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In emotion research, anxiety and fear have always been interconnected, sharing overlapping brain structures and neural circuitry. Recent investigations, however, have unveiled parallel long-range projection pathways originating from the ventral hippocampus, shedding light on their distinct roles in anxiety and fear. Yet, the mechanisms governing the emergence of projection-specific activity patterns to mediate different negative emotions remain elusive. Here, we show a division of labor in local GABAergic inhibitory microcircuits of the ventral hippocampus, orchestrating the activity of subpopulations of pyramidal neurons to shape anxiety and fear behaviors in mice. These findings offer a comprehensive insight into how distinct inhibitory microcircuits are dynamically engaged to encode different emotional states. The mechanisms by which the brain processes the intertwined states of anxiety and fear remain unclear. Here, authors show that distinct inhibitory microcircuits in the ventral hippocampus differentially regulate anxiety and fear behaviors.

Acquiring and exploiting memories of rewarding experiences is critical for survival. The spatial environment in which a rewarding stimulus is encountered regulates memory retrieval. The ventral hippocampus (vH) has been implicated in contextual memories involving rewarding stimuli such as food, social cues or drugs. Yet, the neuronal representations and circuits underlying contextual memories of socially rewarding stimuli are poorly understood. Here, using in vivo electrophysiological recordings, in vivo one-photon calcium imaging, and optogenetics during a social reward contextual conditioning paradigm in male mice, we show that vH neurons discriminate between contexts with neutral or acquired social reward value. The formation of context-discriminating vH neurons following learning was contingent upon the presence of unconditioned stimuli. Moreover, vH neurons showed distinct contextual representations during the retrieval of social reward compared to fear contextual memories. Finally, optogenetic inhibition of locus coeruleus (LC) projections in the vH selectively disrupted social reward contextual memory by impairing vH contextual representations. Collectively, our findings reveal that the vH integrates contextual and social reward information, with memory encoding of these representations supported by input from the LC. The neuronal mechanisms serving contextual memories of socially rewarding stimuli are unclear. Here the authors demonstrate that neurons in the ventral hippocampus of male mice discriminate between neutral and socially rewarding contexts, a process dependent on input from the locus coeruleus.

The utilization of diverse energy storage devices is imperative in the contemporary society. Taking advantage of solar power, a significant environmentally friendly and sustainable energy resource, holds great appeal for future storage of energy because it can solve the dilemma of fossil energy depletion and the resulting environmental problems once and for all. Recently, photo‐assisted energy storage devices, especially photo‐assisted rechargeable metal batteries, are rapidly developed owing to the ability to efficiently convert and store solar energy and the simple configuration, as well as the fact that conventional Li/Zn‐ion batteries are widely commercialized. Considering many puzzles arising from the rapid development of photo‐assisted rechargeable metal batteries, this review commences by introducing the fundamental concepts of batteries and photo‐electrochemistry, followed by an exploration of the current advancements in photo‐assisted rechargeable metal batteries. Specifically, it delves into the elucidation of device components, operating principles, types, and practical applications. Furthermore, this paper categorizes, specifies, and summarizes several detailed examples of photo‐assisted energy storage devices. Lastly, it addresses the challenges and bottlenecks faced by these energy storage systems while providing future perspectives to facilitate their transition from laboratory research to industrial implementation. This review begins with the concepts of batteries and photo‐electrochemistry and proceeds to the current state of the art of photo‐assisted rechargeable metal batteries, where the device components, operating principles, and applications are specifically elucidated. Lastly, it addresses the challenges faced by these energy storage systems while providing perspectives to facilitate their transition from laboratory to industrial implementation.

