Biology subjects

Song, Z.

Publications and source records attributed to Song, Z..

At least 55 records · Page 3Linked to original sources

bioRxiv2025

Whole blood transcriptional signatures of age and survival identified in Long Life Family and Integrative Longevity Omics Studies

Although aging is a universal event, some individuals are able to achieve extreme longevity. The Long-Life Family Study (LLFS) enrolls participants from families enriched with long-lived individuals, serves as a valuable dataset for studying ageing phenotypes and identify potential intervention targets. We analyzed the association between age at blood draw and 16,284 RNAseq-based blood transcriptomic data from 2,167 LLFS participants with ages ranging from 18 to 107, replicated the results in the Integrative Longevity Omics Study (ILO) dataset of 20,884 RNAseq-based blood transcriptomic data from 419 participants, with ages ranging from 60 to 108, and further compared our findings to a published reference aging signature. We identified 4,227 transcripts increasing and 4,044 transcripts decreasing with age, and enrichment analysis revealed age-related upregulation of inflammatory and senescence-related pathways, and downregulation of MYC and Wnt/{beta}-catenin targets, among others. Further, a subset of transcripts showed age associations unique to the longevity-enriched cohorts (LLFS and ILO). We also identified 314 transcripts significantly associated with mortality risk and found that pro-survival gene sets included NK cell-mediated cytotoxicity and GPCR signaling. Finally, increased transcriptomic age predicted using transcriptomic clock was strongly associated with increased mortality. In summary, this study identified robust transcriptomic signatures of aging and mortality in a longevity-enriched population, highlighting key biological pathways such as immune modulation, inflammation, and senescence. Authors notesThis manuscript has been peer-reviewed and accepted by GeroScience (Springer). This bioRxiv article reflects the published version, incorporating revisions made in response to reviewers comments. The main content, results, and conclusions remain unchanged from the previous version, while the Discussion section has been expanded to further address the functional annotation and clinical relevance of the identified markers. Copy of the acceptance letterThe editors are pleased to inform you that your manuscript, JAAA-D-25-01946R1 entitled "Whole blood transcriptional signatures of age and survival identified in Long Life Family and Integrative Longevity Omics Studies" has been accepted for publication in GeroScience as an Original Article. The editors commend you on your outstanding contribution to the journal. Your manuscript can be published online ahead of print within approximately two weeks.

molecular biology↗

bioRxiv2025

The abscisic acid could reverse the cuproptosis in sepsis-associated acute kidney injury through the inhibition of ferredoxin-1

Sepsis-associated acute kidney injury (S-AKI) is a grave clinical condition with a poor prognosis. Prior studies have observed a potential correlation between copper (Cu) and S-AKI, though the underlying mechanisms remain to be fully elucidated. The present study aims to investigate the underlying mechanism between Cu and renal dysfunction under sepsis conditions. Utilizing a cecal ligation and puncture (CLP) murine model, we observed a substantial upregulation of inflammatory factors and deteriorated renal function (p<0.05), concomitant with an augmented mortality rate (p<0..05). Concurrently, the renal tissue exhibited a series of pathological manifestations, including fibrosis and cell death. Concurrently, the expression of the cuproptosis-regulating protein FDX-1 (p<0.05) was found to be elevated in CLP mice. Collectively, these data indicated the activation of cuproptosis in CLP-induced S-AKI. Intriguingly, the application of abscisic acid (ABA), a FDX-1 inhibitor, led to a substantial alleviation of mortality rate and inflammatory factor level (p<0.05). Furthermore, a significant alleviation was observed in renal pathology and biofunction (p<0.05). Collectively, these observations suggest that ABA exerts a protective effect on renal function during cuproptosis promoted S-AKI. Consequently, it can be concluded that ABA has the potential to reverse cuproptosis in S-AKI by inhibiting FDX-1.

molecular biology↗

bioRxiv2025

Increased Genetic Protection Against Alzheimer's Disease in Centenarians

We constructed a polygenic protective score specific to Alzheimers disease (AD PPS) based on the current literature among the participants enrolled in five studies of healthy aging and extreme longevity in the US, Europe, and Asia. This AD PPS did not include variants on Apolipoprotein E (APOE) gene. Comparisons of AD PPS in different data sets of healthy agers and centenarians showed that centenarians have stronger genetic protection against AD compared to individuals without familial longevity. The current study also shows evidence that this genetic protection increases with increasingly older ages in centenarians (centenarians who died before reaching age 105 years, semi-supercentenarians who reached age 105 to 109 years, and supercentenarians who reached age 110 years and older). However, the genetic protection was of modest size: the average increase in AD PPS was approximately one additional protective allele per 5 years of gained lifetime. Additionally, we show that the higher AD PPS was associated with better cognitive function and decreased mortality. Taken together, this analysis suggests that individuals who achieve the most extreme ages, on average, have the greatest protection against AD. This finding is robust to different genetic backgrounds with important implications for universal applicability of therapeutics that target this AD PPS.

