlates with ZFTA-specific metaprograms whereas all other subgroups did not show ZFTA-specific gene expression. Explicit genes such as DLK1 are exclusively upregulated in ZFTA EPN indicating spatially distinct aberrant Notch pathway signaling. Interestingly, this subgroup revealed spatial zones with upregulation of metabolic genes and endothelial markers anti-correlating with a ZFTA-specific program. Ependymal and neuronal-precursor-like signatures were enriched in our unique YAP1 EPN sample in a spatially restricted pattern, whereas GFAP was ubiquitously expressed. PFA was characterized by a neural stem cell (NSC)-like niche accompanied by metabolic and immune-reactive gene signatures. PFB showed a similar cell niche associated with NSC-like and glial-progenitor-like genes enriched simultaneously, further highlighting the NSC characteristic of posterior fossa tumors. Ependymal signatures were absent in PFA and present in PFB indicating more differentiated cell populations in PFB. Summarizing, we confirm presence of distinct intratumoral cell states within ependymoma tissue and reveal their spatial organization. In depth analysis and functional validation in matched ependymoma models will enable interrogation of underlying tumor promoting signaling events driving intratumoral developmental trajectories.

Liposomes loaded with vitamin D3 induce regulatory circuits in human dendritic cells.

Nanomedicine provides a promising platform for manipulating dendritic cells (DCs) and the ensuing adaptive immune response. For the induction of regulatory responses, DCs can be targeted in vivo with nanoparticles incorporating tolerogenic adjuvants and auto-antigens or allergens. Here, we investigated the tolerogenic effect of different liposome formulations loaded with vitamin D3 (VD3). We extensively phenotyped monocyte-derived DCs (moDCs) and skin DCs and assessed DC-induced regulatory CD4+ T cells in coculture. Liposomal VD3 primed-moDCs induced the development of regulatory CD4+ T cells (Tregs) that inhibited bystander memory T cell proliferation. Induced Tregs were of the FoxP3+ CD127low phenotype, also expressing TIGIT. Additionally, liposome-VD3 primed moDCs inhibited the development of T helper 1 (Th1) and T helper 17 (Th17) cells. Skin injection of VD3 liposomes selectively stimulated the migration of CD14+ skin DCs. These results suggest that nanoparticulate VD3 is a tolerogenic tool for DC-mediated induction of regulatory T cell responses.

Implication of the σE Regulon Members OmpO and σN in the ΔompA299-356-Mediated Decrease of Oxidative Stress Tolerance in Stenotrophomonas maltophilia.

Outer membrane protein A (OmpA) is the most abundant porin in bacterial outer membranes. KJΔOmpA299-356, an ompA C-terminal in-frame deletion mutant of Stenotrophomonas maltophilia KJ, exhibits pleiotropic defects, including decreased tolerance to menadione (MD)-mediated oxidative stress. Here, we elucidated the underlying mechanism of the decreased MD tolerance mediated by ΔompA299-356. The transcriptomes of wild-type S. maltophilia and the KJΔOmpA299-356 mutant strain were compared, focusing on 27 genes known to be associated with oxidative stress alleviation; however, no significant differences were identified. OmpO was the most downregulated gene in KJΔOmpA299-356. KJΔOmpA299-356 complementation with the chromosomally integrated ompO gene restored MD tolerance to the wild-type level, indicating the role of OmpO in MD tolerance. To further clarify the possible regulatory circuit involved in ompA defects and ompO downregulation, σ factor expression levels were examined based on the transcriptome results. The expression levels of three σ factors were significantly different (downregulated levels of rpoN and upregulated levels of rpoP and rpoE) in KJΔOmpA299-356. Next, the involvement of the three σ factors in the ΔompA299-356-mediated decrease in MD tolerance was evaluated using mutant strains and complementation assays. rpoN downregulation and rpoE upregulation contributed to the ΔompA299-356-mediated decrease in MD tolerance. OmpA C-terminal domain loss induced an envelope stress response. Activated σE decreased rpoN and ompO expression levels, in turn decreasing swimming motility and oxidative stress tolerance. Finally, we revealed both the ΔompA299-356-rpoE-ompO regulatory circuit and rpoE-rpoN cross regulation. IMPORTANCE The cell envelope is a morphological hallmark of Gram-negative bacteria. It consists of an inner membrane, a peptidoglycan layer, and an outer membrane. OmpA, an outer membrane protein, is characterized by an N-terminal β-barrel domain that is embedded in the outer membrane and a C-terminal globular domain that is suspended in the periplasmic space and connected to the peptidoglycan layer. OmpA is crucial for the maintenance of envelope integrity. Stress resulting from the destruction of envelope integrity is sensed by extracytoplasmic function (ECF) σ factors, which induce responses to various stressors. In this study, we revealed that loss of the OmpA-peptidoglycan (PG) interaction causes peptidoglycan and envelope stress while simultaneously upregulating σP and σE expression levels. The outcomes of σP and σE activation are different and are linked to β-lactam and oxidative stress tolerance, respectively. These findings establish that outer membrane proteins (OMPs) play a critical role in envelope integrity and stress tolerance.

