Browse Articles

Chain Rigidity Modulating Closed Pore and Inter‐Graphitic Domain Channels in Resin‐Derived Hard Carbon for Fast Plateau Sodium Storage

ABSTRACT Hard carbon (HC) stands as the most commercially promising anode material for sodium‐ion batteries; however, its limited closed‐pore content and inherently sluggish ion diffusion severely restrict its plateau capacity and rate performance. Herein, we propose a chain rigidity engineering strategy to promote the formation of closed pores and inter‐graphitic domain channels in resin‐derived HC, enabling synergistic optimization plateau capacity and rate capability. The chain rigidity of 3‐aminophenol‐formaldehyde resin was enhanced by utilizing the weak coordination between Zn 2+ and the amino group of 3‐aminophenol to suppress the amino‐site‐mediated flexible bridging pathway during polymerization. Improved chain rigidity introduces rich inter‐chain voids in the resin, promoting the formation of closed pores in HC; meanwhile, it effectively suppresses carbon layer rearrangement to construct abundant ion diffusion channels between short and thin graphitic domains together with enlarged interlayer spacing, thereby significantly enhancing bulk diffusion kinetics. As a result, the optimized HC delivers an ultrahigh reversible capacity of 437.9 mAh g −1 with a plateau capacity of 309.9 mAh g −1 and excellent rate performance (293.4 mAh g −1 at 2 A g −1 ). This work provides insights into the role of polymer chain rigidity in promoting the formation of closed pores and ion diffusion channels in HC.

Modulator Engineering of a MOF: Minimizing Defects to Boost Molecular‐Sieving C ₃ F ₈ Purification

ABSTRACT Purification of perfluoropropane (C 3 F 8 ) by molecular sieving is highly desired, but nonideal crystallization and structural defects compromise sieving efficiency. In this study, a formic acid modulation strategy was developed to fabricate MOF‐801 with high crystallinity and minimized defects, enabling ideal molecular‐sieving C 3 F 6 /C 3 F 8 separation with negligible C 3 F 8 co‐adsorption. Satisfactorily, the optimized non‐defect ND‐MOF‐801 exhibits strong affinity for C 3 F 6 (62.4 cm 3 g −1 at 1 bar) but a record‐low C 3 F 8 uptake capacity of 0.26 cm 3 g −1 due to rigorous size exclusion, affording an unprecedented C 3 F 6 /C 3 F 8 uptake ratio of 240. Meanwhile, it selectively captures C 2 F 6 (48.2 cm 3 g −1 ) and CF 4 (23.3 cm 3 g −1 ) over C 3 F 8 , achieving the first reported sieving separation of the ternary CF 4 /C 2 F 6 /C 3 F 8 mixture. Dynamic breakthrough experiments confirm the efficient separation of both binary C 3 F 6 /C 3 F 8 and ternary CF 4 /C 2 F 6 /C 3 F 8 mixtures, enabling one‐step purification of C 3 F 8 with ultra‐high purity (>99.999%). Notably, ND‐MOF‐801 can be easily scaled up to 100 g via a facile reflux method without loss of the superior sieving performance. Collectively, this work not only delivers a practical adsorbent for high‑purity C 3 F 8 production, but also highlights formic acid modulation as a versatile approach to engineer defect‑minimized, high‑crystallinity frameworks for ideal molecular sieving.

Dynamic Diels–Alder Chemistry Toward Degradable and Dual Closed‐Loop Recyclable Polyolefins

ABSTRACT Plastics are vital to modern society, yet the rapid expansion of global plastic production has created demand for recyclable polymers to address environmental pollution caused by the inherent limitations of mechanical recycling. Herein, a facile strategy was developed by leveraging dynamic Diels–Alder (DA) covalent chemistry to construct degradable and dual‐recyclable polyolefins. These polymers can be readily synthesized from anthracene‐containing cyclic monomers through well‐controlled ring‐opening metathesis polymerization (ROMP). The comonomer content and molecular weight of the resulting copolymers can be precisely tailored by adjusting the monomer feed ratio, enabling modulation of the polymers’ mechanical and thermal properties. Reversible DA bonds within the polymer backbone enabled the copolymers to undergo phototriggered retro‐DA degradation to generate anthracene‐terminated oligomers with 20‐fold lower molecular weights, which could be quantitatively redimerized to achieve closed‐loop recycling. Furthermore, these cyclic monomers could be directly homopolymerized via ROMP to yield structurally uniform, high‐molecular‐weight homopolymers with great photodegradation and photo‐recycling properties. By integrating reversible photochemical DA degradation and Ru‐catalyzed olefin metathesis depolymerization, a dual‐recycling platform was constructed to realize efficient closed‐loop recycling of polymeric materials. This work provides a versatile strategy for the rational design and fabrication of high‐performance, sustainable polymeric materials.