Microglia, resident immune cells of the brain, react to the presence of pathogens/danger signals with a large repertoire of functional responses including morphological changes, proliferation, chemotaxis, production/release of cytokines, and phagocytosis. In vitro studies suggest that many of these effector functions are Ca 2+ -dependent, but our knowledge about in vivo Ca 2+ signalling in microglia is rudimentary. This is mostly due to technical reasons, as microglia largely resisted all attempts of in vivo labelling with Ca 2+ indicators. Here, we introduce a novel approach, utilizing a microglia-specific microRNA-9-regulated viral vector, enabling the expression of a genetically-encoded ratiometric Ca 2+ sensor Twitch-2B in microglia. The Twitch-2B-assisted in vivo imaging enables recording of spontaneous and evoked microglial Ca 2+ signals and allows for the first time to monitor the steady state intracellular Ca 2+ levels in microglia. Intact in vivo microglia show very homogenous and low steady state intracellular Ca 2+ levels. However, the levels increase significantly after acute slice preparation and cell culturing along with an increase in the expression of activation markers CD68 and IL-1β. These data identify the steady state intracellular Ca 2+ level as a versatile microglial activation marker, which is highly sensitive to the cell’s environment.

The behavior of adult-born cells can be easily monitored in cell culture or in lower model organisms, but longitudi- nal observation of individual mammalian adult-born cells in their native microenvironment still proves to be a chal- lenge. Here we have established an approach named optical cell positioning system for long-term in vlvo single-cell tracking, which integrates red-green-blue cell labeling with repeated angiography. By combining this approach with in vivo two-photon imaging technique, we characterized the/n vivo migration patterns of adult-born neurons in the olfactory bulb. In contrast to the traditional view of mere radial migration of adult-born cells within the bulb, we found that juxtaglomerular cells switch from radial migration to long distance lateral migration upon arrival in their destination layer. This unique long-distance lateral migration has characteristic temporal （stop-and-go） and spatial （migratory, unidirectional or multidirectional） patterns, with a clear cell age-dependent decrease in the migration speed. The active migration of adult-born cells coincides with the time period of initial fate determination and is like- ly to impact on the integration sites of adult-born cells, their odor responsiveness, as well as their survival rate.

ObjectiveThis experiment was conducted to determine the differences in the apparent ileal (AID) and total tract digestibility (ATTD) of nutrients and indispensable amino acids (IAA) in high-fiber diets with wheat middlings, rice bran or alfalfa meal fed to Duroc×(Landrace× Yorkshire) (DLY) and Duroc× (Berkshire×Jiaxing) (DBJ) growing barrows.MethodsEighteen DLY and 18 DBJ growing barrows were randomly allotted to a 2×3 factorial arrangement involving 2 crossbreeds and 3 high-fiber diets. The experiment lasted 15 d with 10 d for diets adaptation, 3 d for feces collection and 2 d for digesta collection. Three diets were based on corn and soybean meal with 25% wheat middlings, rice bran and alfalfa meal respectively.ResultsDBJ had a greater (p<0.05) AID of isoleucine, leucine, lysine, phenylalanine and valine and a lower (p<0.05) AID of methionine than DLY. The hindgut disappearance of acid detergent fiber for DBJ was greater (p<0.05) than DLY. The ATTD of gross energy, dry matter, organic matter, neutral detergent fiber and acid detergent fiber in wheat middlings diet were greater (p<0.05) than in rice bran and alfalfa meal diets. The hindgut disappearance of neutral detergent fiber and acid detergent fiber in wheat middlings diet or rice bran diet were the highest or lowest (p<0.05), and those of alfalfa meal diet were the middle. Barrows fed rice bran diet had a greater (p<0.05) hindgut disappearance of gross energy, dry matter and organic matter and lower hindgut disappearance of neutral detergent fiber and acid detergent fiber than barrows fed alfalfa meal dietConclusionDBJ growing barrows showed a significant higher digestibility of fiber in the hindgut and most IAA in the small intestine compared with DLY barrows. The digestibilities of chemical constituents and IAA were affected by the diets formulated with different fiber sources.

The development and survival of adult-born neurons are believed to be driven by sensory signaling. Here, in vivo analyses of motility, morphology and Ca2+ signaling, as well as transcriptome analyses of adult-born juxtaglomerular cells with reduced endogenous excitability (via cell-specific overexpression of either Kv1.2 or Kir2.1 K+ channels), revealed a pronounced impairment of migration, morphogenesis, survival, and functional integration of these cells into the mouse olfactory bulb, accompanied by a reduction in cytosolic Ca2+ fluctuations, phosphorylation of CREB and pCREB-mediated gene expression. Moreover, K+ channel overexpression strongly downregulated genes involved in neuronal migration, differentiation, and morphogenesis and upregulated apoptosis-related genes, thus locking adult-born cells in an immature and vulnerable state. Surprisingly, cells deprived of sensory-driven activity developed normally. Together, the data reveal signaling pathways connecting the endogenous intermittent neuronal activity/Ca2+ fluctuations as well as enhanced Kv1.2/Kir2.1 K+ channel function to migration, maturation, and survival of adult-born neurons.

