Protocol for cell-type-specific single-cell labeling and manipulation in Drosophila using a sparse driver system.

Here, we present a protocol for cell-type-specific single-cell labeling and manipulation in Drosophila using a sparse driver system. We describe steps for generating constructs and fly lines, titrating heat-shocked durations for precise temporal control and desired sparsity, and co-expressing multiple transgenes for experiments. We demonstrate that this generalizable toolkit enables tunable sparsity, multi-color staining, single-cell trans-synaptic tracing, single-cell manipulation, and cell-autonomous gene function analysis.

Repulsive interactions instruct synaptic partner matching in an olfactory circuit.

Neurons exhibit extraordinary precision in selecting synaptic partners. Whereas cell-surface proteins (CSPs) mediating attractive interactions between developing axons and dendrites have been shown to instruct synaptic partner matching , it is less clear the degree to which repulsive interactions play a role. Here, using a genetic screen guided by single cell transcriptomes , we identified three CSP pairs-Toll2-Ptp10D, Fili-Kek1, and Hbs/Sns-Kirre-in mediating repulsive interactions between non-partner olfactory receptor neuron (ORN) axons and projection neuron (PN) dendrites in the developing olfactory circuit.

Prohormone cleavage prediction uncovers a non-incretin anti-obesity peptide.

Peptide hormones, a class of pharmacologically active molecules, have a critical role in regulating energy homeostasis. Prohormone convertase 1/3 (also known as PCSK1/3) represents a key enzymatic mechanism in peptide processing, as exemplified with the therapeutic target glucagon-like peptide 1 (GLP-1). However, the full spectrum of peptides generated by PCSK1 and their functional roles remain largely unknown.

The sparse driver system for single-cell labeling and manipulation in .

In this protocol, we introduce a sparse driver system for cell-type specific single-cell labeling and manipulation in , enabling complete and simultaneous expression of multiple transgenes in the same cells. The system precisely controls expression probability and sparsity via mutant sites with reduced recombination efficiency and tunable FLP levels adjusted by heat-shock durations. We demonstrate that this generalizable toolkit enables tunable sparsity, multi-color staining, single-cell trans-synaptic tracing, single-cell manipulation, and analysis of cell-autonomous gene function.

Directed evolution of the multicopper oxidase laccase for cell surface proximity labeling and electron microscopy.

Enzymes that oxidize aromatic substrates have shown utility in a range of cell-based technologies including live cell proximity labeling (PL) and electron microscopy (EM), but are associated with drawbacks such as the need for toxic HO. Here, we explore laccases as a novel enzyme class for PL and EM in mammalian cells. LaccID, generated via 11 rounds of directed evolution from an ancestral fungal laccase, catalyzes the one-electron oxidation of diverse aromatic substrates using O instead of toxic HO, and exhibits activity selective to the surface plasma membrane of both living and fixed cells.

Concerted modulation of spontaneous behavior and time-integrated whole-brain neuronal activity by serotonin receptors.

Serotonin neurons from the raphe nuclei project across the entire brain and modulate diverse physiology and behavior by acting on over a dozen receptors. Here, we took a step towards dissecting this complex process by examining the effects of agonists and antagonists of four widely expressed serotonin receptors (2A, 2C, 1A, and 1B) on spontaneous mouse behavior, which we related to time-integrated whole-brain neuronal activity as assessed by the expression of Fos, a canonical immediate-early gene product. Low-dimensional representations of behavioral and Fos map data revealed the dominant factors of variation in each domain, captured predictable differences across drug groups, and enabled predictions of behavioral changes following perturbations in Fos maps and vice versa.

Distinct Neural Representations of Hunger and Thirst in Neonatal Mice before the Emergence of Food- and Water-seeking Behaviors.

Hunger and thirst are two fundamental drives for maintaining homeostasis and elicit distinct food- and water-seeking behaviors essential for survival. For neonatal mammals, however, both hunger and thirst are sated by consuming milk from their mother. While distinct neural circuits underlying hunger and thirst drives in the adult brain have been characterized, it is unclear when these distinctions emerge in neonates and what processes may affect their development.

Dimensionality reduction simplifies synaptic partner matching in an olfactory circuit.

The distribution of postsynaptic partners in three-dimensional (3D) space presents complex choices for a navigating axon. Here, we discovered a dimensionality reduction principle in establishing the 3D glomerular map in the fly antennal lobe. Olfactory receptor neuron (ORN) axons first contact partner projection neuron (PN) dendrites at the 2D spherical surface of the antennal lobe during development, regardless of whether the adult glomeruli are at the surface or interior of the antennal lobe.

Molecular mechanisms of proteoglycan-mediated semaphorin signaling in axon guidance.