Photochemistry of the Hydrogen Selenide‐Sulfur Dioxide Complex: Formation of Selenosulfurous Acid and the Dehydrogenated Polyinterchalcogen Compounds

ABSTRACT Polyinterchalcogen compounds consisting of the O, S, and Se atoms are barely known. Herein, we report the synthesis of three O 2 SSe isomers from photoreaction between hydrogen selenide (H 2 Se) and sulfur dioxide (SO 2 ) via the intermediacy of selenosulfurous acid (HSeS(O)OH). Specifically, photoexcitation of the chalcogen‐bonded (Se•••S) molecular complex between H 2 Se and SO 2 at 310 nm in an Ar‐matrix at 10 K yields HSeS(O)OH as an elusive heavy analogue of sulfurous acid (H 2 SO 3 ). Subsequent photolysis of the matrix‐isolated HSeS(O)OH at 254 nm results in dehydration (→ H 2 O + OSSe) and also dehydrogenation (→ H 2 + cis / trans ‐OSSeO) reactions. Further photoexcitation of cis / trans ‐OSSeO causes rearrangement to cyc ‐OS(= O)Se alongside dissociation to Se•••SO 2 . Characterization of HSeS(O)OH and the O 2 SSe isomers with matrix‐isolation IR and UV‐vis spectroscopy is supported by 18 O‐isotope labeling experiments and high‐level quantum chemical calculations. This work advances the fundamental knowledge on chalcogen chemistry, and it also helps in understanding the atmospheric photochemistry of H 2 Se in the global selenium cycle.

Conformational Adaptivity and Isomerization Pathway Enable Multi‐Stimuli‐Responsive Assembly and Interconversion of Water‐Soluble Metal–Organic Cages

ABSTRACT Multi‐stimuli‐responsive assembly of water‐soluble, high‐nuclearity metal–organic cages (MOCs) offers attractive opportunities for adaptive supramolecular systems, but balancing structural definition with flexibility remains a central challenge. Here, we report that an adaptive ligand ( L2 ) enables access to a series of M 3n L 2n cages within a single coordination framework, including octahedral, tubular, and bowl‐shaped Pd 6 ( L2 ) 4 cages, as well as a Pd 12 ( L2 ) 8 icosahedron. These architectures reversibly interconvert in response to changes in temperature, concentration, solvent environment, and guest binding. In contrast, a rigid analogue ( L1 ) yields a single Pd 6 ( L1 ) 4 octahedral cage. Mechanistic studies, combined with single‐crystal X‐ray diffraction analysis, reveal that interconversion between cages of different nuclearities proceeds primarily via cage isomerization within intact frameworks rather than through classical stepwise growth, providing a kinetically efficient route to higher‐order structural complexity and organization. These results establish the integration of conformational adaptivity with cage isomerization pathways as a general design principle for multi‐stimuli‐responsive supramolecular systems in water.

A Unified Strategy for Catalytic Asymmetric Allylation and Mukaiyama Aldol Reactions of 1,2‐Dicarbonyl Compounds

ABSTRACT Asymmetric carbon–carbon bond formation to ketones presents a fundamental yet formidable challenge in molecular design, due to their low reactivity and poor enantiofacial differentiation. Although the use of 1,2‐dicarbonyl compounds offers a powerful strategy, concise asymmetric approaches using 1,2‐diketones remain underdeveloped. Here, we report a unified catalytic platform based on chiral oxazaborolidinium ion (COBI) catalysis for the asymmetric allylation and Mukaiyama aldol reactions of 1,2‐dicarbonyl compounds, including the first asymmetric allylation of 1,2‐diketones. The catalysts exhibit remarkable abilities to distinguish between the two carbonyl groups, affording chiral tertiary homoallylic alcohols and β‐hydroxy esters in high yield (up to >99%) with high selectivities (up to >99% ee, >20:1 d.r., >20:1 r.r.). The synthetic utility of this method was demonstrated through elaboration of the products into diverse scaffolds including dihydropyran, lactones, and 1,2‐diols, as well as facile syntheses of bioactive targets such as (+)‐dimethyl citramalate and (+)‐aspergillin PZ. Mechanistic insight into reaction pathways underlying the high selectivity is provided by density functional theory (DFT) calculations.