Anxiety is a complex emotional state that unfolds as structured sequences of risk assessment and exploratory behaviors enabling animals to evaluate potential threats in the environment. The ventral hippocampus (vH) regulates anxiety responses, yet the neuronal substrates orchestrating specific ethologically defined anxiety-related behaviors remain unclear. Here, we combined high-resolution 3D behavioral tracking with cell-type specific in vivo calcium imaging and optogenetic manipulations to dissect vH microcircuit dynamics during anxiety. We identified protected and unprotected stretch-attend postures (pSAP and uSAP), along with head dipping, as core anxiety-related risk-assessment behaviors organized along a spatial gradient in the elevated plus maze (EPM). Ventral hippocampal (vH) pyramidal neurons were broadly engaged across all risk-assessment behaviors, consistent with a generalized role in encoding anxiety-related information. In contrast, interneuronal subclasses exhibited striking functional specialization: parvalbumin (PV) interneurons were selectively recruited during uSAP and head dipping, behaviors associated with direct threat exposure, whereas somatostatin (Sst) interneurons were preferentially activated during pSAP, which reflect approach-avoidance conflicts and decision-making processes. Collectively, these findings establish a microcircuit-level framework in which distinct vH neuronal subclasses differentially gate risk-assessment strategies, enabling flexible transitions between avoidance and exploratory behaviors during anxiety.Competing Interest StatementThe authors have declared no competing interest.Funder Information DeclaredSwiss National Science Foundation, https://ror.org/00yjd3n13European Research Council, https://ror.org/0472cxd90Novartis Foundation for medical-biological Research

Acquiring and exploiting memories of rewarding experiences is critical for survival. The spatial environment in which a rewarding stimulus is encountered regulates memory retrieval. The ventral hippocampus (vH) has been implicated in contextual memories involving rewarding stimuli such as food, social cues or drugs. Yet, the spatial representations and circuits underlying contextual memories of socially rewarding stimuli are poorly understood. Here, using in vivo electrophysiological recordings during a social reward contextual conditioning paradigm in mice, we showed that vH neurons discriminate between contexts with neutral or acquired social reward value and exhibit a preferential remapping of their place fields to the context previously paired with social reward cues. The formation of context-discriminating vH neurons following learning was contingent upon the presence of salient reinforcers. Moreover, vH neurons showed different contextual representations during retrieval of social reward and fear contextual memories, suggesting different vH circuits underlie positively and negatively valenced contextual memories. Finally, optogenetic inhibition of locus coeruleus (LC) projections in the vH selectively disrupted social reward contextual memory by impairing vH contextual representations. Collectively, our findings reveal that the vH integrates contextual and social reward information, with memory encoding of these representations supported by input from the LC.

The development and survival of adult-born neurons is believed to be driven by sensory signaling. By genetically manipulating excitability of adult-born cells (via cell-specific overexpression of either Kv1.2 or Kir2.1 K+ channels), longitudinal in vivo monitoring of their Ca2+ signaling and transcriptome analyses, we show that endogenous but not sensory-driven activity governs migration, morphogenesis, survival, and functional integration of adult-born juxtaglomerular neurons in the mouse olfactory bulb. The proper development of these cells required fluctuations of cytosolic Ca2+ levels, phosphorylation of CREB, and pCREB-mediated gene expression. Attenuating Ca2+ fluctuations via K+ channel overexpression strongly downregulated genes involved in neuronal migration, differentiation, and morphogenesis and upregulated apoptosis-related genes, thus locking adult-born cells in the vulnerable and immature state. Together, the data reveal signaling pathways connecting the endogenous intermittent neuronal activity/Ca2+ fluctuations as well as proper Kv1.2/Kir2.1 K+ channel function to migration, maturation, and survival of adult-born neurons. Competing Interest Statement The authors have declared no competing interest.