genetics↗

bioRxiv2025

Promoting social connectedness through multi-person neurofeedback

Humans are inherently driven to build meaningful relationships, but attempts to socially connect with others are not always successful. This study investigates whether social connectedness can be improved by intentionally regulating inter-brain coupling, a neural correlate of successful social interactions. Using a multi-person neurofeedback system (i.e., a multi-brain computer interface), we showed dyads real-time visualizations of the extent to which their brainwaves (EEG signals) were "in sync". Our results showed that, compared to a sham control group, dyads who received multi-brain neurofeedback exhibited an increase in inter-brain coupling, and, critically, that this increase was associated with a higher sense of social connectedness. A chain mediation analysis suggested that this experience of enhanced social connectedness may have been driven by a sense of joint control and shared intentionality. Together, our findings showcase the potential for regulating inter-brain coupling to optimize human social relationships and behaviors.

neuroscience↗

bioRxiv2025

stTrace: Detecting Spatial-Temporal Domains from spatial transcriptome to Trace Developmental Path

Development is essential for the growth and functional maintenance of organisms. Investigating the development process is vital for uncovering the formation of complex biological systems. However, current approaches to studying development from gene expression rely primarily on single-cell gene expression data to infer developmental trajectories, neglecting the spatial distribution of cells within tissues and their interactions. Although spatial transcriptomics provides spatial context for gene expression, existing algorithms focus mainly on identifying spatial regions without further exploring their developmental connections. In this study, we propose an algorithm for detecting spatial-temporal domains in tissue to trace developmental path (stTrace) using spatial transcriptomics. stTrace integrates the degree of cell development, gene expression, and spatial location to identify "spatial-temporal domains", regions where cells share similar functions and developmental stages within the tissue. Moreover, hierarchical relationships exist among these regions, reflecting developmental connections between cells in the tissue. Our experiments on mouse embryo and human breast cancer data revealed that stTrace can detect more refined regions than traditional spatial domain identification algorithms. Furthermore, the directions of developmental paths inferred from hierarchical relationships are consistent with the dynamic trajectories derived from single-cell velocity. Key pointsO_LIWe proposed spatial-temporal domain, which refers to spatially continuous regions where cells exhibit similar gene expression patterns, related functions, and close developmental levels. C_LIO_LIWe present stTrace, a computational framework for identifying spatial-temporal domains by iteratively optimizing two objectives: minimizing Structure Entropy to capture functional similarity and hierarchy, and maximizing the Silhouette Coefficient to ensure temporal compactness. C_LIO_LIIn both mouse embryo and human breast cancer datasets, spatial-temporal domains align better with H&E-stained images and and have better compactness in developmental level. C_LIO_LIstTrace detected developmental paths that are well-mapped with cells temporal information like single-cell velocity and trajectories and application show the usage in studying embryo development and cancer invasion. C_LI

bioinformatics↗

bioRxiv2025

Aligning Neural Population Patterns Facilitates Motor Learning Transfer

Motor learning transfer, the ability to apply skills acquired in one task to enhance performance in a related task, is driven by changes in neural ensemble activities. However, the long-term evolution of neural population dynamics during motor learning transfer remains unclear. Specifically, how do the neural patterns reorganize and stabilize over an extended learning period in the new task? To investigate the neural mechanisms in the motor cortex that enable such transfer, we employed a Brain-Machine Interface (BMI) paradigm in rats. In the experiment, rats first mastered a lever-pressing task before proceeding to a more complex but related lever-discrimination task. We analyzed neural ensemble activities by projecting them into a low-dimensional linear feature space that captures the most prominent dynamic structure. Within this space, we represented neural patterns as clusters and developed an iterative method to align similar clusters between the two tasks. Leveraging this alignment, we introduced a novel decoding approach, Clustering Alignment-based Transfer on Kernel Reinforcement Learning (CATKRL), which utilizes parameters learned from the initial task to enhance efficiency in the new task. Our results revealed that neural patterns for learned actions form distinct clusters with consistent shapes and centroid distances across tasks, and these patterns exhibit rotational evolution during learning. By integrating the cluster alignment mechanism into the RL decoder, we achieved a faster training speed with less data in the lever-discrimination task. Our results suggest that aligning neural pattern clusters can enhance BMI decoding efficiency by leveraging consistent neural representations. This approach not only provides valuable insights into the brain mechanisms underlying motor learning transfer but also holds promise for advancing multi-task learning in neuroprosthetics.