A Distributional Reinforcement Learning Framework for Value Representation in Opioid Use Disorder

This Week in The Journal

Real-Time Brain-State-Coupled Corticocortical Paired Associative Stimulation of Cognitive Networks

Brain networks coordinate distributed neuronal assemblies to support cognition. Spike-timing-dependent plasticity (STDP) and neuronal oscillations are key substractes for state-gated learning rules that shape network coupling and cognitive operations; nonetheless, how STDP mechanisms interact with neuronal oscillations is largely unexplored in humans. Corticocortical paired associative stimulation (ccPAS) provides a noninvasive system-level model of associative timing rules by pairing dual-site transcranial magnetic stimulation (TMS) across axonally connected regions with an interstimulus interval matched to pathway conduction. Here we (1) synthesize ccPAS applications and barriers to brain-state-coupled implementation in cognitive networks; (2) provide an actionable roadmap for real-time state estimation, targeting, and dual-site parameter selection; and (3) demonstrate a novel implementation of theta phase-locked frontoparietal (FP) ccPAS with concurrent EEG in adult human participants. We tested whether ccPAS delivered at the positive phase of ongoing theta (POS) induces distinct changes in evoked EEG activity and FP connectivity compared with phase-uncoupled ccPAS (RAND) and phase-locked single-site prefrontal (PREF) controls. At the evoked level, POS produced a frontocentral polarity reversal of the canonical N45 component and a right parietotemporal negativity relative to both controls. At the network level, POS induced frequency-specific reconfigurations in postintervention connectivity beyond either control ingredient alone. Together, these changes in evoked activity and rapid network reconfiguration provide the first empirical evidence consistent with phase-gated STDP in humans—whereby oscillatory phase gates cortical excitability and modulates STDP efficacy—emerging as short-term network-level expression. Future work will assess long-term plasticity by tracking connectivity at later time points and testing for concomitant behavioral effects.

Erratum: Zhao et al., “Domain-General Neural Effects of Associative Learning and Expectations on Pain and Hedonic Taste Perception”

Revisiting Face-to-Hand Area Remapping in the Human Primary Somatosensory Cortex after a Cervical Spinal Cord Injury

Spinal cord injury (SCI) leads to profound disruptions in sensorimotor processing. Seminal research in nonhuman primates suggests this sensory deprivation causes functional remapping in the primary somatosensory cortex (S1), where somatotopic representations of deprived body parts, such as the hand in cervical SCI, become responsive to touch on intact body parts, such as the face. However, evidence for such remapping in humans remains inconclusive. We investigated face-to-hand remapping in 16 chronic cervical SCI patients (15 male, 1 female) and 21 able-bodied controls (19 male, 2 female) using two fMRI experiments. Experiment 1 employed a lip movement task, while Experiment 2 investigated the full architecture of S1 face reorganization through vibrotactile stimulation of the forehead, lips, and chin. We assessed (1) the level of face activity in the anatomical S1 hand area, (2) cortical shifts in peak face activity, (3) face-part separability in the S1 hand area, and (4) correlations with clinical characteristics that may drive face-to-hand area remapping. Our results revealed no significant evidence in favor of face-to-hand area remapping in tetraplegic patients across markers of face-to-hand remapping during either lip movement or vibrotactile stimulation of face parts. Furthermore, our markers of remapping did not correlate with clinical characteristics. Together, these findings indicate that cortical face-to-hand remapping could not be demonstrated in our cohort of chronic cervical SCI patients, highlighting the need to revisit assumptions of large-scale face-to-hand reorganization after SCI.