High-Performance Charge Pump Regulator with Integrated CMOS Voltage Sensing Control Circuit

This paper introduces a design for a charge pump DC-DC boost regulator with an integrated low-voltage control circuit. With a charge pump and feedback circuits implemented in 0.35 µm CMOS technology, the proposed DC-DC boost regulator offers an efficient device solution for low-power applications. The proposed design employs an error amplifier, oscillator, and comparator in the control circuit which is designed with a supply voltage of 1.8–3.5 V and 2 MHz frequency. Stability is obtained via a pole-zero compensation in the feedback circuit. The charge pump regulator with four pump stages and the whole regulator circuit are analyzed using the Cadence simulation tool. Measurements of the fabricated 0.35 µm CMOS regulator show that the transient time of the error amplifier is controlled within 1.0 µsec and the output voltage is accurately controlled from 7.8 V to 9.4 V with 27–38 mV ripple and 4.5 mA maximum current.

Semi-Implantable Wireless Power Transfer (WPT) System Integrated With On-Chip Power Management Unit (PMU) for Neuromodulation Application

Miniaturization of the neuromodulation system is important for non-invasive or sub-invasive optogenetic application. This work presents an optimized wireless power transfer (WPT) system integrated with an on-chip rectification circuitry and an off-chip stimulation circuitry for optogenetic stimulation of freely moving rodents. The proposed WPT system is built using parallel transmitter (TX) coils on printed circuit board (PCB) and wire-wound based receiver (RX) coil followed by a seven-stage voltage doubler and a low dropout regulator (LDO) circuit designed in 180 nm standard Complementary Metal Oxide Semiconductor (CMOS) process. A pulse stimulation is used to stimulate the neurons which is generated using a commercially available off-the-shelf (COTS) components based oscillator circuit. The intensity of the stimulation is controlled by using a COTS based LED driver circuit which controls the current through the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula> LED. The total dimension of the RX coil is 8 mm × 3.4 mm. The maximum power transfer efficiency (PTE) of the proposed WPT system is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim$</tex-math></inline-formula> 35% and the power conversion efficiency (PCE) of the rectifier is 52%. The proposed system with reconfigurable stimulation frequency is suitable for exciting different brain areas for long-term health monitoring.

A Fully-Integrated Micro-Display System With Hybrid Voltage Regulator

A fully-integrated active matrix light-emitting diode (AMLED) micro-display system is demonstrated in this paper. The system consists of a 36 × 64 AMLED array chip based on GaN-on-Silicon epilayers and a silicon driving chip integrating an on-chip hybrid voltage regulator, pixel drivers, and peripheral circuits. Then two chips are bonded with low-cost Au-free flip-chip bonding technology. As such, this system is able to directly operate with a battery without any external passive components. Multiple techniques were proposed to achieve the system integration: (1) A fully-integrated hybrid voltage regulator consisting of a step-up switched-capacitor (SC) converter cascaded by a step-down linear voltage regulator was fabricated in a 0.18 μm CMOS technology. It achieved only 1.38% output voltage ripple without external capacitors, and be able to deliver a maximum power of 216mW with peak efficiencies of 91% in the linear mode and 78% in the SC mode; (2) Micro-LEDs are fabricated on GaN-on-Silicon substrate that significantly suppresses the light crosstalk between pixels and reduces the cost; (3) An Au-free flip-chip bonding technique is developed to reduce the bonding cost and achieved reliable connections between AMLED array chip and silicon driving chip. The whole system achieved 635 pixel/in (PPI) pixel density. Images and videos with 4-bit grayscale could be rendered. This prototype achieved a high integration level and demonstrates the tremendous potential of the highly efficient, low cost fully integrated AMLED micro-display system.