neuroscience↗

bioRxiv2025

Myelin Mapping in the Human Brain Using an Empirical Extension of the Ridge Regression Theorem

PurposeMyelin water fraction (MWF) mapping in the central nervous system is a topic of intense research activity. One framework for this requires parameter estimation from a decaying biexponential signal. However, this is often an ill-posed nonlinear problem resulting in unreliable parameter estimates. For linear least-squares (LLS) problems, the ridge regression theorem (RRT) shows that a Tikhonov regularization parameter exists that will reduce mean square error (MSE) in parameter estimates. We present and apply a nonlinear version of the RRT,{lambda} -NL-RR, to MWF mapping. MethodsFor simulated and experimental data, we estimated parameter values with conventional nonlinear least-squares (NLLS) and compared these with values obtained from{lambda} -NL-RR, with the regularization parameter value defined by generalized cross validation. We applied regularization only to signals identified as biexponential according to the Bayesian information criterion. ResultsUnder conditions of modest SNR and closely spaced exponential time constants in which conventional biexponential analysis methods yield particularly inaccurate results,{lambda} -NL-RR decreases MSE by ~10-15%. ConclusionRegularization of the NLLS parameter estimation problem for the biexponential model decreased MSE for simulated and in vivo MRI brain data. In addition, this work provides a general framework for regularization of a broad class of NLLS problems.

biophysics↗

bioRxiv2025

Identify Alzheimer's disease subtypes and makers from multi-omic data of human brain and blood with a subspace merging algorithm

Identifying Alzheimers disease (AD) subtypes is essential for AD diagnosis and treatment. We integrated multiomics data from brain tissues of the ROSMAP and MSBB studies using a subspace merging algorithm and identified two AD patient clusters with notable cognitive and AD pathology differences. Analysis of differentially expressed genes (DEGs) in brain and blood samples pinpointed the LDLR gene as a potential blood biomarker linked to brain gene expression changes. Furthermore, we conducted PheWAS analysis on All of Us Projects EHR and WGS dataset for 105 eQTLs associated with the DEGs and revealed significant associations between these eQTLs and several phenotypes, shedding light on potential regulatory roles of these genes in diverse physiological processes. Our study successfully integrated multiomics data and proposes LDLR as a candidate blood biomarker for AD subtyping. The identified phenotypic signatures provide valuable insights on molecular mechanisms underlying AD heterogeneity, paving the way for personalized AD treatment.

bioinformatics↗

bioRxiv2025

Nanosecond pulsed electric field precisely manipulates cytoplasmic Ca2+ oscillations during oocyte activation

Oocyte activation deficiency (OAD) is a primary cause of fertilization failure following intracytoplasmic sperm injection (ICSI), a problem that can potentially be overcome through artificial oocyte activation (AOA). However, concerns persist regarding the safety and efficacy of AOA techniques in clinical practice. In this study, nanosecond pulsed electric field (nsPEF) is proposed as a safe and controllable method for oocyte activation in vitro by precisely manipulating Ca2+ signaling in the ooplasm. Mouse oocytes collected from oviducts were exposed to nsPEF stimulation at varying intensities to induce distinct Ca2+ signaling patterns. Subsequently, these oocytes underwent parthenogenetic activation and were cultured to assess developmental potential up to the blastocyst stage. The sperm-initiated physiological Ca2+ oscillations are successfully mimicked by one series of Ca2+ signals induced by nsPEF at low or medium intensities, and improve activation efficiency and developmental potential compared to calcium ionophore A23187. Low-intensity nsPEF pulses mediated repetitive extracellular Ca2+ influx in a non-invasive, electro-permeable manner. Medium-intensity nsPEF stimulation triggered periodic Ca2+ release from the endoplasmic reticulum (ER) via the PIP2-IP3-IP3R pathway, producing physiological-like Ca2+ oscillations. The non-invasive nsPEF method ensures safe oocyte activation by preserving cellular integrity and minimizing stress responses. The efficacy of nsPEF in precisely manipulating Ca2+ signaling patterns was further validated in human unfertilized oocytes. Our findings present a novel AOA approach with enhanced safety and efficacy, especially for patients experiencing repeated fertilization failures. It is anticipated that nsPEF is emerging as a promising technology for addressing male infertility issues, and may offer a potential alternative fertility treatment, bypassing sperm for initiation of oocyte activation.