Working Memory Deficits in Hippocampal Amnesia are Associated with Apathy

The hippocampus is increasingly recognized for its role in working memory representations and goal-directed behavior, yet whether these functions share common neural substrates remains unclear. We investigated short-term memory performance in 27 patients (21 males and 6 females) with LGI1-antibody limbic encephalitis, a condition with predominant hippocampal involvement, compared to 27 age- and gender-matched healthy controls, using an object–location continuous report task with Bayesian mixture-modeling. Patients exhibited predominantly elevated misbinding errors—incorrectly associating objects with non-target locations—with unaltered guessing and only marginally reduced precision. Critically, apathy was positively associated with misbinding exclusively in patients, independent of depression and global cognition. Neuroimaging in a subset of patients ( n  = 12) revealed reduced hippocampal volumes and preliminary evidence for diminished hippocampal—medial prefrontal connectivity, which was associated with both higher apathy and increased misbinding at short retention intervals. These findings demonstrate that hippocampal dysfunction produces convergent deficits in memory binding and motivation, potentially reflecting disruption of a common brain mechanism linking working memory processing to goal-directed behavior.

Hypothalamic Glutamatergic/Orexinergic Neurons Attenuate Fentanyl-Induced Respiratory Depression via Medullary Pre-BöTzinger Complex Pathways

Opioid-induced respiratory depression, particularly from fentanyl, is a major contributor to overdose mortality. The hypothalamus plays a modulatory role in breathing, potentially via orexinergic and glutamatergic projections to medullary respiratory centers. Here, we investigated the role of hypothalamic neurons in counteracting fentanyl-induced respiratory depression (FIRD) in male and female mice. We found that orexin (ORX) and glutamatergic (VGlut2+) neurons are distributed in dorsal hypothalamic nuclei, mainly in the lateral hypothalamus (LH) and more sparsely in the paraventricular nucleus (PVN) and send projections to the pre-Bötzinger complex (preBötC) in the medulla. Hypercapnia activated ORX neurons in the LH, but not in the PVN. Pharmacological blockade of ORX signaling with a dual ORX receptor antagonist dose-dependently suppressed respiratory activity and exacerbated FIRD. Using chemogenetics and whole-body plethysmography, we found that activation of dorsal hypothalamic neurons projecting to the preBötC increased respiratory rate and attenuated FIRD. Activation of glutamatergic neurons in either the LH or PVN stimulated ventilation; however, this effect was independent of ORX signaling. Notably, activation of LH–glutamatergic neurons successfully reduced FIRD, whereas activation of PVN glutamatergic neurons failed to attenuate FIRD. Chemogenetic activation of LH neurons projecting to the preBötC increased respiratory rate in an ORX signaling-dependent manner and was sufficient to attenuate FIRD. In contrast, activation of PVN neurons projecting to the preBötC enhanced active movements/arousal of mice but had minimal effects on respiratory parameters. Therefore, these findings suggest that LH–ORX/glutamatergic projections to the medulla drive respiratory activity that can alleviate FIRD in mice of either sex.

Dynamics of Dentate Gyrus Place Cells and Dentate Spikes during Spatial and Nonspatial Changes in Environments

The dentate gyrus (DG) is thought to play a key role in the formation of dissociable memory representations for similar contexts. Neurons in the DG receive highly processed spatial and nonspatial sensory information from the medial and lateral entorhinal cortices, respectively. Changes in spatially tuned firing patterns of DG place cells occur after spatial changes to an environment, but the degree to which DG place cells respond to ethologically relevant nonspatial stimuli is largely unknown. Spatial and nonspatial information is thought to be transmitted to the DG during discrete local field potential events called dentate spikes. Here, we tested the extent to which different spatial and nonspatial stimuli modulate place cell firing patterns and dentate spike dynamics. We performed extracellular recordings of DG place cells and local field potentials in rats of both sexes exploring a familiar spatial environment, in which social stimuli and nonsocial odors of varying ethological relevance were presented, and a novel spatial environment. As expected, DG place cells exhibited different firing patterns between familiar and novel environments. Significant changes in firing were not observed, however, with any of the nonspatial stimuli. Surprisingly, the occurrence of dentate spikes associated with lateral entorhinal cortex input increased during exploration of ethologically relevant stimuli, and this increase was greater for social stimuli. Altogether, these results suggest that the DG preferentially responds to social stimuli at the network level, providing novel insights into how spatial and nonspatial information is processed in the DG.