The precise assembly of a functional nervous system relies on axon guidance cues. Beyond engaging their cognate receptors and initiating signaling cascades that modulate cytoskeletal dynamics, guidance cues also bind components of the extracellular matrix, notably proteoglycans, yet the role and mechanisms of these interactions remain poorly understood. We found that secreted semaphorins bind specifically to glycosaminoglycan (GAG) chains of proteoglycans, showing a preference based on the degree of sulfation.

Molecular and cellular mechanisms of teneurin signaling in synaptic partner matching.

In developing brains, axons exhibit remarkable precision in selecting synaptic partners among many non-partner cells. Evolutionarily conserved teneurins are transmembrane proteins that instruct synaptic partner matching. However, how intracellular signaling pathways execute teneurins' functions is unclear.

Embryonically active piriform cortex neurons promote intracortical recurrent connectivity during development.

Neuronal activity plays a critical role in the maturation of circuits that propagate sensory information into the brain. How widely does early activity regulate circuit maturation across the developing brain? Here, we used targeted recombination in active populations (TRAP) to perform a brain-wide survey for prenatally active neurons in mice and identified the piriform cortex as an abundantly TRAPed region. Whole-cell recordings in neonatal slices revealed preferential interconnectivity within embryonically TRAPed piriform neurons and their enhanced synaptic connectivity with other piriform neurons.

A cerebellar granule cell-climbing fiber computation to learn to track long time intervals.

In classical cerebellar learning, Purkinje cells (PkCs) associate climbing fiber (CF) error signals with predictive granule cells (GrCs) that were active just prior (∼150 ms). The cerebellum also contributes to behaviors characterized by longer timescales. To investigate how GrC-CF-PkC circuits might learn seconds-long predictions, we imaged simultaneous GrC-CF activity over days of forelimb operant conditioning for delayed water reward.

Analysis of the Current Status of Nurses' Knowledge of Pressure Injuries and Factors Influencing It in Shaanxi Province, China: A Cross-Sectional Study.

Background: Pressure injuries are present in all healthcare environments and not only pose a significant health risk to individuals but also impose a heavy economic burden on society and families. Nurses, as the primary caregivers responsible for the prevention and management of pressure injuries, have knowledge that directly determines the incidence of pressure injuries.

Aim: To understand the current status of nurses' knowledge of pressure injuries in Shaanxi Province and the factors influencing it.

Embryonically Active Piriform Cortex Neurons Promote Intracortical Recurrent Connectivity during Development.

Neuronal activity plays a critical role in the maturation of circuits that propagate sensory information into the brain. How widely does early activity regulate circuit maturation across the developing brain? Here, we used Targeted Recombination in Active Populations (TRAP) to perform a brain-wide survey for prenatally active neurons in mice and identified the piriform cortex as an abundantly TRAPed region. Whole-cell recordings in neonatal slices revealed preferential interconnectivity within embryonically TRAPed piriform neurons and their enhanced synaptic connectivity with other piriform neurons.

Discriminative Grandparental Investment in China : Evidence from an Undergraduate Questionnaire Study.

Many studies in Western societies show a pattern of discriminative grandparental investment as follows: maternal grandmothers (MGMs) > maternal grandfathers (MGFs) > paternal grandmothers (PGMs) > paternal grandfathers (PGFs). This pattern is in line with the expectation from evolutionary reasoning. Yet whether or not this pattern applies in China is in question.

[Research on the Progress of Applying Virtual Reality Technology in Preventing Falls in the Elderly].

The primary cause of injury and death in the elderly has been reflected in fall the elderly, so the application of reasonable and effective prevention strategies has great significance in reducing the risk of fall in the elderly. The research progress of virtual reality technology applied in preventing fall in the elderly at home and abroad over the years was systematically reviewed in this study. The mechanism of the technology in preventing fall in the elderly was mainly elaborated from five aspects of improving balance ability, gait disturbance, cognitive impairment, muscle strength and the fear psychology of falling.

A neural circuit for male sexual behavior and reward.

Male sexual behavior is innate and rewarding. Despite its centrality to reproduction, a molecularly specified neural circuit governing innate male sexual behavior and reward remains to be characterized. We have discovered a developmentally wired neural circuit necessary and sufficient for male mating.

Expansion spatial transcriptomics.

Capture array-based spatial transcriptomics methods have been widely used to resolve gene expression in tissues; however, their spatial resolution is limited by the density of the array. Here we present expansion spatial transcriptomics to overcome this limitation by clearing and expanding tissue prior to capturing the entire polyadenylated transcriptome with an enhanced protocol. This approach enables us to achieve higher spatial resolution while retaining high library quality, which we demonstrate using mouse brain samples.

Aging Fly Cell Atlas identifies exhaustive aging features at cellular resolution.

Aging is characterized by a decline in tissue function, but the underlying changes at cellular resolution across the organism remain unclear. Here, we present the Aging Fly Cell Atlas, a single-nucleus transcriptomic map of the whole aging . We characterized 163 distinct cell types and performed an in-depth analysis of changes in tissue cell composition, gene expression, and cell identities.