developmental biology↗

bioRxiv2025

CHD7 binds to insulators during neuronal differentiation

Spiral ganglion neurons (SGNs) are crucial for hearing, and the loss of SGNs causes hearing loss. Stem cell-based therapies offer a promising approach for SGN regeneration and require understanding the mechanisms governing SGN differentiation. We investigated the chromatin remodeler CHD7 in neuronal differentiation using immortalized multipotent otic progenitor (iMOP) cells. We demonstrated that CHD7 knockdown impaired neuronal differentiation. Genome-wide analysis revealed CHD7 binding at diverse cis-regulatory elements, with notable enrichment at sites marked by the insulator-binding protein CTCF between topologically associating domains (TADs). Insulators marked by the enrichment of CHD7 and CTCF resided near genes critical for neuronal differentiation, including Mir9-2. Targeting these regulatory regions in iMOPs with CRISPR interference (CRISPRi) and activation (CRISPRa) increased miR-9 transcription, irrespective of the method. Blocking the CHD7 and CTCF marked sites suggested that the elements function as insulators to regulate gene expression. The study highlights CHD7 activity at insulators and underscores an unreported mechanism for promoting neuronal differentiation.

molecular biology↗

bioRxiv2025

High-Quality Cell Capture Reveals Transcriptomic Changes After Single-Axon Injury of Mauthner Cells

In vivo single-cell capture methods based on micropipettes are essential for correlating morphological characteristics with transcriptomic profiling under physiological conditions. However, they often suffer from significant contamination of off-target cells. Consequently, we developed Hip-seq, which significantly reduces heavily contaminated cells, decreases contamination levels, improves cell reproducibility, and enhances data analysis accuracy compared to patch-seq. Using Hip-seq, we found that axon regeneration failure could be due to abnormal activation of translation and the circadian clock. Axon-regenerable central neurons reactivated axon development-related genes during regeneration. And one-to-one associated analysis helped identify pro-regenerative genes.

neuroscience↗

bioRxiv2025

Virus-host interactome reveals host cellular pathways perturbed by tick-borne encephalitis virus infection

Tick-borne encephalitis virus (TBEV) poses an increasingly significant threat to public health. Here, we delved into the virus-host interactome and discovered that TBEV has a profound impact on multiple host cellular pathways. Viral pre-membrane protein (prM), non-structural proteins NS1, NS2B3, NS4A, and NS5 remodel the hosts innate immune responses. PrM and NS2B3 are involved in autophagy, NS4A is associated with neurodegenerative diseases, and NS5 participates in spliceosome dynamics, ribosomal biogenesis, cell cycle regulation, and DNA damage response. Notably, TBEV infection causes G0/G1 cell cycle arrest in host cells. NS5 interacts with histone acetyltransferase P300 to upregulate P16 expression, suppressing CDK4 and resulting in cell cycle arrest. Elevated P16 and reduced CDK4 levels were observed in TBEV-infected brain organoids. The P300 inhibitors and CDK4 agonist can reverse virus-induced cell cycle arrest and inhibit viral replication. Further analysis uncovered potential antiviral targets like KAT6A, XIAP, and RIOK1/BRD9. These findings provide valuable insights into TBEV pathogenicity and hold promise for antiviral drug development.

microbiology↗

bioRxiv2025

Preclinical Evaluation of P4B-2412 as Phosphodiesterase 4B Radioligand for Positron Emission Tomography Imaging