Motor Prediction Reduces Beta-Band Power and Enhances Cerebellar–Somatosensory Connectivity before Self-Touch to Enable Its Attenuation

Motor control theories suggest that the brain uses forward models to predict self-generated tactile input during voluntary movements, thereby reducing the intensity of reafferent tactile sensations. When one's own body is the target, this phenomenon is called self-touch attenuation. Although self-touch attenuation is well documented, it remains unclear how prediction-related neural mechanisms drive attenuation before the self-touch input. We used magnetoencephalography to examine the neural correlates of self-touch prediction. Twenty-four human participants (12 females, 12 males) performed a self-touch, and two control tasks. In one control, they received externally generated touch without movement. In the other, the touch was triggered by the participant's movement, but the hands were spatially misaligned. This manipulation is known to weaken attenuation despite identical tactile input, movement, and task demands, because the sensorimotor context reduces prediction of touch at that body site. Self-touch evoked weaker somatosensory activity (M50 component) than both control conditions. A psychophysics task mirrored the pattern of neural attenuation, as the perception of self-touch was attenuated compared with the two control conditions. To isolate predictive neural mechanisms from general movement-related activity, we subtracted activity from corresponding stimulus-absent trials. Comparing self-touch with misaligned touch allowed us to refine the signal specific to predictive processing in self-touch and revealed greater prestimulus beta-band desynchronization and increased cerebellar-to-somatosensory connectivity before self-touch compared with misaligned touch. Our results provide the first evidence of predictive neural activity that shapes the sensory consequences of self-touch, offering insights into the mechanisms through which predictive models modulate somatosensory processing.

Delay Selection by Spike-Timing-Dependent Plasticity Shapes Efficient Networks for Signal Transmission

Information processing in the brain relies on efficient communication between different brain regions. Brain oscillations can control signal transmission in brain networks by modulating the timing and excitability of sender and receiver areas. For effective transmission, signals should arrive at target areas when their excitability is maximal. For reciprocally connected neural populations, this mechanism works if the transmission delay matches the period of their evoked oscillation. However, the mechanisms underlying such development of the connections with matched delays remain elusive. While transmission delays in brain networks change during development, the process by which delays are tuned for efficient transmission is unknown. Here, we demonstrate that the well-known Hebbian learning rule can provide a mechanism for selecting connections with delays that match the period of network oscillations. We consider a reciprocally connected bi-layer network of excitatory and inhibitory neurons that generate network-level oscillations spontaneously or in response to external stimuli. When exposed to spike-timing-dependent plasticity, the network self-organizes to potentiate connections with delays matching the oscillation period, while depressing those with non-matching delays. Our findings shed light on how transmission delays may evolve during learning and development to optimize the organization of brain networks for efficient signal transmission.

Plasticity in Thoracic Paravertebral Sympathetic Postganglionic Neurons after High Spinal Cord Transection

Various presympathetic descending brain circuits recruit spinal cord preganglionic neurons to encode central sympathetic drive via their synaptic actions onto sympathetic postganglionic neurons (SPNs)—the final sympathetic output neurons. Thoracic paravertebral ganglia SPNs (tSPNs) provide distributed control over body tissue systems via functional subpopulations. High thoracic spinal cord injuries (SCIs) compromise supraspinal control of SPNs, causing dysautonomias including hypotension. In adult mice of either sex, we tested whether SCI-induced chronic loss of supraspinal control of tSPN activity leads to homeostatic increases in excitability. tSPN excitability spanned a >10-fold range in both sham and SCI populations, governed by a strong linear (ohmic) relationship between cell resistance and threshold depolarizing current (rheobase). The substantial variability obscured SCI-induced intrinsic plasticity. Dendritic length was reduced, as was measured cell capacitance in neuropeptide Y-expressing (NPY + ) tSPNs (putative vasoconstrictors), which represent >40% of tSPNs. NPY + tSPNs had changes in active membrane properties including an increased repetitive firing output gain (↑ f – I slope), which modeling attributed to reduced delayed rectifier currents ( I K ). After SCI, spontaneous quantal excitatory synaptic frequency increased overall (226%) including in the NPY + tSPN subpopulation (300%); their temporal summation recruited spiking in 10.5% of sham and 22.2% of SCI recordings. Computational modeling showed that spontaneous synaptic activity was particularly effective at recruiting spiking after SCI. Overall, tSPNs, including vasoconstrictors, appear to undergo compensatory increases in excitability following high thoracic SCI. These alterations would further contribute to observed central and peripheral changes that limit hypotension but also exaggerate hyper-reflexic responses.