Solar Wireless Electric Vehicle Charging

Abstract: The paper describes about the dynamic electric vehicle charging system from solar. It reduces fuel and pollution. Nowadays electric vehicle are growing in numbers because of high rates of fuel Electric vehicle has now hit the road worldwide and are slowly growing in numbers. Also it is proven that electric vehicle helpful in reducing cost of travel and which is cheaper than fuel. So we have developed an electric charging system with unique ideas for solving charging system problem. In this electric vehicle no need of any wire, no need of external power supply, no need to stop vehicle for charging, we can charge EV in moving condition. In this system we use, battery, transformer, Atmega controller, LCD display, regulatory circuit, solar panel, coils of copper, AC to DC converters to develop the system more accurate. This whole system describes that how an electric vehicle can be charged in moving condition and also eliminating the need to stop the vehicle and charge it. Thus, insulating in the copper coil in the road, we can charge the electric vehicle in the moving condition.

Landscape and perturbation of enhancer-driven core transcription regulatory circuits in cancer

Landscape and perturbation of enhancer-driven core transcription regulatory circuits in cancer

Artificial Leaky Integrate-and-Fire Sensory Neuron for In-Sensor Computing Neuromorphic Perception at the Edge.

Neuromorphic perception and computing show great promise in terms of energy efficiency and data bandwidth compared to von Neumann's computing architecture. In-sensor computing allows perception information processing at the edge, which is highly dependent on the functional fusion of receptors and neurons. Here, a leaky integrate-and-fire (LIF) artificial spiking sensory neuron (ASSN) based on a NbOx memristor and an a-IGZO thin-film transistor (TFT) is successfully developed. The ASSN is fabricated mainly through simple sputter deposition processes, showing the prospect of high process compatibility and potential for integration fabrication. The device shows excellent spike encoding ability to deliver the neuromorphic information through spike rate and time-to-first spike. Moreover, in the ASSN, the a-IGZO TFT not only provides the fundamental spike signal computing function of the artificial neuron but also has NO2 gas and ultraviolet (UV) light dual sensitivity to introduce the neuromorphic perception capability. As a result, the ASSN successfully exhibits an inhibitory property under NO2 stimulation while exhibiting an excitatory state under UV light stimulation. Futhermore, self-adaption and lateral regulation circuits between different ASSNs are proposed at the edge in mimicking biological neurons' rich interconnection and feedback mechanisms. The ASSNs successfully achieve self-regulation after a huge response during a burst stimulus. In addition, the neuron transmits a more obvious output when the target-sensitive events occur through the edge internal regulation. The self-adaption and lateral regulation demonstrated in ASSN move an important step forward to in-sensor computing, which provides the potential for a multiscene perception in complex environments.

Improving the Output Efficiency of Triboelectric Nanogenerator by a Power Regulation Circuit

Triboelectric nanogenerator (TENG) is a promising technology for harvesting energy from various sources, such as human motion, wind and vibration. At the same time, a matching backend management circuit is essential to improve the energy utilization efficiency of TENG. Therefore, this work proposes a power regulation circuit (PRC) suitable for TENG, which is composed of a valley-filling circuit and a switching step-down circuit. The experimental results indicate that after incorporating a PRC, the conduction time of each cycle of the rectifier circuit doubles, increasing the number of current pulses in the TENG output and resulting in an output charge that is 1.6 fold that of the original circuit. Compared with the initial output signal, the charging rate of the output capacitor increased significantly by 75% with a PRC at a rotational speed of 120 rpm, significantly improving the utilization efficiency of the TENG’s output energy. At the same time, when the TENG powers LEDs, the flickering frequency of LEDs is reduced after adding a PRC, and the light emission is more stable, which further verifies the test results. The PRC proposed in this study can enable the energy harvested by the TENG to be utilized more efficiently, which has a certain promoting effect on the development and application of TENG technology.