Phosphodiesterase 4B (PDE4B) plays a critical role in cAMP hydrolysis and is highly expressed in brain regions associated with neuroinflammation and neurodegenerative disorders. Selective PDE4B radioligands hold significant potential for elucidating disease mechanisms and enabling target occupancy measurements. In this study, we developed [18F]P4B-2412, a novel PDE4B-selective radioligand, and evaluated its utility for PET imaging. [18F]P4B-2412 was synthesized with high radiochemical yield (27.2%), excellent radiochemical purity (99%), and favorable molar activity (66.2 {+/-} 2.5 GBq/mol). In vitro autoradiography revealed high PDE4B binding, while dynamic PET imaging demonstrated high in vivo specificity for PDE4B in rodent brain regions. Notably, [18F]P4B-2412 exhibited excellent metabolic stability in vitro and in vivo. These findings establish [18F]P4B-2412 as a promising PET probe for imaging PDE4B in vivo, offering a valuable tool for investigating neuroinflammation and advancing CNS drug development.

neuroscience↗

bioRxiv2025

Star-Shaped Glatiramer Acetate Mitigates Pulmonary Dysfunction and Brain Neurodegeneration in a Murine Model of Cryptococcus-Associated IRIS

Cryptococcal-associated immune reconstitution inflammatory syndrome (C-IRIS) is a clinical worsening or new presentation of cryptococcal disease following the initiation of antiretroviral therapy. C-IRIS is primarily driven by an influx of pathological CD4+ T cells, which triggers a hyperinflammatory response. The murine model of C-IRIS is a way to study the disease in mice and understand how the immune system triggers life-threatening outcomes in patients. We previously developed a murine C-IRIS model and demonstrated that C-IRIS is triggered by pathological CD4+ T cells, particularly Th1 cells, in the brain, which triggers neurodegeneration and pulmonary dysfunction. Using this unique mouse model, we tested the therapeutic effect of a star-shaped glatiramer acetate (sGA), which is a more effective isomeric form than linear GA. Here, we observed that sGA suppresses Th1 differentiation in the lung tissues, reducing CD4+ T cell and Th1 cell count. It also reduced microglia populations in the brain. Together, these changes improved respiratory dysfunction caused by C-IRIS, lowered mortality rate, and reduced brain neurodegeneration. These findings suggest that sGA could be an effective therapeutic strategy for managing C-IRIS.

immunology↗

bioRxiv2025

Optimization of Extraction Process by Response Surface Methodology of Total Flavonoids from Ziziphus Jujube Flesh and its Sedative-Hypnotic Effects

Background & aimsThis study optimizes the extraction process of total flavonoids from Ziziphus jujube flesh (TFZJF) by response surface methodology and investigating its sedative-hypnotic effects and mechanisms in a para-chlorophenylalanine (PCPA)-induced insomnia mouse model. It provides theoretical support for the further comprehensive utilization of Ziziphus jujube fruit and flesh. MethodsSingle-factor experiment and Box-Behnken response surface design were used to study the ethanol reflux extraction process of TFZJF, with flavonoid extraction rate as the indicator, to obtain the optimal extraction process of TFZJF. An insomnia model in mice was induced via an intraperitoneal injection of PCPA, and the effects of TFZJF on this model, along with its underlying mechanisms, were assessed using various approaches, including sodium pentobarbital-induced sleep potentiation, HE staining of tissue sections, ELISA, RT-PCR, WB, and serum metabolomics. ResultsThe results showed that the optimized extraction conditions for TFZJF included a solid-liquid ratio (SLR) of 1:25 g{middle dot}mL-1, ethanol concentration of 60%, and extraction time of 60 min, yielding an extraction efficiency of 1.98%. Data from the experimental groups indicated dose-dependent sleep improvement in the insomnia model, with the high-dose TFZJF (TFZJF-H) group exhibiting the most significant effect, followed by the medium-dose (TFZJF-M) and low-dose (TFZJF-L) groups. Metabolomic analysis revealed that TFZJF administration positively impacted the metabolic profile of PCPA-induced insomnia, particularly affecting pathways related to phenylalanine, tyrosine, cytochrome P450, and alanine metabolism on non-targeted metabolomics. ConclusionsThe extraction process is stable and reliable, which can be used for the extraction of TFZJF; meanwhile, TFZJF demonstrated significant sleep-enhancing effects in the PCPA-induced insomnia mouse model, supporting its potential for resource development and the utilization of non-medicinal parts of Ziziphus jujube.