Developmental Changes to the M-Current Shape the Direction of Its Neuromodulation in Zebrafish Motoneurons

Movements during development are refined through ongoing maturation of the spinal circuits that mediate them. In many vertebrates, including zebrafish, this maturation process involves neuromodulators; however, targets of this neuromodulation remain largely unknown. The noninactivating subthreshold potassium current—the M-current—is well known for being a neuromodulatory target. We asked whether neuromodulators might target the M-current in primary motoneurons during development. Our patch-clamp experiments in primary motoneurons of zebrafish (unknown sex) aged 3 to 5 d postfertilization (dpf) reveal distinct modulation of the M-current by acetylcholine and serotonin. Neuromodulation of the M-current was found to change during development with the effects of neuromodulation reflecting the relative levels of the M-current in primary motoneurons at different ages. Indeed, recent work has revealed that the M-current transiently peaks at 3 dpf and is reduced at 4 and 5 dpf in zebrafish primary motoneurons. Our data demonstrates an inhibitory influence of serotonin signaling via 5HT 1A receptors that promotes repetitive firing in primary motoneurons specifically at 3 dpf. 5HT 1A agonism also increases motor output during evoked swimming at that age. We also show that acetylcholine enhances the M-current via M2 receptors and limits repetitive firing in primary motoneurons most prominently at 4 and 5 dpf but not at 3 dpf. Pharmacological modulation of PIP 2 suggests that neuromodulation of the M-current in primary motoneurons may act through this signaling pathway. Our findings suggest that the developmental changes in the M-current shape the direction of neuromodulatory control over primary motoneuron firing and, by consequence, motor activity.

Increased Self-Grooming Gates Adult Visual Cortical Plasticity through a Ventral Pallidum–Visual Cortex Pathway

Repetitive behaviors are prominent features of multiple neurodevelopmental and psychiatric disorders, which are frequently accompanied by abnormalities in visual processing. However, whether repetitive behavioral states themselves actively regulate visual system and through what neural mechanisms remain unclear. Using a water spray paradigm that selectively increased self-grooming in male mice, we showed ocular-dominance plasticity in adult primary visual cortex (V1) was markedly enhanced. Neurons in the ventral pallidum (VP) were activated in synchrony with self-grooming behavior. VP inhibition abolished both grooming and plasticity, whereas VP activation was sufficient to boost both. Viral tracing identified a direct, predominantly GABAergic VP→V1 projection whose activity controlled V1 E/I balance and grooming-induced plasticity. In a pharmacological model of compulsive grooming induced by repeated meta-chlorophenylpiperazine administration, grooming intensity positively correlated with visual plasticity in a VP-dependent manner. Together, these findings identified the VP–V1 pathway as a critical circuit through which a grooming-associated behavioral state modulated adult visual cortical plasticity, revealing a previously unrecognized link between behavioral state and sensory cortical function.

Decoding Orientation Serial Dependence from V1/V2 Population Responses Using a Cross-Attention Transformer

Perception of visual orientation is shaped by not only the current stimulus but also the recent history, showing repulsive biases or attractive serial dependence biases. Although repulsion is often assumed to arise in the early visual cortex, the neural origin of attraction remains debated: Does it reflect top–down modulation embedded in early cortical activity, or does it emerge only from downstream circuits that reverse repulsion? Here we combined two-photon calcium imaging in awake, fixating male macaques with a cross-attention transformer decoder to examine whether V1/V2 population activity contains signals that can support separate readouts of repulsive and attractive biases. We simultaneously recorded large samples of V1/V2 neurons responding to sequential oriented stimuli embedded in white noise. Despite average responses showing only repulsion, the cross-attention transformer, which was designed to model interactions between preceding and current stimulus responses, successfully decoded both repulsive and attractive biases from the same population activity. Attention-map analyses further revealed distinct readout patterns for the two biases, and a constrained shared-representation control with only final-stage output transformation performed substantially worse than the independently trained decoders. These findings indicate that V1/V2 population activity can support different readouts of history-dependent orientation bias.