Oskar acts with the transcription factor Creb to regulate long-term memory in crickets

Novel genes have the potential to drive the evolution of new biological mechanisms, or to integrate into preexisting regulatory circuits and contribute to the regulation of older, conserved biological functions. One such gene, the novel insect-specific gene oskar, was first identified based on its role in establishing the Drosophila melanogaster germ line. We previously showed that this gene likely arose through an unusual domain transfer event involving bacterial endosymbionts and played a somatic role before evolving its well-known germ line function. Here, we provide empirical support for this hypothesis in the form of evidence for a neural role for oskar. We show that oskar is expressed in the adult neural stem cells of a hemimetabolous insect, the cricket Gryllus bimaculatus. In these stem cells, called neuroblasts, oskar is required together with the ancient animal transcription factor Creb to regulate long-term (but not short-term) olfactory memory. We provide evidence that oskar positively regulates Creb, which plays a conserved role in long-term memory across animals, and that oskar in turn may be a direct target of Creb. Together with previous reports of a role for oskar in nervous system development and function in crickets and flies, our results are consistent with the hypothesis that oskar's original somatic role may have been in the insect nervous system. Moreover, its colocalization and functional cooperation with the conserved pluripotency gene piwi in the nervous system may have facilitated oskar's later co-option to the germ line in holometabolous insects.

Disinhibition of Mesolimbic Dopamine Circuit by the Lateral Hypothalamus Regulates Pain Sensation.

Our recent study demonstrated the critical role of the mesolimbic dopamine (DA) circuit and its brain-derived neurotropic factor (BDNF) signaling in mediating neuropathic pain. The present study aims to investigate the functional role of GABAergic inputs from the lateral hypothalamus (LH) to the ventral tegmental area (VTA; LHGABA→VTA) in regulating the mesolimbic DA circuit and its BDNF signaling underlying physiological and pathologic pain. We demonstrated that optogenetic manipulation of the LHGABA→VTA projection bidirectionally regulated pain sensation in naive male mice. Optogenetic inhibition of this projection generated an analgesic effect in mice with pathologic pain induced by chronic constrictive injury (CCI) of the sciatic nerve and persistent inflammatory pain by complete Freund's adjuvant (CFA). Trans-synaptic viral tracing revealed a monosynaptic connection between LH GABAergic neurons and VTA GABAergic neurons. Functionally, in vivo calcium/neurotransmitter imaging showed an increased DA neuronal activity, decreased GABAergic neuronal activity in the VTA, and increased dopamine release in the NAc, in response to optogenetic activation of the LHGABA→VTA projection. Furthermore, repeated activation of the LHGABA→VTA projection was sufficient to increase the expression of mesolimbic BDNF protein, an effect seen in mice with neuropathic pain. Inhibition of this circuit induced a decrease in mesolimbic BDNF expression in CCI mice. Interestingly, the pain behaviors induced by activation of the LHGABA→VTA projection could be prevented by pretreatment with intra-NAc administration of ANA-12, a TrkB receptor antagonist. These results demonstrated that LHGABA→VTA projection regulated pain sensation by targeting local GABAergic interneurons to disinhibit the mesolimbic DA circuit and regulating accumbal BDNF release.SIGNIFICANCE STATEMENT The mesolimbic dopamine (DA) system and its brain-derived neurotropic factor (BDNF) signaling have been implicated in pain regulation, however, underlying mechanisms remain poorly understood. The lateral hypothalamus (LH) sends different afferent fibers into and strongly influences the function of mesolimbic DA system. Here, utilizing cell type- and projection-specific viral tracing, optogenetics, in vivo calcium and neurotransmitter imaging, our current study identified the LHGABA→VTA projection as a novel neural circuit for pain regulation, possibly by targeting the VTA GABA-ergic neurons to disinhibit mesolimbic pathway-specific DA release and BDNF signaling. This study provides a better understanding of the role of the LH and mesolimbic DA system in physiological and pathological pain.