biochemistry↗

bioRxiv2025

DNALONGBENCH: A Benchmark Suite for Long-Range DNA Prediction Tasks

Modeling long-range DNA dependencies is crucial for understanding genome structure and function across a wide range of biological contexts. However, effectively capturing these extensive dependencies, which may span millions of base pairs in tasks such as three-dimensional (3D) chromatin folding prediction, remains a significant challenge. Furthermore, a comprehensive benchmark suite for evaluating tasks that rely on long-range dependencies is notably absent. To address this gap, we introduce DNALO_SCPLOWONGC_SCPLOWBO_SCPLOWENCHC_SCPLOW, a benchmark dataset encompassing five important genomics tasks that consider long-range dependencies up to 1 million base pairs: enhancer-target gene interaction, expression quantitative trait loci, 3D genome organization, regulatory sequence activity, and transcription initiation signals. To comprehensively assess DNALO_SCPLOWONGC_SCPLOWBO_SCPLOWENCHC_SCPLOW, we evaluate the performance of five methods: a task-specific expert model, a convolutional neural network (CNN)-based model, and three fine-tuned DNA foundation models - HyenaDNA, Caduceus-Ph, and Caduceus-PS. We envision DNALO_SCPLOWONGC_SCPLOWBO_SCPLOWENCHC_SCPLOW as a standardized resource with the potential to facilitate comprehensive comparisons and rigorous evaluations of emerging DNA sequence-based deep learning models that account for long-range dependencies.

bioinformatics↗

bioRxiv2024

A Novel Bispecific Antibody CVL006 Superior to AK112 for Dual Targeting of PD-L1 and VEGF in Cancer Therapy

Both preclinical and clinical studies have shown that combining anti-VEGF/VEGFR drugs with immune checkpoint inhibitors (ICIs) significantly enhances anticancer efficacy. Currently, PDL-1/ VEGF bispecific antibodies demonstrate superior antitumor activity compared to monotherapy or even the combination of PD-L1 inhibitors with anti-VEGF antibodies. This enhanced efficacy results from the simultaneous blockade of the PD-1/PD-L1 pathway and the inhibition of VEGF-driven angiogenesis. In this study, we developed a novel bispecific antibody, CVL006, by fusing an anti-PDL1 VHH domain with a humanized IgG1 anti-VEGF monoclonal antibody while retaining antibody-dependent cellular cytotoxicity (ADCC) functionality. CVL006 demonstrated high affinity and specificity for both human PD-L1 and VEGF, effectively blocking both the VEGF/VEGFR signaling pathway and the PD-L1/PD-1 axis. This dual blockade not only suppressed VEGF-induced angiogenesis but also reactivated T cells, increasing the secretion of cytokines essential for immune response. In vivo studies further indicated that CVL006 achieved superior antitumor efficacy compared to the PD-L1 inhibitor atezolizumab in mouse models, with greater tumor growth inhibition and reduced angiogenesis. To compare with approved bispecific antibody PD-1/VEGF AK112 (ivonescimab), CVL006 showed superior antitumor efficacy in vivo. These findings underscore the therapeutic potential of CVL006, which integrates immune checkpoint inhibition with disruption of tumor vascularization, offering a robust and comprehensive anticancer strategy.

pharmacology and toxicology↗

bioRxiv2024

Multiple within species comparisons show Tanganyikan cichlid fish have larger brains in less structurally complex habitats

Many studies have found a link between higher habitat structural complexity and increased relative brain size in vertebrates. Here we explore this relationship in a multi-species comparison, comparing ten species of wild cichlids that differ in their social and territorial behaviour, but which occur across four ecologically similar but structurally diverse rocky habitats. This design allows us to perform repeated intra-specific comparisons, avoiding confounds associated with comparisons across species boundaries. We sampled 147 fish, analysing brain size and architecture while controlling for body mass and species-specific variability and compared this with habitat complexity, quantified using underwater video and three-dimensional reconstructions. Our results challenge the Clever Foraging Hypothesis (CFH), which posits that greater habitat complexity correlates with larger brain sizes. Contrary to CFH, fish from the least complex habitat had significantly larger brains. Additionally, brain architecture analysis indicated a significant enlargement of the cerebellum in fish from less complex habitats, whereas the hypothalamus showed a non-significant negative trend. Taken together, these results indicate that lower habitat complexity may impose higher cognitive demands on spatial memory and navigation due to limited refuges and increased predation risk. This study highlights the need to reconsider the assumed linear positive relationship between environmental complexity and brain development, suggesting that simpler environments might also impose significant cognitive and ecological challenges that drive brain evolution. Our findings underscore the importance of considering intra-species variability and the specific ecological and cognitive demands of different habitats in studies of brain evolution.

evolutionary biology↗